diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index fa48408..3e7dc30 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -16,8 +16,10 @@ name: CI
 on:
   push:
     branches: [master, main]
+  # Every pull request, whatever it targets. A base-branch filter here would
+  # skip each layer of a stacked PR except the bottom one, which is exactly the
+  # work that most needs checking before it reaches master.
   pull_request:
-    branches: [master, main]
 
 # Least privilege: jobs only read the repo. Override per-job if more is needed.
 permissions:
diff --git a/.github/workflows/pages.yml b/.github/workflows/pages.yml
index 7009ed2..faa5c70 100644
--- a/.github/workflows/pages.yml
+++ b/.github/workflows/pages.yml
@@ -43,7 +43,7 @@ jobs:
         run: npm run build
 
       # Static Pages has no gateway/nginx to rewrite the fragment asset prefix,
-      # and /__wf/* is outside the project-site mount. Point the marketplace
+      # and /__wf/* is outside the project-site mount. Point the knowledge base
       # stylesheet at its real served path (/knowledge-base/style.css → dist/style.css).
       - name: Rewrite fragment asset paths for static hosting
         run: find dist -name '*.html' -exec sed -i 's#/__wf/knowledge-base/#/knowledge-base/#g' {} +
diff --git a/.github/workflows/pr-requirements.yml b/.github/workflows/pr-requirements.yml
index 1dec647..4767bef 100644
--- a/.github/workflows/pr-requirements.yml
+++ b/.github/workflows/pr-requirements.yml
@@ -5,9 +5,10 @@
 name: PR Requirements
 
 on:
+  # No base-branch filter: a stacked PR targets the layer below it, and each
+  # layer needs the same hygiene checks as the one that reaches master.
   pull_request:
     types: [opened, synchronize, reopened, edited, labeled, unlabeled]
-    branches: [master]
 
 # Least privilege: read PR metadata only.
 permissions:
@@ -19,6 +20,25 @@ jobs:
     name: PR Requirements
     runs-on: ubuntu-latest
     steps:
+      # A stacked PR targets the layer below it rather than master, so a fixed
+      # allow-list of `master` fails every layer but the bottom one. Allow the
+      # base branch as well when it is itself a convention-named branch — that
+      # still rejects a PR aimed at some unrelated branch, which is what the
+      # check is for, while letting a stack be reviewed layer by layer.
+      - name: Resolve allowed target branches
+        id: targets
+        env:
+          KB_BASE_REF: ${{ github.event.pull_request.base.ref }}
+          KB_BRANCH_PATTERN: '^(feat|feature|fix|bugfix|hotfix|release|support|chore|docs|ci|test)/[a-zA-Z0-9._/-]+$'
+        run: |
+          set -euo pipefail
+          if printf '%s' "$KB_BASE_REF" | grep -Eq "$KB_BRANCH_PATTERN"; then
+            echo "Stacked PR: also allowing the layer below ($KB_BASE_REF)."
+            echo "list=master,$KB_BASE_REF" >> "$GITHUB_OUTPUT"
+          else
+            echo "list=master" >> "$GITHUB_OUTPUT"
+          fi
+
       - name: Check PR requirements
         uses: AbsaOSS/check-pr-requirements@adb22f6d88c93fd801e787a63d948d6fbbdd4af3 # v0.2.0
         with:
@@ -48,4 +68,4 @@ jobs:
           # segments in dependabot branches (e.g. dependabot/npm_and_yarn/…).
           branch-pattern: "^(feat|feature|fix|bugfix|hotfix|release|support|chore|docs|ci|test|dependabot)/[a-zA-Z0-9._/-]+$"
           max-files-changed: "50"
-          allowed-target-branches: "master"
+          allowed-target-branches: ${{ steps.targets.outputs.list }}
diff --git a/.github/workflows/validate-doc-app.yml b/.github/workflows/validate-doc-app.yml
index 4c424ef..ecca0a1 100644
--- a/.github/workflows/validate-doc-app.yml
+++ b/.github/workflows/validate-doc-app.yml
@@ -1,6 +1,6 @@
 # Reusable workflow — validate a doc app against the knowledge-base contract.
 #
-# Called by doc-app repos in their own CI to verify the app meets the marketplace
+# Called by doc-app repos in their own CI to verify the app meets the knowledge base
 # contract before raising a PR or publishing a release.
 #
 # Usage in a doc repo (.github/workflows/validate.yml):
@@ -28,7 +28,7 @@ permissions:
 
 jobs:
   validate:
-    name: Validate marketplace contract
+    name: Validate knowledge base contract
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
@@ -106,15 +106,15 @@ jobs:
           echo "✓ dist/${ENTRY} found"
 
       # ── Validate headless HTML structure ───────────────────────────────────
-      - name: Check data-mp-headless attribute
+      - name: Check data-kb-headless attribute
         run: |
           ENTRY=$(node -e "const m=require('./marketplace.json'); console.log(m.entryPoint || 'index.html')")
-          if ! grep -q 'data-mp-headless="true"' "dist/${ENTRY}"; then
-            echo "::error file=dist/${ENTRY}::Missing data-mp-headless=\"true\" on <html> element."
-            echo "Add data-mp-headless=\"true\" to the <html> tag when building with --headless."
+          if ! grep -q 'data-kb-headless="true"' "dist/${ENTRY}"; then
+            echo "::error file=dist/${ENTRY}::Missing data-kb-headless=\"true\" on <html> element."
+            echo "Add data-kb-headless=\"true\" to the <html> tag when building with --headless."
             exit 1
           fi
-          echo "✓ data-mp-headless=\"true\" found"
+          echo "✓ data-kb-headless=\"true\" found"
 
       - name: Check no fixed site header in headless output
         run: |
diff --git a/AGENTS.md b/AGENTS.md
index 110739b..6c5f3d8 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -121,13 +121,13 @@ add a registry entry that requires network or a sibling checkout without it.
 ### Two build modes, one document
 
 Every page renders through `src/layouts/Base.astro`. Headless (web-fragment) and
-standalone differ only by `data-mp-headless` and the shadow-DOM compat styles —
+standalone differ only by `data-kb-headless` and the shadow-DOM compat styles —
 not by a different layout. Changes that add a mode-specific code path need a
 strong reason.
 
 ### Light only
 
-The marketplace has no dark mode: no theme toggle, no persisted theme, no `dark`
+The knowledge base has no dark mode: no theme toggle, no persisted theme, no `dark`
 class, no dark palette. A sub-app's own theme bootstrap is removed twice:
 `scripts/hoist-inline-scripts.js` deletes it while it is still inline, and
 `src/utils/transform.js` strips any that survives, along with a `dark` body
diff --git a/CLAUDE.md b/CLAUDE.md
index fc8b5de..5bdcc77 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -72,7 +72,7 @@ Orchestrator: `scripts/build-vite.js`. Flags: `--local`, `--headless`.
 - `src/pages/index.astro` — Landing catalog page
 - `src/utils/apps.js` — `getAppPages()` enumerates sub-app HTML (manifest-driven or filesystem crawl)
 - `src/utils/transform.js` — `transformSubAppHtml()`: URL rewriting, document splitting (head/body/title/body-class), headless transforms
-- `src/layouts/Base.astro` — The one document shell: head, marketplace CSS (which carries the self-hosted Inter faces), `<ClientRouter />`, shadow-DOM compat styles
+- `src/layouts/Base.astro` — The one document shell: head, knowledge base CSS (which carries the self-hosted Inter faces), `<ClientRouter />`, shadow-DOM compat styles
 - `src/components/Masthead.astro` — Persistent Knowledge base header + Library/current-app sub-nav (all pages, both modes)
 - `src/components/AppCard.astro`, `src/components/AppIcon.astro` — Catalog card and its icon
 - `src/templates/shadow-compat.js` — Shadow-DOM design-token styles, injected into the body by the layout
@@ -90,21 +90,21 @@ An `apps.json` entry is one of:
 
 - **default (packaged)** — a repo publishes a headless static site as `dist.tar.gz` plus `marketplace.json`. Every HTML file becomes a route.
 - **`type: "iframe"`** — no artifact; a single route renders a full-viewport `<iframe>` for an external URL. Explicit stopgap (issue #10).
-- **`type: "single-page"`** — one release artifact holding *many* docs, published by `actions/publish-single-page-docs` from plain markdown. The entry carries **no per-doc metadata** (`{ "repo": …, "type": "single-page", "version": "latest" }`); the build reads the artifact's `bundle.json` and **expands** the entry into one app per doc, extracting each into `apps/{slug}/`. The expansion is recorded in `apps/.single-page.json` and spliced back into the registry by `loadRegistry()` so Astro sees the same registry the build did. Slugs must be globally unique — `resolveRegistry()` fails the build otherwise. Rendering: masthead, no sidebar, content in a centred `main.mp-single-page` reading column. See issue #35 and `contract/SINGLE_PAGE.md`.
+- **`type: "single-page"`** — one release artifact holding *many* docs, published by `actions/publish-single-page-docs` from plain markdown. The entry carries **no per-doc metadata** (`{ "repo": …, "type": "single-page", "version": "latest" }`); the build reads the artifact's `bundle.json` and **expands** the entry into one app per doc, extracting each into `apps/{slug}/`. The expansion is recorded in `apps/.single-page.json` and spliced back into the registry by `loadRegistry()` so Astro sees the same registry the build did. Slugs must be globally unique — `resolveRegistry()` fails the build otherwise. Rendering: masthead, no sidebar, content in a centred `main.kb-single-page` reading column. See issue #35 and `contract/SINGLE_PAGE.md`.
 
 ### Two Modes
 
 Both modes render the same document: the masthead (`Masthead.astro`) — branding plus the Library / current-app sub-navigation — on every page, and nothing else chrome-like. There is no fixed top bar and no app switcher; the masthead is the navigation.
 
-**Non-headless** (standalone): Plain marketplace pages. Navigation is Astro's `<ClientRouter />` (view transitions).
+**Non-headless** (standalone): Plain knowledge base pages. Navigation is Astro's `<ClientRouter />` (view transitions).
 
-**Headless** (web-fragment): Marks `data-mp-headless="true"` on `<html>`, for embedding in a web-fragments gateway. That attribute is the only difference in the output — the shadow-DOM compat styles are emitted in both modes.
+**Headless** (web-fragment): Marks `data-kb-headless="true"` on `<html>`, for embedding in a web-fragments gateway. That attribute is the only difference in the output — the shadow-DOM compat styles are emitted in both modes.
 
 Resolution order: a per-app `"headless"` in `apps.json` wins; otherwise `isHeadlessBuild()`.
 
 ### Light Only
 
-The marketplace has no dark mode: no theme toggle, no persisted theme, no `dark` class, no dark palette. A sub-app's own theme bootstrap is removed twice over — `hoist-inline-scripts.js` deletes it while it is still inline, and `transformSubAppHtml()` strips any that reaches Astro, along with a `dark` body class — so an embedding host's theme cannot bleed into the fragment.
+The knowledge base has no dark mode: no theme toggle, no persisted theme, no `dark` class, no dark palette. A sub-app's own theme bootstrap is removed twice over — `hoist-inline-scripts.js` deletes it while it is still inline, and `transformSubAppHtml()` strips any that reaches Astro, along with a `dark` body class — so an embedding host's theme cannot bleed into the fragment.
 
 Known gap: inline `on*` handlers in sub-app HTML are not stripped (#67). They are inert under the CSP but not under `astro dev`.
 
@@ -118,8 +118,8 @@ Root-relative `url()` inside a sub-app's **copied CSS files** is a separate rewr
 
 Apps registered in `apps.json` must comply with:
 - `contract/schema.json` — JSON Schema for `marketplace.json` manifest (packaged apps)
-- `contract/HEADLESS_RULES.md` — Structural requirements (headless HTML, relative paths, `data-mp-headless` attribute)
-- `contract/STYLE_GUIDE.md` — Design tokens and typography (light only — the marketplace has no dark mode)
+- `contract/HEADLESS_RULES.md` — Structural requirements (headless HTML, relative paths, `data-kb-headless` attribute)
+- `contract/STYLE_GUIDE.md` — Design tokens and typography (light only — the knowledge base has no dark mode)
 - `contract/SINGLE_PAGE.md` — `bundle.json` format + the copy-paste onboarding workflow for single-page docs
 
 ## Testing
@@ -133,7 +133,7 @@ Self-contained Playwright E2E — `npm test` auto-starts everything (no external
    `tests/fragment-server.mjs` serves `dist/` mirroring the production **nginx** rewrites
    (`/__wf/knowledge-base/*` → `/knowledge-base/*`). NB: `astro preview` is NOT used — its
    Vite `configurePreviewServer` rewrite hook does not run for static output, so the
-   marketplace CSS 404s; the nginx-mirror server is the faithful fragment endpoint.
+   knowledge base CSS 404s; the nginx-mirror server is the faithful fragment endpoint.
 2. **:4201 host** — `tests/host/server.mjs`, a minimal Express "wrapping web-fragment
    application" (`FragmentGateway` + `getNodeMiddleware`) that proxies/embeds the :3000
    fragment on a single origin via `<web-fragment fragment-id="knowledge-base">`.
@@ -141,7 +141,7 @@ Self-contained Playwright E2E — `npm test` auto-starts everything (no external
 Tests drive the host origin (`http://localhost:4201`). Suites (`tests/`), all four
 commands listed in `AGENTS.md`:
 - `build-integrity.spec.js` — `dist/` output: both apps enumerated, absolute URL rewriting,
-  headless markup and the per-app `"headless"` override, the content-hashed marketplace
+  headless markup and the per-app `"headless"` override, the content-hashed knowledge base
   stylesheet plus its stable `dist/style.css` alias, no inline script anywhere, and
   single-page bundle expansion (`tests/fixtures/single-page-bundle/` → two apps).
 - `transform.spec.js` — unit tests for `transformSubAppHtml()`: the malformed and
@@ -159,7 +159,7 @@ commands listed in `AGENTS.md`:
 
 Two build-pipeline pieces support this: `apps.json` entries may carry a `prebuilt` path
 (tarball or dist dir) consumed by `scripts/build-vite.js` (`preparePrebuilt`) for hermetic
-offline builds; and the build copies the marketplace stylesheet — identified as the local
+offline builds; and the build copies the knowledge base stylesheet — identified as the local
 stylesheet the landing page loads — to a stable `dist/style.css` alias. Pages themselves
 reference the content-hashed bundle Astro injects, so nothing depends on that filename.
 
@@ -172,7 +172,7 @@ in the committed `apps.json` without breaking CI, which only has this repo.
 ## Environment Variables
 
 - `GITHUB_TOKEN` — GitHub API auth for fetching Release artifacts
-- `MP_HEADLESS` — `true` produces web-fragment output; **anything else, including unset, means standalone**. `scripts/build-vite.js` always exports an explicit value, so the default only applies when `astro build`/`astro dev` runs directly. Read it through `isHeadlessBuild()`, never inline. A per-app `"headless"` in `apps.json` overrides it in either direction.
+- `KB_HEADLESS` — `true` produces web-fragment output; **anything else, including unset, means standalone**. `scripts/build-vite.js` always exports an explicit value, so the default only applies when `astro build`/`astro dev` runs directly. Read it through `isHeadlessBuild()`, never inline. A per-app `"headless"` in `apps.json` overrides it in either direction.
 - `AWS_REGION`, `ECR_REPOSITORY`, `ECS_CLUSTER`, `ECS_SERVICE` — deployment config
 - `KB_EXAMPLE_ARTIFACT` — overrides the packaged artifact `scripts/setup-test-apps.mjs` registers
 - `KB_CONTAINER_PORT`, `KB_SKIP_BUILD` — container-suite harness (`tests/container/serve.mjs`); CI sets `KB_SKIP_BUILD` because its image job already built the image
diff --git a/README.md b/README.md
index 7270247..c101978 100644
--- a/README.md
+++ b/README.md
@@ -72,9 +72,9 @@ npm test
 | `npm run build:local` | Build each app from a local checkout (`localPath`) |
 | `npm run build:local:headless` | Local + headless |
 
-`--headless` (or `MP_HEADLESS=true`) produces fragment-ready output, marked with
-`data-mp-headless="true"` on `<html>`. Anything else — including an unset
-`MP_HEADLESS` — means standalone. An individual app can pin either mode with
+`--headless` (or `KB_HEADLESS=true`) produces fragment-ready output, marked with
+`data-kb-headless="true"` on `<html>`. Anything else — including an unset
+`KB_HEADLESS` — means standalone. An individual app can pin either mode with
 `"headless": true|false` in its `apps.json` entry, which wins over the build flag.
 
 Orchestrator: `scripts/build-vite.js` (flags: `--local`, `--headless`).
@@ -119,7 +119,7 @@ never quietly produce an empty deployment.
 Teams that already host their docs elsewhere and can't yet produce a headless
 package can be listed immediately with an **iframe** entry — no `repo`,
 `marketplace.json`, or artifact needed. It renders as a full-viewport `<iframe>`
-below the marketplace masthead and shows an **External** badge in the catalogue.
+below the knowledge base masthead and shows an **External** badge in the catalogue.
 
 ```jsonc
 {
@@ -135,7 +135,7 @@ below the marketplace masthead and shows an **External** badge in the catalogue.
 ```
 
 The external site must permit embedding (its CSP `frame-ancestors` /
-`X-Frame-Options` must not block the marketplace origin). See issue #10.
+`X-Frame-Options` must not block the knowledge base origin). See issue #10.
 
 ### single-page onboarding (markdown, zero config)
 
@@ -275,13 +275,13 @@ app.use(getNodeMiddleware(gateway));           // before host static/catch-all r
 
 ## Contract for doc apps
 
-Apps must comply with the marketplace contract before they can be registered:
+Apps must comply with the knowledge base contract before they can be registered:
 
 | Document | Description |
 |---|---|
 | [`contract/schema.json`](contract/schema.json) | JSON Schema for `marketplace.json` |
-| [`contract/HEADLESS_RULES.md`](contract/HEADLESS_RULES.md) | Headless HTML, relative paths, `data-mp-headless` |
-| [`contract/STYLE_GUIDE.md`](contract/STYLE_GUIDE.md) | Design tokens (`--color-kb-*`) and typography — light only; the marketplace has no dark mode |
+| [`contract/HEADLESS_RULES.md`](contract/HEADLESS_RULES.md) | Headless HTML, relative paths, `data-kb-headless` |
+| [`contract/STYLE_GUIDE.md`](contract/STYLE_GUIDE.md) | Design tokens (`--color-kb-*`) and typography — light only; the knowledge base has no dark mode |
 | [`contract/SINGLE_PAGE.md`](contract/SINGLE_PAGE.md) | `bundle.json` format + zero-config markdown onboarding |
 
 > The checklist and workflows below apply to **packaged** doc apps. Single-page
@@ -290,7 +290,7 @@ Apps must comply with the marketplace contract before they can be registered:
 ### Checklist
 - [ ] `marketplace.json` in repo root, valid against `contract/schema.json`
 - [ ] `npm run build -- --headless` produces a headless `dist/`
-- [ ] `data-mp-headless="true"` on `<html>` in headless output
+- [ ] `data-kb-headless="true"` on `<html>` in headless output
 - [ ] No fixed site-level header in headless output
 - [ ] All asset paths relative (no leading `/`)
 - [ ] GitHub Release tagged `v*` with a `dist.tar.gz` asset
@@ -369,7 +369,7 @@ knowledge-base/
 │   ├── layouts/Base.astro
 │   ├── components/            ← AppCard, AppIcon, Masthead
 │   ├── templates/shadow-compat.js ← Shadow-DOM design-token styles
-│   ├── styles/marketplace.css ← Design tokens + Tailwind
+│   ├── styles/knowledge-base.css ← Design tokens + Tailwind
 │   └── utils/
 │       ├── apps.js            ← loadRegistry() + getAppPages() page enumeration
 │       ├── config.js          ← PATH_PREFIX / BASE_PATH + isHeadlessBuild()
diff --git a/actions/publish-single-page-docs/README.md b/actions/publish-single-page-docs/README.md
index 31d4e05..2605e74 100644
--- a/actions/publish-single-page-docs/README.md
+++ b/actions/publish-single-page-docs/README.md
@@ -45,5 +45,5 @@ npm run selftest
 
 The self-test is deliberately **not** part of the knowledge base's Playwright
 suite: that suite must stay hermetic and must not depend on this action's
-`node_modules`. The marketplace side of the feature is covered there instead, via
+`node_modules`. The knowledge base side of the feature is covered there instead, via
 the `tests/fixtures/single-page-bundle/` fixture.
diff --git a/actions/publish-single-page-docs/src/bundle.js b/actions/publish-single-page-docs/src/bundle.js
index bb074a8..f9f86a8 100644
--- a/actions/publish-single-page-docs/src/bundle.js
+++ b/actions/publish-single-page-docs/src/bundle.js
@@ -8,10 +8,10 @@
  *   {slug}/assets/doc.css
  *   {slug}/assets/mermaid.min.js   (only when that doc uses mermaid)
  *   {slug}/assets/mermaid-init.js  (ditto — kept out of the HTML so the
- *                                   marketplace can run script-src 'self')
+ *                                   knowledge base can run script-src 'self')
  *
  * One release asset carries every doc from the repo; the knowledge base expands
- * the manifest into one marketplace app per doc (see contract/SINGLE_PAGE.md).
+ * the manifest into one knowledge base app per doc (see contract/SINGLE_PAGE.md).
  */
 
 import { execFileSync } from 'node:child_process';
@@ -62,7 +62,7 @@ export function buildBundle(docs, stageDir) {
 
     if (usesMermaid) {
       copyFileSync(resolveMermaidBundle(), join(docDir, MERMAID_PATH));
-      // The init runs from a file, not an inline <script>, so the marketplace
+      // The init runs from a file, not an inline <script>, so the knowledge base
       // can serve these pages under script-src 'self'.
       writeFileSync(join(docDir, MERMAID_INIT_PATH), MERMAID_INIT_JS);
     }
@@ -91,7 +91,7 @@ export function buildBundle(docs, stageDir) {
  * Locates the vendored mermaid bundle.
  *
  * The UMD build is used deliberately: it is fully self-contained (no dynamic
- * chunk imports), so a doc directory copied into the marketplace keeps working
+ * chunk imports), so a doc directory copied into the knowledge base keeps working
  * behind the fragment CSP without any CDN.
  */
 function resolveMermaidBundle() {
diff --git a/actions/publish-single-page-docs/src/markdown.js b/actions/publish-single-page-docs/src/markdown.js
index 6069977..5aaa9bd 100644
--- a/actions/publish-single-page-docs/src/markdown.js
+++ b/actions/publish-single-page-docs/src/markdown.js
@@ -3,7 +3,7 @@
  *
  * Rendering happens inside the action so an onboarding repo needs no toolchain
  * of its own: no mkdocs, no theme, no config file. What the repo commits is the
- * markdown; everything below turns it into a page the marketplace can re-host.
+ * markdown; everything below turns it into a page the knowledge base can re-host.
  *
  * Covered by design: tables, task lists, autolinks, footnotes, strikethrough,
  * highlighted code fences and ```mermaid diagrams.
@@ -51,7 +51,7 @@ function createRenderer(state) {
     level: [1, 2, 3, 4],
     permalink: anchor.permalink.linkInsideHeader({
       symbol: '#',
-      class: 'mp-anchor',
+      class: 'kb-anchor',
       placement: 'after',
     }),
   });
@@ -76,11 +76,11 @@ function createRenderer(state) {
       body = escapeHtml(token.content);
     }
     const langClass = lang ? ` language-${escapeHtml(lang)}` : '';
-    return `<pre class="mp-code"><code class="hljs${langClass}">${body}</code></pre>\n`;
+    return `<pre class="kb-code"><code class="hljs${langClass}">${body}</code></pre>\n`;
   };
 
   // ── Tables scroll inside their own box rather than widening the page ───────
-  md.renderer.rules.table_open  = () => '<div class="mp-table-wrap">\n<table>\n';
+  md.renderer.rules.table_open  = () => '<div class="kb-table-wrap">\n<table>\n';
   md.renderer.rules.table_close = () => '</table>\n</div>\n';
 
   // ── External links open in a new tab, and never leak the referrer ──────────
diff --git a/actions/publish-single-page-docs/src/sanitize.js b/actions/publish-single-page-docs/src/sanitize.js
index c091c20..818e87f 100644
--- a/actions/publish-single-page-docs/src/sanitize.js
+++ b/actions/publish-single-page-docs/src/sanitize.js
@@ -24,7 +24,7 @@
  * (tables, task lists, footnotes, anchors, highlighted code, mermaid), plus the
  * common structural and inline HTML an author might hand-write. Class and id
  * attributes are kept because the rendering pipeline depends on them —
- * `mp-code`, `mp-anchor`, `hljs-*`, `task-list-item`, `footnotes`, heading ids.
+ * `kb-code`, `kb-anchor`, `hljs-*`, `task-list-item`, `footnotes`, heading ids.
  */
 
 import sanitizeHtml from 'sanitize-html';
diff --git a/actions/publish-single-page-docs/src/selftest.js b/actions/publish-single-page-docs/src/selftest.js
index 7c7c4e6..91556c1 100644
--- a/actions/publish-single-page-docs/src/selftest.js
+++ b/actions/publish-single-page-docs/src/selftest.js
@@ -6,7 +6,7 @@
  * headless rules, and the shape of bundle.json. Also pins the validation error
  * messages, since those are the action's user interface for onboarding repos.
  *
- * Kept out of the marketplace's Playwright suite on purpose: that suite must stay
+ * Kept out of the knowledge base's Playwright suite on purpose: that suite must stay
  * hermetic and must not depend on this action's node_modules.
  */
 
@@ -154,11 +154,11 @@ try {
   });
 
   check('document complies with contract/HEADLESS_RULES.md', () => {
-    assert.match(html, /<html lang="en" data-mp-headless="true">/);
+    assert.match(html, /<html lang="en" data-kb-headless="true">/);
     assert.doesNotMatch(html, /<base\b/i);
     assert.doesNotMatch(html, /localStorage/);
     assert.doesNotMatch(html, /\bclass="dark"/);
-    // No site-level header and no sidebar — the marketplace masthead is the chrome.
+    // No site-level header and no sidebar — the knowledge base masthead is the chrome.
     assert.doesNotMatch(html, /<header class="fixed/);
     assert.doesNotMatch(html, /id="sidebar"/);
     // All asset references are relative (no leading slash).
@@ -175,7 +175,7 @@ try {
   });
 
   check('highlights code fences', () => {
-    assert.match(html, /<pre class="mp-code"><code class="hljs language-js">/);
+    assert.match(html, /<pre class="kb-code"><code class="hljs language-js">/);
     assert.match(html, /hljs-keyword/);
   });
 
@@ -193,7 +193,7 @@ try {
       'mermaid init not written',
     );
     // Every <script> must carry a src. An inline one would force the
-    // marketplace's CSP to allow script-src 'unsafe-inline', which would allow
+    // knowledge base's CSP to allow script-src 'unsafe-inline', which would allow
     // an injected script too.
     for (const [tag] of html.matchAll(/<script\b[^>]*>/g)) {
       assert.match(tag, /\bsrc=/, `inline <script> in the document: ${tag}`);
@@ -204,7 +204,7 @@ try {
     assert.match(html, /<link rel="stylesheet" href="assets\/doc\.css">/);
     const css = readFileSync(join(stage, 'my-service', 'assets', 'doc.css'), 'utf8');
     assert.match(css, /--color-kb-500: #af144b;/);
-    assert.match(css, /\.mp-doc\b/);
+    assert.match(css, /\.kb-doc\b/);
   });
 
   check('packs a tarball with bundle.json at the root', () => {
@@ -246,7 +246,7 @@ try {
 
   check('strips inline <style> and style attributes', () => {
     // CSS is not inert: it can exfiltrate through url(), and absolute positioning
-    // lets a doc cover the marketplace masthead.
+    // lets a doc cover the knowledge base masthead.
     const html = rendered('<style>body{background:url("https://evil.example/beacon")}</style>\n\n<p style="position:fixed;inset:0">covered</p>\n');
     assert.doesNotMatch(html, /<style/i);
     assert.doesNotMatch(html, /evil\.example/);
@@ -285,7 +285,7 @@ try {
     ].join('\n'));
 
     assert.match(html, /<h1[^>]*id="heading"/, 'heading anchors');
-    assert.match(html, /class="mp-anchor"/, 'anchor permalinks');
+    assert.match(html, /class="kb-anchor"/, 'anchor permalinks');
     assert.match(html, /task-list-item/, 'task lists');
     // Attribute order is not stable through the sanitiser, so assert each
     // independently rather than pinning a sequence.
diff --git a/actions/publish-single-page-docs/src/template.js b/actions/publish-single-page-docs/src/template.js
index 3c4a653..9e74039 100644
--- a/actions/publish-single-page-docs/src/template.js
+++ b/actions/publish-single-page-docs/src/template.js
@@ -4,10 +4,10 @@
  * Deliberately dependency-free: the knowledge base's own test fixture generator
  * (scripts/setup-test-apps.mjs) imports this module so the fixture and the real
  * action agree on the document shell without pulling the action's node_modules
- * into the marketplace build.
+ * into the knowledge base build.
  *
  * Everything emitted here must satisfy contract/HEADLESS_RULES.md:
- *   • data-mp-headless="true" on <html>
+ *   • data-kb-headless="true" on <html>
  *   • no <base> tag, all asset paths relative
  *   • no site-level <header>, no sidebar, no theme toggle
  *   • light only — no dark palette, no localStorage theme bootstrap
@@ -36,9 +36,9 @@ export function escapeHtml(str) {
  *
  * Two jobs:
  *   1. Declare the canonical design tokens so the artifact also looks right when
- *      opened standalone (in the marketplace the same :root block is declared by
- *      src/styles/marketplace.css with identical values).
- *   2. Style the prose, scoped to `.mp-doc`, so nothing leaks into the masthead
+ *      opened standalone (in the knowledge base the same :root block is declared by
+ *      src/styles/knowledge-base.css with identical values).
+ *   2. Style the prose, scoped to `.kb-doc`, so nothing leaks into the masthead
  *      or into a host application when the page is embedded as a web fragment.
  *
  * Colours/radii follow contract/STYLE_GUIDE.md, including its dark slate code
@@ -78,9 +78,9 @@ export const DOC_CSS = `/* Generated by AbsaOSS/knowledge-base/actions/publish-s
 body { margin: 0; font-family: var(--font-sans); color: var(--text-body); }
 
 /* ── Reading column ───────────────────────────────────────────────────────── */
-/* Standalone only. Inside the marketplace the .mp-single-page wrapper owns the
+/* Standalone only. Inside the knowledge base the .kb-single-page wrapper owns the
    measure, so this stays a max-width rather than a fixed layout. */
-.mp-doc {
+.kb-doc {
   max-width: 50rem;
   margin: 0 auto;
   padding: 2.5rem 1.5rem 5rem;
@@ -89,58 +89,58 @@ body { margin: 0; font-family: var(--font-sans); color: var(--text-body); }
   color: var(--text-body);
   overflow-wrap: break-word;
 }
-.mp-single-page > .mp-doc { padding: 0; max-width: none; }
+.kb-single-page > .kb-doc { padding: 0; max-width: none; }
 
 /* ── Lede (rendered when the markdown has no top-level heading) ───────────── */
-.mp-doc-lede { margin: 0 0 2.5rem; }
-.mp-doc-lede p { font-size: 1.125rem; color: var(--text-muted); margin: 0.5rem 0 0; }
+.kb-doc-lede { margin: 0 0 2.5rem; }
+.kb-doc-lede p { font-size: 1.125rem; color: var(--text-muted); margin: 0.5rem 0 0; }
 
 /* ── Headings ─────────────────────────────────────────────────────────────── */
-.mp-doc h1, .mp-doc h2, .mp-doc h3,
-.mp-doc h4, .mp-doc h5, .mp-doc h6 {
+.kb-doc h1, .kb-doc h2, .kb-doc h3,
+.kb-doc h4, .kb-doc h5, .kb-doc h6 {
   color: var(--text-heading);
   font-weight: 700;
   letter-spacing: -0.02em;
   line-height: 1.25;
   scroll-margin-top: 2rem;
 }
-.mp-doc h1 { font-size: 2.25rem; margin: 0 0 1.25rem; }
-.mp-doc h2 { font-size: 1.5rem;  margin: 3rem 0 1rem; padding-bottom: 0.5rem; border-bottom: 1px solid var(--border); }
-.mp-doc h3 { font-size: 1.1875rem; margin: 2.25rem 0 0.75rem; }
-.mp-doc h4 { font-size: 1rem;    margin: 1.75rem 0 0.5rem; }
-.mp-doc h5, .mp-doc h6 { font-size: 0.9375rem; margin: 1.5rem 0 0.5rem; }
+.kb-doc h1 { font-size: 2.25rem; margin: 0 0 1.25rem; }
+.kb-doc h2 { font-size: 1.5rem;  margin: 3rem 0 1rem; padding-bottom: 0.5rem; border-bottom: 1px solid var(--border); }
+.kb-doc h3 { font-size: 1.1875rem; margin: 2.25rem 0 0.75rem; }
+.kb-doc h4 { font-size: 1rem;    margin: 1.75rem 0 0.5rem; }
+.kb-doc h5, .kb-doc h6 { font-size: 0.9375rem; margin: 1.5rem 0 0.5rem; }
 
 /* Heading anchors — revealed on hover, invisible to the reading eye otherwise */
-.mp-doc .mp-anchor {
+.kb-doc .kb-anchor {
   color: var(--text-hint, #9ca3af);
   text-decoration: none;
   margin-left: 0.4rem;
   opacity: 0;
   transition: opacity 0.2s;
 }
-.mp-doc h1:hover .mp-anchor, .mp-doc h2:hover .mp-anchor,
-.mp-doc h3:hover .mp-anchor, .mp-doc h4:hover .mp-anchor { opacity: 1; }
+.kb-doc h1:hover .kb-anchor, .kb-doc h2:hover .kb-anchor,
+.kb-doc h3:hover .kb-anchor, .kb-doc h4:hover .kb-anchor { opacity: 1; }
 
 /* ── Flow ─────────────────────────────────────────────────────────────────── */
-.mp-doc p  { margin: 0 0 1.25rem; }
-.mp-doc ul, .mp-doc ol { margin: 0 0 1.25rem; padding-left: 1.5rem; }
-.mp-doc li { margin: 0.375rem 0; }
-.mp-doc li > ul, .mp-doc li > ol { margin: 0.375rem 0; }
-.mp-doc hr { border: 0; border-top: 1px solid var(--border); margin: 2.5rem 0; }
-.mp-doc img, .mp-doc video { max-width: 100%; height: auto; border-radius: var(--radius-md); }
+.kb-doc p  { margin: 0 0 1.25rem; }
+.kb-doc ul, .kb-doc ol { margin: 0 0 1.25rem; padding-left: 1.5rem; }
+.kb-doc li { margin: 0.375rem 0; }
+.kb-doc li > ul, .kb-doc li > ol { margin: 0.375rem 0; }
+.kb-doc hr { border: 0; border-top: 1px solid var(--border); margin: 2.5rem 0; }
+.kb-doc img, .kb-doc video { max-width: 100%; height: auto; border-radius: var(--radius-md); }
 
-.mp-doc a { color: var(--color-kb-500); text-decoration: none; }
-.mp-doc a:hover { color: var(--color-kb-600); text-decoration: underline; }
+.kb-doc a { color: var(--color-kb-500); text-decoration: none; }
+.kb-doc a:hover { color: var(--color-kb-600); text-decoration: underline; }
 
-.mp-doc strong { color: var(--text-heading); font-weight: 600; }
+.kb-doc strong { color: var(--text-heading); font-weight: 600; }
 
 /* ── Task lists (GFM) ─────────────────────────────────────────────────────── */
-.mp-doc .contains-task-list { list-style: none; padding-left: 0.25rem; }
-.mp-doc .task-list-item { display: flex; align-items: flex-start; gap: 0.5rem; }
-.mp-doc .task-list-item-checkbox { margin-top: 0.45rem; accent-color: var(--color-kb-500); }
+.kb-doc .contains-task-list { list-style: none; padding-left: 0.25rem; }
+.kb-doc .task-list-item { display: flex; align-items: flex-start; gap: 0.5rem; }
+.kb-doc .task-list-item-checkbox { margin-top: 0.45rem; accent-color: var(--color-kb-500); }
 
 /* ── Blockquotes ──────────────────────────────────────────────────────────── */
-.mp-doc blockquote {
+.kb-doc blockquote {
   margin: 0 0 1.25rem;
   padding: 0.75rem 1rem;
   border-left: 4px solid var(--color-kb-500);
@@ -148,11 +148,11 @@ body { margin: 0; font-family: var(--font-sans); color: var(--text-body); }
   border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
   color: var(--text-body);
 }
-.mp-doc blockquote > :last-child { margin-bottom: 0; }
+.kb-doc blockquote > :last-child { margin-bottom: 0; }
 
 /* ── Tables ───────────────────────────────────────────────────────────────── */
-.mp-doc .mp-table-wrap { overflow-x: auto; margin: 0 0 1.5rem; }
-.mp-doc table {
+.kb-doc .kb-table-wrap { overflow-x: auto; margin: 0 0 1.5rem; }
+.kb-doc table {
   border-collapse: collapse;
   width: 100%;
   font-size: 0.9375rem;
@@ -160,14 +160,14 @@ body { margin: 0; font-family: var(--font-sans); color: var(--text-body); }
   border-radius: var(--radius-md);
   overflow: hidden;
 }
-.mp-doc thead { background: var(--bg-strong); }
-.mp-doc th, .mp-doc td { padding: 0.625rem 0.875rem; text-align: left; border-bottom: 1px solid var(--border); }
-.mp-doc th { color: var(--text-heading); font-weight: 600; }
-.mp-doc tbody tr:last-child td { border-bottom: 0; }
-.mp-doc tbody tr:hover { background: var(--bg-strong); }
+.kb-doc thead { background: var(--bg-strong); }
+.kb-doc th, .kb-doc td { padding: 0.625rem 0.875rem; text-align: left; border-bottom: 1px solid var(--border); }
+.kb-doc th { color: var(--text-heading); font-weight: 600; }
+.kb-doc tbody tr:last-child td { border-bottom: 0; }
+.kb-doc tbody tr:hover { background: var(--bg-strong); }
 
 /* ── Code ─────────────────────────────────────────────────────────────────── */
-.mp-doc code {
+.kb-doc code {
   font-family: var(--font-mono);
   background: var(--bg-strong);
   border: 1px solid var(--border);
@@ -175,7 +175,7 @@ body { margin: 0; font-family: var(--font-sans); color: var(--text-body); }
   padding: 1px 5px;
   font-size: 0.85em;
 }
-.mp-doc pre.mp-code {
+.kb-doc pre.kb-code {
   margin: 0 0 1.5rem;
   padding: 1rem 1.125rem;
   background: #0f172a;
@@ -183,7 +183,7 @@ body { margin: 0; font-family: var(--font-sans); color: var(--text-body); }
   border-radius: var(--radius-md);
   overflow-x: auto;
 }
-.mp-doc pre.mp-code code {
+.kb-doc pre.kb-code code {
   background: none;
   border: 0;
   padding: 0;
@@ -193,21 +193,21 @@ body { margin: 0; font-family: var(--font-sans); color: var(--text-body); }
 }
 
 /* highlight.js token colours, tuned for the slate code surface above */
-.mp-doc .hljs-comment, .mp-doc .hljs-quote { color: #64748b; font-style: italic; }
-.mp-doc .hljs-keyword, .mp-doc .hljs-selector-tag, .mp-doc .hljs-built_in { color: #c4b5fd; }
-.mp-doc .hljs-string, .mp-doc .hljs-regexp, .mp-doc .hljs-addition { color: #86efac; }
-.mp-doc .hljs-number, .mp-doc .hljs-literal, .mp-doc .hljs-deletion { color: #fca5a5; }
-.mp-doc .hljs-title, .mp-doc .hljs-title.class_, .mp-doc .hljs-title.function_,
-.mp-doc .hljs-section, .mp-doc .hljs-name { color: #93c5fd; }
-.mp-doc .hljs-attr, .mp-doc .hljs-attribute, .mp-doc .hljs-variable,
-.mp-doc .hljs-template-variable, .mp-doc .hljs-property { color: #fcd34d; }
-.mp-doc .hljs-type, .mp-doc .hljs-meta, .mp-doc .hljs-symbol, .mp-doc .hljs-bullet { color: #67e8f9; }
-.mp-doc .hljs-emphasis { font-style: italic; }
-.mp-doc .hljs-strong { font-weight: 700; }
+.kb-doc .hljs-comment, .kb-doc .hljs-quote { color: #64748b; font-style: italic; }
+.kb-doc .hljs-keyword, .kb-doc .hljs-selector-tag, .kb-doc .hljs-built_in { color: #c4b5fd; }
+.kb-doc .hljs-string, .kb-doc .hljs-regexp, .kb-doc .hljs-addition { color: #86efac; }
+.kb-doc .hljs-number, .kb-doc .hljs-literal, .kb-doc .hljs-deletion { color: #fca5a5; }
+.kb-doc .hljs-title, .kb-doc .hljs-title.class_, .kb-doc .hljs-title.function_,
+.kb-doc .hljs-section, .kb-doc .hljs-name { color: #93c5fd; }
+.kb-doc .hljs-attr, .kb-doc .hljs-attribute, .kb-doc .hljs-variable,
+.kb-doc .hljs-template-variable, .kb-doc .hljs-property { color: #fcd34d; }
+.kb-doc .hljs-type, .kb-doc .hljs-meta, .kb-doc .hljs-symbol, .kb-doc .hljs-bullet { color: #67e8f9; }
+.kb-doc .hljs-emphasis { font-style: italic; }
+.kb-doc .hljs-strong { font-weight: 700; }
 
 /* ── Mermaid ──────────────────────────────────────────────────────────────── */
 /* Pre-render the source is hidden; mermaid swaps in an <svg> in its place. */
-.mp-doc pre.mermaid {
+.kb-doc pre.mermaid {
   margin: 0 0 1.5rem;
   padding: 1.25rem;
   background: var(--bg-card);
@@ -222,17 +222,17 @@ body { margin: 0; font-family: var(--font-sans); color: var(--text-body); }
 /* margin-inline:auto, not the parent's text-align. Mermaid sets display:block on
    the <svg> it swaps in, and a block box ignores text-align — so a diagram
    narrower than the column sat flush left. */
-.mp-doc pre.mermaid svg { max-width: 100%; height: auto; display: block; margin-inline: auto; }
+.kb-doc pre.mermaid svg { max-width: 100%; height: auto; display: block; margin-inline: auto; }
 
 /* ── Footnotes (GFM) ──────────────────────────────────────────────────────── */
-.mp-doc .footnotes {
+.kb-doc .footnotes {
   margin-top: 3rem;
   padding-top: 1.5rem;
   border-top: 1px solid var(--border);
   font-size: 0.875rem;
   color: var(--text-muted);
 }
-.mp-doc .footnotes hr { display: none; }
+.kb-doc .footnotes hr { display: none; }
 `;
 
 // ── Mermaid bootstrap ─────────────────────────────────────────────────────────
@@ -240,9 +240,9 @@ body { margin: 0; font-family: var(--font-sans); color: var(--text-body); }
 /**
  * Init script for the vendored mermaid bundle.
  *
- * Vendored rather than loaded from a CDN: marketplace pages are re-hosted inside
+ * Vendored rather than loaded from a CDN: knowledge base pages are re-hosted inside
  * a web fragment behind a strict CSP, so every asset a doc needs must live in its
- * own artifact. `startOnLoad` is off because the marketplace swaps pages with
+ * own artifact. `startOnLoad` is off because the knowledge base swaps pages with
  * Astro's ClientRouter — rendering is driven from both the initial load and the
  * `astro:page-load` event instead.
  *
@@ -251,7 +251,7 @@ body { margin: 0; font-family: var(--font-sans); color: var(--text-body); }
  * It used to be an inline <script> in the document. That is the one thing that
  * makes a meaningful Content-Security-Policy impossible: allowing it means
  * `script-src 'unsafe-inline'`, which allows every injected script too, and
- * hashing it would hard-couple the marketplace's nginx config to this action's
+ * hashing it would hard-couple the knowledge base's nginx config to this action's
  * exact bytes — bundles published by an older version would then break. As a
  * file it is covered by `script-src 'self'` and nothing has to know about it.
  */
@@ -301,14 +301,14 @@ export function mermaidBootstrap() {
 export function renderDocument({ title, description, bodyHtml, usesMermaid = false, hasHeading = true }) {
   // Only synthesise a lede when the author's markdown has no <h1> of its own —
   // duplicating the title above an existing heading reads as a bug.
-  const lede = hasHeading ? '' : `  <header class="mp-doc-lede">
+  const lede = hasHeading ? '' : `  <header class="kb-doc-lede">
     <h1>${escapeHtml(title)}</h1>
     <p>${escapeHtml(description)}</p>
   </header>
 `;
 
   return `<!DOCTYPE html>
-<html lang="en" data-mp-headless="true">
+<html lang="en" data-kb-headless="true">
 <head>
 <meta charset="utf-8">
 <meta name="viewport" content="width=device-width, initial-scale=1">
@@ -317,7 +317,7 @@ export function renderDocument({ title, description, bodyHtml, usesMermaid = fal
 <link rel="stylesheet" href="${CSS_PATH}">
 </head>
 <body>
-<article class="mp-doc">
+<article class="kb-doc">
 ${lede}${bodyHtml.trim()}
 </article>
 ${usesMermaid ? mermaidBootstrap() + '\n' : ''}</body>
diff --git a/contract/HEADLESS_RULES.md b/contract/HEADLESS_RULES.md
index 07a957f..0a2ac04 100644
--- a/contract/HEADLESS_RULES.md
+++ b/contract/HEADLESS_RULES.md
@@ -1,8 +1,8 @@
 # Headless Build Rules
 
-Doc apps included in the marketplace must produce **headless HTML output** — pages that
+Doc apps included in the knowledge base must produce **headless HTML output** — pages that
 contain content (sidebar + prose) but **do not** include a site-level top navigation bar.
-The marketplace injects its own persistent 56 px chrome at the top of every page.
+The knowledge base injects its own persistent 56 px chrome at the top of every page.
 
 > **Simpler alternative — single-page docs.** If what you have is a markdown file or
 > two rather than a documentation *site*, none of this applies to you. Add the
@@ -14,10 +14,10 @@ The marketplace injects its own persistent 56 px chrome at the top of every page
 > elsewhere and cannot yet produce a headless package can be listed immediately with an
 > `apps.json` entry of `"type": "iframe"` + a `"url"` (no `marketplace.json`, no release
 > artifact, no headless build). The page is rendered as a full-viewport `<iframe>` inside
-> the marketplace chrome. This is an **explicit stopgap** — such entries should carry
+> the knowledge base chrome. This is an **explicit stopgap** — such entries should carry
 > `"temporary": true` and be migrated to a proper headless package when possible. The
 > external site must allow embedding (its CSP `frame-ancestors` / `X-Frame-Options` must
-> not block the marketplace origin). See issue #10.
+> not block the knowledge base origin). See issue #10.
 
 ---
 
@@ -26,7 +26,7 @@ The marketplace injects its own persistent 56 px chrome at the top of every page
 Your build script must support a `--headless` CLI flag that produces headless output.
 
 ```bash
-# Headless build (used by marketplace and release workflow)
+# Headless build (used by knowledge base and release workflow)
 npm run build -- --headless
 
 # Standalone build (for local dev / preview)
@@ -38,10 +38,10 @@ When `--headless` is active:
 | Requirement | Detail |
 |---|---|
 | **No global `<header>`** | Do not render the site-level fixed top bar that contains the app logo and main navigation links. |
-| **Sidebar offset** | Set sidebar's `top` to `0` (marketplace resets it to `var(--mp-chrome-h)` via injected CSS). |
-| **`data-mp-headless` attribute** | Add `data-mp-headless="true"` to the `<html>` element so the marketplace can identify and verify headless pages. |
-| **Theme toggle** | Omit the theme toggle button from the site header. The marketplace chrome provides its own. |
-| **Relative asset paths** | All `href`, `src`, `action` attribute values must be **relative** (no leading `/`). The marketplace mounts apps at `/apps/{slug}/`, so absolute paths will 404. |
+| **Sidebar offset** | Set sidebar's `top` to `0`. The knowledge base no longer injects a fixed bar, so nothing is reserved above your content. |
+| **`data-kb-headless` attribute** | Add `data-kb-headless="true"` to the `<html>` element so the knowledge base can identify and verify headless pages. |
+| **Theme toggle** | Omit the theme toggle button from the site header. The knowledge base is light only and strips any theme bootstrap your page ships. |
+| **Relative asset paths** | All `href`, `src`, `action` attribute values must be **relative** (no leading `/`). The knowledge base mounts apps at `/apps/{slug}/`, so absolute paths will 404. |
 
 ---
 
@@ -69,7 +69,7 @@ It must validate against the [JSON Schema](./schema.json).
 
 ### Recommended: `pages` navigation manifest
 
-The optional `pages` array tells the marketplace the **exact set of routes** your app exposes, along with human-readable titles and ordering. When present it replaces the default filesystem crawl used to discover HTML files.
+The optional `pages` array tells the knowledge base the **exact set of routes** your app exposes, along with human-readable titles and ordering. When present it replaces the default filesystem crawl used to discover HTML files.
 
 | Field | Required | Description |
 |-------|----------|-------------|
@@ -80,7 +80,7 @@ The optional `pages` array tells the marketplace the **exact set of routes** you
 
 > **Note:** `pages` should be written into `dist/marketplace.json` (not the root `marketplace.json`) by your build script at build time. See the example app for a reference implementation that generates this from MkDocs navigation config.
 >
-> If `pages` is absent the marketplace falls back to crawling all `.html` files in `dist/` — existing apps require no changes.
+> If `pages` is absent the knowledge base falls back to crawling all `.html` files in `dist/` — existing apps require no changes.
 
 ### Slug rules
 - Lowercase letters, numbers, and hyphens only: `^[a-z0-9-]+$`
@@ -95,7 +95,7 @@ The `<body>` of each doc page must follow this structure:
 
 ```html
 <body>
-  <!-- ✅ Sidebar — marketplace repositions top offset -->
+  <!-- ✅ Sidebar — knowledge base repositions top offset -->
   <nav id="sidebar" class="fixed top-0 ...">
     ...
   </nav>
@@ -135,8 +135,8 @@ At minimum the following CSS custom properties must be present:
 ```
 
 Copy the `@theme` block and `:root` variable declarations from  
-[`src/styles/marketplace.css`](../src/styles/marketplace.css) in this repository.  
-There is deliberately no `.dark` set — the marketplace is light-only.
+[`src/styles/knowledge-base.css`](../src/styles/knowledge-base.css) in this repository.  
+There is deliberately no `.dark` set — the knowledge base is light-only.
 
 ---
 
@@ -171,7 +171,7 @@ Before opening a PR to add your app to `apps.json`:
 - [ ] `npm run build -- --headless` succeeds and produces `dist/`
 - [ ] `dist/` contains `index.html` (or your configured `entryPoint`)
 - [ ] No `<header class="fixed top-0...">` present in any headless HTML page
-- [ ] `data-mp-headless="true"` is on the `<html>` element
+- [ ] `data-kb-headless="true"` is on the `<html>` element
 - [ ] All asset paths are relative (no leading `/`)
 - [ ] Design tokens are defined in your CSS
 - [ ] A GitHub Release with `dist.tar.gz` exists on your repo
diff --git a/contract/SINGLE_PAGE.md b/contract/SINGLE_PAGE.md
index b01688e..4f5ad22 100644
--- a/contract/SINGLE_PAGE.md
+++ b/contract/SINGLE_PAGE.md
@@ -135,7 +135,7 @@ GitHub-flavoured markdown, rendered by `markdown-it`:
   [STYLE_GUIDE.md](./STYLE_GUIDE.md)
 - ` ```mermaid ` blocks, rendered client-side from a **vendored** mermaid bundle
 
-Mermaid is vendored into the artifact rather than loaded from a CDN: marketplace
+Mermaid is vendored into the artifact rather than loaded from a CDN: knowledge base
 pages are re-hosted inside a web fragment behind a strict CSP, so every asset a
 doc needs must live in its own artifact. If the script never runs, the diagram
 source stays visible rather than disappearing.
@@ -161,7 +161,7 @@ along with their `class` and `id` attributes.
 |---|---|
 | `<script>` | Would run on the knowledge base origin |
 | `on*` attributes (`onclick`, `onerror`, …) | Same |
-| `<style>` and `style="…"` | CSS can exfiltrate via `url()` and can cover the marketplace masthead |
+| `<style>` and `style="…"` | CSS can exfiltrate via `url()` and can cover the knowledge base masthead |
 | `<iframe>`, `<object>`, `<embed>` | Arbitrary embedded documents |
 | `<form>` and form controls (except task-list checkboxes) | Credential-phishing surface |
 | `javascript:` and `data:` URLs | Script execution by another name |
@@ -184,7 +184,7 @@ my-service/
   index.html
   assets/doc.css
   assets/mermaid.min.js     ← only when that doc uses mermaid
-  assets/mermaid-init.js    ← ditto; kept out of the HTML so the marketplace
+  assets/mermaid-init.js    ← ditto; kept out of the HTML so the knowledge base
                               can serve script-src 'self'
 my-service-releases/
   index.html
@@ -224,29 +224,29 @@ describing a *set* of apps rather than one app. Packaged doc sites keep using
 
 Each `index.html` satisfies [HEADLESS_RULES.md](./HEADLESS_RULES.md):
 
-- `data-mp-headless="true"` on `<html>`
+- `data-kb-headless="true"` on `<html>`
 - no `<base>` tag, every asset path relative
 - no site-level `<header>`, no sidebar, no theme toggle
 - light only — no dark palette, no `localStorage` theme bootstrap
 
-The body is a single `<article class="mp-doc">`. All prose styling lives in
-`assets/doc.css`, scoped to `.mp-doc`, so nothing leaks into the masthead or into
+The body is a single `<article class="kb-doc">`. All prose styling lives in
+`assets/doc.css`, scoped to `.kb-doc`, so nothing leaks into the masthead or into
 a host application when the page is embedded as a web fragment.
 
 ---
 
 ## How the knowledge base renders it
 
-The marketplace expands one `single-page` registry entry into one app per doc,
+The knowledge base expands one `single-page` registry entry into one app per doc,
 then renders each in its own reading column:
 
 ```html
-<main id="content" class="mp-single-page">
-  <article class="mp-doc"> … </article>
+<main id="content" class="kb-single-page">
+  <article class="kb-doc"> … </article>
 </main>
 ```
 
-`.mp-single-page` (in `src/styles/marketplace.css`) owns the measure — ~800px of
+`.kb-single-page` (in `src/styles/knowledge-base.css`) owns the measure — ~800px of
 content, centred, with generous vertical rhythm — so every single-page doc reads
 identically regardless of which repo published it. The persistent masthead is the
 only navigation; there is no sidebar and no in-app chrome.
diff --git a/contract/STYLE_GUIDE.md b/contract/STYLE_GUIDE.md
index 3fc1d18..95cef1d 100644
--- a/contract/STYLE_GUIDE.md
+++ b/contract/STYLE_GUIDE.md
@@ -1,6 +1,6 @@
 # Style Guide
 
-All doc apps in the marketplace must produce pages that are visually consistent with the
+All doc apps in the knowledge base must produce pages that are visually consistent with the
 the knowledge-base design system. This guide defines the required visual standards.
 
 ---
@@ -52,7 +52,7 @@ Ensure Inter is loaded from Google Fonts or bundled:
 
 ## Dark mode
 
-**There is none.** The marketplace is light-only: no theme toggle, no persisted
+**There is none.** The knowledge base is light-only: no theme toggle, no persisted
 preference, no dark palette.
 
 Do not ship a dark-mode bootstrap. When an app is integrated, the build strips any
@@ -61,7 +61,7 @@ dark theme would be dropped at integration time anyway — and inside a web frag
 it would clash with the host application's own theme.
 
 An app may still define `.dark` styles for its **standalone** deployment; they will
-simply never activate inside the marketplace.
+simply never activate inside the knowledge base.
 
 ---
 
@@ -70,8 +70,8 @@ simply never activate inside the marketplace.
 - Fixed left sidebar, **64px wide** (`w-64`)
 - Background: `var(--bg-card)`
 - Border right: `1px solid var(--border)`
-- `id="sidebar"` required so the marketplace can position it
-- `top: 0` — the marketplace renders no fixed top bar, so nothing needs offsetting
+- `id="sidebar"` required so the knowledge base can position it
+- `top: 0` — the knowledge base renders no fixed top bar, so nothing needs offsetting
 
 ---
 
@@ -143,7 +143,7 @@ padding: 0.75rem 1rem;
 
 - [ ] Only brand color tokens used (no raw hex brand colors)
 - [ ] Inter font loaded
-- [ ] Light CSS variable set defined (no dark set — the marketplace is light-only)
+- [ ] Light CSS variable set defined (no dark set — the knowledge base is light-only)
 - [ ] `id="sidebar"` present on the left navigation
 - [ ] `id="content"` or `<main>` wraps the prose area
 - [ ] No inline styles that override design tokens with hardcoded values
diff --git a/contract/schema.json b/contract/schema.json
index aae0912..1b7bb1f 100644
--- a/contract/schema.json
+++ b/contract/schema.json
@@ -2,7 +2,7 @@
   "$schema": "http://json-schema.org/draft-07/schema#",
   "$id": "contract/schema.json",
   "title": "marketplace.json",
-  "description": "Metadata manifest required in every doc app repo to be included in the docs marketplace.",
+  "description": "Metadata manifest required in every doc app repo to be included in the docs knowledge base.",
   "type": "object",
   "required": ["marketplaceVersion", "name", "slug", "description", "entryPoint"],
   "additionalProperties": false,
@@ -16,7 +16,7 @@
       "type": "string",
       "minLength": 2,
       "maxLength": 64,
-      "description": "Human-readable app name shown in the marketplace."
+      "description": "Human-readable app name shown in the knowledge base."
     },
     "slug": {
       "type": "string",
@@ -29,7 +29,7 @@
       "type": "string",
       "minLength": 10,
       "maxLength": 280,
-      "description": "Short description shown on the marketplace catalog card."
+      "description": "Short description shown on the knowledge base catalog card."
     },
     "icon": {
       "type": "string",
@@ -54,7 +54,7 @@
     },
     "pages": {
       "type": "array",
-      "description": "Optional navigation manifest. When present, the marketplace uses this list as the authoritative source of static routes instead of crawling the dist/ filesystem.",
+      "description": "Optional navigation manifest. When present, the knowledge base uses this list as the authoritative source of static routes instead of crawling the dist/ filesystem.",
       "items": {
         "type": "object",
         "required": ["title", "path", "order"],
diff --git a/package-lock.json b/package-lock.json
index 4d17d92..0d7e7f8 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -3796,9 +3796,9 @@
       }
     },
     "node_modules/fast-uri": {
-      "version": "3.1.5",
-      "resolved": "https://registry.npmjs.org/fast-uri/-/fast-uri-3.1.5.tgz",
-      "integrity": "sha512-gHwA1O9LDIcKunMKhObS/HimwtehO1nPUECKAu5TpKgaO19fcWEl4bliWe1jWxVFvIXztJjjQ4L8XQ1EU9f7Jw==",
+      "version": "3.1.7",
+      "resolved": "https://registry.npmjs.org/fast-uri/-/fast-uri-3.1.7.tgz",
+      "integrity": "sha512-dOvZVzjdZdz7phd9v6jCbwxrBW3fK6n8Rc0CtdmM4bumzMnxywBYhuph6J819RRw/ku+rLbelwfMunktuzVVHg==",
       "funding": [
         {
           "type": "github",
diff --git a/package.json b/package.json
index 926b14f..a6a7f09 100644
--- a/package.json
+++ b/package.json
@@ -7,17 +7,17 @@
     "node": ">=24"
   },
   "scripts": {
-    "dev": "MP_HEADLESS=false astro dev",
-    "dev:headless": "MP_HEADLESS=true astro dev",
-    "dev:fetch": "node scripts/fetch-apps.js && MP_HEADLESS=false astro dev",
+    "dev": "KB_HEADLESS=false astro dev",
+    "dev:headless": "KB_HEADLESS=true astro dev",
+    "dev:fetch": "node scripts/fetch-apps.js && KB_HEADLESS=false astro dev",
     "build": "node scripts/build-vite.js",
     "build:headless": "node scripts/build-vite.js --headless",
     "build:local": "node scripts/build-vite.js --local",
     "build:local:headless": "node scripts/build-vite.js --local --headless",
     "preview": "astro preview",
-    "preview:local": "MP_HEADLESS=false astro preview",
-    "preview:local:headless": "MP_HEADLESS=true astro preview",
-    "preview:embedded": "MP_HEADLESS=true astro preview",
+    "preview:local": "KB_HEADLESS=false astro preview",
+    "preview:local:headless": "KB_HEADLESS=true astro preview",
+    "preview:embedded": "KB_HEADLESS=true astro preview",
     "test:apps": "node scripts/setup-test-apps.mjs",
     "serve:test": "node tests/fragment-server.mjs",
     "host:test": "node tests/host/server.mjs",
diff --git a/scripts/build-vite.js b/scripts/build-vite.js
index 3104207..234ef44 100644
--- a/scripts/build-vite.js
+++ b/scripts/build-vite.js
@@ -36,7 +36,7 @@ const ROOT = join(__dirname, '..');
 const APPS_DIR = join(ROOT, 'apps');
 
 const LOCAL_MODE = process.argv.includes('--local');
-const HEADLESS   = process.argv.includes('--headless') || process.env.MP_HEADLESS === 'true';
+const HEADLESS   = process.argv.includes('--headless') || process.env.KB_HEADLESS === 'true';
 
 const log  = (msg) => console.log('\x1b[36m→\x1b[0m ' + msg);
 const ok   = (msg) => console.log('\x1b[32m✓\x1b[0m ' + msg);
@@ -251,7 +251,7 @@ async function build() {
   const packagedResolved = resolvedApps.filter(a => a.type !== 'iframe');
 
   // 1b. Hoist inline <script> bodies out of sub-app HTML into files.
-  //     The marketplace serves script-src 'self'; an inline script anywhere would
+  //     The knowledge base serves script-src 'self'; an inline script anywhere would
   //     force 'unsafe-inline' on every page. Bundles published before the action
   //     stopped emitting one still contain it, and this repo does not control
   //     when those repos re-publish — so it is fixed here rather than assumed.
@@ -339,13 +339,13 @@ async function build() {
 
   // 3. Run Astro build
   step('3/4  Running astro build');
-  // Always explicit: src/utils/config.js treats an unset MP_HEADLESS as
+  // Always explicit: src/utils/config.js treats an unset KB_HEADLESS as
   // standalone, and a build that says "--headless" must not depend on that.
-  const env = { ...process.env, MP_HEADLESS: HEADLESS ? 'true' : 'false' };
+  const env = { ...process.env, KB_HEADLESS: HEADLESS ? 'true' : 'false' };
   execSync('npx astro build', { cwd: ROOT, stdio: 'inherit', env });
   ok('Astro build complete');
 
-  // Publish dist/style.css as an alias of the marketplace stylesheet.
+  // Publish dist/style.css as an alias of the knowledge base stylesheet.
   //
   // Pages do not need it: Astro injects the <link> from Base.astro's CSS import,
   // with whatever content-hashed name the bundle got. The alias exists because
@@ -353,8 +353,8 @@ async function build() {
   // something outside this repository may still ask for it.
   //
   // The bundle is identified by *use*, not by filename: it is the local
-  // stylesheet the marketplace's own landing page loads. That is the definition
-  // of "the marketplace stylesheet", and it cannot drift from what the pages
+  // stylesheet the knowledge base's own landing page loads. That is the definition
+  // of "the knowledge base stylesheet", and it cannot drift from what the pages
   // actually reference the way a filename pattern could (#50).
   const distRoot = join(ROOT, 'dist');
   if (existsSync(distRoot)) {
@@ -367,7 +367,7 @@ async function build() {
 
     if (hrefs.length !== 1) {
       fail(
-        'Expected the landing page to load exactly one local stylesheet — the marketplace bundle — ' +
+        'Expected the landing page to load exactly one local stylesheet — the knowledge base bundle — ' +
         'but found ' + hrefs.length + (hrefs.length ? ': ' + hrefs.join(', ') : '') +
         '. dist/style.css can only alias an unambiguous one.',
       );
@@ -376,7 +376,7 @@ async function build() {
     const bundle = join(distRoot, hrefs[0].slice(('/' + PATH_PREFIX).length));
     if (!existsSync(bundle)) fail('The landing page references ' + hrefs[0] + ', which is not in dist/.');
     copyFileSync(bundle, join(distRoot, 'style.css'));
-    ok('Marketplace CSS ' + hrefs[0] + ' aliased → dist/style.css');
+    ok('Knowledge base CSS ' + hrefs[0] + ' aliased → dist/style.css');
   }
 
   // 4. Summary
diff --git a/scripts/fetch-apps.js b/scripts/fetch-apps.js
index 654cfbe..1335b8d 100644
--- a/scripts/fetch-apps.js
+++ b/scripts/fetch-apps.js
@@ -44,6 +44,32 @@ const REPO_RE = /^[A-Za-z0-9._-]+\/[A-Za-z0-9._-]+$/;
 /** Git tag characters we are willing to put in a URL path. */
 const VERSION_RE = /^[A-Za-z0-9._/-]+$/;
 
+/** The marker a headless artifact must carry on `<html>`. */
+const HEADLESS_MARKER = 'data-kb-headless="true"';
+/** Its pre-rename spelling — see issue #77. */
+const LEGACY_HEADLESS_MARKER = 'data-mp-headless';
+
+/**
+ * Warns when an artifact's entry point is not marked headless.
+ *
+ * A bundle published before the rename carries `data-mp-headless` instead, which
+ * is indistinguishable from "not headless at all" to every downstream consumer.
+ * Saying so explicitly is the difference between a publisher re-reading the
+ * contract and a publisher re-reading their build script.
+ */
+function checkHeadlessMarker(html, label, hint) {
+  if (html.includes(HEADLESS_MARKER)) return;
+  if (html.includes(LEGACY_HEADLESS_MARKER)) {
+    warn(
+      `${label} carries ${LEGACY_HEADLESS_MARKER}, which this knowledge base no longer reads.\n` +
+      `     The artifact was produced against the pre-rename contract — republish it with a\n` +
+      `     current AbsaOSS/knowledge-base action so it emits ${HEADLESS_MARKER}.`
+    );
+    return;
+  }
+  warn(`${label} is missing ${HEADLESS_MARKER} on <html>.\n     ${hint}`);
+}
+
 /**
  * Rejects registry values that must never reach a URL or a subprocess argument.
  *
@@ -197,9 +223,11 @@ async function fetchBundle(app) {
     copyDir(doc.docDir, appsSlugDir);
 
     const html = readFileSync(join(appsSlugDir, doc.entryPoint), 'utf8');
-    if (!html.includes('data-mp-headless="true"')) {
-      warn(`${doc.slug}: ${doc.entryPoint} is missing data-mp-headless="true" — see contract/HEADLESS_RULES.md.`);
-    }
+    checkHeadlessMarker(
+      html,
+      `${doc.slug}: ${doc.entryPoint}`,
+      'See contract/HEADLESS_RULES.md.',
+    );
     ok(`${doc.slug} ready (single-page doc, ${release.tag_name})`);
   }
 
@@ -299,12 +327,11 @@ export async function fetchApps(apps) {
     const indexHtml = join(distDir, app.entryPoint || 'index.html');
     if (existsSync(indexHtml)) {
       const html = readFileSync(indexHtml, 'utf8');
-      if (!html.includes('data-mp-headless="true"')) {
-        warn(
-          `${slug}/index.html is missing data-mp-headless="true" on <html>.\n` +
-          `     See contract/HEADLESS_RULES.md — ensure the app is built with --headless.`
-        );
-      }
+      checkHeadlessMarker(
+        html,
+        `${slug}/index.html`,
+        'See contract/HEADLESS_RULES.md — ensure the app is built with --headless.',
+      );
     } else {
       warn(`${slug}: entryPoint '${app.entryPoint || 'index.html'}' not found in artifact.`);
     }
diff --git a/scripts/hoist-inline-scripts.js b/scripts/hoist-inline-scripts.js
index f0d891f..f179b1a 100644
--- a/scripts/hoist-inline-scripts.js
+++ b/scripts/hoist-inline-scripts.js
@@ -3,7 +3,7 @@
  *
  * WHY
  *
- * The marketplace serves a Content-Security-Policy with `script-src 'self'`. An
+ * The knowledge base serves a Content-Security-Policy with `script-src 'self'`. An
  * inline <script> anywhere in a page defeats that: allowing it means adding
  * 'unsafe-inline', which allows an injected script too, and hashing every one is
  * not possible because the HTML comes from other repositories' release artifacts.
@@ -14,7 +14,7 @@
  * Enforcing the CSP without this step would silently break every already-published
  * doc's diagrams — verified against the sibling example repo's real artifact.
  *
- * So the marketplace hoists them itself, at build time, before anything else
+ * So the knowledge base hoists them itself, at build time, before anything else
  * reads apps/. Old bundles and new ones end up equally CSP-clean.
  *
  * ORDER IS PRESERVED
@@ -31,7 +31,7 @@
  * WHAT IS DELETED
  *
  * A sub-app's dark-mode bootstrap is dropped rather than hoisted. The
- * marketplace is light-only and src/utils/transform.js strips that script — but
+ * knowledge base is light-only and src/utils/transform.js strips that script — but
  * only while it is still inline, and this step runs first. Hoisting it would
  * turn it into an external file the strip can no longer recognise, and it would
  * then run in the browser and re-add `dark` (#48).
diff --git a/scripts/setup-test-apps.mjs b/scripts/setup-test-apps.mjs
index 8b91580..88f30a5 100644
--- a/scripts/setup-test-apps.mjs
+++ b/scripts/setup-test-apps.mjs
@@ -53,17 +53,17 @@ if (!existsSync(artifactAbs)) {
 // The document shell comes from the real action (actions/publish-single-page-docs/src/
 // template.js — deliberately dependency-free) so the fixture cannot drift from
 // what a published bundle looks like. Only the *body* HTML is hand-written here,
-// standing in for the markdown-it output, which keeps the marketplace test suite
+// standing in for the markdown-it output, which keeps the knowledge base test suite
 // free of the action's node_modules.
 
 const BUNDLE_DIR = 'tests/fixtures/single-page-bundle';
 
 /** Body of doc 1 — headings, prose, table, code fence, task list, mermaid. */
-const PLATFORM_OVERVIEW_BODY = `<h1 id="platform-overview" tabindex="-1">Platform Overview <a class="mp-anchor" href="#platform-overview">#</a></h1>
+const PLATFORM_OVERVIEW_BODY = `<h1 id="platform-overview" tabindex="-1">Platform Overview <a class="kb-anchor" href="#platform-overview">#</a></h1>
 <p>The platform runs every service behind a single gateway. See
 <a href="https://example.com/handbook" target="_blank" rel="noopener noreferrer">the handbook</a> for the long version.</p>
-<h2 id="endpoints" tabindex="-1">Endpoints <a class="mp-anchor" href="#endpoints">#</a></h2>
-<div class="mp-table-wrap">
+<h2 id="endpoints" tabindex="-1">Endpoints <a class="kb-anchor" href="#endpoints">#</a></h2>
+<div class="kb-table-wrap">
 <table>
 <thead>
 <tr><th>Endpoint</th><th>Method</th><th>Notes</th></tr>
@@ -74,24 +74,24 @@ const PLATFORM_OVERVIEW_BODY = `<h1 id="platform-overview" tabindex="-1">Platfor
 </tbody>
 </table>
 </div>
-<h2 id="configuration" tabindex="-1">Configuration <a class="mp-anchor" href="#configuration">#</a></h2>
-<pre class="mp-code"><code class="hljs language-js"><span class="hljs-keyword">export</span> <span class="hljs-keyword">const</span> port = <span class="hljs-title class_">Number</span>(process.<span class="hljs-property">env</span>.<span class="hljs-property">PORT</span> ?? <span class="hljs-number">8080</span>);</code></pre>
-<h2 id="rollout-status" tabindex="-1">Rollout status <a class="mp-anchor" href="#rollout-status">#</a></h2>
+<h2 id="configuration" tabindex="-1">Configuration <a class="kb-anchor" href="#configuration">#</a></h2>
+<pre class="kb-code"><code class="hljs language-js"><span class="hljs-keyword">export</span> <span class="hljs-keyword">const</span> port = <span class="hljs-title class_">Number</span>(process.<span class="hljs-property">env</span>.<span class="hljs-property">PORT</span> ?? <span class="hljs-number">8080</span>);</code></pre>
+<h2 id="rollout-status" tabindex="-1">Rollout status <a class="kb-anchor" href="#rollout-status">#</a></h2>
 <ul class="contains-task-list">
 <li class="task-list-item"><input class="task-list-item-checkbox" checked disabled type="checkbox"> Contract published</li>
 <li class="task-list-item"><input class="task-list-item-checkbox" disabled type="checkbox"> Load-tested</li>
 </ul>
-<h2 id="request-flow" tabindex="-1">Request flow <a class="mp-anchor" href="#request-flow">#</a></h2>
+<h2 id="request-flow" tabindex="-1">Request flow <a class="kb-anchor" href="#request-flow">#</a></h2>
 <pre class="mermaid">flowchart LR
   client --&gt; gateway --&gt; service</pre>`;
 
 /** Body of doc 2 — a second doc in the same bundle, proving expansion. */
-const RELEASE_PROCESS_BODY = `<h1 id="release-process" tabindex="-1">Release Process <a class="mp-anchor" href="#release-process">#</a></h1>
+const RELEASE_PROCESS_BODY = `<h1 id="release-process" tabindex="-1">Release Process <a class="kb-anchor" href="#release-process">#</a></h1>
 <p>Releases are cut from <code>master</code> on demand.</p>
 <blockquote>
 <p>A release is only complete once the docs bundle is attached to it.</p>
 </blockquote>
-<h2 id="steps" tabindex="-1">Steps <a class="mp-anchor" href="#steps">#</a></h2>
+<h2 id="steps" tabindex="-1">Steps <a class="kb-anchor" href="#steps">#</a></h2>
 <ol>
 <li>Tag the commit.</li>
 <li>Publish the GitHub Release.</li>
@@ -171,7 +171,7 @@ function writeSinglePageBundle() {
     if (doc.usesMermaid) {
       writeFileSync(join(docDir, MERMAID_PATH), MERMAID_STUB);
       // Real init script, not a stub: it is the thing that must stay out of the
-      // HTML for the marketplace's script-src 'self' to hold, so the fixture
+      // HTML for the knowledge base's script-src 'self' to hold, so the fixture
       // ships it exactly as the action does.
       writeFileSync(join(docDir, MERMAID_INIT_PATH), MERMAID_INIT_JS);
     }
@@ -223,7 +223,7 @@ const apps = [
     temporary: true,
     // Pinned standalone so the suite covers the per-app override in the
     // direction that used to be impossible: the harness builds headless, and
-    // this app must still come out without data-mp-headless (#52). This entry
+    // this app must still come out without data-kb-headless (#52). This entry
     // is the one with no headless assertions of its own, so it can carry the
     // pin without weakening another test.
     headless: false,
diff --git a/src/components/AppCard.astro b/src/components/AppCard.astro
index fb1c0cf..e6dbef7 100644
--- a/src/components/AppCard.astro
+++ b/src/components/AppCard.astro
@@ -20,14 +20,14 @@ const href = `${base}/${app.slug}/`;
 const delayClass = delay > 0 && delay <= 4 ? ` delay-${delay}` : '';
 ---
 
-<a href={href} class={`mp-card animate-fade-up${delayClass}`} aria-label={app.name}>
-  <div class="mp-card-icon" style="color:var(--color-kb-500)">
+<a href={href} class={`kb-card animate-fade-up${delayClass}`} aria-label={app.name}>
+  <div class="kb-card-icon" style="color:var(--color-kb-500)">
     <AppIcon icon={app.icon || 'book-open'} size={20} />
   </div>
   <h2 class="text-[15px] font-semibold mb-1.5 leading-snug" style="color:var(--text-heading)">{app.name}</h2>
   <p class="text-[13px] leading-relaxed flex-1 mb-4" style="color:var(--text-body)">{app.description}</p>
   <div class="flex flex-wrap gap-1.5 mt-auto">
-    {app.type === 'iframe' && <span class="mp-tag mp-tag-external" title="Embedded via iframe (external site)">External</span>}
-    {(app.tags || []).map(tag => <span class="mp-tag">{tag}</span>)}
+    {app.type === 'iframe' && <span class="kb-tag kb-tag-external" title="Embedded via iframe (external site)">External</span>}
+    {(app.tags || []).map(tag => <span class="kb-tag">{tag}</span>)}
   </div>
 </a>
diff --git a/src/components/Masthead.astro b/src/components/Masthead.astro
index 7ae73af..5ac1667 100644
--- a/src/components/Masthead.astro
+++ b/src/components/Masthead.astro
@@ -34,47 +34,47 @@ const { activeApp, base = '/knowledge-base', appRoot = false } = Astro.props;
 const onLibrary = !activeApp;
 ---
 
-<div id="mp-masthead" class={`mp-masthead${onLibrary ? '' : ' mp-masthead--compact'}`}>
+<div id="kb-masthead" class={`kb-masthead${onLibrary ? '' : ' kb-masthead--compact'}`}>
   {!onLibrary && (
-    <span class="mp-masthead-brand" aria-hidden="true">Knowledge base</span>
+    <span class="kb-masthead-brand" aria-hidden="true">Knowledge base</span>
   )}
-  <div class="mp-masthead-inner">
-    <div class="mp-masthead-eyebrow animate-fade-up">
-      <span class="mp-masthead-badge">
+  <div class="kb-masthead-inner">
+    <div class="kb-masthead-eyebrow animate-fade-up">
+      <span class="kb-masthead-badge">
         <svg width="15" height="15" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true">
           <path d="M2 3h6a4 4 0 0 1 4 4v14a3 3 0 0 0-3-3H2z"/><path d="M22 3h-6a4 4 0 0 0-4 4v14a3 3 0 0 1 3-3h7z"/>
         </svg>
       </span>
-      <span class="mp-masthead-kicker">Docs</span>
+      <span class="kb-masthead-kicker">Docs</span>
     </div>
 
     {/* On the catalog the masthead IS the page heading; on a documentation page the
         sub-app supplies its own <h1>, so the masthead title stays non-heading text. */}
     {onLibrary
-      ? <h1 class="mp-masthead-title animate-fade-up delay-1">Knowledge base</h1>
-      : <p class="mp-masthead-title animate-fade-up delay-1">Knowledge base</p>
+      ? <h1 class="kb-masthead-title animate-fade-up delay-1">Knowledge base</h1>
+      : <p class="kb-masthead-title animate-fade-up delay-1">Knowledge base</p>
     }
 
-    <p class="mp-masthead-desc animate-fade-up delay-2">
+    <p class="kb-masthead-desc animate-fade-up delay-2">
       Browse and access all documentation sites. Each app is independently
       maintained and deployed — one consistent experience.
     </p>
 
-    <nav class="mp-masthead-nav" aria-label="Knowledge base sections">
+    <nav class="kb-masthead-nav" aria-label="Knowledge base sections">
       {onLibrary
-        ? <span class="mp-masthead-link active" aria-current="page">Library</span>
-        : <a class="mp-masthead-link" href={`${base}/`}>Library</a>
+        ? <span class="kb-masthead-link active" aria-current="page">Library</span>
+        : <a class="kb-masthead-link" href={`${base}/`}>Library</a>
       }
 
       {activeApp && (appRoot
         ? (
-          <span class="mp-masthead-link active" aria-current="page">
+          <span class="kb-masthead-link active" aria-current="page">
             <AppIcon icon={activeApp.icon || 'book-open'} size={14} />
             <span>{activeApp.name}</span>
           </span>
         )
         : (
-          <a class="mp-masthead-link active" href={`${base}/${activeApp.slug}/`}>
+          <a class="kb-masthead-link active" href={`${base}/${activeApp.slug}/`}>
             <AppIcon icon={activeApp.icon || 'book-open'} size={14} />
             <span>{activeApp.name}</span>
           </a>
diff --git a/src/layouts/Base.astro b/src/layouts/Base.astro
index d79cf84..203ca2d 100644
--- a/src/layouts/Base.astro
+++ b/src/layouts/Base.astro
@@ -1,14 +1,14 @@
 ---
 // src/layouts/Base.astro
 //
-// The single document shell for every marketplace page — landing catalog,
+// The single document shell for every knowledge base page — landing catalog,
 // packaged sub-app pages and iframe entries alike. It owns <head>, the fonts,
-// the marketplace stylesheet, <ClientRouter /> and the shadow-DOM compat styles,
+// the knowledge base stylesheet, <ClientRouter /> and the shadow-DOM compat styles,
 // so none of that has to be string-injected into sub-app documents any more.
 //
-// The marketplace is light-only. There is no theme toggle, no persisted theme and
+// The knowledge base is light-only. There is no theme toggle, no persisted theme and
 // no `dark` class anywhere, so an embedding host's theme can never bleed in.
-import '../styles/marketplace.css';
+import '../styles/knowledge-base.css';
 import { ClientRouter } from 'astro:transitions';
 import { shadowCompatStyle } from '../templates/shadow-compat.js';
 import { isHeadlessBuild } from '../utils/config.js';
@@ -42,11 +42,11 @@ const bodyClasses = [
 ---
 
 <!DOCTYPE html>
-<html lang="en" data-mp-headless={effectiveHeadless ? 'true' : undefined}>
+<html lang="en" data-kb-headless={effectiveHeadless ? 'true' : undefined}>
 <head>
   <meta charset="UTF-8" />
   <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-  <meta name="description" content="Documentation marketplace — browse all doc sites in one place." />
+  <meta name="description" content="Documentation knowledge base — browse all doc sites in one place." />
   <title>{title}</title>
   {/*
     CSS layer ordering fix — must appear before sub-app stylesheets.
@@ -71,7 +71,7 @@ const bodyClasses = [
   */}
   <style is:inline>@layer base;</style>
   <slot name="head" />
-  {/* Inter is self-hosted: its @font-face lives in marketplace.css, which the
+  {/* Inter is self-hosted: its @font-face lives in knowledge-base.css, which the
       layout already imports, so there is nothing to link here (#54). */}
   <ClientRouter />
 </head>
diff --git a/src/pages/[...path].astro b/src/pages/[...path].astro
index e6602b4..0541008 100644
--- a/src/pages/[...path].astro
+++ b/src/pages/[...path].astro
@@ -8,7 +8,7 @@
 //
 // Packaged pages are not emitted verbatim: transformSubAppHtml() rewrites their
 // URLs and splits the document, and Base.astro re-hosts the parts. That keeps the
-// masthead, fonts, marketplace CSS and ClientRouter in one place for all page
+// masthead, fonts, knowledge base CSS and ClientRouter in one place for all page
 // types (issue #24).
 
 import { readFileSync } from 'node:fs';
@@ -61,8 +61,8 @@ const atAppRoot = !props.fileRelDir;
     </main>
   ) : props.singlePage ? (
     /* Single-page docs bring no navigation of their own — no sidebar, no in-app
-       chrome — so the marketplace supplies the reading column instead. */
-    <main id="content" class="mp-single-page" set:html={parts!.bodyHtml} />
+       chrome — so the knowledge base supplies the reading column instead. */
+    <main id="content" class="kb-single-page" set:html={parts!.bodyHtml} />
   ) : (
     <Fragment set:html={parts!.bodyHtml} />
   )}
diff --git a/src/styles/marketplace.css b/src/styles/knowledge-base.css
similarity index 88%
rename from src/styles/marketplace.css
rename to src/styles/knowledge-base.css
index 5811a49..3ad9405 100644
--- a/src/styles/marketplace.css
+++ b/src/styles/knowledge-base.css
@@ -53,7 +53,7 @@
 }
 
 /* ── Semantic CSS variables ─────────────────────────────────────────────── */
-/* The marketplace is light-only — there is deliberately no dark palette here,
+/* The knowledge base is light-only — there is deliberately no dark palette here,
    so an embedding host's dark theme cannot bleed into the fragment.
    Note: @tailwindcss/vite compiles :root to :root,:host automatically, so
    custom properties are available inside shadow DOMs via :host inheritance.
@@ -92,48 +92,48 @@ body, wf-body {
 }
 
 /* ── Masthead ───────────────────────────────────────────────────────────── */
-/* Rendered on every page by Base.astro — the marketplace's only navigation.
+/* Rendered on every page by Base.astro — the knowledge base's only navigation.
    Written as plain classes rather than utilities because it also sits on
    packaged sub-app pages, whose own CSS is loaded alongside it: class selectors
    beat the element selectors doc themes typically use for h1/p. */
-.mp-masthead {
+.kb-masthead {
   background: var(--bg-card);
   border-bottom: 1px solid var(--border);
 }
-.mp-masthead-inner {
+.kb-masthead-inner {
   max-width: 72rem;
   margin: 0 auto;
   padding: 3rem 1.5rem 0;
 }
 @media (min-width: 768px) {
-  .mp-masthead-inner { padding-left: 2.5rem; padding-right: 2.5rem; }
+  .kb-masthead-inner { padding-left: 2.5rem; padding-right: 2.5rem; }
 }
 
 /* Compact mode: app pages — only the nav strip is shown */
-.mp-masthead--compact {
+.kb-masthead--compact {
   display: flex;
   align-items: center;
 }
-.mp-masthead--compact .mp-masthead-inner {
+.kb-masthead--compact .kb-masthead-inner {
   flex: 1;
   min-width: 0;
   padding-top: 0;
   padding-bottom: 0;
 }
-.mp-masthead--compact .mp-masthead-eyebrow,
-.mp-masthead--compact .mp-masthead-title,
-.mp-masthead--compact .mp-masthead-desc {
+.kb-masthead--compact .kb-masthead-eyebrow,
+.kb-masthead--compact .kb-masthead-title,
+.kb-masthead--compact .kb-masthead-desc {
   display: none;
 }
-.mp-masthead--compact .mp-masthead-nav {
+.kb-masthead--compact .kb-masthead-nav {
   margin: 0;
 }
 
-/* Brand wordmark — sits in the left gutter, outside mp-masthead-inner */
-.mp-masthead-brand {
+/* Brand wordmark — sits in the left gutter, outside kb-masthead-inner */
+.kb-masthead-brand {
   display: none;
 }
-.mp-masthead--compact .mp-masthead-brand {
+.kb-masthead--compact .kb-masthead-brand {
   display: block;
   position: absolute;
   font-size: 0.9375rem;
@@ -145,20 +145,20 @@ body, wf-body {
   padding: 0 1rem 0 1.5rem;
 }
 @media (min-width: 768px) {
-  .mp-masthead--compact .mp-masthead-brand { padding-left: 2.5rem; }
+  .kb-masthead--compact .kb-masthead-brand { padding-left: 2.5rem; }
 }
 /* Below the large-display threshold, hide the brand */
 @media (max-width: 767px) {
-  .mp-masthead--compact .mp-masthead-brand { display: none; }
+  .kb-masthead--compact .kb-masthead-brand { display: none; }
 }
 
-.mp-masthead-eyebrow {
+.kb-masthead-eyebrow {
   display: flex;
   align-items: center;
   gap: 0.5rem;
   margin-bottom: 0.75rem;
 }
-.mp-masthead-badge {
+.kb-masthead-badge {
   width: 2rem;
   height: 2rem;
   border-radius: var(--radius-xl);
@@ -170,7 +170,7 @@ body, wf-body {
   color: var(--color-kb-500);
 }
 
-.mp-masthead-kicker {
+.kb-masthead-kicker {
   font-size: 0.75rem;
   font-weight: 700;
   text-transform: uppercase;
@@ -178,7 +178,7 @@ body, wf-body {
   color: var(--color-kb-500);
 }
 
-.mp-masthead-title {
+.kb-masthead-title {
   font-size: 2.25rem;
   line-height: 1.1;
   font-weight: 700;
@@ -186,7 +186,7 @@ body, wf-body {
   margin: 0 0 0.5rem;
   color: var(--text-heading);
 }
-.mp-masthead-desc {
+.kb-masthead-desc {
   font-size: 1rem;
   line-height: 1.625;
   max-width: 36rem;
@@ -195,14 +195,14 @@ body, wf-body {
 }
 
 /* Sub-navigation: Library + the app currently being viewed */
-.mp-masthead-nav {
+.kb-masthead-nav {
   display: flex;
   align-items: center;
   gap: 0.25rem;
   margin: 0;
   overflow-x: auto;
 }
-.mp-masthead-link {
+.kb-masthead-link {
   display: inline-flex;
   align-items: center;
   gap: 0.4rem;
@@ -216,8 +216,8 @@ body, wf-body {
   border-bottom: 2px solid transparent;
   transition: color var(--transition), border-color var(--transition);
 }
-a.mp-masthead-link:hover { color: var(--text-heading); }
-.mp-masthead-link.active {
+a.kb-masthead-link:hover { color: var(--text-heading); }
+.kb-masthead-link.active {
   color: var(--color-kb-500);
   border-bottom-color: var(--color-kb-500);
   font-weight: 600;
@@ -235,7 +235,7 @@ a.mp-masthead-link:hover { color: var(--text-heading); }
 .delay-4 { animation-delay: 0.4s; }
 
 /* ── Landing page card grid ──────────────────────────────────────────────── */
-.mp-card {
+.kb-card {
   display: flex;
   flex-direction: column;
   background: var(--bg-card);
@@ -246,13 +246,13 @@ a.mp-masthead-link:hover { color: var(--text-heading); }
   transition: box-shadow var(--transition), border-color var(--transition), transform var(--transition);
   box-shadow: var(--shadow-sm);
 }
-.mp-card:hover {
+.kb-card:hover {
   box-shadow: var(--shadow-md);
   border-color: var(--color-kb-100);
   transform: translateY(-2px);
 }
 
-.mp-card-icon {
+.kb-card-icon {
   width: 2.5rem;
   height: 2.5rem;
   border-radius: var(--radius-md);
@@ -266,11 +266,11 @@ a.mp-masthead-link:hover { color: var(--text-heading); }
 
 /* ── Single-page docs (issue #35) ────────────────────────────────────────── */
 /* A single-page doc is one markdown file rendered by actions/publish-single-page-docs: no
-   sidebar, no in-app navigation, nothing but prose. The marketplace owns the
+   sidebar, no in-app navigation, nothing but prose. The knowledge base owns the
    measure so every such doc reads identically regardless of which repo published
    it — ~800px of content, centred, with room to breathe underneath. The prose
-   itself is styled by the artifact's own assets/doc.css, scoped to .mp-doc. */
-.mp-single-page {
+   itself is styled by the artifact's own assets/doc.css, scoped to .kb-doc. */
+.kb-single-page {
   flex: 1 1 auto;
   width: 100%;
   max-width: 53rem;      /* 848px − 2×1.5rem padding = 800px of content */
@@ -279,11 +279,11 @@ a.mp-masthead-link:hover { color: var(--text-heading); }
   box-sizing: border-box;
 }
 @media (max-width: 640px) {
-  .mp-single-page { padding: 2rem 1.25rem 3.5rem; }
+  .kb-single-page { padding: 2rem 1.25rem 3.5rem; }
 }
 
 /* ── Tag pills ───────────────────────────────────────────────────────────── */
-.mp-tag {
+.kb-tag {
   display: inline-flex;
   align-items: center;
   padding: 2px 8px;
@@ -296,7 +296,7 @@ a.mp-masthead-link:hover { color: var(--text-heading); }
 }
 
 /* iframe-onboarding entries (issue #10) — flags an externally embedded app */
-.mp-tag-external {
+.kb-tag-external {
   background: var(--color-kb-50);
   color: var(--color-kb-600);
   border-color: var(--color-kb-100);
diff --git a/src/templates/shadow-compat.js b/src/templates/shadow-compat.js
index b5c5c07..d177808 100644
--- a/src/templates/shadow-compat.js
+++ b/src/templates/shadow-compat.js
@@ -1,6 +1,6 @@
 // src/templates/shadow-compat.js
 //
-// Inline <style> block injected into every marketplace page by Base.astro.
+// Inline <style> block injected into every knowledge base page by Base.astro.
 //
 // @tailwindcss/vite strips custom element selectors (wf-html, wf-document) during
 // its CSS optimisation pass, making it impossible to target shadow DOM elements
@@ -10,10 +10,10 @@
 //
 // wf-html / wf-document get explicit declarations of every design token, so
 // shadow-root elements have them directly. Belt-and-suspenders — :root and :host
-// in marketplace.css already cover inheritance, but direct assignment avoids any
+// in knowledge-base.css already cover inheritance, but direct assignment avoids any
 // edge-case inheritance break inside a reframed fragment.
 //
-// The marketplace is light-only: there is no dark-mode override here or anywhere
+// The knowledge base is light-only: there is no dark-mode override here or anywhere
 // else, so an embedding host's own dark theme can never bleed into the fragment.
 
 export const shadowCompatStyle = `
diff --git a/src/utils/config.js b/src/utils/config.js
index a2369ba..d8c089c 100644
--- a/src/utils/config.js
+++ b/src/utils/config.js
@@ -8,7 +8,7 @@
  * The URL prefix everything is served under.
  *
  * **Not configurable, deliberately.** The build used to advertise a
- * `--path-prefix=` flag and an `MP_PREFIX` variable that nothing in the Astro
+ * `--path-prefix=` flag and an environment variable that nothing in the Astro
  * build ever read, so `--path-prefix=docs` produced a `dist/` that still said
  * `knowledge-base` everywhere and only the closing build summary agreed with the
  * flag (#46). Making it real means templating `nginx.conf`, the `/__wf/` rewrite
@@ -38,5 +38,5 @@ export const BASE_PATH = `/${PATH_PREFIX}`;
  * override is resolved in src/utils/apps.js and passed down as a prop.
  */
 export function isHeadlessBuild(env = process.env) {
-  return env.MP_HEADLESS === 'true';
+  return env.KB_HEADLESS === 'true';
 }
diff --git a/src/utils/single-page.js b/src/utils/single-page.js
index 58953c9..7c0d945 100644
--- a/src/utils/single-page.js
+++ b/src/utils/single-page.js
@@ -10,7 +10,7 @@
 //
 // Everything the catalog needs lives in the artifact's bundle.json manifest, so
 // onboarding a new doc never touches this repository. The build "expands" one
-// registry entry into N marketplace apps, one per doc.
+// registry entry into N knowledge base apps, one per doc.
 //
 // Imported by both scripts/fetch-apps.js (GitHub path) and scripts/build-vite.js
 // (prebuilt/local path) so the two never drift, and by src/utils/apps.js so Astro
@@ -107,7 +107,7 @@ export function readBundleManifest(bundleRoot, source) {
 }
 
 /**
- * Turns a bundle manifest into marketplace app entries — one per doc.
+ * Turns a bundle manifest into knowledge base app entries — one per doc.
  *
  * Each returned entry looks like a normal apps.json app (slug/name/description/
  * icon/tags) so every downstream consumer — catalog cards, masthead, routing —
diff --git a/src/utils/transform.js b/src/utils/transform.js
index c844a11..c26357b 100644
--- a/src/utils/transform.js
+++ b/src/utils/transform.js
@@ -4,7 +4,7 @@
 //
 // Packaged sub-app pages arrive as complete pre-built documents. Rather than
 // emitting them verbatim, the catchall route renders them through Base.astro so
-// the layout owns the masthead, fonts, marketplace CSS and <ClientRouter /> for
+// the layout owns the masthead, fonts, knowledge base CSS and <ClientRouter /> for
 // every page. This module rewrites the sub-app URLs and splits the document into
 // the parts the layout needs.
 //
@@ -14,7 +14,7 @@
 // every "surely no document does that" assumption a regex makes eventually meets
 // a document that does. Pattern matching got this wrong four ways (#48):
 // a `</body>` inside a script truncated the page, a `<` inside the theme
-// bootstrap defeated the strip that keeps the marketplace light-only, several
+// bootstrap defeated the strip that keeps the knowledge base light-only, several
 // URL-bearing attributes were never rewritten, and `href="/x"` inside a code
 // sample in the prose was rewritten as if it were a link. parse5 is the same
 // tokenizer a browser uses, it is build-time only, and it knows the difference
@@ -213,7 +213,7 @@ export function transformSubAppHtml(html, slug, fileRelDir, prefix) {
       }
     }
 
-    // 6a. Light-only marketplace: the sub-app's theme bootstrap never runs.
+    // 6a. Light-only knowledge base: the sub-app's theme bootstrap never runs.
     if (el.tagName === 'script' && !attrOf(el, 'src') && isThemeBootstrap(textOf(el))) {
       doomed.push(el);
       continue;
diff --git a/tests/artifact-safety.spec.js b/tests/artifact-safety.spec.js
index 32d8755..3f9516f 100644
--- a/tests/artifact-safety.spec.js
+++ b/tests/artifact-safety.spec.js
@@ -93,14 +93,14 @@ test.describe('extractTarball', () => {
     const tar = join(workDir, 'dist.tar.gz');
     writeTarball(tar, [
       { name: 'bundle.json', content: '{"marketplaceVersion":"1"}' },
-      { name: 'my-doc/index.html', content: '<html data-mp-headless="true"></html>' },
+      { name: 'my-doc/index.html', content: '<html data-kb-headless="true"></html>' },
     ]);
 
     const dest = join(workDir, 'out');
     extractTarball(tar, dest, 'good-bundle');
 
     expect(readFileSync(join(dest, 'bundle.json'), 'utf8')).toContain('marketplaceVersion');
-    expect(readFileSync(join(dest, 'my-doc', 'index.html'), 'utf8')).toContain('data-mp-headless');
+    expect(readFileSync(join(dest, 'my-doc', 'index.html'), 'utf8')).toContain('data-kb-headless');
   });
 
   test('refuses a member that escapes the root via ".."', () => {
diff --git a/tests/build-integrity.spec.js b/tests/build-integrity.spec.js
index 1813ae2..b7cd733 100644
--- a/tests/build-integrity.spec.js
+++ b/tests/build-integrity.spec.js
@@ -4,7 +4,7 @@
  * Static checks on the built `dist/` output (no browser). Validates that the
  * build pipeline integrated both apps, enumerated every sub-app page, rewrote
  * URLs to absolute /{prefix}/{slug}/ paths, marked pages headless, and emitted
- * the marketplace stylesheet at the stable name the sub-app pages reference.
+ * the knowledge base stylesheet at the stable name the sub-app pages reference.
  *
  * dist/ is produced by the Playwright webServer (setup-test-apps + build:headless)
  * before any test runs.
@@ -31,15 +31,15 @@ function htmlFiles(dir, acc = []) {
 }
 
 /**
- * The marketplace stylesheet a page loads. Astro injects this <link> from
+ * The knowledge base stylesheet a page loads. Astro injects this <link> from
  * Base.astro's CSS import, so the name is content-hashed and changes whenever
  * the stylesheet does — assert the shape, never a literal filename.
  */
-function marketplaceCssHref(html) {
+function kbCssHref(html) {
   const href = [...html.matchAll(/<link\b[^>]*\brel="stylesheet"[^>]*>/gi)]
     .map((tag) => tag[0].match(/\bhref="([^"]+)"/)?.[1])
     .find((h) => h?.startsWith('/knowledge-base/_astro/'));
-  expect(href, 'page does not load the marketplace stylesheet').toBeTruthy();
+  expect(href, 'page does not load the knowledge base stylesheet').toBeTruthy();
   return href;
 }
 
@@ -64,13 +64,13 @@ test.describe('Build integrity', () => {
     }
   });
 
-  test('the marketplace stylesheet is published at the stable /style.css alias too', () => {
+  test('the knowledge base stylesheet is published at the stable /style.css alias too', () => {
     // Pages reference the content-hashed bundle; /knowledge-base/style.css stays
     // available as an alias of the same bytes for anything outside this
     // repository that still asks for it by that path.
     expect(existsSync(join(DIST, 'style.css')), 'dist/style.css alias missing').toBe(true);
     expect(read('style.css'), 'the alias is not a copy of the bundle the pages load')
-      .toBe(read(marketplaceCssHref(read('index.html')).slice('/knowledge-base/'.length)));
+      .toBe(read(kbCssHref(read('index.html')).slice('/knowledge-base/'.length)));
   });
 
   test('landing lists both app cards with absolute slug links', () => {
@@ -81,10 +81,10 @@ test.describe('Build integrity', () => {
     expect(html).toContain('href="/knowledge-base/guide-mirror/"');
   });
 
-  test('sub-app pages are marked headless and reference the marketplace CSS', () => {
+  test('sub-app pages are marked headless and reference the knowledge base CSS', () => {
     const html = read('user-guide/index.html');
-    expect(html).toContain('data-mp-headless="true"');
-    expect(marketplaceCssHref(html)).toMatch(/\.css$/);
+    expect(html).toContain('data-kb-headless="true"');
+    expect(kbCssHref(html)).toMatch(/\.css$/);
   });
 
   test('sub-app pages are re-hosted by the layout, keeping their own head + body', () => {
@@ -137,15 +137,15 @@ test.describe('iframe onboarding', () => {
     // The harness builds with --headless, and external-docs is pinned standalone
     // in apps.json. Base.astro used to OR the prop with the global flag, so the
     // override could only ever turn headless on (#52).
-    expect(read('external-docs/index.html')).not.toContain('data-mp-headless');
+    expect(read('external-docs/index.html')).not.toContain('data-kb-headless');
     // …while its neighbours in the same build are still headless.
-    expect(read('user-guide/index.html')).toContain('data-mp-headless="true"');
+    expect(read('user-guide/index.html')).toContain('data-kb-headless="true"');
   });
 
   test('landing shows the iframe app card with an External badge', () => {
     const html = read('index.html');
     expect(html).toContain('External Docs');
-    expect(html).toContain('mp-tag-external');
+    expect(html).toContain('kb-tag-external');
   });
 
   test('packaged apps are unaffected by the iframe entry', () => {
@@ -184,18 +184,18 @@ test.describe('single-page onboarding', () => {
 
   test('renders in the centred reading column, with no sidebar', () => {
     const html = read('platform-overview/index.html');
-    expect(html).toMatch(/<main id="content" class="mp-single-page"/);
-    expect(html).toContain('class="mp-doc"');
+    expect(html).toMatch(/<main id="content" class="kb-single-page"/);
+    expect(html).toContain('class="kb-doc"');
     // Single-page docs have no navigation of their own — the masthead is it.
     expect(html).not.toContain('id="sidebar"');
     expect(html).not.toMatch(/<nav[^>]*aria-label="Documentation"/);
-    expect(html).toContain('id="mp-masthead"');
+    expect(html).toContain('id="kb-masthead"');
   });
 
   test('is re-hosted by the layout like any packaged page', () => {
     const html = read('platform-overview/index.html');
-    expect(html).toContain('data-mp-headless="true"');
-    expect(marketplaceCssHref(html)).toMatch(/\.css$/);
+    expect(html).toContain('data-kb-headless="true"');
+    expect(kbCssHref(html)).toMatch(/\.css$/);
     expect(html.match(/<html\b/gi) ?? []).toHaveLength(1);
     expect(html.match(/<head\b/gi) ?? []).toHaveLength(1);
     expect(html.match(/<body\b/gi) ?? []).toHaveLength(1);
@@ -217,7 +217,7 @@ test.describe('single-page onboarding', () => {
     const html = read('platform-overview/index.html');
     expect(html).toContain('<table>');                        // GFM tables
     expect(html).toContain('task-list-item');                 // GFM task lists
-    expect(html).toContain('<pre class="mp-code">');          // fenced code
+    expect(html).toContain('<pre class="kb-code">');          // fenced code
     expect(html).toContain('hljs-keyword');                   // syntax highlighting
     expect(html).toMatch(/<pre class="mermaid">flowchart LR/); // mermaid source survives
   });
@@ -240,12 +240,12 @@ test.describe('single-page onboarding', () => {
 test.describe('Masthead', () => {
   const STRAPLINE = 'Browse and access all documentation sites';
 
-  const nav = (html) => html.match(/<nav class="mp-masthead-nav"[\s\S]*?<\/nav>/)?.[0] ?? '';
+  const nav = (html) => html.match(/<nav class="kb-masthead-nav"[\s\S]*?<\/nav>/)?.[0] ?? '';
 
   test('renders on the landing page, packaged pages and iframe pages', () => {
     for (const p of ['index.html', 'user-guide/index.html', 'user-guide/docs/index.html', 'external-docs/index.html']) {
       const html = read(p);
-      expect(html, `masthead missing on ${p}`).toContain('id="mp-masthead"');
+      expect(html, `masthead missing on ${p}`).toContain('id="kb-masthead"');
       expect(html, `strapline missing on ${p}`).toContain(STRAPLINE);
     }
   });
@@ -292,7 +292,7 @@ test.describe('Masthead', () => {
 // ─────────────────────────────────────────────────────────────────────────────
 // CSP preconditions
 //
-// The marketplace serves script-src 'self' with no 'unsafe-inline'. That only
+// The knowledge base serves script-src 'self' with no 'unsafe-inline'. That only
 // holds while nothing inline survives the build — so the build output is the
 // thing asserted, not the intent. If this fails, the CSP is about to start
 // breaking pages silently.
@@ -363,13 +363,13 @@ test.describe('no inline scripts in the build output', () => {
 
 // ── CSS asset handling (#49, #50) ───────────────────────────────────────────
 test.describe('stylesheet emission', () => {
-  test('the marketplace stylesheet is content-hashed, not pinned to a constant name', () => {
+  test('the knowledge base stylesheet is content-hashed, not pinned to a constant name', () => {
     // Forcing "style.css" onto every CSS asset made Rollup disambiguate the
     // collisions as style.css / style2.css / …, which the build then had to
     // guess between — and it left the one stylesheet every page loads unable to
     // be cache-busted (#50). Every page's <link> is Astro-injected, so nothing
     // needed the constant name in the first place.
-    expect(marketplaceCssHref(read('index.html')))
+    expect(kbCssHref(read('index.html')))
       .toMatch(/^\/knowledge-base\/_astro\/[^/]+\.[A-Za-z0-9_-]{8,}\.css$/);
     expect(readdirSync(DIST).filter((f) => /^style\d+\.css$/.test(f)),
       'a style2.css means two bundles collided on one name again').toEqual([]);
@@ -391,7 +391,7 @@ test.describe('stylesheet emission', () => {
 
     // …and the faces it does load are same-origin, hashed and present.
     const fonts = [...read('style.css').matchAll(/url\((\/knowledge-base\/[^)]+\.woff2)\)/g)].map((m) => m[1]);
-    expect(fonts.length, 'no self-hosted font in the marketplace stylesheet').toBeGreaterThan(0);
+    expect(fonts.length, 'no self-hosted font in the knowledge base stylesheet').toBeGreaterThan(0);
     for (const font of fonts) {
       expect(existsSync(join(DIST, font.replace('/knowledge-base/', ''))), `${font} is not in dist/`).toBe(true);
     }
diff --git a/tests/container.spec.js b/tests/container.spec.js
index a3f2682..9f353a0 100644
--- a/tests/container.spec.js
+++ b/tests/container.spec.js
@@ -46,7 +46,7 @@ test.describe('routing', () => {
   test('a packaged sub-app page is served', async ({ request }) => {
     const res = await request.get('/knowledge-base/user-guide/');
     expect(res.status()).toBe(200);
-    expect(await res.text()).toContain('data-mp-headless');
+    expect(await res.text()).toContain('data-kb-headless');
   });
 
   // The production-only rule. nginx.conf uses an INTERNAL rewrite here, not a
@@ -72,13 +72,13 @@ test.describe('routing', () => {
 
   // Sub-app pages hardcode this path; the gateway/nginx rewrite is what makes it
   // resolve to dist/style.css. If it 404s, every sub-app page loses its styling.
-  test('the fragment-prefixed marketplace stylesheet resolves', async ({ request }) => {
+  test('the fragment-prefixed knowledge base stylesheet resolves', async ({ request }) => {
     const res = await request.get('/__wf/knowledge-base/style.css');
     expect(res.status()).toBe(200);
     expect(res.headers()['content-type']).toContain('text/css');
   });
 
-  test('the marketplace stylesheet also resolves under the normal prefix', async ({ request }) => {
+  test('the knowledge base stylesheet also resolves under the normal prefix', async ({ request }) => {
     const res = await request.get('/knowledge-base/style.css');
     expect(res.status()).toBe(200);
     expect(res.headers()['content-type']).toContain('text/css');
diff --git a/tests/fixtures/docs-example.dist.tar.gz b/tests/fixtures/docs-example.dist.tar.gz
index fedcace..6cfa198 100644
Binary files a/tests/fixtures/docs-example.dist.tar.gz and b/tests/fixtures/docs-example.dist.tar.gz differ
diff --git a/tests/fixtures/single-page-bundle/platform-overview/assets/doc.css b/tests/fixtures/single-page-bundle/platform-overview/assets/doc.css
index 7242cc4..501f347 100644
--- a/tests/fixtures/single-page-bundle/platform-overview/assets/doc.css
+++ b/tests/fixtures/single-page-bundle/platform-overview/assets/doc.css
@@ -32,9 +32,9 @@
 body { margin: 0; font-family: var(--font-sans); color: var(--text-body); }
 
 /* ── Reading column ───────────────────────────────────────────────────────── */
-/* Standalone only. Inside the marketplace the .mp-single-page wrapper owns the
+/* Standalone only. Inside the knowledge base the .kb-single-page wrapper owns the
    measure, so this stays a max-width rather than a fixed layout. */
-.mp-doc {
+.kb-doc {
   max-width: 50rem;
   margin: 0 auto;
   padding: 2.5rem 1.5rem 5rem;
@@ -43,58 +43,58 @@ body { margin: 0; font-family: var(--font-sans); color: var(--text-body); }
   color: var(--text-body);
   overflow-wrap: break-word;
 }
-.mp-single-page > .mp-doc { padding: 0; max-width: none; }
+.kb-single-page > .kb-doc { padding: 0; max-width: none; }
 
 /* ── Lede (rendered when the markdown has no top-level heading) ───────────── */
-.mp-doc-lede { margin: 0 0 2.5rem; }
-.mp-doc-lede p { font-size: 1.125rem; color: var(--text-muted); margin: 0.5rem 0 0; }
+.kb-doc-lede { margin: 0 0 2.5rem; }
+.kb-doc-lede p { font-size: 1.125rem; color: var(--text-muted); margin: 0.5rem 0 0; }
 
 /* ── Headings ─────────────────────────────────────────────────────────────── */
-.mp-doc h1, .mp-doc h2, .mp-doc h3,
-.mp-doc h4, .mp-doc h5, .mp-doc h6 {
+.kb-doc h1, .kb-doc h2, .kb-doc h3,
+.kb-doc h4, .kb-doc h5, .kb-doc h6 {
   color: var(--text-heading);
   font-weight: 700;
   letter-spacing: -0.02em;
   line-height: 1.25;
   scroll-margin-top: 2rem;
 }
-.mp-doc h1 { font-size: 2.25rem; margin: 0 0 1.25rem; }
-.mp-doc h2 { font-size: 1.5rem;  margin: 3rem 0 1rem; padding-bottom: 0.5rem; border-bottom: 1px solid var(--border); }
-.mp-doc h3 { font-size: 1.1875rem; margin: 2.25rem 0 0.75rem; }
-.mp-doc h4 { font-size: 1rem;    margin: 1.75rem 0 0.5rem; }
-.mp-doc h5, .mp-doc h6 { font-size: 0.9375rem; margin: 1.5rem 0 0.5rem; }
+.kb-doc h1 { font-size: 2.25rem; margin: 0 0 1.25rem; }
+.kb-doc h2 { font-size: 1.5rem;  margin: 3rem 0 1rem; padding-bottom: 0.5rem; border-bottom: 1px solid var(--border); }
+.kb-doc h3 { font-size: 1.1875rem; margin: 2.25rem 0 0.75rem; }
+.kb-doc h4 { font-size: 1rem;    margin: 1.75rem 0 0.5rem; }
+.kb-doc h5, .kb-doc h6 { font-size: 0.9375rem; margin: 1.5rem 0 0.5rem; }
 
 /* Heading anchors — revealed on hover, invisible to the reading eye otherwise */
-.mp-doc .mp-anchor {
+.kb-doc .kb-anchor {
   color: var(--text-hint, #9ca3af);
   text-decoration: none;
   margin-left: 0.4rem;
   opacity: 0;
   transition: opacity 0.2s;
 }
-.mp-doc h1:hover .mp-anchor, .mp-doc h2:hover .mp-anchor,
-.mp-doc h3:hover .mp-anchor, .mp-doc h4:hover .mp-anchor { opacity: 1; }
+.kb-doc h1:hover .kb-anchor, .kb-doc h2:hover .kb-anchor,
+.kb-doc h3:hover .kb-anchor, .kb-doc h4:hover .kb-anchor { opacity: 1; }
 
 /* ── Flow ─────────────────────────────────────────────────────────────────── */
-.mp-doc p  { margin: 0 0 1.25rem; }
-.mp-doc ul, .mp-doc ol { margin: 0 0 1.25rem; padding-left: 1.5rem; }
-.mp-doc li { margin: 0.375rem 0; }
-.mp-doc li > ul, .mp-doc li > ol { margin: 0.375rem 0; }
-.mp-doc hr { border: 0; border-top: 1px solid var(--border); margin: 2.5rem 0; }
-.mp-doc img, .mp-doc video { max-width: 100%; height: auto; border-radius: var(--radius-md); }
+.kb-doc p  { margin: 0 0 1.25rem; }
+.kb-doc ul, .kb-doc ol { margin: 0 0 1.25rem; padding-left: 1.5rem; }
+.kb-doc li { margin: 0.375rem 0; }
+.kb-doc li > ul, .kb-doc li > ol { margin: 0.375rem 0; }
+.kb-doc hr { border: 0; border-top: 1px solid var(--border); margin: 2.5rem 0; }
+.kb-doc img, .kb-doc video { max-width: 100%; height: auto; border-radius: var(--radius-md); }
 
-.mp-doc a { color: var(--color-kb-500); text-decoration: none; }
-.mp-doc a:hover { color: var(--color-kb-600); text-decoration: underline; }
+.kb-doc a { color: var(--color-kb-500); text-decoration: none; }
+.kb-doc a:hover { color: var(--color-kb-600); text-decoration: underline; }
 
-.mp-doc strong { color: var(--text-heading); font-weight: 600; }
+.kb-doc strong { color: var(--text-heading); font-weight: 600; }
 
 /* ── Task lists (GFM) ─────────────────────────────────────────────────────── */
-.mp-doc .contains-task-list { list-style: none; padding-left: 0.25rem; }
-.mp-doc .task-list-item { display: flex; align-items: flex-start; gap: 0.5rem; }
-.mp-doc .task-list-item-checkbox { margin-top: 0.45rem; accent-color: var(--color-kb-500); }
+.kb-doc .contains-task-list { list-style: none; padding-left: 0.25rem; }
+.kb-doc .task-list-item { display: flex; align-items: flex-start; gap: 0.5rem; }
+.kb-doc .task-list-item-checkbox { margin-top: 0.45rem; accent-color: var(--color-kb-500); }
 
 /* ── Blockquotes ──────────────────────────────────────────────────────────── */
-.mp-doc blockquote {
+.kb-doc blockquote {
   margin: 0 0 1.25rem;
   padding: 0.75rem 1rem;
   border-left: 4px solid var(--color-kb-500);
@@ -102,11 +102,11 @@ body { margin: 0; font-family: var(--font-sans); color: var(--text-body); }
   border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
   color: var(--text-body);
 }
-.mp-doc blockquote > :last-child { margin-bottom: 0; }
+.kb-doc blockquote > :last-child { margin-bottom: 0; }
 
 /* ── Tables ───────────────────────────────────────────────────────────────── */
-.mp-doc .mp-table-wrap { overflow-x: auto; margin: 0 0 1.5rem; }
-.mp-doc table {
+.kb-doc .kb-table-wrap { overflow-x: auto; margin: 0 0 1.5rem; }
+.kb-doc table {
   border-collapse: collapse;
   width: 100%;
   font-size: 0.9375rem;
@@ -114,14 +114,14 @@ body { margin: 0; font-family: var(--font-sans); color: var(--text-body); }
   border-radius: var(--radius-md);
   overflow: hidden;
 }
-.mp-doc thead { background: var(--bg-strong); }
-.mp-doc th, .mp-doc td { padding: 0.625rem 0.875rem; text-align: left; border-bottom: 1px solid var(--border); }
-.mp-doc th { color: var(--text-heading); font-weight: 600; }
-.mp-doc tbody tr:last-child td { border-bottom: 0; }
-.mp-doc tbody tr:hover { background: var(--bg-strong); }
+.kb-doc thead { background: var(--bg-strong); }
+.kb-doc th, .kb-doc td { padding: 0.625rem 0.875rem; text-align: left; border-bottom: 1px solid var(--border); }
+.kb-doc th { color: var(--text-heading); font-weight: 600; }
+.kb-doc tbody tr:last-child td { border-bottom: 0; }
+.kb-doc tbody tr:hover { background: var(--bg-strong); }
 
 /* ── Code ─────────────────────────────────────────────────────────────────── */
-.mp-doc code {
+.kb-doc code {
   font-family: var(--font-mono);
   background: var(--bg-strong);
   border: 1px solid var(--border);
@@ -129,7 +129,7 @@ body { margin: 0; font-family: var(--font-sans); color: var(--text-body); }
   padding: 1px 5px;
   font-size: 0.85em;
 }
-.mp-doc pre.mp-code {
+.kb-doc pre.kb-code {
   margin: 0 0 1.5rem;
   padding: 1rem 1.125rem;
   background: #0f172a;
@@ -137,7 +137,7 @@ body { margin: 0; font-family: var(--font-sans); color: var(--text-body); }
   border-radius: var(--radius-md);
   overflow-x: auto;
 }
-.mp-doc pre.mp-code code {
+.kb-doc pre.kb-code code {
   background: none;
   border: 0;
   padding: 0;
@@ -147,21 +147,21 @@ body { margin: 0; font-family: var(--font-sans); color: var(--text-body); }
 }
 
 /* highlight.js token colours, tuned for the slate code surface above */
-.mp-doc .hljs-comment, .mp-doc .hljs-quote { color: #64748b; font-style: italic; }
-.mp-doc .hljs-keyword, .mp-doc .hljs-selector-tag, .mp-doc .hljs-built_in { color: #c4b5fd; }
-.mp-doc .hljs-string, .mp-doc .hljs-regexp, .mp-doc .hljs-addition { color: #86efac; }
-.mp-doc .hljs-number, .mp-doc .hljs-literal, .mp-doc .hljs-deletion { color: #fca5a5; }
-.mp-doc .hljs-title, .mp-doc .hljs-title.class_, .mp-doc .hljs-title.function_,
-.mp-doc .hljs-section, .mp-doc .hljs-name { color: #93c5fd; }
-.mp-doc .hljs-attr, .mp-doc .hljs-attribute, .mp-doc .hljs-variable,
-.mp-doc .hljs-template-variable, .mp-doc .hljs-property { color: #fcd34d; }
-.mp-doc .hljs-type, .mp-doc .hljs-meta, .mp-doc .hljs-symbol, .mp-doc .hljs-bullet { color: #67e8f9; }
-.mp-doc .hljs-emphasis { font-style: italic; }
-.mp-doc .hljs-strong { font-weight: 700; }
+.kb-doc .hljs-comment, .kb-doc .hljs-quote { color: #64748b; font-style: italic; }
+.kb-doc .hljs-keyword, .kb-doc .hljs-selector-tag, .kb-doc .hljs-built_in { color: #c4b5fd; }
+.kb-doc .hljs-string, .kb-doc .hljs-regexp, .kb-doc .hljs-addition { color: #86efac; }
+.kb-doc .hljs-number, .kb-doc .hljs-literal, .kb-doc .hljs-deletion { color: #fca5a5; }
+.kb-doc .hljs-title, .kb-doc .hljs-title.class_, .kb-doc .hljs-title.function_,
+.kb-doc .hljs-section, .kb-doc .hljs-name { color: #93c5fd; }
+.kb-doc .hljs-attr, .kb-doc .hljs-attribute, .kb-doc .hljs-variable,
+.kb-doc .hljs-template-variable, .kb-doc .hljs-property { color: #fcd34d; }
+.kb-doc .hljs-type, .kb-doc .hljs-meta, .kb-doc .hljs-symbol, .kb-doc .hljs-bullet { color: #67e8f9; }
+.kb-doc .hljs-emphasis { font-style: italic; }
+.kb-doc .hljs-strong { font-weight: 700; }
 
 /* ── Mermaid ──────────────────────────────────────────────────────────────── */
 /* Pre-render the source is hidden; mermaid swaps in an <svg> in its place. */
-.mp-doc pre.mermaid {
+.kb-doc pre.mermaid {
   margin: 0 0 1.5rem;
   padding: 1.25rem;
   background: var(--bg-card);
@@ -176,14 +176,14 @@ body { margin: 0; font-family: var(--font-sans); color: var(--text-body); }
 /* margin-inline:auto, not the parent's text-align. Mermaid sets display:block on
    the <svg> it swaps in, and a block box ignores text-align — so a diagram
    narrower than the column sat flush left. */
-.mp-doc pre.mermaid svg { max-width: 100%; height: auto; display: block; margin-inline: auto; }
+.kb-doc pre.mermaid svg { max-width: 100%; height: auto; display: block; margin-inline: auto; }
 
 /* ── Footnotes (GFM) ──────────────────────────────────────────────────────── */
-.mp-doc .footnotes {
+.kb-doc .footnotes {
   margin-top: 3rem;
   padding-top: 1.5rem;
   border-top: 1px solid var(--border);
   font-size: 0.875rem;
   color: var(--text-muted);
 }
-.mp-doc .footnotes hr { display: none; }
+.kb-doc .footnotes hr { display: none; }
diff --git a/tests/fixtures/single-page-bundle/platform-overview/index.html b/tests/fixtures/single-page-bundle/platform-overview/index.html
index 86e99ad..90fafc3 100644
--- a/tests/fixtures/single-page-bundle/platform-overview/index.html
+++ b/tests/fixtures/single-page-bundle/platform-overview/index.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<html lang="en" data-mp-headless="true">
+<html lang="en" data-kb-headless="true">
 <head>
 <meta charset="utf-8">
 <meta name="viewport" content="width=device-width, initial-scale=1">
@@ -8,12 +8,12 @@
 <link rel="stylesheet" href="assets/doc.css">
 </head>
 <body>
-<article class="mp-doc">
-<h1 id="platform-overview" tabindex="-1">Platform Overview <a class="mp-anchor" href="#platform-overview">#</a></h1>
+<article class="kb-doc">
+<h1 id="platform-overview" tabindex="-1">Platform Overview <a class="kb-anchor" href="#platform-overview">#</a></h1>
 <p>The platform runs every service behind a single gateway. See
 <a href="https://example.com/handbook" target="_blank" rel="noopener noreferrer">the handbook</a> for the long version.</p>
-<h2 id="endpoints" tabindex="-1">Endpoints <a class="mp-anchor" href="#endpoints">#</a></h2>
-<div class="mp-table-wrap">
+<h2 id="endpoints" tabindex="-1">Endpoints <a class="kb-anchor" href="#endpoints">#</a></h2>
+<div class="kb-table-wrap">
 <table>
 <thead>
 <tr><th>Endpoint</th><th>Method</th><th>Notes</th></tr>
@@ -24,14 +24,14 @@ <h2 id="endpoints" tabindex="-1">Endpoints <a class="mp-anchor" href="#endpoints
 </tbody>
 </table>
 </div>
-<h2 id="configuration" tabindex="-1">Configuration <a class="mp-anchor" href="#configuration">#</a></h2>
-<pre class="mp-code"><code class="hljs language-js"><span class="hljs-keyword">export</span> <span class="hljs-keyword">const</span> port = <span class="hljs-title class_">Number</span>(process.<span class="hljs-property">env</span>.<span class="hljs-property">PORT</span> ?? <span class="hljs-number">8080</span>);</code></pre>
-<h2 id="rollout-status" tabindex="-1">Rollout status <a class="mp-anchor" href="#rollout-status">#</a></h2>
+<h2 id="configuration" tabindex="-1">Configuration <a class="kb-anchor" href="#configuration">#</a></h2>
+<pre class="kb-code"><code class="hljs language-js"><span class="hljs-keyword">export</span> <span class="hljs-keyword">const</span> port = <span class="hljs-title class_">Number</span>(process.<span class="hljs-property">env</span>.<span class="hljs-property">PORT</span> ?? <span class="hljs-number">8080</span>);</code></pre>
+<h2 id="rollout-status" tabindex="-1">Rollout status <a class="kb-anchor" href="#rollout-status">#</a></h2>
 <ul class="contains-task-list">
 <li class="task-list-item"><input class="task-list-item-checkbox" checked disabled type="checkbox"> Contract published</li>
 <li class="task-list-item"><input class="task-list-item-checkbox" disabled type="checkbox"> Load-tested</li>
 </ul>
-<h2 id="request-flow" tabindex="-1">Request flow <a class="mp-anchor" href="#request-flow">#</a></h2>
+<h2 id="request-flow" tabindex="-1">Request flow <a class="kb-anchor" href="#request-flow">#</a></h2>
 <pre class="mermaid">flowchart LR
   client --&gt; gateway --&gt; service</pre>
 </article>
diff --git a/tests/fixtures/single-page-bundle/release-process/assets/doc.css b/tests/fixtures/single-page-bundle/release-process/assets/doc.css
index 7242cc4..501f347 100644
--- a/tests/fixtures/single-page-bundle/release-process/assets/doc.css
+++ b/tests/fixtures/single-page-bundle/release-process/assets/doc.css
@@ -32,9 +32,9 @@
 body { margin: 0; font-family: var(--font-sans); color: var(--text-body); }
 
 /* ── Reading column ───────────────────────────────────────────────────────── */
-/* Standalone only. Inside the marketplace the .mp-single-page wrapper owns the
+/* Standalone only. Inside the knowledge base the .kb-single-page wrapper owns the
    measure, so this stays a max-width rather than a fixed layout. */
-.mp-doc {
+.kb-doc {
   max-width: 50rem;
   margin: 0 auto;
   padding: 2.5rem 1.5rem 5rem;
@@ -43,58 +43,58 @@ body { margin: 0; font-family: var(--font-sans); color: var(--text-body); }
   color: var(--text-body);
   overflow-wrap: break-word;
 }
-.mp-single-page > .mp-doc { padding: 0; max-width: none; }
+.kb-single-page > .kb-doc { padding: 0; max-width: none; }
 
 /* ── Lede (rendered when the markdown has no top-level heading) ───────────── */
-.mp-doc-lede { margin: 0 0 2.5rem; }
-.mp-doc-lede p { font-size: 1.125rem; color: var(--text-muted); margin: 0.5rem 0 0; }
+.kb-doc-lede { margin: 0 0 2.5rem; }
+.kb-doc-lede p { font-size: 1.125rem; color: var(--text-muted); margin: 0.5rem 0 0; }
 
 /* ── Headings ─────────────────────────────────────────────────────────────── */
-.mp-doc h1, .mp-doc h2, .mp-doc h3,
-.mp-doc h4, .mp-doc h5, .mp-doc h6 {
+.kb-doc h1, .kb-doc h2, .kb-doc h3,
+.kb-doc h4, .kb-doc h5, .kb-doc h6 {
   color: var(--text-heading);
   font-weight: 700;
   letter-spacing: -0.02em;
   line-height: 1.25;
   scroll-margin-top: 2rem;
 }
-.mp-doc h1 { font-size: 2.25rem; margin: 0 0 1.25rem; }
-.mp-doc h2 { font-size: 1.5rem;  margin: 3rem 0 1rem; padding-bottom: 0.5rem; border-bottom: 1px solid var(--border); }
-.mp-doc h3 { font-size: 1.1875rem; margin: 2.25rem 0 0.75rem; }
-.mp-doc h4 { font-size: 1rem;    margin: 1.75rem 0 0.5rem; }
-.mp-doc h5, .mp-doc h6 { font-size: 0.9375rem; margin: 1.5rem 0 0.5rem; }
+.kb-doc h1 { font-size: 2.25rem; margin: 0 0 1.25rem; }
+.kb-doc h2 { font-size: 1.5rem;  margin: 3rem 0 1rem; padding-bottom: 0.5rem; border-bottom: 1px solid var(--border); }
+.kb-doc h3 { font-size: 1.1875rem; margin: 2.25rem 0 0.75rem; }
+.kb-doc h4 { font-size: 1rem;    margin: 1.75rem 0 0.5rem; }
+.kb-doc h5, .kb-doc h6 { font-size: 0.9375rem; margin: 1.5rem 0 0.5rem; }
 
 /* Heading anchors — revealed on hover, invisible to the reading eye otherwise */
-.mp-doc .mp-anchor {
+.kb-doc .kb-anchor {
   color: var(--text-hint, #9ca3af);
   text-decoration: none;
   margin-left: 0.4rem;
   opacity: 0;
   transition: opacity 0.2s;
 }
-.mp-doc h1:hover .mp-anchor, .mp-doc h2:hover .mp-anchor,
-.mp-doc h3:hover .mp-anchor, .mp-doc h4:hover .mp-anchor { opacity: 1; }
+.kb-doc h1:hover .kb-anchor, .kb-doc h2:hover .kb-anchor,
+.kb-doc h3:hover .kb-anchor, .kb-doc h4:hover .kb-anchor { opacity: 1; }
 
 /* ── Flow ─────────────────────────────────────────────────────────────────── */
-.mp-doc p  { margin: 0 0 1.25rem; }
-.mp-doc ul, .mp-doc ol { margin: 0 0 1.25rem; padding-left: 1.5rem; }
-.mp-doc li { margin: 0.375rem 0; }
-.mp-doc li > ul, .mp-doc li > ol { margin: 0.375rem 0; }
-.mp-doc hr { border: 0; border-top: 1px solid var(--border); margin: 2.5rem 0; }
-.mp-doc img, .mp-doc video { max-width: 100%; height: auto; border-radius: var(--radius-md); }
+.kb-doc p  { margin: 0 0 1.25rem; }
+.kb-doc ul, .kb-doc ol { margin: 0 0 1.25rem; padding-left: 1.5rem; }
+.kb-doc li { margin: 0.375rem 0; }
+.kb-doc li > ul, .kb-doc li > ol { margin: 0.375rem 0; }
+.kb-doc hr { border: 0; border-top: 1px solid var(--border); margin: 2.5rem 0; }
+.kb-doc img, .kb-doc video { max-width: 100%; height: auto; border-radius: var(--radius-md); }
 
-.mp-doc a { color: var(--color-kb-500); text-decoration: none; }
-.mp-doc a:hover { color: var(--color-kb-600); text-decoration: underline; }
+.kb-doc a { color: var(--color-kb-500); text-decoration: none; }
+.kb-doc a:hover { color: var(--color-kb-600); text-decoration: underline; }
 
-.mp-doc strong { color: var(--text-heading); font-weight: 600; }
+.kb-doc strong { color: var(--text-heading); font-weight: 600; }
 
 /* ── Task lists (GFM) ─────────────────────────────────────────────────────── */
-.mp-doc .contains-task-list { list-style: none; padding-left: 0.25rem; }
-.mp-doc .task-list-item { display: flex; align-items: flex-start; gap: 0.5rem; }
-.mp-doc .task-list-item-checkbox { margin-top: 0.45rem; accent-color: var(--color-kb-500); }
+.kb-doc .contains-task-list { list-style: none; padding-left: 0.25rem; }
+.kb-doc .task-list-item { display: flex; align-items: flex-start; gap: 0.5rem; }
+.kb-doc .task-list-item-checkbox { margin-top: 0.45rem; accent-color: var(--color-kb-500); }
 
 /* ── Blockquotes ──────────────────────────────────────────────────────────── */
-.mp-doc blockquote {
+.kb-doc blockquote {
   margin: 0 0 1.25rem;
   padding: 0.75rem 1rem;
   border-left: 4px solid var(--color-kb-500);
@@ -102,11 +102,11 @@ body { margin: 0; font-family: var(--font-sans); color: var(--text-body); }
   border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
   color: var(--text-body);
 }
-.mp-doc blockquote > :last-child { margin-bottom: 0; }
+.kb-doc blockquote > :last-child { margin-bottom: 0; }
 
 /* ── Tables ───────────────────────────────────────────────────────────────── */
-.mp-doc .mp-table-wrap { overflow-x: auto; margin: 0 0 1.5rem; }
-.mp-doc table {
+.kb-doc .kb-table-wrap { overflow-x: auto; margin: 0 0 1.5rem; }
+.kb-doc table {
   border-collapse: collapse;
   width: 100%;
   font-size: 0.9375rem;
@@ -114,14 +114,14 @@ body { margin: 0; font-family: var(--font-sans); color: var(--text-body); }
   border-radius: var(--radius-md);
   overflow: hidden;
 }
-.mp-doc thead { background: var(--bg-strong); }
-.mp-doc th, .mp-doc td { padding: 0.625rem 0.875rem; text-align: left; border-bottom: 1px solid var(--border); }
-.mp-doc th { color: var(--text-heading); font-weight: 600; }
-.mp-doc tbody tr:last-child td { border-bottom: 0; }
-.mp-doc tbody tr:hover { background: var(--bg-strong); }
+.kb-doc thead { background: var(--bg-strong); }
+.kb-doc th, .kb-doc td { padding: 0.625rem 0.875rem; text-align: left; border-bottom: 1px solid var(--border); }
+.kb-doc th { color: var(--text-heading); font-weight: 600; }
+.kb-doc tbody tr:last-child td { border-bottom: 0; }
+.kb-doc tbody tr:hover { background: var(--bg-strong); }
 
 /* ── Code ─────────────────────────────────────────────────────────────────── */
-.mp-doc code {
+.kb-doc code {
   font-family: var(--font-mono);
   background: var(--bg-strong);
   border: 1px solid var(--border);
@@ -129,7 +129,7 @@ body { margin: 0; font-family: var(--font-sans); color: var(--text-body); }
   padding: 1px 5px;
   font-size: 0.85em;
 }
-.mp-doc pre.mp-code {
+.kb-doc pre.kb-code {
   margin: 0 0 1.5rem;
   padding: 1rem 1.125rem;
   background: #0f172a;
@@ -137,7 +137,7 @@ body { margin: 0; font-family: var(--font-sans); color: var(--text-body); }
   border-radius: var(--radius-md);
   overflow-x: auto;
 }
-.mp-doc pre.mp-code code {
+.kb-doc pre.kb-code code {
   background: none;
   border: 0;
   padding: 0;
@@ -147,21 +147,21 @@ body { margin: 0; font-family: var(--font-sans); color: var(--text-body); }
 }
 
 /* highlight.js token colours, tuned for the slate code surface above */
-.mp-doc .hljs-comment, .mp-doc .hljs-quote { color: #64748b; font-style: italic; }
-.mp-doc .hljs-keyword, .mp-doc .hljs-selector-tag, .mp-doc .hljs-built_in { color: #c4b5fd; }
-.mp-doc .hljs-string, .mp-doc .hljs-regexp, .mp-doc .hljs-addition { color: #86efac; }
-.mp-doc .hljs-number, .mp-doc .hljs-literal, .mp-doc .hljs-deletion { color: #fca5a5; }
-.mp-doc .hljs-title, .mp-doc .hljs-title.class_, .mp-doc .hljs-title.function_,
-.mp-doc .hljs-section, .mp-doc .hljs-name { color: #93c5fd; }
-.mp-doc .hljs-attr, .mp-doc .hljs-attribute, .mp-doc .hljs-variable,
-.mp-doc .hljs-template-variable, .mp-doc .hljs-property { color: #fcd34d; }
-.mp-doc .hljs-type, .mp-doc .hljs-meta, .mp-doc .hljs-symbol, .mp-doc .hljs-bullet { color: #67e8f9; }
-.mp-doc .hljs-emphasis { font-style: italic; }
-.mp-doc .hljs-strong { font-weight: 700; }
+.kb-doc .hljs-comment, .kb-doc .hljs-quote { color: #64748b; font-style: italic; }
+.kb-doc .hljs-keyword, .kb-doc .hljs-selector-tag, .kb-doc .hljs-built_in { color: #c4b5fd; }
+.kb-doc .hljs-string, .kb-doc .hljs-regexp, .kb-doc .hljs-addition { color: #86efac; }
+.kb-doc .hljs-number, .kb-doc .hljs-literal, .kb-doc .hljs-deletion { color: #fca5a5; }
+.kb-doc .hljs-title, .kb-doc .hljs-title.class_, .kb-doc .hljs-title.function_,
+.kb-doc .hljs-section, .kb-doc .hljs-name { color: #93c5fd; }
+.kb-doc .hljs-attr, .kb-doc .hljs-attribute, .kb-doc .hljs-variable,
+.kb-doc .hljs-template-variable, .kb-doc .hljs-property { color: #fcd34d; }
+.kb-doc .hljs-type, .kb-doc .hljs-meta, .kb-doc .hljs-symbol, .kb-doc .hljs-bullet { color: #67e8f9; }
+.kb-doc .hljs-emphasis { font-style: italic; }
+.kb-doc .hljs-strong { font-weight: 700; }
 
 /* ── Mermaid ──────────────────────────────────────────────────────────────── */
 /* Pre-render the source is hidden; mermaid swaps in an <svg> in its place. */
-.mp-doc pre.mermaid {
+.kb-doc pre.mermaid {
   margin: 0 0 1.5rem;
   padding: 1.25rem;
   background: var(--bg-card);
@@ -176,14 +176,14 @@ body { margin: 0; font-family: var(--font-sans); color: var(--text-body); }
 /* margin-inline:auto, not the parent's text-align. Mermaid sets display:block on
    the <svg> it swaps in, and a block box ignores text-align — so a diagram
    narrower than the column sat flush left. */
-.mp-doc pre.mermaid svg { max-width: 100%; height: auto; display: block; margin-inline: auto; }
+.kb-doc pre.mermaid svg { max-width: 100%; height: auto; display: block; margin-inline: auto; }
 
 /* ── Footnotes (GFM) ──────────────────────────────────────────────────────── */
-.mp-doc .footnotes {
+.kb-doc .footnotes {
   margin-top: 3rem;
   padding-top: 1.5rem;
   border-top: 1px solid var(--border);
   font-size: 0.875rem;
   color: var(--text-muted);
 }
-.mp-doc .footnotes hr { display: none; }
+.kb-doc .footnotes hr { display: none; }
diff --git a/tests/fixtures/single-page-bundle/release-process/index.html b/tests/fixtures/single-page-bundle/release-process/index.html
index 661fc0f..7cd6cc6 100644
--- a/tests/fixtures/single-page-bundle/release-process/index.html
+++ b/tests/fixtures/single-page-bundle/release-process/index.html
@@ -1,5 +1,5 @@
 <!DOCTYPE html>
-<html lang="en" data-mp-headless="true">
+<html lang="en" data-kb-headless="true">
 <head>
 <meta charset="utf-8">
 <meta name="viewport" content="width=device-width, initial-scale=1">
@@ -8,13 +8,13 @@
 <link rel="stylesheet" href="assets/doc.css">
 </head>
 <body>
-<article class="mp-doc">
-<h1 id="release-process" tabindex="-1">Release Process <a class="mp-anchor" href="#release-process">#</a></h1>
+<article class="kb-doc">
+<h1 id="release-process" tabindex="-1">Release Process <a class="kb-anchor" href="#release-process">#</a></h1>
 <p>Releases are cut from <code>master</code> on demand.</p>
 <blockquote>
 <p>A release is only complete once the docs bundle is attached to it.</p>
 </blockquote>
-<h2 id="steps" tabindex="-1">Steps <a class="mp-anchor" href="#steps">#</a></h2>
+<h2 id="steps" tabindex="-1">Steps <a class="kb-anchor" href="#steps">#</a></h2>
 <ol>
 <li>Tag the commit.</li>
 <li>Publish the GitHub Release.</li>
diff --git a/tests/fragment-server.mjs b/tests/fragment-server.mjs
index e9c75cd..a9cce11 100644
--- a/tests/fragment-server.mjs
+++ b/tests/fragment-server.mjs
@@ -7,7 +7,7 @@
  * Why not `astro preview`? For static output Astro uses its own preview server,
  * so the Vite `configurePreviewServer` hook in astro.config.mjs (the
  * /__wf/knowledge-base/* → /knowledge-base/* rewrite) never runs and the
- * marketplace stylesheet 404s. In production nginx performs that rewrite, so this
+ * knowledge base stylesheet 404s. In production nginx performs that rewrite, so this
  * server replicates nginx's two location rules to test the real contract:
  *
  *   /__wf/knowledge-base/<f>  → serve dist/<f>            (fragment assets)
diff --git a/tests/host/server.mjs b/tests/host/server.mjs
index 3ebb375..99a90c6 100644
--- a/tests/host/server.mjs
+++ b/tests/host/server.mjs
@@ -43,7 +43,7 @@ gateway.registerFragment({
   // Client-rendered embed (no SSR piercing) — matches the Astro fragment recipe.
   piercing: false,
   // One pattern for pages + _astro assets + ClientRouter fetches, one for the
-  // /__wf/ marketplace CSS route the sub-app HTML references.
+  // /__wf/ knowledge base CSS route the sub-app HTML references.
   routePatterns: ['/knowledge-base/:_*', '/__wf/knowledge-base/:_*'],
   onSsrFetchError: () => ({
     response: new Response('<p>knowledge-base fragment endpoint unreachable</p>', {
diff --git a/tests/standalone.spec.js b/tests/standalone.spec.js
index ce4fe61..3351a34 100644
--- a/tests/standalone.spec.js
+++ b/tests/standalone.spec.js
@@ -7,7 +7,7 @@
  *
  * Coverage:
  *   ─ HTTP header safety   X-Frame-Options must not block the gateway's hidden iframe
- *   ─ Headless contract    data-mp-headless present; no chrome bar, no dark mode
+ *   ─ Headless contract    data-kb-headless present; no chrome bar, no dark mode
  *   ─ CSS stability        data-astro-transition-persist on every <link rel=stylesheet>
  *                          (prevents web-fragments issue #297: head style accumulation)
  *   ─ Asset routing        /__wf/knowledge-base/* rewrite returns 200
@@ -115,27 +115,31 @@ test.describe('Headless contract', () => {
     await page.waitForLoadState('networkidle');
   });
 
-  // MP_HEADLESS=true must set data-mp-headless="true" on <html>.
+  // KB_HEADLESS=true must set data-kb-headless="true" on <html>.
   // The gateway reads this to confirm the fragment was built for embedding.
-  test('html element has data-mp-headless="true"', async ({ page }) => {
-    await expect(page.locator('html')).toHaveAttribute('data-mp-headless', 'true');
+  test('html element has data-kb-headless="true"', async ({ page }) => {
+    await expect(page.locator('html')).toHaveAttribute('data-kb-headless', 'true');
   });
 
   // There is no chrome nav bar in either mode any more — the masthead is the
   // whole navigation. A fixed bar escaped the shadow boundary when reframed
   // pierced the DOM, duplicating a nav over the host app.
   test('no chrome nav bar is rendered; the masthead is the navigation', async ({ page }) => {
-    await expect(page.locator('#mp-chrome')).toHaveCount(0);
-    await expect(page.locator('#mp-masthead')).toHaveCount(1);
+    await expect(page.locator('#kb-chrome')).toHaveCount(0);
+    await expect(page.locator('#kb-masthead')).toHaveCount(1);
   });
 
   // Light-only: no theme bootstrap, no toggle, no dark class.
   test('no dark mode is shipped', async ({ page }) => {
     await expect(page.locator('html.dark, .dark')).toHaveCount(0);
+    // Both spellings of the persisted-theme key: `mp-theme` predates the rename
+    // in #77, and a sub-app bundle published before it still writes that one.
     const themeApi = await page.evaluate(
-      () => typeof window.toggleTheme + '|' + (localStorage.getItem('mp-theme') ?? 'unset'),
+      () => typeof window.toggleTheme
+        + '|' + (localStorage.getItem('kb-theme') ?? 'unset')
+        + '|' + (localStorage.getItem('mp-theme') ?? 'unset'),
     );
-    expect(themeApi).toBe('undefined|unset');
+    expect(themeApi).toBe('undefined|unset|unset');
   });
 
   test('page title is set', async ({ page }) => {
@@ -171,7 +175,7 @@ test.describe('CSS link stability (#297)', () => {
 
     for (let i = 0; i < count; i++) {
       const href = await links.nth(i).getAttribute('href');
-      // Astro auto-injects the bundled marketplace stylesheet (/knowledge-base/styleN.css)
+      // Astro auto-injects the bundled knowledge base stylesheet (/knowledge-base/styleN.css)
       // from a CSS `import`; that link is framework-managed and cannot carry the attribute.
       // Astro keeps it across navigation by href-match, and the behavioural
       // "CSS link count does not grow" test below is the authoritative #297 guard.
@@ -192,7 +196,7 @@ test.describe('CSS link stability (#297)', () => {
     await page.goto('/knowledge-base/user-guide/');
     // Don't fail if example isn't built — skip gracefully
     const status = await page.evaluate(() => document.readyState);
-    if (await page.locator('html').getAttribute('data-mp-headless') === null) {
+    if (await page.locator('html').getAttribute('data-kb-headless') === null) {
       test.skip(); // page did not load as a fragment page
       return;
     }
@@ -203,7 +207,7 @@ test.describe('CSS link stability (#297)', () => {
 
     for (let i = 0; i < count; i++) {
       const href = await links.nth(i).getAttribute('href');
-      // Same exemption as the landing page: the bundled marketplace stylesheet is
+      // Same exemption as the landing page: the bundled knowledge base stylesheet is
       // injected by Astro from the layout's CSS import and cannot carry the attribute.
       if (/^\/knowledge-base\/_astro\/.+\.css$/.test(href ?? '')) continue;
       const persist = await links.nth(i).getAttribute('data-astro-transition-persist');
@@ -237,7 +241,7 @@ test.describe('CSS link stability (#297)', () => {
     // counting there would still see the sub-app's stylesheets. Wait for landing-only
     // content (the catalog cards) to prove the swap landed.
     await page.goBack();
-    await page.locator('.mp-card').first().waitFor({ state: 'visible', timeout: 10_000 });
+    await page.locator('.kb-card').first().waitFor({ state: 'visible', timeout: 10_000 });
     await page.waitForLoadState('networkidle');
 
     const afterCount = await page.locator('link[rel="stylesheet"]').count();
diff --git a/tests/support/fragment.js b/tests/support/fragment.js
index 2e0b9ee..545446a 100644
--- a/tests/support/fragment.js
+++ b/tests/support/fragment.js
@@ -29,9 +29,9 @@ export async function gotoFragment(page, fragmentRoute = '/knowledge-base/') {
  * Resolves once the fragment's reframed BODY has rendered content.
  *
  * The reframed document is <wf-document><wf-html><wf-head/><wf-body/></wf-document>
- * inside web-fragment-host.shadowRoot. <wf-html> (with data-mp-headless) appears
+ * inside web-fragment-host.shadowRoot. <wf-html> (with data-kb-headless) appears
  * before <wf-body> fills, so we must wait on wf-body having children — waiting on
- * data-mp-headless alone races the content in. (wf-body only exists in the reframed
+ * data-kb-headless alone races the content in. (wf-body only exists in the reframed
  * shadow tree, never in the host document, so this can't match the host's <body>.)
  */
 export async function waitForFragmentReady(page, { timeout = 20_000 } = {}) {
diff --git a/tests/web-fragment.spec.js b/tests/web-fragment.spec.js
index 819d3b6..6ed3e5d 100644
--- a/tests/web-fragment.spec.js
+++ b/tests/web-fragment.spec.js
@@ -10,7 +10,7 @@
  *   1. Shadow-DOM isolation (fragment reframed; host chrome must not leak in)
  *   2. Routing + smooth SPA transitions (fetch + swap, no host reload, history)
  *   3. Cross-app navigation between registered apps
- *   4. Asset loading on the host origin (no 404s; marketplace CSS resolves)
+ *   4. Asset loading on the host origin (no 404s; knowledge base CSS resolves)
  */
 
 import { test, expect } from '@playwright/test';
@@ -60,8 +60,8 @@ test.describe('Shadow-DOM isolation', () => {
   });
 
   test('fragment document is in headless mode', async ({ page }) => {
-    const el = await queryInShadow(page, '[data-mp-headless]');
-    expect(el, 'data-mp-headless not found inside fragment').not.toBeNull();
+    const el = await queryInShadow(page, '[data-kb-headless]');
+    expect(el, 'data-kb-headless not found inside fragment').not.toBeNull();
   });
 
   test('fragment is light only (no dark class)', async ({ page }) => {
@@ -71,8 +71,8 @@ test.describe('Shadow-DOM isolation', () => {
   test('no chrome bar exists; the masthead is the fragment navigation', async ({ page }) => {
     // A fixed chrome bar escaped the shadow boundary and overlapped the host, so
     // it was removed outright — the masthead carries the navigation instead.
-    expect(await queryInShadow(page, '#mp-chrome'), '#mp-chrome must not appear in fragment').toBeNull();
-    expect(await queryInShadow(page, '#mp-masthead'), 'masthead missing from fragment').not.toBeNull();
+    expect(await queryInShadow(page, '#kb-chrome'), '#kb-chrome must not appear in fragment').toBeNull();
+    expect(await queryInShadow(page, '#kb-masthead'), 'masthead missing from fragment').not.toBeNull();
   });
 });
 
@@ -87,7 +87,7 @@ test.describe('Landing catalog', () => {
   });
 
   test('app card links are absolute /knowledge-base/ paths', async ({ page }) => {
-    const hrefs = await shadowHrefs(page, '.mp-card');
+    const hrefs = await shadowHrefs(page, '.kb-card');
     const internal = hrefs.filter(h => h && !h.startsWith('http') && !h.startsWith('#'));
     expect(internal.length).toBeGreaterThan(0);
     for (const h of internal) expect(h).toMatch(/^\/knowledge-base\//);
@@ -161,7 +161,7 @@ test.describe('In-app SPA navigation (smooth, no reload)', () => {
 test.describe('Cross-app navigation', () => {
   test('clicking the User Guide card navigates into that app', async ({ page }) => {
     await gotoFragment(page, '/knowledge-base/');
-    await clickFragmentLink(page, '.mp-card[href="/knowledge-base/user-guide/"]');
+    await clickFragmentLink(page, '.kb-card[href="/knowledge-base/user-guide/"]');
 
     // Showcase/landing of the docs app.
     await waitForFragmentText(page, /Docs Example|MkDocs|Publish/i);
@@ -170,7 +170,7 @@ test.describe('Cross-app navigation', () => {
 
   test('clicking the Guide Mirror card navigates into the second app', async ({ page }) => {
     await gotoFragment(page, '/knowledge-base/');
-    await clickFragmentLink(page, '.mp-card[href="/knowledge-base/guide-mirror/"]');
+    await clickFragmentLink(page, '.kb-card[href="/knowledge-base/guide-mirror/"]');
 
     // The mirror's internal links prove we are inside the guide-mirror slug.
     await page.waitForFunction(() => {
@@ -190,7 +190,7 @@ test.describe('Cross-app navigation', () => {
 
 // ─────────────────────────────────────────────────────────────────────────────
 // Single-page docs (issue #35): one bundle in apps.json, one card and one route
-// per doc, rendered in the marketplace's own reading column.
+// per doc, rendered in the knowledge base's own reading column.
 test.describe('Single-page docs', () => {
   test('expanded docs appear as ordinary catalog cards', async ({ page }) => {
     await gotoFragment(page, '/knowledge-base/');
@@ -198,14 +198,14 @@ test.describe('Single-page docs', () => {
     expect(text).toContain('Platform Overview');
     expect(text).toContain('Release Process');
 
-    const hrefs = await shadowHrefs(page, '.mp-card');
+    const hrefs = await shadowHrefs(page, '.kb-card');
     expect(hrefs).toContain('/knowledge-base/platform-overview/');
     expect(hrefs).toContain('/knowledge-base/release-process/');
   });
 
   test('clicking a doc card navigates into it without reloading the host', async ({ page }) => {
     await gotoFragment(page, '/knowledge-base/');
-    await clickFragmentLink(page, '.mp-card[href="/knowledge-base/platform-overview/"]');
+    await clickFragmentLink(page, '.kb-card[href="/knowledge-base/platform-overview/"]');
 
     await waitForFragmentText(page, /Platform Overview/i);
     expect(await hostStillAlive(page)).toBe(true);
@@ -214,13 +214,13 @@ test.describe('Single-page docs', () => {
   test('renders in the centred column with the masthead and no sidebar', async ({ page }) => {
     await gotoFragment(page, '/knowledge-base/platform-overview/');
 
-    const column = await queryInShadow(page, 'main.mp-single-page');
+    const column = await queryInShadow(page, 'main.kb-single-page');
     expect(column, 'centred reading column missing from fragment').not.toBeNull();
     expect(column.text).toMatch(/Platform Overview/i);
 
     // Nothing but the masthead: a single-page doc ships no navigation of its own.
     expect(await queryInShadow(page, 'nav#sidebar'), 'single-page doc must not render a sidebar').toBeNull();
-    expect(await queryInShadow(page, '#mp-masthead'), 'masthead missing').not.toBeNull();
+    expect(await queryInShadow(page, '#kb-masthead'), 'masthead missing').not.toBeNull();
   });
 });
 
@@ -240,7 +240,7 @@ test.describe('Asset loading on the host origin', () => {
     expect(bad, `host-origin requests returned errors:\n${bad.join('\n')}`).toEqual([]);
   });
 
-  test('marketplace stylesheet resolves through the gateway', async ({ page }) => {
+  test('knowledge base stylesheet resolves through the gateway', async ({ page }) => {
     // /__wf/knowledge-base/style.css → /knowledge-base/style.css → dist/style.css
     const res = await page.request.get('/knowledge-base/style.css');
     expect(res.status(), '/knowledge-base/style.css should resolve (200)').toBe(200);