diff --git a/.machine_readable/svc/k9/README.adoc b/.machine_readable/svc/k9/README.adoc
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+// SPDX-License-Identifier: MPL-2.0
+= K9 Contractiles — nextgen-languages self-validation
+:toc: left
+:icons: font
+
+== Why K9 lives here
+
+Per **ADR-001 (2026-04-18)** (see `../README.adoc`), K9 self-validating
+components live under `.machine_readable/svc/k9/` rather than under
+`contractiles/`, so the contractile directory stays a pure six-verb set
+(intend, trust, must, bust, adjust, dust). The verb contractiles *declare*
+invariants; the K9 validators here *machine-check* them.
+
+NOTE: `../../MUST.contractile` historically points its `enforcement` at
+`contractiles/k9/must-check.k9.ncl`. The canonical location is here
+(`svc/k9/must-check.k9.ncl`) per ADR-001; the stale path in MUST.contractile
+is a known doc gap (it lives outside this sweep's write-scope and is left as
+a TODO for a future MUST.contractile refresh).
+
+== The Leash — three security levels
+
+K9 components declare their trust requirements:
+
+[horizontal]
+`'Kennel`:: Pure data, no execution (safest; no signature)
+`'Yard`:: Nickel evaluation with contracts (medium trust; signature recommended)
+`'Hunt`:: Full execution with Just recipes (signature *required*)
+
+== Components in this directory
+
+`must-check.k9.ncl`:: **Yard.** The runnable surface of the hard invariants
+declared in `../../MUST.contractile` and
+`../../contractiles/must/Mustfile.a2ml`. CI runs it on every PR
+(`quality.yml`); violations of `error`-severity checks block merge.
+
+`methodology-guard.k9.ncl`:: **Yard.** Checks that agent work respects the
+methodology constraints in `../../agent_instructions/methodology.a2ml`
+(believe_me / assert_total ceilings, state-file template-placeholder
+rejection, coverage staleness).
+
+`template-kennel.k9.ncl`:: **Kennel.** Starting point for new pure-data K9
+components.
+
+== Validate / run
+
+[source,bash]
+----
+# Typecheck a Yard/Kennel component (no I/O)
+nickel typecheck svc/k9/must-check.k9.ncl
+
+# Evaluate a Yard component (validation, no side effects)
+nickel eval svc/k9/methodology-guard.k9.ncl
+
+# Export Kennel data
+nickel export svc/k9/template-kennel.k9.ncl > out.json
+----
+
+== Dependencies
+
+* **Nickel** — configuration language and contract evaluator.
+* **k9-svc** (https://github.com/hyperpolymath/k9-svc) — the `must` shim,
+  signing, and the full SPEC. IANA media type `application/vnd.k9+nickel`.
+
+== Adding a K9 component
+
+1. Pick the lowest sufficient leash (Kennel > Yard > Hunt).
+2. Document what it does in the `pedigree.metadata.description`.
+3. Put real contracts in Yard/Hunt components — a Yard file with no
+   contracts is just a Kennel file in disguise.
+4. Sign Hunt components before committing; never run unsigned Hunt.
+5. Wire `error`-severity validators into `quality.yml`.
diff --git a/.machine_readable/svc/k9/methodology-guard.k9.ncl b/.machine_readable/svc/k9/methodology-guard.k9.ncl
new file mode 100644
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+++ b/.machine_readable/svc/k9/methodology-guard.k9.ncl
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+K9!
+# SPDX-License-Identifier: MPL-2.0
+# Copyright (c) 2026 Jonathan D.A. Jewell (hyperpolymath) <j.d.a.jewell@open.ac.uk>
+#
+# K9 Validator: Methodology Guard (nextgen-languages)
+# Security Level: Yard (Nickel evaluation; no I/O)
+#
+# Checks that agent work respects the methodology constraints declared in
+# ../../agent_instructions/methodology.a2ml.
+#
+# Usage: k9 validate methodology-guard
+
+let methodology_guard = {
+  pedigree = {
+    schema_version = "1.0.0",
+    component_type = "methodology-validator",
+    security = {
+      leash = 'Yard,
+      trust_level = "validated-config",
+      allow_network = false,
+      allow_filesystem_write = false,
+      allow_subprocess = false,
+    },
+    metadata = {
+      name = "methodology-guard",
+      version = "1.0.0",
+      description = "Validates that agent work respects declared methodology constraints",
+      author = "Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk>",
+      paired_files = [
+        "../../agent_instructions/methodology.a2ml",
+      ],
+    },
+  },
+
+  name = "methodology-guard",
+  version = "1.0.0",
+  description = "Validates that agent work respects declared methodology constraints",
+
+  source_of_truth = ".machine_readable/agent_instructions/methodology.a2ml",
+
+  checks = {
+    believe_me_ceiling = {
+      description = "believe_me count must not exceed the declared ceiling",
+      severity = "error",
+      pattern = "believe_me",
+      ceiling_key = "methodology.divergent-invariants.believe-me-ceiling",
+      default_ceiling = 0,
+      note = "Hub-level scan; submodule trees enforce their own ceilings.",
+    },
+
+    assert_total_ceiling = {
+      description = "assert_total count must not exceed the declared ceiling",
+      severity = "error",
+      pattern = "assert_total",
+      ceiling_key = "methodology.divergent-invariants.assert-total-ceiling",
+      default_ceiling = 0,
+    },
+
+    state_not_template = {
+      description = "STATE.a2ml must not contain template placeholders",
+      severity = "warning",
+      file = ".machine_readable/6a2/STATE.a2ml",
+      reject_patterns = ["{{PLACEHOLDER}}", "{{PROJECT}}", "rsr-template-repo"],
+      reject_key = "methodology.state-validation.reject-if-contains",
+    },
+
+    state_not_stale = {
+      description = "STATE.a2ml last-updated should be within the staleness threshold",
+      severity = "info",
+      file = ".machine_readable/6a2/STATE.a2ml",
+      staleness_key = "methodology.state-validation.staleness-threshold-days",
+      default_staleness_days = 90,
+    },
+
+    coverage_updated = {
+      description = "coverage.a2ml should be refreshed within 30 days",
+      severity = "info",
+      file = ".machine_readable/agent_instructions/coverage.a2ml",
+      staleness_days = 30,
+    },
+
+    spike_required = {
+      description = "Sessions must ship code, not only designs (methodology.spike-required)",
+      severity = "info",
+      key = "methodology.spike-required",
+      expected = true,
+    },
+  },
+
+  # KNOWN GAP: methodology.a2ml still carries template defaults for
+  # unique-strength, divergent-invariants.rules, and known-constraints.
+  # Until those are filled, the divergent-mode checks fall back to defaults.
+  open_gaps = [
+    "methodology.unique-strength.description == {{PROJECT_UNIQUE_STRENGTH}}",
+    "methodology.divergent-invariants.rules == []",
+    "methodology.known-constraints.constraints == []",
+  ],
+}
+in methodology_guard
diff --git a/.machine_readable/svc/k9/must-check.k9.ncl b/.machine_readable/svc/k9/must-check.k9.ncl
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+++ b/.machine_readable/svc/k9/must-check.k9.ncl
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+K9!
+# SPDX-License-Identifier: MPL-2.0
+# K9 Yard-level validator: MUST-check
+# Security Level: Yard (Nickel evaluation with contracts; no I/O)
+#
+# Runnable surface of the hard invariants declared in
+# ../../MUST.contractile and ../../contractiles/must/Mustfile.a2ml.
+# CI (quality.yml) runs this on every PR; `error`-severity failures block
+# merge. Keep the check IDs aligned with Mustfile.a2ml section names.
+
+{
+  pedigree = {
+    schema_version = "1.0.0",
+    component_type = "must-validator",
+    security = {
+      leash = 'Yard,
+      trust_level = "validated-config",
+      allow_network = false,
+      allow_filesystem_write = false,
+      allow_subprocess = false,
+    },
+    metadata = {
+      name = "must-check",
+      version = "1.0.0",
+      description = "Machine-checks the nextgen-languages MUST invariants (hub-level hygiene; submodule trees are each repo's own concern).",
+      author = "Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk>",
+      paired_files = [
+        "../../MUST.contractile",
+        "../../contractiles/must/Mustfile.a2ml",
+      ],
+    },
+  },
+
+  # Each check declares a severity and a shell predicate (exit 0 = pass).
+  # A K9 'Yard runner evaluates these; it does not itself run the shell —
+  # the predicate string is handed to the CI executor named in `run`.
+  checks = {
+    license_present = {
+      description = "LICENSE file must exist",
+      severity = 'error,
+      predicate = "test -f LICENSE",
+    },
+
+    ai_manifest_present = {
+      description = "0-AI-MANIFEST.a2ml entry point must exist",
+      severity = 'error,
+      predicate = "test -f 0-AI-MANIFEST.a2ml",
+    },
+
+    machine_readable_dir = {
+      description = ".machine_readable/ directory preserved",
+      severity = 'error,
+      predicate = "test -d .machine_readable",
+    },
+
+    no_root_scm_duplication = {
+      description = "No STATE/META/ECOSYSTEM state file orphaned in repo root (canonical home is .machine_readable/6a2/)",
+      severity = 'error,
+      predicate = "! ls STATE.* META.* ECOSYSTEM.* 2>/dev/null | head -1 | grep -q .",
+    },
+
+    six_a_two_complete = {
+      description = "The 6a2 metadata set is complete (>= 6 .a2ml files)",
+      severity = 'warning,
+      predicate = "test $(ls .machine_readable/6a2/*.a2ml 2>/dev/null | wc -l) -ge 6",
+    },
+
+    spdx_on_machine_readable = {
+      description = "Every .a2ml under .machine_readable/ carries an SPDX header",
+      severity = 'warning,
+      predicate = "! grep -rL 'SPDX-License-Identifier' .machine_readable --include='*.a2ml' 2>/dev/null | head -1 | grep -q .",
+    },
+
+    no_agpl = {
+      description = "No AGPL references in dotfiles (estate policy is MPL-2.0)",
+      severity = 'error,
+      predicate = "! grep -rE 'AGPL-3[.]0' .gitignore .gitattributes .editorconfig 2>/dev/null | head -1 | grep -q .",
+    },
+
+    actions_sha_pinned = {
+      description = "Third-party GitHub Actions are SHA-pinned (reusable callers to hyperpolymath/standards excepted)",
+      severity = 'warning,
+      predicate = "! grep -rEn 'uses:[[:space:]]+[^#]+@(main|master|v[0-9]+)[[:space:]]*$' .github/workflows 2>/dev/null | grep -v 'hyperpolymath/standards' | head -1 | grep -q .",
+    },
+
+    hypatia_waiver_registry = {
+      description = "Hypatia accepted-findings registry exists (NEUROSYM.a2ml)",
+      severity = 'warning,
+      predicate = "grep -q '\\[accepted-findings\\]' .machine_readable/6a2/NEUROSYM.a2ml",
+    },
+
+    kitchenspeak_postulate_axiom = {
+      description = "KitchenSpeak Agda postulates remain annotated as trusted base (AXIOM marker)",
+      severity = 'warning,
+      predicate = "test ! -d kitchenspeak/proofs/agda || ! grep -rl 'postulate' kitchenspeak/proofs/agda --include='*.agda' 2>/dev/null | xargs -r grep -L 'AXIOM' 2>/dev/null | head -1 | grep -q .",
+    },
+  },
+
+  run = {
+    executor = "ci:quality.yml",
+    on_error_severity = "exit-nonzero",   # error-severity failures block merge
+    on_warning_severity = "report-only",
+    report_format = "a2ml",
+  },
+}
diff --git a/.machine_readable/svc/k9/template-kennel.k9.ncl b/.machine_readable/svc/k9/template-kennel.k9.ncl
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+K9!
+# SPDX-License-Identifier: MPL-2.0
+# K9 Kennel-level template: Pure data configuration
+# Security Level: Kennel (data-only, no execution)
+# No signature required — safe for any use.
+
+{
+  pedigree = {
+    schema_version = "1.0.0",
+    component_type = "TODO: describe component type (e.g., 'language-metadata', 'build-config')",
+    security = {
+      leash = 'Kennel,
+      trust_level = "data-only",
+      allow_network = false,
+      allow_filesystem_write = false,
+      allow_subprocess = false,
+    },
+    metadata = {
+      name = "TODO: component-name",
+      version = "1.0.0",
+      description = "TODO: Brief description of what this component contains",
+      author = "Jonathan D.A. Jewell <j.d.a.jewell@open.ac.uk>",
+    },
+  },
+
+  # Pure data only. No contracts, no recipes — promote to template-yard
+  # (Nickel contracts) or a Hunt component if you need validation/execution.
+  config = {
+    setting_1 = "value",
+    setting_2 = 42,
+    setting_3 = true,
+
+    nested = {
+      key = "value",
+    },
+
+    list = [
+      "item1",
+      "item2",
+    ],
+  },
+
+  export = {
+    format = "json",   # or "yaml", "toml"
+    destination = "output.json",
+  },
+}
+
+# Usage:
+# 1. Fill in TODO items above.
+# 2. Replace config = { ... } with your data.
+# 3. Validate: nickel typecheck your-file.k9.ncl
+# 4. Export:   nickel export your-file.k9.ncl > output.json