feat(api): support backend-mediated Realtime WebRTC calls

[apcha-oai]

Summary

Add Realtime call creation to the blocking and asynchronous clients so server-side applications can exchange an SDP offer and optional session configuration for an SDP answer.

This removes the need for a handwritten HTTP request for WebRTC signaling. The new operation preserves the API’s SDP and JSON content types and returns the SDP answer through HttpResponse.

[github-actions]

Castiron custom code

✅ No new custom-code files detected.

53 mixed files remain; 0 existing customizations changed.

Compared 3c63360e04f6 → ce510974a425. Generated baselines verified.

53 existing customizations unchanged

• openai-java-core/src/main/kotlin/com/openai/models/audio/AudioResponseFormat.kt
• openai-java-core/src/main/kotlin/com/openai/models/chat/completions/ChatCompletionCreateParams.kt
• openai-java-core/src/main/kotlin/com/openai/models/chat/completions/ChatCompletionMessageFunctionToolCall.kt
• openai-java-core/src/main/kotlin/com/openai/models/chat/completions/ChatCompletionToolMessageParam.kt
• openai-java-core/src/main/kotlin/com/openai/models/embeddings/Embedding.kt
• openai-java-core/src/main/kotlin/com/openai/models/embeddings/EmbeddingCreateParams.kt
• openai-java-core/src/main/kotlin/com/openai/models/responses/ResponseCreateParams.kt
• openai-java-core/src/main/kotlin/com/openai/models/responses/ResponseFunctionToolCall.kt
• openai-java-core/src/main/kotlin/com/openai/models/responses/ResponseFunctionWebSearch.kt
• openai-java-core/src/main/kotlin/com/openai/models/responses/ResponseInputItem.kt
• openai-java-core/src/main/kotlin/com/openai/models/responses/ResponseTextConfig.kt
• openai-java-core/src/main/kotlin/com/openai/models/videos/Video.kt
• openai-java-core/src/main/kotlin/com/openai/services/async/BetaServiceAsync.kt
• openai-java-core/src/main/kotlin/com/openai/services/async/BetaServiceAsyncImpl.kt
• openai-java-core/src/main/kotlin/com/openai/services/async/ResponseServiceAsync.kt
• openai-java-core/src/main/kotlin/com/openai/services/async/ResponseServiceAsyncImpl.kt
• openai-java-core/src/main/kotlin/com/openai/services/async/WebhookServiceAsync.kt
• openai-java-core/src/main/kotlin/com/openai/services/async/WebhookServiceAsyncImpl.kt
• openai-java-core/src/main/kotlin/com/openai/services/async/audio/TranscriptionServiceAsyncImpl.kt
• openai-java-core/src/main/kotlin/com/openai/services/async/chat/ChatCompletionServiceAsync.kt
• openai-java-core/src/main/kotlin/com/openai/services/async/finetuning/checkpoints/PermissionServiceAsyncImpl.kt
• openai-java-core/src/main/kotlin/com/openai/services/blocking/BetaService.kt
• openai-java-core/src/main/kotlin/com/openai/services/blocking/BetaServiceImpl.kt
• openai-java-core/src/main/kotlin/com/openai/services/blocking/ResponseService.kt
• openai-java-core/src/main/kotlin/com/openai/services/blocking/ResponseServiceImpl.kt
• openai-java-core/src/main/kotlin/com/openai/services/blocking/WebhookService.kt
• openai-java-core/src/main/kotlin/com/openai/services/blocking/WebhookServiceImpl.kt
• openai-java-core/src/main/kotlin/com/openai/services/blocking/audio/TranscriptionServiceImpl.kt
• openai-java-core/src/main/kotlin/com/openai/services/blocking/chat/ChatCompletionService.kt
• openai-java-core/src/main/kotlin/com/openai/services/blocking/finetuning/checkpoints/PermissionServiceImpl.kt
• openai-java-core/src/test/kotlin/com/openai/models/beta/responses/BetaResponsesServerEventTest.kt
• openai-java-core/src/test/kotlin/com/openai/models/responses/ResponsesServerEventTest.kt
• openai-java-core/src/test/kotlin/com/openai/services/async/CompletionServiceAsyncTest.kt
• openai-java-core/src/test/kotlin/com/openai/services/async/ImageServiceAsyncTest.kt
• openai-java-core/src/test/kotlin/com/openai/services/async/ResponseServiceAsyncTest.kt
• openai-java-core/src/test/kotlin/com/openai/services/async/WebhookServiceAsyncTest.kt
• openai-java-core/src/test/kotlin/com/openai/services/async/audio/TranscriptionServiceAsyncTest.kt
• openai-java-core/src/test/kotlin/com/openai/services/async/beta/ResponseServiceAsyncTest.kt
• openai-java-core/src/test/kotlin/com/openai/services/async/beta/ThreadServiceAsyncTest.kt
• openai-java-core/src/test/kotlin/com/openai/services/async/beta/threads/RunServiceAsyncTest.kt

13 more in the full report.

A changed generated baseline means this report cannot reliably identify which handwritten lines changed.

Inspect the custom-code diff

Download the exact patch produced by this run (requires repository access):

gh run download 32891187028 --repo openai/openai-java \
  --name castiron-custom-code-32891187028-1 --dir /tmp/castiron-custom-code-32891187028-1
git apply --stat /tmp/castiron-custom-code-32891187028-1/custom-code.patch
cat /tmp/castiron-custom-code-32891187028-1/custom-code.patch

Or reproduce it from an SDK checkout containing the vendored reporter:

git fetch --no-tags origin 3c63360e04f6873a2386860ce0ac0ef3a783e955 ce510974a425bcc16b22c87fbf7c06948ded82ca
python3 scripts/castiron/custom_code_report.py report \
  --base 3c63360e04f6873a2386860ce0ac0ef3a783e955 \
  --head ce510974a425bcc16b22c87fbf7c06948ded82ca --fetch --require-head-hash --public \
  --out /tmp/castiron-custom-code-ce510974a425
cat /tmp/castiron-custom-code-ce510974a425/custom-code.patch

This is the current full custom patch for mixed files, not an attribution of only the handwritten lines changed by this PR.

Full report and patch

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-08-25T19:44:38.608824Z	ce51097	Draft marked ready
🔒 Security Review	✅ Completed 2026-08-25T19:45:07.166378Z	ce51097	Draft marked ready

ℹ️ About Codex in GitHub

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• Comment "@codex review" or "@codex security review".

Codex reacts with 👀 while any review is running, comments if it has suggestions, and reacts with 👍 once all reviews finish with no findings.

[openai-sdks]

OkTest Summary

✅ 237/237 SDK tests passed in 18.476s for Java SDK PR #937.

Test results — 42 files

Test	Result	Time
tests/chat-completions-complex-body.test.ts	✅ Passed	866ms
tests/chat-completions-create.test.ts	✅ Passed	882ms
tests/chat-completions-stream.test.ts	✅ Passed	391ms
tests/files-content-binary.test.ts	✅ Passed	294ms
tests/files-create-multipart.test.ts	✅ Passed	385ms
tests/files-list-pagination.test.ts	✅ Passed	254ms
tests/initialize-config.test.ts	✅ Passed	185ms
tests/instance-isolation.test.ts	✅ Passed	295ms
tests/models-list.test.ts	✅ Passed	192ms
tests/responses-background-lifecycle.test.ts	✅ Passed	322ms
tests/responses-body-method-errors.test.ts	✅ Passed	775ms
tests/responses-cancel-timeout.test.ts	✅ Passed	219ms
tests/responses-cancel.test.ts	✅ Passed	342ms
tests/responses-compact-retries.test.ts	✅ Passed	486ms
tests/responses-compact.test.ts	✅ Passed	361ms
tests/responses-create-advanced-stream.test.ts	✅ Passed	397ms
tests/responses-create-advanced.test.ts	✅ Passed	1.473s
tests/responses-create-disconnect.test.ts	✅ Passed	1.144s
tests/responses-create-errors.test.ts	✅ Passed	423ms
tests/responses-create-malformed-api-responses.test.ts	✅ Passed	393ms
tests/responses-create-retries.test.ts	✅ Passed	308ms
tests/responses-create-stream-failures.test.ts	✅ Passed	260ms
tests/responses-create-stream-timeout.test.ts	✅ Passed	368ms
tests/responses-create-stream-wire.test.ts	✅ Passed	6.579s
tests/responses-create-stream.test.ts	✅ Passed	553ms
tests/responses-create-terminal-states.test.ts	✅ Passed	505ms
tests/responses-create-timeout.test.ts	✅ Passed	224ms
tests/responses-create.test.ts	✅ Passed	292ms
tests/responses-delete.test.ts	✅ Passed	283ms
tests/responses-input-items-errors.test.ts	✅ Passed	286ms
tests/responses-input-items-list.test.ts	✅ Passed	327ms
tests/responses-input-items-options.test.ts	✅ Passed	745ms
tests/responses-input-tokens-count-timeout.test.ts	✅ Passed	311ms
tests/responses-input-tokens-count.test.ts	✅ Passed	429ms
tests/responses-malformed-inputs.test.ts	✅ Passed	5.361s
tests/responses-not-found-errors.test.ts	✅ Passed	498ms
tests/responses-parse.test.ts	✅ Passed	815ms
tests/responses-retrieve-retries.test.ts	✅ Passed	834ms
tests/responses-retrieve.test.ts	✅ Passed	497ms
tests/responses-stored-method-errors.test.ts	✅ Passed	1.121s
tests/retry-behavior.test.ts	✅ Passed	3.558s
tests/sdk-error-shape.test.ts	✅ Passed	487ms

View OkTest run #32891153919

_{SDK merge (234e174ce21c) · head (ce510974a425) · base (3c63360e04f6) · OkTest (2b1bdfd25e98)}

[jbeckwith-oai]

Reviewed both blocking and async Realtime call generation. Project-key requests correctly remain typed multipart even when optional session is omitted; SDP/JSON part media types, omission/null handling, repeatable request bodies, bearer authentication, and full closeable HttpResponse/Location headers are preserved. WireMock, API compatibility, Java version, security, and generation checks are green. Approved.