ci: add AI summaries to Slack notifications

[zhongkechen]

Summary

• generate concise AI summaries for pull request, issue, and release Slack notifications
• isolate model inference from webhook-bearing delivery jobs and load support code from the immutable workflow revision
• validate, bound, and sanitize model output with a deterministic fallback
• add unit and workflow-structure tests to the GitHub scripts CI job

Testing

• hatch run test:all .github/scripts/tests/test_build_lambda_layer.py .github/scripts/tests/test_notify_workflow.py .github/scripts/tests/test_parse_sdk_branch.py .github/scripts/tests/test_summarize_notification.py
• hatch fmt --check .github/scripts/summarize_notification.py .github/scripts/tests/test_summarize_notification.py .github/scripts/tests/test_notify_workflow.py

[github-actions]

Claude AI review

job.workflow_repository and job.workflow_sha are not valid GitHub Actions contexts — the job context only exposes container, services, and status. Both expressions therefore resolve to empty strings.

Impact: the checkout will not pin to the immutable workflow revision as the comment above claims. With an empty ref, actions/checkout falls back to the event's default ref, and an empty repository will either fail the step (making needs.summarize.result != 'success', which skips all three notify jobs and silently drops every Slack notification) or clone an unintended target. Either way the stated "same immutable revision as this workflow" guarantee is not enforced.

Fix: use the documented github contexts. For a workflow defined in this repo, github.repository is the workflow's repository and github.workflow_sha is the commit SHA of the running workflow file.

Also update the corresponding assertions in test_notify_workflow.py (they currently assert the invalid literal strings, so the test passes while the workflow is broken).

Suggested change

	repository: ${{ job.workflow_repository }}
	ref: ${{ job.workflow_sha }}
	repository: ${{ github.repository }}
	ref: ${{ github.workflow_sha }}

[github-actions]

Claude AI review

This PR is limited to CI: a new .github/scripts/summarize_notification.py, its unit tests, a workflow-structure test, and a rewrite of .github/workflows/notify.yml. No SDK package (core, testing, otel, examples) is modified, so replay determinism, serialization, and public-API compatibility are not affected.

The Python script is generally solid — untrusted GitHub content is passed as user data (not instructions), the model ID is regex-validated, the response is size-bounded, the summary is length-bounded and sanitized (control chars, </>, and @channel|everyone|here broadcasts), and there is a deterministic fallback path. Truncation stays within MAX_SUMMARY_CHARS, and normalize_summary collapses all whitespace so the GITHUB_OUTPUT write cannot inject extra keys.

One confirmed finding (see inline comment): the summarize job checks out its toolkit using ${{ job.workflow_repository }} and ${{ job.workflow_sha }}, which are not valid GitHub Actions contexts (the job context only exposes container, services, and status). Both expressions evaluate to empty strings, so the checkout does not pin to the immutable workflow revision as the adjacent comment claims. Fix at .github/workflows/notify.yml:32-33.

Residual test risk: test_notify_workflow_generates_summary_from_immutable_toolkit asserts the literal strings ${{ job.workflow_repository }} / ${{ job.workflow_sha }}, so it enshrines the invalid contexts rather than catching them — the structural tests validate YAML shape but never that the referenced contexts resolve. There is also no coverage for main() or the empty-token fallback branch, though those are lower risk.

Reviewed commit cc49f9414d11f4cf6e2f8c58ce4bfedf47268bd9. Workflow run

[github-actions]

Codex AI review

[P1] Use the webhook-trigger transport for these payloads. An incoming webhook requires text, blocks, or attachments, but all three jobs send only custom workflow variables, so Slack will reject the message as no_text or deliver nothing. Set webhook-type: webhook-trigger in all three jobs, or convert each payload into a valid incoming-webhook message, and assert the transport in the workflow test.

[github-actions]

Codex AI review

[P2] Enforce the no-link/plain-text contract in normalization. Model output may ignore the prompt, and the fallback directly includes the untrusted title. Bare URLs and Slack formatting such as *text* survive these replacements, allowing PR or issue authors to inject clickable or formatted content into Slack. Strip or neutralize URLs and Slack markup in normalize_summary, and add tests covering both model and fallback output.

[github-actions]

Codex AI review

Found two actionable issues, including one that prevents Slack notification delivery. No tests were executed per review constraints.

Reviewed commit cc49f9414d11f4cf6e2f8c58ce4bfedf47268bd9. Workflow run