[breaking-change] Daily Breaking Change Analysis - 2026-05-21

[github-actions]

Summary

• Total Breaking Changes: 1
• Severity: HIGH
• Commits Analyzed: 1 relevant commit
• Status: ⚠️ Requires Immediate Review

Critical Breaking Changes

Commit	File	Category	Change	Impact
ec58ed3	pkg/parser/schemas/main_workflow_schema.json	Schema Field Removal	Removed pull_request_reviewer event	Workflows using on.pull_request_reviewer will fail validation

Full Code Diff Analysis

Detailed Commit Analysis

PR #33770: Remove synthetic pull_request_reviewer event support

• Merged: 2026-05-21T14:59:47Z
• Breaking Pattern: Schema field removal (Category 5)

What was removed:

1. pull_request_reviewer from JSON schema (pkg/parser/schemas/main_workflow_schema.json)
2. All compiler logic: PullRequestReviewer from WorkflowData, validation functions, event processing
3. Four workflows were migrated to use pull_request: [ready_for_review] + slash_command: review
4. Documentation and tests were cleaned up
5. The changeset file .changeset/patch-add-pull-request-reviewer-trigger.md was deleted

Why this is breaking:
According to scratchpad/breaking-cli-rules.md Category 5:

Schema Changes - Breaking:

• Removing fields from workflow frontmatter schema
• Making optional fields required
• Changing the type of a field
• Removing allowed values from enums

The pull_request_reviewer field was removed from the schema entirely. Any user workflows that use on.pull_request_reviewer: will now:

• Trigger unknown-event warnings during compilation
• Fail validation if strict mode is enabled
• Need manual migration to the new pull_request: [ready_for_review] + slash_command: review pattern

PR description excerpt:

Removes the experimental on.pull_request_reviewer synthetic trigger entirely — no legacy compatibility. Workflows using it are migrated to pull_request: [ready_for_review] + slash_command: review.

Breaking Change Patterns Detected

1. Schema field removal - pull_request_reviewer completely removed from main_workflow_schema.json
2. No backward compatibility - PR explicitly states "no legacy compatibility"
3. Missing major changeset - The PR deleted the changeset file instead of creating a major version changeset
4. Experimental feature removal - While marked experimental, it was in the schema and users may have adopted it

All Commits Analyzed

Commits from last 24 hours (2026-05-20 16:00 to 2026-05-21 16:00):

1. ec58ed3 - chore: bump default gh-aw-mcpg to v0.3.16 and gh-aw-firewall to v0.25.50 (chore: bump default gh-aw-mcpg to v0.3.16 and gh-aw-firewall to v0.25.50 #33664)
   • Version bumps only - NOT BREAKING

Recently merged PRs with CLI/Schema impact:

1. Remove synthetic pull_request_reviewer event support #33770 - Remove synthetic pull_request_reviewer event support ⚠️ BREAKING
2. Add default 3-day runtime install cooldown with per-runtime opt-out #33775 - Add default 3-day runtime install cooldown with per-runtime opt-out - NOT BREAKING (adds new optional field)
3. Demote strict-mode ecosystem domain guidance from warning to info #33776 - Demote strict-mode ecosystem domain guidance from warning to info - NOT BREAKING (validation level change)
4. [docs] Consolidate developer specifications into instructions file (v9.13) #33773 - Consolidate developer specifications - NOT BREAKING (docs only)
5. Fix TypeScript error: parseInt receiving string | undefined in effective_tokens.cjs #33756 - Fix TypeScript error in effective_tokens.cjs - NOT BREAKING (bug fix)
6. [ab-advisor] A/B experiment: sub_agent_strategy for agent-persona-explorer #33753 - A/B experiment for agent-persona-explorer - NOT BREAKING (workflow changes)
7. [docs] Update documentation for features from 2026-05-21 #33745 - Update documentation - NOT BREAKING (docs only)
8. Harden aw-portfolio-yield finalization and add Sentry OTel fallback #33739 - Harden aw-portfolio-yield finalization - NOT BREAKING (workflow hardening)
9. [instructions] Sync safe-outputs.md with release v0.74.8 schema #33730 - Sync safe-outputs.md with release - NOT BREAKING (docs)
10. fix: add required_field_removals to toolsMeta JSDoc type #33707 - Fix JSDoc type - NOT BREAKING (type definition fix)

Action Checklist

Complete the following items to address these breaking changes:

• Review all breaking changes detected - Verify that PR Remove synthetic pull_request_reviewer event support #33770 removal is correctly categorized as breaking
• Create a changeset file in .changeset/ directory - Create major-remove-pull-request-reviewer.md with the changeset format
• Add migration guidance to changeset - Include clear migration instructions in the changeset file
• Document breaking changes in CHANGELOG.md - Add entry under "Breaking Changes" section
• Verify backward compatibility was considered - PR explicitly states "no legacy compatibility" - this was intentional

Recommendations

Immediate Actions:

1. Create a major changeset file for this schema removal
2. Update CHANGELOG.md with breaking change notice and migration guide
3. Document the migration path in release notes

Migration Instructions:
Replace on.pull_request_reviewer: with on.pull_request: [ready_for_review] plus slash_command: review:

# Before
on:
  pull_request_reviewer: review

# After  
on:
  pull_request:
    - ready_for_review
  slash_command: review

Version Bump Guidance:

• This change requires a MAJOR version bump (e.g., v0.x.0 → v1.0.0 or v1.x.0 → v2.0.0)
• The changeset system will automatically determine the correct bump based on the major changeset type

Why This Matters:
Even though this was marked "experimental", it was:

• Part of the public schema
• Used in 4 workflows in the repository
• Potentially adopted by external users
• Removed without a major changeset

Removing schema fields without a major version bump violates semantic versioning principles.

Reference

See scratchpad/breaking-cli-rules.md for the complete breaking change policy.

Relevant Workflow Run: §26237492527

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Once all checklist items are complete, close this issue.

⚠️ Compatibility report by Breaking Change Checker · ● 1.4M · ◷

• expires on May 23, 2026, 4:07 PM UTC