feat(copilot): let Run agent cancel workflow runs

[j15z]

Summary

The Run agent can now cancel workflow runs by workflow and execution ID. Internal, Copilot, and v2 callers share the same authorized cancellation operation without changing the public v2 terminal no-op contract.

Cancellation remains consistent for queued, active, paused, resumed, and workflow-group executions. Internal and Copilot callers continue to receive conflicts for completed or failed runs, while v2 returns its existing successful no-op response. The Copilot handler now matches the v2 contract by requiring both workflowId and executionId, with no fallback to the current workflow context.

Related: simstudioai/mothership#459

Type of Change

• Bug fix
• New feature
• Breaking change
• Documentation
• Other: ___________

Testing

• bun run lint
• bun run apps/sim/scripts/check-block-registry.ts origin/staging
• bun run check:audits
• bun run --cwd apps/sim test -- lib/copilot/tool-executor/router.test.ts lib/copilot/tools/handlers/workflow/mutations.test.ts
• bun run --cwd apps/sim type-check
• bun run check:api-validation:strict
• Focused Vitest coverage for the cancellation service, application use case, internal and v2 routes, and Copilot handler

Post-Deploy Monitoring & Validation

• For the first 24 hours, the workflow/Copilot on-call should monitor cancellation error counts and logs for workflowId is required, executionId is required, and run-control failures.
• Healthy behavior: explicit workflow/run pairs reach the canonical cancellation use case; queued, active, and paused runs cancel successfully; existing terminal-run behavior remains unchanged for each surface.
• Roll back this change if valid calls with both IDs fail unexpectedly or if any cancellation is applied outside the supplied workflow.

Checklist

• Code follows project style guidelines
• Self-reviewed my changes
• Tests added/updated and passing
• No new warnings introduced
• I confirm that I have read and agree to the terms outlined in the Contributor License Agreement (CLA)

Screenshots/Videos

Not applicable—no UI changes.

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Project	Deployment	Actions	Updated
docs	Ready	Preview	Sep 1, 2026 3:55am UTC

[greptile-apps]

Greptile Summary

The PR centralizes workflow-run cancellation behind a shared authorized application use case and exposes it to the Run agent while preserving surface-specific terminal behavior.

• Adds Copilot cancellation with explicit workflow and execution parameters.
• Consolidates internal, v2, and Copilot cancellation behavior.
• Expands paused, resumed, queued, and workflow-group reconciliation coverage.
• Updates API contracts, generated clients, route policies, and cancellation tests.

Confidence Score: 4/5

The PR is not yet safe to merge because a mismatched workflow/execution pair can cancel the execution belonging to a different workflow instead of being rejected.

The new contract requires both identifiers, but every changed adapter passes only the execution ID and the shared use case resolves the canonical workflow without asserting the supplied workflow ID.

Files Needing Attention: apps/sim/lib/copilot/tools/handlers/workflow/mutations.ts, apps/sim/lib/workflows/application/cancel-run.ts, and both cancellation route adapters

Important Files Changed

Filename	Overview
apps/sim/lib/copilot/tools/handlers/workflow/mutations.ts	Delegates Run-agent cancellation to the shared use case, but drops the newly required workflowId and therefore does not enforce the workflow/execution pair.
apps/sim/lib/workflows/application/cancel-run.ts	Provides the shared authorization and cancellation boundary, but resolves cancellation only by runId without asserting the caller-supplied workflow.
apps/sim/lib/execution/cancel-workflow-execution.ts	Implements expanded cancellation and reconciliation across queued, active, paused, resumed, and workflow-group executions.
apps/sim/lib/workflows/executor/human-in-the-loop-manager.ts	Adds transactional paused-run cancellation, rollback, terminal-race, and resume-finalization transitions.
apps/sim/app/api/v2/workflows/[workflowId]/runs/[runId]/cancel/route.ts	Adopts the shared cancellation use case and v2-specific terminal policy, but discards the workflow-scoped path parameter.
apps/sim/app/api/workflows/[id]/executions/[executionId]/cancel/route.ts	Reduces the internal route to authentication and presentation, but does not forward the workflow ID for run-binding validation.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart LR
  C[Copilot cancellation] --> A[Cancellation adapter]
  I[Internal cancellation route] --> A
  V[v2 cancellation route] --> A
  A --> U[cancelWorkflowRun]
  U --> R[Resolve execution and canonical workflow]
  R --> Z[Authorize canonical workspace]
  Z --> X[Cancel queued, active, paused, or grouped execution]

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