fix(cancellation): workflow cancellation handled for non-local envs

[icecrasher321]

Summary

Locally workflow aborts work. But in Prod/Staging envs the abort signal does not actually propagate correctly. Need to use an executor set / redis to make this work. This PR does it using the standard pattern of redis with in memory fallback we have.

Type of Change

• Bug fix

Testing

Tested both paths manually

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)

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1 Skipped Deployment

Project	Deployment	Review	Updated (UTC)
docs	Skipped		Dec 24, 2025 10:07am

[greptile-apps]

Greptile Summary

• Implements distributed workflow cancellation system using Redis with in-memory fallback to fix cancellation failures in production/staging environments
• Removes direct executor instance tracking through onExecutorCreated callbacks and replaces with external cancellation API endpoint
• Adds async cancellation checks in execution engine to query distributed cancellation state at critical execution points

Important Files Changed

Filename	Overview
apps/sim/lib/execution/cancellation.ts	New module implementing Redis-backed cancellation storage with TTL and in-memory fallback
apps/sim/executor/execution/engine.ts	Added async cancellation checks that query distributed state instead of relying on local context
apps/sim/app/api/workflows/[id]/execute/cancel/route.ts	New API endpoint for requesting workflow cancellation via external system
apps/sim/executor/execution/executor.ts	Added setter to isCancelled property to enable external cancellation mechanisms
apps/sim/app/api/workflows/[id]/execute/route.ts	Refactored to remove direct executor tracking and integrate with new cancellation system

Confidence score: 4/5

• This PR addresses a critical production bug with a well-architected solution that follows established codebase patterns
• Score reflects good implementation but potential for race conditions and the type safety issue in the cancel route handler
• Pay close attention to apps/sim/lib/execution/cancellation.ts for Redis fallback logic and apps/sim/app/api/workflows/[id]/execute/cancel/route.ts for the type safety issue

Sequence Diagram

sequenceDiagram
    participant User
    participant "Route Handler" as Route
    participant "Auth System" as Auth
    participant "Preprocessing" as Preprocess
    participant "Execution Core" as Core
    participant "DAG Executor" as DAG
    participant "Execution Engine" as Engine
    participant "Cancellation Service" as Cancel
    participant "Logging Session" as Log

    User->>Route: "POST /api/workflows/[id]/execute"
    Route->>Auth: "checkHybridAuth(req)"
    Auth-->>Route: "auth result"
    Route->>Route: "parse and validate request body"
    Route->>Preprocess: "preprocessExecution()"
    Preprocess-->>Route: "workflow record & actor user"
    Route->>Core: "executeWorkflowCore()"
    Core->>Log: "loggingSession.safeStart()"
    Core->>Core: "load workflow state"
    Core->>DAG: "new Executor()"
    Core->>DAG: "execute(workflowId, triggerBlockId)"
    DAG->>Engine: "run(triggerBlockId)"
    
    loop "While has work"
        Engine->>Cancel: "isCancellationRequested(executionId)"
        Cancel-->>Engine: "cancellation status"
        alt "not cancelled"
            Engine->>Engine: "processQueue()"
            Engine->>Engine: "executeNode()"
        else "cancelled"
            Engine->>Engine: "break execution loop"
        end
    end
    
    Engine-->>DAG: "execution result"
    DAG-->>Core: "execution result"
    Core->>Log: "safeComplete() or safeCompleteWithError()"
    Core-->>Route: "execution result"
    Route-->>User: "JSON response"

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[greptile-apps]

_{8 files reviewed, 2 comments}

_{Edit Code Review Agent Settings | Greptile}

[greptile-apps]

style: The catch block silently ignores cancellation API errors. Consider logging the error to help with debugging cancellation issues in production.

_{Note: If this suggestion doesn't match your team's coding style, reply to this and let me know. I'll remember it for next time!}

Prompt To Fix With AI

This is a comment left during a code review.
Path: apps/sim/hooks/use-execution-stream.ts
Line: 241:245

Comment:
**style:** The catch block silently ignores cancellation API errors. Consider logging the error to help with debugging cancellation issues in production.

<sub>Note: If this suggestion doesn't match your team's coding style, reply to this and let me know. I'll remember it for next time!</sub>

How can I resolve this? If you propose a fix, please make it concise.

[greptile-apps]

style: Avoid using any type. Use unknown instead for better type safety

Suggested change

	let body: any = {}
	let body: unknown = {}

Context Used: Context from dashboard - TypeScript conventions and type safety (source)

Prompt To Fix With AI

This is a comment left during a code review.
Path: apps/sim/app/api/workflows/[id]/execute/cancel/route.ts
Line: 21:21

Comment:
**style:** Avoid using `any` type. Use `unknown` instead for better type safety

```suggestion
  let body: unknown = {}
```

**Context Used:** Context from `dashboard` - TypeScript conventions and type safety ([source](https://app.greptile.com/review/custom-context?memory=b4f0be8d-a787-4d5a-9098-a66b1449df25))

How can I resolve this? If you propose a fix, please make it concise.

[Sg312]

Is this the best place to put this?

[Sg312]

This check needs to move into redis