feat(executor): run from/until block by Sg312 · Pull Request #3029 · simstudioai/sim

Sg312 · 2026-01-27T20:51:00Z

Summary

Adds run from block and run until block functionality to the executor

Type of Change

New feature

Testing

Tested with @icecrasher321

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)

vercel · 2026-01-27T20:51:05Z

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Review	Updated (UTC)
docs	Ready	Preview, Comment	Jan 28, 2026 8:48pm

icecrasher321

Tested all edge cases

greptile-apps · 2026-01-28T20:56:15Z

Greptile Overview

Greptile Summary

Implemented run-from-block and run-until-block execution features that allow users to execute workflows starting from a specific block or stopping after a target block. The implementation includes comprehensive validation, snapshot management, and UI integration.

Key Changes:

Added computeExecutionSets() to calculate dirty blocks (blocks needing re-execution) and upstream blocks (blocks with cached outputs) using BFS graph traversal
Created new API endpoint /api/workflows/[id]/execute-from-block with SSE streaming support
Extended DAGExecutor with executeFromBlock() method that filters snapshots, removes non-dirty incoming edges, and initializes execution from the target block
Added stopAfterBlockId support in ExecutionEngine to halt execution after a specific block completes
Implemented snapshot storage per workflow in execution store for caching block outputs between runs
Added UI menu items and handlers for "Run from block" and "Run until block" with validation checks

Implementation Approach:
The feature reuses cached outputs from previous executions by filtering the execution snapshot to include only reachable upstream blocks. Non-dirty incoming edges are removed so convergent blocks don't wait for cached dependencies. Loop and parallel containers are handled by resolving to their sentinel-start nodes.

Validation:

Blocks inside loops/parallels cannot be run-from targets (only container blocks themselves)
All upstream dependencies must have been executed in the source snapshot
Comprehensive test suite with 1500+ lines covering linear flows, branching, convergence, loops, parallels, and edge cases

Confidence Score: 4/5

Safe to merge with minor fixes - well-tested feature with isolated issues
Strong implementation with comprehensive testing, but has 3 issues: type mismatch in executor.ts:144, missing upstream logs in run-from-block mode, and incomplete snapshot merging that doesn't preserve loop/parallel state
executor/execution/executor.ts (type annotation and log preservation), use-workflow-execution.ts (snapshot merging completeness)

Important Files Changed

Filename	Overview
apps/sim/executor/utils/run-from-block.ts	New utility module for run-from-block validation and execution set computation with comprehensive test coverage
apps/sim/executor/execution/executor.ts	Added executeFromBlock method with snapshot filtering logic and dirty set tracking
apps/sim/executor/execution/engine.ts	Added run-from-block initialization and stopAfterBlockId handling in execution engine
apps/sim/app/api/workflows/[id]/execute-from-block/route.ts	New API route for run-from-block execution with SSE streaming support
apps/sim/lib/workflows/executor/execution-core.ts	Added runFromBlock parameter support and conditional executor invocation
apps/sim/app/workspace/[workspaceId]/w/[workflowId]/hooks/use-workflow-execution.ts	Added handleRunFromBlock and handleRunUntilBlock with snapshot merging and validation logic

Sequence Diagram

sequenceDiagram
    participant User
    participant UI as Block Menu
    participant Hook as useWorkflowExecution
    participant Stream as useExecutionStream
    participant API as execute-from-block API
    participant Core as execution-core
    participant Executor as DAGExecutor
    participant Engine as ExecutionEngine
    participant Store as ExecutionStore

    User->>UI: Right-click block, select "Run from block"
    UI->>Hook: handleRunFromBlock(blockId)
    Hook->>Store: getLastExecutionSnapshot(workflowId)
    Store-->>Hook: Return snapshot
    
    alt No snapshot or dependencies not satisfied
        Hook-->>User: Show error notification
    else Valid snapshot
        Hook->>Stream: executeFromBlock(workflowId, startBlockId, snapshot)
        Stream->>API: POST /api/workflows/{id}/execute-from-block
        API->>API: Validate auth & request body
        API->>Core: executeWorkflowCore(runFromBlock options)
        Core->>Executor: executeFromBlock(workflowId, startBlockId, snapshot)
        
        Executor->>Executor: validateRunFromBlock()
        Executor->>Executor: computeExecutionSets()
        Note over Executor: Compute dirty set (blocks to re-execute)<br/>and upstream set (cached blocks)
        
        Executor->>Executor: Filter snapshot to reachable upstream
        Executor->>Executor: Remove incoming edges from non-dirty sources
        Executor->>Engine: run()
        
        Engine->>Engine: initializeQueue(startBlockId)
        loop Until no work remaining
            Engine->>Engine: executeNodeAsync(nodeId)
            alt Block in dirty set
                Engine->>Engine: Re-execute block
            else Block not in dirty set
                Engine->>Engine: Use cached output
            end
            Engine->>API: Send SSE events (block:started, block:completed)
            API->>Stream: Stream SSE events
            Stream->>Hook: Trigger callbacks
            Hook->>Store: Update execution state
            Hook->>UI: Update active blocks visualization
        end
        
        Engine-->>Executor: Return ExecutionResult
        Executor-->>Core: Return result
        Core->>API: Send execution:completed event
        API->>Stream: Stream final result
        Stream->>Hook: onExecutionCompleted
        Hook->>Store: setLastExecutionSnapshot() (merge with existing)
        Hook->>UI: Update UI state
        UI-->>User: Show execution complete
    end

greptile-apps

_{6 files reviewed, 3 comments}

_{Edit Code Review Agent Settings | Greptile}

greptile-apps · 2026-01-28T20:56:19Z

apps/sim/executor/execution/executor.ts

+
+    // Filter snapshot to include all blocks reachable from dirty blocks
+    // This preserves sibling branch outputs that dirty blocks may reference
+    const filteredBlockStates: Record<string, any> = {}


type mismatch - filteredBlockStates is Record<string, any> but should match the type expected by blockStates field

Suggested change

const filteredBlockStates: Record<string, any> = {}

const filteredBlockStates: Record<string, BlockState> = {}

Prompt To Fix With AI

This is a comment left during a code review. Path: apps/sim/executor/execution/executor.ts Line: 144:144 Comment: type mismatch - `filteredBlockStates` is `Record<string, any>` but should match the type expected by `blockStates` field ```suggestion const filteredBlockStates: Record<string, BlockState> = {} ``` How can I resolve this? If you propose a fix, please make it concise.

greptile-apps · 2026-01-28T20:56:20Z

apps/sim/executor/execution/executor.ts

      isDeployedContext: this.contextExtensions.isDeployedContext,
      blockStates: state.getBlockStates(),
-      blockLogs: snapshotState?.blockLogs ?? [],
+      blockLogs: overrides?.runFromBlockContext ? [] : (snapshotState?.blockLogs ?? []),


when runFromBlockContext exists, blockLogs are reset to empty array, but this discards upstream execution logs that may be needed for debugging and tracing

Prompt To Fix With AI

This is a comment left during a code review. Path: apps/sim/executor/execution/executor.ts Line: 268:268 Comment: when `runFromBlockContext` exists, `blockLogs` are reset to empty array, but this discards upstream execution logs that may be needed for debugging and tracing How can I resolve this? If you propose a fix, please make it concise.

greptile-apps · 2026-01-28T20:56:21Z

apps/sim/app/workspace/[workspaceId]/w/[workflowId]/hooks/use-workflow-execution.ts

+                const mergedBlockStates: Record<string, BlockState> = {
+                  ...effectiveSnapshot.blockStates,
+                }
+                for (const [bId, state] of accumulatedBlockStates) {
+                  mergedBlockStates[bId] = state
+                }


merging logic doesn't preserve loop/parallel execution state from the snapshot - only blockStates are merged but loopExecutions and parallelExecutions from effectiveSnapshot should also be included in updatedSnapshot

Prompt To Fix With AI

This is a comment left during a code review. Path: apps/sim/app/workspace/[workspaceId]/w/[workflowId]/hooks/use-workflow-execution.ts Line: 1656:1661 Comment: merging logic doesn't preserve loop/parallel execution state from the snapshot - only `blockStates` are merged but `loopExecutions` and `parallelExecutions` from `effectiveSnapshot` should also be included in `updatedSnapshot` How can I resolve this? If you propose a fix, please make it concise.

Sg312 added 14 commits January 26, 2026 16:19

Run from block

3d0b810

Fixes

e8534be

Fix

da5d4ac

Fix

be95a7d

Minor improvements

72594df

Fix

5c1e620

Fix trace spans

d38fb29

Fix loop l ogs

3231955

Change ordering

6e54194

Run u ntil block

23ab11a

Lint

2c333bf

Clean up

7a0aaa4

Fix

8dc45e6

Allow run from block for triggers

415acda

Consolidation

c14c614

vercel bot temporarily deployed to Preview January 27, 2026 20:55 Inactive

Fix lint

f55f6cc

vercel bot temporarily deployed to Preview January 27, 2026 22:08 Inactive

icecrasher321 self-requested a review January 27, 2026 22:12

icecrasher321 self-assigned this Jan 27, 2026

Fix

2f504ce

vercel bot temporarily deployed to Preview January 27, 2026 22:55 Inactive

Fix mock payload

6f66d33

vercel bot temporarily deployed to Preview January 27, 2026 22:59 Inactive

Fix

d80608c

vercel bot temporarily deployed to Preview January 28, 2026 00:20 Inactive

Fix trigger clear snapshot

c201a7c

vercel bot temporarily deployed to Preview January 28, 2026 00:53 Inactive

Merge branch 'staging' into feat/run-from-block-2

08bea87

Fix bugs

79857e1

vercel bot temporarily deployed to Preview January 28, 2026 02:16 Inactive

Catch error

994a664

vercel bot temporarily deployed to Preview January 28, 2026 02:22 Inactive

Fix

28fbd0c

vercel bot temporarily deployed to Preview January 28, 2026 02:25 Inactive

Fix

0ead5aa

vercel bot temporarily deployed to Preview January 28, 2026 02:35 Inactive

I think it works??

a9f271c

vercel bot temporarily deployed to Preview January 28, 2026 04:04 Inactive

Fix

0d6b485

vercel bot temporarily deployed to Preview January 28, 2026 04:08 Inactive

Fix

e526ff0

vercel bot temporarily deployed to Preview January 28, 2026 19:46 Inactive

Add tests

c931793

vercel bot temporarily deployed to Preview January 28, 2026 19:47 Inactive

Fix lint

828d74f

vercel bot temporarily deployed to Preview January 28, 2026 20:42 Inactive

Merge branch 'staging' into feat/run-from-block-2

76503be

vercel bot deployed to Preview January 28, 2026 20:48 View deployment

icecrasher321 marked this pull request as ready for review January 28, 2026 20:52

icecrasher321 approved these changes Jan 28, 2026

View reviewed changes

Sg312 merged commit 655fe4f into staging Jan 28, 2026
11 checks passed

greptile-apps bot reviewed Jan 28, 2026

View reviewed changes

greptile-apps bot mentioned this pull request Jan 28, 2026

feat(timeout): add API block timeout configuration #3053

Merged

6 tasks

waleedlatif1 deleted the feat/run-from-block-2 branch January 29, 2026 00:27

This was referenced Jan 29, 2026

v0.5.75: search modal overhaul, helm chart updates, run from block, terminal and visual debugging improvements #3058

Merged

Single block run #1727

Closed

Sebmono mentioned this pull request Jan 30, 2026

[PR] feat(executor): run from/until block Sandgarden-Demo/sim#45

Closed

6 tasks

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

feat(executor): run from/until block#3029

feat(executor): run from/until block#3029
Sg312 merged 35 commits intostagingfrom
feat/run-from-block-2

Sg312 commented Jan 27, 2026

Uh oh!

vercel bot commented Jan 27, 2026 •

edited

Loading

Uh oh!

icecrasher321 left a comment

Uh oh!

Uh oh!

greptile-apps bot commented Jan 28, 2026

Uh oh!

greptile-apps bot left a comment

Uh oh!

greptile-apps bot Jan 28, 2026

Uh oh!

greptile-apps bot Jan 28, 2026

Uh oh!

greptile-apps bot Jan 28, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

	const filteredBlockStates: Record<string, any> = {}
	const filteredBlockStates: Record<string, BlockState> = {}

Conversation

Sg312 commented Jan 27, 2026

Summary

Type of Change

Testing

Checklist

Uh oh!

vercel bot commented Jan 27, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

icecrasher321 left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

greptile-apps bot commented Jan 28, 2026

Greptile Overview

Greptile Summary

Confidence Score: 4/5

Important Files Changed

Sequence Diagram

Uh oh!

greptile-apps bot left a comment

Choose a reason for hiding this comment

Uh oh!

greptile-apps bot Jan 28, 2026

Choose a reason for hiding this comment

Uh oh!

greptile-apps bot Jan 28, 2026

Choose a reason for hiding this comment

Uh oh!

greptile-apps bot Jan 28, 2026

Choose a reason for hiding this comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

vercel bot commented Jan 27, 2026 •

edited

Loading