Build Week 2026 · Developer Tools

Your workflow failed.
Now prove the fix.

Import a workflow and one failed execution. PatchWitness reconstructs the exact branch, redacts secrets, proposes the smallest repair, and builds a replayable proof bundle.

1failure in

4proof stages

0blind deploys

Incident intake

Evidence

Download workflow JSON Download execution JSON

n8n workflow export5 nodes detected

Upload workflow JSONDrop the workflow exported from n8n● Demo workflow loaded

View or paste workflow JSON

{
  "name": "Customer Support Voice Assistant",
  "nodes": [
    {
      "id": "trigger",
      "name": "Message Trigger",
      "type": "automation.trigger",
      "parameters": {}
    },
    {
      "id": "download",
      "name": "Download Voice File",
      "type": "automation.file",
      "parameters": {
        "operation": "download"
      }
    },
    {
      "id": "transcribe",
      "name": "Transcribe Voice",
      "type": "automation.http",
      "parameters": {
        "method": "POST",
        "url": "https://api.example.invalid/transcribe"
      }
    },
    {
      "id": "classify",
      "name": "Classify Request",
      "type": "automation.code",
      "parameters": {
        "code": "return { intent: 'support' };"
      }
    },
    {
      "id": "send",
      "name": "Send Message Reply",
      "type": "automation.message",
      "parameters": {
        "operation": "send",
        "chatId": "={{ $json.chatId }}"
      }
    }
  ],
  "connections": {
    "Message Trigger": {
      "main": [
        [
          {
            "node": "Download Voice File"
          }
        ]
      ]
    },
    "Download Voice File": {
      "main": [
        [
          {
            "node": "Transcribe Voice"
          }
        ]
      ]
    },
    "Transcribe Voice": {
      "main": [
        [
          {
            "node": "Classify Request"
          }
        ]
      ]
    },
    "Classify Request": {
      "main": [
        [
          {
            "node": "Send Message Reply"
          }
        ]
      ]
    }
  }
}

Failed execution exportresultData + terminal error

Upload failed execution JSONDrop an n8n execution export or API response● Demo execution loaded

View or paste execution JSON

Analysis monitor

ready

✓
Workflow JSON5 nodes validated
✓
Execution JSONfailure trace validated
·
Privacy boundaryscan before analysis
·
Repair compilerminimal diff + dry run
·
Proof bundlewaiting for replay gates

Demo evidence is loaded and ready for analysis.

◆ Secrets are redacted before model analysis.

PW-20260903-005

Failure reconstructed

94%confidence

01Message Triggerconfirmed

02Download Voice Fileconfirmed

03Transcribe Voiceconfirmed

04Classify Requestconfirmed

05Send Message Replyfailure

Primary diagnosis

The failure is not a messaging credential problem. Send Message Reply received a payload that no longer carried the original conversation identifier after Download Voice File.

criticalDownload Voice File

Conversation state was dropped across a binary-data boundary

The execution crossed “Download Voice File” before “Send Message Reply” returned “Bad Request: chat not found”. Binary and API nodes often replace the item payload, so chatId is no longer guaranteed downstream.

mediumReplay gate

Replay must isolate side-effecting nodes

1 node(s) can send, publish, delete, or execute actions. PatchWitness marks them as dry-run only until assertions pass.

The PatchWitness loop

From “it failed” to
evidence you can trust.

Reconstruct

Trace only the executed branch. No guesswork from a static canvas.

Constrain

Redact credentials, isolate side effects, and define the data contract.

Repair

GPT-5.6 proposes the smallest patch with evidence attached to every claim.

Prove

Replay assertions become a portable receipt for humans and CI systems.

Your workflow failed.Now prove the fix.