Free local n8n guard generator

Stop a green workflow from hiding a failed AI-agent tool.

Define the one non-secret value that proves a tool completed. Generate a fail-closed n8n Code node that throws when that evidence is absent and emits a versioned _ardToolReceipt when it is present.

No uploadNo browser storageFail closed

Define evidence, not optimism

Build one explicit tool-receipt boundary.

Use a redacted sample or synthetic replacement. Never paste passwords, API keys, OAuth tokens, authorization headers, private keys, regulated data, or customer data. Inputs never leave this browser and are never stored.

01 Tool or node label For a full execution export, this must exactly match the n8n runData node name to select its output items. 02 Required success-evidence JSON path Relative to each n8n item. Use dot/bracket syntax such as json.result.id or an RFC 6901 pointer such as /json/result/id. Choose evidence that exists only after the intended side effect succeeds. 03 Correlation JSON path (optional) When configured, the generated guard also fails closed if the correlation value is missing. The non-secret value is copied into the receipt for downstream reconciliation.

04 Redacted sample execution or item JSON (optional)

Safety limits: 500,000 sample characters, 1,000 inspected items, 20,000 inspected values, 24 nesting levels, and 32 path segments. No network or browser-storage calls.

Local receipt-guard result

Fail-closed artifacts

—Sample items

—Evidence pass

—Correlation pass

1.0.0Receipt version

What the local check found

Generated guard behavior

Reads every input item with own-property path checks.
Throws on missing or empty required evidence.
Throws on missing correlation evidence when configured.
Emits _ardToolReceipt without copying the success-evidence value.

n8n Code node snippet RUN ONCE FOR ALL ITEMS

Importable single-node workflow JSON INACTIVE BY DEFAULT

This is static, local evidence only—not production proof. Confirm the Code node's placement, run the published production path, and reconcile the receipt against the real external outcome. A present field can still be stale, fabricated, or semantically wrong.

Request the $1,000 rescue

Deploy with a real proof contract

A receipt is a checkpoint, not the outcome itself.

01

Choose evidence after the side effect

Prefer a created record ID, acknowledged message ID, stored object version, or another response that the successful tool call alone produces.
02

Place the guard immediately after the tool

Do not let a catch, merge, or continue-on-error branch convert the tool failure into a green downstream path before the evidence check runs.
03

Reconcile outside the workflow

Independently verify the record, message, file, payment, or other outcome. Static path presence cannot prove a deployed workflow or external system behaved correctly.

Stop a green workflow from hiding a failed AI-agent tool.

Build one explicit tool-receipt boundary.

Fail-closed artifacts

What the local check found

Generated guard behavior

A receipt is a checkpoint, not the outcome itself.

Choose evidence after the side effect

Place the guard immediately after the tool

Reconcile outside the workflow