n8n-expression-syntax
Pass
Audited by Gen Agent Trust Hub on Sep 7, 2026
Risk Level: SAFEINDIRECT_PROMPT_INJECTIONNO_CODE
Full Analysis
- [SAFE]: The skill is entirely instructional markdown and contains no executable scripts or command-line operations.
- [DATA_EXPOSURE]: The skill documents the syntax for accessing environment variables (e.g.,
{{$env.API_KEY}}). This identifies access to sensitive data, but the documentation proactively mitigates risk by instructing users to use the platform's native credential system instead of expressions for sensitive keys. - [INDIRECT_PROMPT_INJECTION]: The skill provides instructions for ingesting untrusted data from webhooks (e.g.,
{{$json.body.name}}). While this describes an attack surface for indirect prompt injection, it also defines clear boundary markers (double curly braces) for data interpolation. Ingestion points: Webhook node output and$json.body(SKILL.md). Boundary markers: Explicit instructions to wrap dynamic content in double curly braces{{ }}. Capability inventory: Instructional only; documents access to previous node data, environment variables, and current JSON context. Sanitization: Not addressed in documentation, though it notes that certain contexts (like Code nodes) require direct variable access instead of template expressions.
Audit Metadata