Overview
MCP Blacksmith can validate your OpenAPI specification for structural issues, missing definitions, and common problems before generating a server. Validation is optional but recommended for specs you haven’t tested before.What’s checked
- Schema validity — Correct OpenAPI structure per the specification version
- Reference resolution — All
$refreferences point to existing definitions - Required fields — Operations have the required metadata (paths, methods, responses)
- Type consistency — Parameter types match their declared schemas
- Security scheme definitions — Referenced security schemes exist in
securitySchemes
How to use
In the dashboard:- Upload your spec
- Open the Validation tab
- Click Validate to run the analysis
- Review any issues — each includes the location in your spec and a suggested fix
Validation results
Issues are categorized by severity:| Severity | Meaning |
|---|---|
| Error | Will likely cause generation failures or broken tools |
| Warning | Generation will work, but results may be suboptimal |
| Info | Suggestions for improving spec quality |