Openapi To Mcp Skill

OpenAPI To MCP Skill

Use this to turn an API into a narrow, safe agent tool surface.

Workflow

1. Prefer a local OpenAPI/Swagger spec file. If the spec must be fetched, record

the URL and do not send credentials.

1. Run the read-only surface audit when a local spec is available:

``bash python3 plugins/codex-supercharge/scripts/openapi_surface_audit.py path/to/openapi.json ``

1. Inspect auth, servers, paths, schemas, request bodies, response shapes, rate

limits, and write methods.

1. Group endpoints into workflows, not raw endpoint dumps.
2. Mark each operation:

• read-only
• write
• destructive
• admin
• credential-sensitive

1. Generate a minimal MCP/tool plan or capability manifest.
2. Create a Codex skill that teaches when and how to use the API.
3. Add safety confirmations for write/destructive/admin operations.

Tool Plan Template

# API Tool Plan
## Auth
## Read Tools
## Write Tools
## Destructive Tools
## Admin And Credential-Sensitive Tools
## Rate Limits
## Error Handling
## Required Confirmations
## Example Prompts

Skill Rule

The skill should describe business workflows, not every endpoint. Keep endpoint details in a reference file.

References

• references/openapi-tool-surface.md
• references/mcp-server-catalog.md
• Source inspiration only, code not executed: sources/toolcast
• Capability-manifest inspiration: sources/roam-code/src/roam/capability.py

Skip When

• The API has no spec or stable docs to inspect.
• The user only needs a one-off HTTP call, not an agent/tool surface.
• The task is only MCP conformance/release gating; use

$auto-skill-build-mcp-conformance-harness.

Validation

• Auth, rate limits, write/destructive operations, and confirmations are explicit.
• Generated tool groups map to workflows rather than raw endpoint dumps.
• Credential-sensitive operations route through $mcp-safety-review.
• openapi_surface_audit.py was run or the reason it could not run is stated.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: Arnie016
• Source: Arnie016/codex-prompt-templates
• License: MIT
• Homepage: https://github.com/Arnie016/codex-prompt-templates

Install and usage instructions live in the source repository linked above.