Choosing the right auth strategy for MCP
JWT, OAuth, and API keys-how to align your MCP tools with enterprise identity systems.
Key Takeaways
- Auth strategies should match your risk profile and user model.
- JWT and OAuth enable per-user attribution and scoping.
- API keys are useful for simple service access.
- LegacyAI detects auth schemes from OpenAPI.
Choosing the right strategy
Auth choices determine what an AI agent can access and how actions are attributed. Use JWT or OAuth when you need user-level control and traceability.
Quick comparison
- API keys: simple and fast, but coarse-grained.
- JWT: supports scopes and per-user claims.
- OAuth: best for enterprise delegation and consent.
Implementation tips
- Never hardcode tokens in MCP configs.
- Rotate credentials on a schedule.
- Scope tools to the least privilege needed.
FAQ
Is OAuth required for enterprise?
Not always, but it provides the strongest delegation model and auditability.
Can I mix auth types?
Yes. Different tools can use different auth schemes based on risk and usage.
How do I scope tools?
Use separate tokens or scopes per tool and avoid broad, global access.
What if my spec lacks security definitions?
Add security schemes to the OpenAPI spec so MCP tools inherit correct auth.
How does LegacyAI help?
LegacyAI detects auth schemes from OpenAPI and maps them to MCP tools automatically.
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