Free TierAPI Key AuthOpenAPI Spec
Cerbos is an open-source authorization-as-a-service platform that allows you to define, test, and enforce fine-grained access control policies. It provides a centralized policy engine accessible via gRPC and HTTP APIs for permission decisions.
#1 of 7 in Authorization · #1 of 6 in Access Control · #1 of 58 in Security
Checklist Breakdown
16 of 33 checks passed.
14 unscored.
Can an agent find and understand this tool without a web search?
✓
Published OpenAPI/Swagger spec
✗
Has llms.txt or llms-full.txt
✗
Has an MCP server (official or well-maintained)
✗
MCP server listed in a public registry
✓
API reference docs are publicly accessible
✓
Docs include runnable code examples
✓
Has a public changelog or release notes
✓
Has a public status page
Can an agent create an account and get credentials without human intervention?
✓
Signup does not require CAPTCHA
✓
Signup does not require phone verification
✓
Supports API key auth (not only OAuth)
✓
API key obtainable without manual approval
✓
No mandatory billing info to start
✓
Can sign up without creating an organization
Can an agent operate autonomously without upfront payment or contracts?
✓
Has a free tier
✓
Usage-based pricing available
✓
No minimum contract or commitment
✓
Pricing page is public (no 'contact sales')
✓
Free tier sufficient for testing (not just a trial)
How well does the API work for non-human consumers?
—
SDK available in 2+ languages
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Structured error responses (JSON with error codes)
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Idempotency support on write endpoints
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Pagination on list endpoints
—
Webhook/event support
—
Sandbox or test mode available
—
Rate limit headers in responses
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Consistent REST resource naming
Does the tool fail gracefully when an agent makes a mistake?
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Meaningful error messages (not just 500)
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429 responses include Retry-After header
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Documented uptime SLA (99.9%+)
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Graceful degradation under rate limits
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Request IDs in responses for debugging
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API versioning supported
Reviewer Notes
Cerbos excels in agent tooling with clear OpenAPI specs, structured JSON responses, and a self-hostable open-source option—agents can easily integrate authorization checks. Discovery is solid with good documentation and multiple SDK options. The main weakness is limited documentation on programmatic account setup for the cloud version and no MCP server, which reduces discoverability. The free tier and sandbox environment are strong positives, though the pricing model for production cloud deployments isn't fully transparent, creating some uncertainty for autonomous agent cost planning.
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