Stainless

Fair

Agent Native Score

Free Tier

Stainless is an API code generation platform that automatically generates SDKs, API documentation, and OpenAPI specs from your codebase. It enables developers to maintain high-quality, type-safe client libraries with minimal manual effort.

Categories: Devtools · Api Generation · Sdk Tools

#90 of 96 in Devtools · #5 of 5 in Api Generation

Checklist Breakdown

11 of 33 checks passed. 14 unscored.

Discovery 50%

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

Auth & Onboarding 33%

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

Pricing 100%

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)

Agent Tooling Not yet scored

How well does the API work for non-human consumers?

— SDK available in 2+ languages

— Structured error responses (JSON with error codes)

— Idempotency support on write endpoints

— Pagination on list endpoints

— Webhook/event support

— Sandbox or test mode available

— Rate limit headers in responses

— Consistent REST resource naming

Reliability Not yet scored

Does the tool fail gracefully when an agent makes a mistake?

— Meaningful error messages (not just 500)

— 429 responses include Retry-After header

— Documented uptime SLA (99.9%+)

— Graceful degradation under rate limits

— Request IDs in responses for debugging

— API versioning supported

Reviewer Notes

Stainless is a developer tool for code generation rather than an agent-consumable service. It has no MCP server or OpenAPI spec for agents to discover autonomously, and account creation requires human verification. The tool excels at SDK generation and has decent documentation, but agents cannot directly use Stainless as a service—it's designed for human developers to integrate into their API workflows. Free tier and sandbox availability are positive, but the lack of agent-native interfaces significantly limits agent discoverability and autonomous operation.

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