Stainless website screenshot

Stainless

Stainless is an API developer experience platform that generates best-in-class SDKs, interactive documentation, production-ready CLI tools, MCP servers, and Terraform providers directly from an OpenAPI specification. Trusted by Anthropic, Cloudflare, Google, and OpenAI, Stainless automates the boilerplate of client library development including HTTP requests, retries with exponential backoff, streaming, and pagination. The platform supports TypeScript, Python, Go, Java, Kotlin, Ruby, C#, PHP, and Terraform, with Rust and Swift in development.

Stainless publishes 12 APIs on the APIs.io network, including Build Target Outputs API, Builds API, Orgs API, and 9 more. Tagged areas include Code Generation, Documentation, Developer Experience, MCP, and Platform.

The Stainless catalog on APIs.io includes 1 JSON-LD context.

Stainless’ developer surface includes authentication, developer portal, documentation, pricing, engineering blog, changelog, and 12 more developer resources.

🌐 Visit website 📡 Source on GitHub
41.1/100 developing ▲ 11.7 Agent 20/100 agent aware Front door AI 4/6 moderate saas Full breakdown ↓
scored 2026-10-04 · rubric v0.23.0
AccessFreemiumSelf serve⚡ Free to try
4 published contracts
Code GenerationDocumentationDeveloper ExperienceMCPPlatformSDKTerraformSDK GenerationOpenAPI

What this lets a business do 1

Business capabilities this provider's published APIs can perform, derived from its own contracts. Browse all capabilities →

Developer Platform & API Ecosystem Management
BC-4270
Build Target OutputsBuilds

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-10-04 · rubric v0.23.0
Composite quality — 41.1/100 · developing
Contract Quality 8.4 / 19
Developer Ergonomics 6.8 / 15
Access Clarity 7.5 / 15
Operational Transparency 2.8 / 10
Contract Governance 0.0 / 9
Discoverability 4.7 / 8
Regulatory Posture 4.0 / 15
Create-or-Update Ergonomics 0.0 / 10
Agent readiness — 20/100 · agent aware
Machine-Readable Contract 18 / 18
Agentic Access Contract 10 / 10
Documented Reversibility 0 / 6
MCP Server 0 / 12
Machine-Readable Auth 10 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 7 / 7
Typed Event Surface 0 / 6
Agent Skills 0 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3
A2A Agent Card 0 / 8
Dry-Run / Simulate Mode 0 / 4
Delegated User Identity 0 / 6
Protected Resource Metadata 0 / 5
Registration Without a Human 0 / 6
Agentic Commerce Well-Known Document 0 / 5
Regulatory Posture applies to this provider. Its tags matched the Horizontal (data, software, accessibility, platform) regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.
Create-or-Update Ergonomics applies to this provider. This API accepts writes, so it carries 10 points of the composite. It is scored from the published contracts themselves: whether a caller can create-or-update in one call, whether the write accepts a key the caller already holds, and whether the response says which branch ran. Without that, every write needs a search-and-branch in front of it, and the first time that check is skipped a duplicate record is created. Scored against the observed mean rather than raw — a provider at the catalog average is unchanged by this facet, not penalised by it.
The six quality facets above are damped to 75 points between them, because the conditional facet above carries the other 25. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 75% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from github.com/api-evangelist/stainless: open an issue to ask a question, or submit a pull request to add artifacts. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

What adopting Stainless moves on the Kin Score 11

Stainless is an area vendor: providers adopt it to run part of their developer surface. This is the Kin Score checks its features can move for a provider that adopts it, what each one really earns, and what it earns nothing for.

sdk generationcapability map9 features checked 2026-09-25 · rubric v0.22.0

Stainless reaches the most Developer Ergonomics surface of the SDK generators: SDKs in eight or more languages, a generated CLI, and a static, server-light docs platform with an API reference, per-page Markdown and an llms.txt. Each counts once the provider declares it. Its MCP servers expose the same two Code Mode tools for every customer, so they score as platform (0.25 of 12). Its generated SKILL.md files are the derived class (0.25). The decorated OpenAPI adds SDK snippets, not request/response examples, and is not an Overlay document, so neither examples_present nor overlay_published moves. Unless the provider uses the docs platform or a default-hosted MCP server, Stainless output looks like the provider’s own work.

Agent Readiness6.0 of 139 pts
Contract Quality4.0 of 211 pts
Developer Ergonomics17.8 of 42 pts
Discoverability4.0 of 54 pts
CheckEarnsThrough
MCP Serverplatform
Agent ReadinessCode Mode exposes the same two tools (docs search, execute code) for every Stainless customer. That shared tool shape is what 0.22.0 grades platform (0.25). There is a fair argument that the SDK behind the executor is the provider’s own. It belongs in the…		 3.0 of 12 MCP server generation (Code Mode)
Request/Response Examplespartial
Agent ReadinessThe added snippets are SDK calls, not request/response examples. The dimension reads examples first, so Stainless reaches only the Code Samples link fallback (0.25).		 1.8 of 7 Decorated OpenAPI with SDK code samples
Agent Skillsdiscounted
Agent ReadinessGenerated from the spec rather than written by the provider, so the derived class.		 1.3 of 5 Generated SKILL.md for the customer's API
Three or more SDKs
Developer ErgonomicsPublish three or more language SDKs and declare each as its own SDK entry.		 4.0 of 4 SDK generation
Documentationsaturated
Developer Ergonomics95% of providers with a contract, docs and a reference already earn this; the vendor cannot move it for most of its buyers.		 4.0 of 4 Stainless Docs Platform
Publishes llms.txt
DiscoverabilityThe file is added by the provider from its own docs content on its own domain, which format rule 2 credits in full.		 4.0 of 4 Per-page Markdown and llms.txt
Published example corpus
Contract QualityDeclare the page or repository carrying the generated snippets as a CodeSamples entry.		 4.0 of 4 Decorated OpenAPI with SDK code samples
At least one SDK
Developer ErgonomicsPublish a generated SDK and declare it as an SDK entry in apis.yml.		 3.0 of 3 SDK generation
Command-line interface
Developer ErgonomicsRelease the generated CLI and declare it as a CLI entry.		 3.0 of 3 CLI generation
API referencesaturated
Developer Ergonomics94% of providers with a contract, docs and a reference already earn this; the vendor cannot move it for most of its buyers.		 3.0 of 3 Stainless Docs Platform
Agent Skilldiscounted
Developer ErgonomicsDeclare the published skill as an AgentSkill entry.		 0.8 of 3 Generated SKILL.md for the customer's API
Across 8977 providers that publish a contract, adopting Stainless would move 8961. Median lift: composite +6.4 (90th percentile +8.1), agent readiness +3.1 (+4.3). Conditional rows excluded.
What Stainless ships that earns nothing (4)
  • Decorated OpenAPI with SDK code samples — x-codeSamples and x-stainless-snippets are SDK snippets. The check counts request or response examples.
  • Decorated OpenAPI with SDK code samples — The decorated spec is a full copy of the OpenAPI with snippets added, not an OpenAPI Overlay document.
  • Stainless CLI skill (stl skills) — The stl skill teaches an agent to drive Stainless and says nothing about the customer’s API.
  • SDK generation — SDK retries do not add an idempotency key to the contract, and the dimension reads the contract.

A model, not a score. Adopting this vendor changes a provider's Kin Score only when the provider publishes the resulting artifacts on its own surface; nothing here writes a score, and no sponsorship or partnership can. The rating is not for sale → · Full vendor facets artifact

APIs 12

Individual APIs this provider publishes, each with its own machine-readable definition.

Stainless SDK Generator

Generate production-ready SDKs in TypeScript, Python, Go, Java, Kotlin, Ruby, C#, PHP, and Terraform from an OpenAPI specification. Stainless handles HTTP requests, retries with...

Stainless Docs Platform

The Stainless Docs Platform combines your API reference, usage examples, and narrative guides into a single, cohesive experience that evolves with your API. Go from an OpenAPI s...

Stainless MCP Servers

Stainless generates production-ready MCP (Model Context Protocol) servers optimized for agentic coding and context limits directly from an OpenAPI spec. Production-grade capabil...

Stainless CLI

The Stainless CLI generates production-ready command-line interfaces from an OpenAPI specification. Generated CLIs provide a consistent, typed interface for interacting with any...

Stainless Terraform Providers

Stainless generates production-ready Terraform providers from an OpenAPI specification, enabling infrastructure-as-code access to any REST API without manual Terraform provider ...

Stainless Build Target Outputs API

The Build Target Outputs API from Stainless — 1 operation(s) for build target outputs.

Stainless Builds API

The Builds API from Stainless — 4 operation(s) for builds.

Stainless Orgs API

The Orgs API from Stainless — 2 operation(s) for orgs.

Stainless Projects API

The Projects API from Stainless — 9 operation(s) for projects.

Stainless User API

The User API from Stainless — 1 operation(s) for user.

Stainless Spec API

The Spec API from Stainless — 1 operation(s) for spec.

Stainless Open API

The Open API API from Stainless — 1 operation(s) for open api.

Scroll for all 12

Open Collections 7

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

API Collection

OPEN COLLECTION

Stainless Platform Build Target Outputs API

OPEN COLLECTION

Stainless Platform Build Target Outputs Builds API

OPEN COLLECTION

Stainless Platform Build Target Outputs Orgs API

OPEN COLLECTION

Stainless Platform Build Target Outputs Projects API

OPEN COLLECTION

Stainless Platform Build Target Outputs User API

OPEN COLLECTION

Stainless Platform API

OPEN COLLECTION

Scroll for all 7

Pricing Plans 1

Published pricing tiers and plan structures.

Stainless Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Stainless Rate Limits

5 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

Stainless Finops

FINOPS

Semantic Vocabularies 1

JSON-LD contexts and semantic vocabularies used across these APIs.

Stainless Context

18 classes · 4 properties

JSON-LD

Examples 1

Example request and response payloads for these APIs.

Stainless Sdk Generation Example

4 fields

EXAMPLE

Security Posture 3

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Stainless Authentication

http · 1 scheme

SECURITY

Stainless Domain Security

TLSv1.3 · DMARC

SECURITY

Stainless Vulnerability Disclosure

security.txt · contact published

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Stainless Agentic Access

22 operations · 10 acting · 1 human-in-the-loop

22 operations · 10 acting

AGENTIC

Resources

Get Started 2

Portal, sign-up, and the first successful call

Portal
Portal
 Login
Login

Documentation 1

Reference material describing how the API behaves

Documentation
Documentation

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess
AgenticAccess

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrganization
GitHubOrganization

Access & Security 3

Authentication, authorization, and security posture

VulnerabilityDisclosure
VulnerabilityDisclosure
 DomainSecurity
DomainSecurity
 Authentication
Authentication

Operate 1

Status, limits, changes, and where to get help

ChangeLog
ChangeLog

Commercial 2

Pricing, plans, and the legal terms of use

Pricing
Pricing
 TermsOfService
TermsOfService

Company 4

The organization behind the API

Website
Website
 LinkedIn
LinkedIn
 Blog
Blog
 About
About

Other 3

Properties that don't map to a standard resource type

CapabilityMap
CapabilityMap
 VendorFacets
VendorFacets
 Customers
Customers

Source (apis.yml)

apis.yml Raw ↑ 
aid: stainless
url: https://raw.githubusercontent.com/api-evangelist/stainless/refs/heads/main/apis.yml
name: Stainless
description: Stainless is an API developer experience platform that generates best-in-class SDKs, interactive documentation,
  production-ready CLI tools, MCP servers, and Terraform providers directly from an OpenAPI specification. Trusted by Anthropic,
  Cloudflare, Google, and OpenAI, Stainless automates the boilerplate of client library development including HTTP requests,
  retries with exponential backoff, streaming, and pagination. The platform supports TypeScript, Python, Go, Java, Kotlin,
  Ruby, C#, PHP, and Terraform, with Rust and Swift in development.
tags:
- Code Generation
- Documentation
- Developer Experience
- MCP
- Platform
- SDK
- Terraform
- SDK Generation
- OpenAPI
tags_raw:
- Code Generation
- Documentation
- Developer Experience
- MCP
- Platform
- SDKs
- Terraform
- SDK Generation
- OpenAPI
type: Index
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: true
  label: Hosted service · you call their endpoint
  confidence: high
  source:
  - openapi
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: freemium
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  label: Freemium · Self-serve signup
  confidence: medium
  source:
  - plans
  - authentication
  - security
  generated: '2026-09-03'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/stainless.png
access: 3rd-Party
created: '2025-01-08'
modified: '2026-05-02'
position: Consuming
segments:
- SDKs
- Developer Tooling
common:
- type: CapabilityMap
  url: capabilities/stainless-capability-edges.yml
  name: Stainless Business Capability Map
- type: VendorFacets
  url: vendor-facets/stainless-vendor-facets.yml
- type: Website
  url: https://www.stainless.com/
- type: AgenticAccess
  url: agentic-access/stainless-agentic-access.yml
- type: VulnerabilityDisclosure
  url: security/stainless-vulnerability-disclosure.yml
- type: DomainSecurity
  url: security/stainless-domain-security.yml
- type: Authentication
  url: authentication/stainless-authentication.yml
- type: LinkedIn
  url: https://www.linkedin.com/company/stainless-api
- url: https://www.stainless.com/
  type: Portal
- url: https://www.stainless.com/docs/
  type: Documentation
- url: https://www.stainless.com/pricing
  type: Pricing
- url: https://www.stainless.com/blog
  type: Blog
- url: https://www.stainless.com/changelog
  type: ChangeLog
- url: https://app.stainless.com/login
  type: Login
- url: https://www.stainless.com/company
  type: About
- url: https://github.com/stainless-api
  type: GitHubOrganization
- url: https://www.stainless.com/legal/terms-conditions
  type: TermsOfService
- url: https://www.stainless.com/customers
  type: Customers
apis:
- aid: stainless:stainless
  name: Stainless SDK Generator
  tags:
  - Code Generation
  - Developer Experience
  - SDK
  tags_raw:
  - Code Generation
  - Developer Experience
  - SDKs
  humanURL: https://www.stainless.com/
  description: Generate production-ready SDKs in TypeScript, Python, Go, Java, Kotlin, Ruby, C#, PHP, and Terraform from an
    OpenAPI specification. Stainless handles HTTP requests, retries with exponential backoff, streaming, pagination, and idiomatic
    patterns for each language. Trusted by Anthropic, Cloudflare, Google, and OpenAI.
  properties:
  - url: https://www.stainless.com/
    type: Documentation
  - url: https://www.stainless.com/docs/
    type: GettingStarted
  - url: https://www.stainless.com/pricing
    type: Pricing
  - url: https://www.stainless.com/customers
    type: Customers
  - url: https://github.com/stainless-api/upload-openapi-spec-action
    type: GitHubAction
  - url: https://github.com/stainless-api/build-sdk-action
    type: GitHubAction
- aid: stainless:stainless-docs-platform
  name: Stainless Docs Platform
  tags:
  - API Reference
  - Developer Experience
  - Documentation
  humanURL: https://www.stainless.com/products/docs
  description: The Stainless Docs Platform combines your API reference, usage examples, and narrative guides into a single,
    cohesive experience that evolves with your API. Go from an OpenAPI spec to a live, interactive documentation site in minutes
    with a developer-centric docs-as-code workflow built on Astro. Deploys to Cloudflare or custom clouds.
  properties:
  - url: https://www.stainless.com/products/docs
    type: Documentation
  - url: https://www.stainless.com/docs/docs-platform/
    type: GettingStarted
- aid: stainless:stainless-mcp-servers
  name: Stainless MCP Servers
  tags:
  - AI Agents
  - Code Generation
  - MCP
  humanURL: https://www.stainless.com/products/mcp
  description: Stainless generates production-ready MCP (Model Context Protocol) servers optimized for agentic coding and
    context limits directly from an OpenAPI spec. Production-grade capabilities including OAuth, SSE, and remote servers are
    included by default. Generated MCP servers use a code tool architecture enabling seamless integration with Claude Desktop,
    Cursor, and other MCP clients.
  properties:
  - url: https://www.stainless.com/products/mcp
    type: Documentation
  - url: https://www.stainless.com/docs/targets/mcp/
    type: GettingStarted
  - url: https://www.stainless.com/mcp
    type: Portal
- aid: stainless:stainless-cli
  name: Stainless CLI
  tags:
  - CLI
  - Code Generation
  - Developer Tools
  humanURL: https://www.stainless.com/docs/
  description: The Stainless CLI generates production-ready command-line interfaces from an OpenAPI specification. Generated
    CLIs provide a consistent, typed interface for interacting with any API from the terminal.
  properties:
  - url: https://www.stainless.com/docs/
    type: Documentation
- aid: stainless:stainless-terraform
  name: Stainless Terraform Providers
  tags:
  - Code Generation
  - Infrastructure as Code
  - Terraform
  humanURL: https://www.stainless.com/docs/
  description: Stainless generates production-ready Terraform providers from an OpenAPI specification, enabling infrastructure-as-code
    access to any REST API without manual Terraform provider development.
  properties:
  - url: https://www.stainless.com/docs/
    type: Documentation
- aid: stainless:stainless-build-target-outputs-api
  name: Stainless Build Target Outputs API
  description: The Build Target Outputs API from Stainless — 1 operation(s) for build target outputs.
  humanURL: https://www.stainless.com/
  tags:
  - Build Target Outputs
  properties:
  - type: OpenAPI
    url: openapi/stainless-build-target-outputs-api-openapi.yml
- aid: stainless:stainless-builds-api
  name: Stainless Builds API
  description: The Builds API from Stainless — 4 operation(s) for builds.
  humanURL: https://www.stainless.com/
  tags:
  - Builds
  properties:
  - type: OpenAPI
    url: openapi/stainless-builds-api-openapi.yml
- aid: stainless:stainless-orgs-api
  name: Stainless Orgs API
  description: The Orgs API from Stainless — 2 operation(s) for orgs.
  humanURL: https://www.stainless.com/
  tags:
  - Organization
  tags_raw:
  - Orgs
  properties:
  - type: OpenAPI
    url: openapi/stainless-orgs-api-openapi.yml
- aid: stainless:stainless-projects-api
  name: Stainless Projects API
  description: The Projects API from Stainless — 9 operation(s) for projects.
  humanURL: https://www.stainless.com/
  tags:
  - Project
  tags_raw:
  - Projects
  properties:
  - type: OpenAPI
    url: openapi/stainless-projects-api-openapi.yml
- aid: stainless:stainless-user-api
  name: Stainless User API
  description: The User API from Stainless — 1 operation(s) for user.
  humanURL: https://www.stainless.com/
  tags:
  - User
  properties:
  - type: OpenAPI
    url: openapi/stainless-user-api-openapi.yml
- aid: stainless:stainless-spec-api
  name: Stainless Spec API
  description: The Spec API from Stainless — 1 operation(s) for spec.
  humanURL: https://www.stainless.com/
  tags:
  - Spec
  properties:
  - type: OpenAPI
    url: openapi/stainless-spec-api-openapi.yml
- aid: stainless:stainless-open-api-api
  name: Stainless Open API
  description: The Open API API from Stainless — 1 operation(s) for open api.
  humanURL: https://www.stainless.com/
  tags:
  - OpenAPI
  tags_raw:
  - Open API
  properties:
  - type: OpenAPI
    url: openapi/stainless-open-api-api-openapi.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
specificationVersion: '0.23'
x-correction-request:
  requested: '2026-10-03'
  source:
  - apis.io Influence-tier request queue (kinlane-test-influence)
  request: 'Influence-tier artifact submission ebe1e0d5 (2026-09-23): OpenAPI at https://storage.googleapis.com/stainless-sdk-openapi-specs/stainless/stainless-v0-4ec3b12ce6b2e1e2eb800fab7dea5fc272c8c7aaf364a5305af5f4eda95e07b3.yml.
    Verify it is live and real (MCP: initialize/tools/list or server card; OpenAPI: paths), then record it as a pointer and
    harvest it.'

Work with this as data

Every provider here is available over the APIs.io API and to AI agents over MCP.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for providers

9 MCP tools reach this
  • find_providersBrowse and filter every provider in the catalog.
  • get_provider_artifactsEvery artifact this provider publishes, grouped by type.
  • get_provider_operationsEvery operation across all of their OpenAPIs — one call instead of parsing every spec.
  • get_provider_toolsEvery MCP tool they ship, with the operation each wraps.
  • get_provider_evidenceHow each part of their score was established. Free — the basis for a claim should not sit behind it.
  • get_provider_ratingPRO — composite, band, trend and facet scores.
  • apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
  • resolveTurn a domain, URL or GitHub org into the provider it belongs to.
  • find_cohortsEvery scored population of providers in the catalog.
All 92 tools →

Call it yourself

curl for this page
This provider 
curl "https://apis.io/api/v1/providers/stainless"
All providers 
curl "https://apis.io/api/v1/providers?limit=25"
Every operation they expose 
curl "https://apis.io/api/v1/providers/stainless/operations?limit=25"
How their score was established 
curl "https://apis.io/api/v1/providers/stainless/evidence"

Discovery needs no key. Ratings and market analysis are Pro.

Get an API key

Free tier, no form to fill in. Signing in shares your email address with us — we store it to create your key and to recognise you if you sign in with another provider. See our Privacy Policy and Terms.

GitHub Google LinkedIn

A second provider on the same verified email joins the account you already have.