Stainless

Stainless is a company surfaced via the API Evangelist harvest backlog (source: vc-portfolio; backed by sequoia-capital) and added to the network as a stub for full-pipeline profiling.

Stainless is listed with 1 API on the APIs.io network. Tagged areas include Company.

The Stainless catalog on APIs.io includes 1 JSON-LD context and 1 Spectral governance ruleset.

Stainless’ developer surface includes getting-started guide, documentation, and 12 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

16.2/100 emerging Agent 23/100 agent aware Full breakdown ↓
scored 2026-10-31 · rubric v0.25.0 · Show this score on your site →

1 API

Company

Kin Score

Kin Score How this is scored →
scored 2026-10-31 · rubric v0.25.0

Composite quality — 16.2/100 · emerging

Contract Quality 4.3 / 21

Developer Ergonomics 3.6 / 17

Access Clarity 0.0 / 17

Operational Transparency 1.2 / 11

Contract Governance 2.2 / 10

Discoverability 3.0 / 9

Regulatory Posture 1.6 / 15

Agent readiness — 23/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 0 / 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 0 / 7

Typed Event Surface 0 / 6

Agent Skills 0 / 5

Well-Known Catalog 4 / 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

Pagination 5 / 5

Distinct Operations 3 / 3

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 could not be measured. We hold no machine-readable contract for this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero: never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and several others — scorable at all.

The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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Agent readiness — checks not met, largest first (exact, from this profile):

MCP Server +12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship
Agentic Access Contract +10 pts — agentic_access artifact present (x-agentic-access), graded by author
Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented)
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes
Rate-Limit Signaling +7 pts — OpenAPI responses document X-RateLimit-* / RateLimit headers (verified), else a rate_limits artifact or RateLimits link (documented)

10 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Contract Quality scores 20.1 — up to +20.0 composite points
Access Clarity scores 0.0 — up to +20.0 composite points
Developer Ergonomics scores 21.4 — up to +15.7 composite points

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

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 the provider profile at artifacts.apis.io/stainlessapi-com/apis.yml: open an issue on github.com/api-evangelist/stainlessapi-com to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

APIs 1

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

Stainless API

Stainless API as documented publicly: 24 operations. Contract generated from the documentation by API Evangelist (2026-10-24); not the provider's own document.

Semantic Vocabularies 1

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

Stainlessapi Com Context

2 classes · 4 properties

JSON-LD

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Stainless API Rules

10 rules · 8 errors 1 warnings 1 info

SPECTRAL

JSON Schema 2

Standalone JSON Schema definitions for this provider's data models.

GetAccountsAccountidFriendsResponse

3 properties

JSON SCHEMA

GetStatusResponse

1 properties

JSON SCHEMA

Security Posture 1

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

Stainlessapi Com Domain Security

DMARC

SECURITY

Resources

Get Started 1

Portal, sign-up, and the first successful call

GettingStarted

GettingStarted

Documentation 1

Reference material describing how the API behaves

Documentation

Documentation

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

WellKnown

WellKnown

Design & Contract 5

Pagination, idempotency, versioning, errors, and events

Spectral

JSONLD

Vocabulary

DataModel

Conformance

Access & Security 3

Authentication, authorization, and security posture

SecurityTxt

SecurityTxt

SecurityTxt

SecurityTxt

DomainSecurity

DomainSecurity

Company 1

The organization behind the API

Website

Website

Other 2

Properties that don't map to a standard resource type

Hosts

Hosts

Vendors

Vendors

Source (apis.yml)

aid: stainlessapi-com
name: Stainless
description: 'Stainless is a company surfaced via the API Evangelist harvest backlog (source: vc-portfolio; backed by sequoia-capital)
  and added to the network as a stub for full-pipeline profiling.'
url: https://raw.githubusercontent.com/api-evangelist/stainlessapi-com/refs/heads/main/apis.yml
x-type: company
x-source: harvest:vc-portfolio
x-tier: profiled
x-tier-reason: enrichment pass 2026-10-24 (modular-v1; was harvest)
specificationVersion: '0.20'
created: '2026-10-23'
modified: '2026-10-23'
tags:
- Company
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: Spectral
  url: rules/stainlessapi-com-rules.yml
- type: JSONLD
  url: json-ld/stainlessapi-com-context.jsonld
- type: Vocabulary
  url: vocabulary/stainlessapi-com-vocabulary.yml
- type: DataModel
  url: data-model/stainlessapi-com-data-model.yml
- type: Conformance
  url: conformance/stainlessapi-com-conformance.yml
- type: SecurityTxt
  url: well-known/stainlessapi-com-www-security.txt
- type: SecurityTxt
  url: well-known/stainlessapi-com-api-security.txt
- type: WellKnown
  url: well-known/stainlessapi-com-well-known.yml
- type: Hosts
  url: hosts/stainlessapi-com-hosts.yml
- type: Vendors
  url: vendors/stainlessapi-com-vendors.yml
- type: GettingStarted
  url: https://www.stainless.com/docs/quickstart-studio
- type: Documentation
  url: https://docs.stainlessapi.com/
- type: DomainSecurity
  url: security/stainlessapi-com-domain-security.yml
- type: Website
  url: https://www.stainlessapi.com/
apis:
- aid: stainlessapi-com:stainlessapi-com-api
  name: Stainless API
  description: 'Stainless API as documented publicly: 24 operations. Contract generated from the documentation by API Evangelist
    (2026-10-24); not the provider''s own document.'
  humanURL: https://www.stainless.com/docs/api
  properties:
  - type: OpenAPI
    url: openapi/_ae-authored/stainlessapi-com-openapi-generated.yml
    x-provenance: generated
  - type: JSONSchema
    url: json-schema/stainlessapi-com-get-accounts-accountid-friends-response-schema.json
  - type: JSONSchema
    url: json-schema/stainlessapi-com-get-status-response-schema.json
x-backed-by:
- sequoia-capital
x-enrichment:
  date: '2026-10-24'
  status: enriched
  artifacts_added: 17
  pass: modular-v1
  engine: identity=local,contract=local,surfaces=local,docs=local,regulatory=local

Stainless API — frequently asked questions

Does Stainless have an API?

Yes. APIs.io lists 1 API from Stainless, including Stainless API.

Is there an OpenAPI specification for the Stainless API?

Yes. APIs.io indexes 1 OpenAPI specification for Stainless, each linked for download from this page.

How do I authenticate with the Stainless API?

Stainless uses bearer-token authentication.

Is the Stainless API ready for AI agents?

Stainless has a Kin Score of 16.2 out of 100 (emerging) and an Agent Readiness score of 22.8 (agent-aware), scored by API Evangelist on 2026-10-31.

Work with this as data

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MCP server

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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.

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