Steel

Steel is the open-source browser API for AI agents and apps. The Steel Cloud REST API (https://api.steel.dev/v1) launches and manages cloud browser sessions, runs stateless quick actions (scrape, screenshot, pdf, search), and exposes a live session viewer, while long-running automation connects to a per-session Chrome DevTools Protocol (CDP) WebSocket driven with Playwright, Puppeteer, or Selenium. The same surface ships self-hosted under Apache-2.0 as steel-browser.

Steel publishes 4 API contracts indexed on the APIs.io network, including Files API, Quick Actions API, Session Actions API, and 1 more. Tagged areas include Browser, Browser Automation, Web Scraping, AI Agents, and Open Source.

The Steel catalog on APIs.io includes 1 Spectral governance ruleset.

Steel’s developer surface includes engineering blog, authentication, documentation, and 8 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

26.5/100 thin ▬ flat Agent 19/100 agent aware Front door AI 6/6 dominant Heartbeat 82/100 alive saas Full breakdown ↓
scored 2026-11-13 · rubric v0.28.0 · Show this score on your site →

AccessFreemiumSelf serve⚡ Free to try

1 published contract

Browser Browser Automation Web Scraping AI Agents Open Source

Kin Score

Kin Score How this is scored →
scored 2026-11-13 · rubric v0.28.0

Composite quality — 26.5/100 · thin

Contract Quality 8.3 / 19

Developer Ergonomics 4.8 / 15

Access Clarity 1.0 / 15

Operational Transparency 1.2 / 10

Contract Governance 1.2 / 9

Discoverability 5.0 / 8

Regulatory Posture 0.9 / 15

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 19/100 · 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

Pagination 0 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

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/.

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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 Ask about this →
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) Ask about this →
Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes Ask about this →
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0 Ask about this →
Request/Response Examples +7 pts — share of operations carrying request/response examples; else an Examples / Code Samples link Ask about this →
Registration Without a Human +6 pts — a `registration_endpoint` in the served RFC 8414 / OIDC discovery document Ask about this →

10 more unmet checks in the Agent Readiness table above.

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

Access Clarity scores 6.4 — up to +18.7 composite points Ask about this →
Contract Quality scores 44.5 — up to +13.9 composite points Ask about this →
Developer Ergonomics scores 32.1 — up to +13.6 composite points Ask about this →

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.

Not sure how this applies to your stack? Ask about any one item. Kin Lane reads every question, looks at your profile and your situation, and replies with what a fix would take — scoped to that one area, priced up front, yours whether you ship it or not. Ask a question →

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/steel-dev/apis.yml: open an issue on github.com/api-evangelist/steel-dev 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 →

Markets this provider is in provisional

The Kin Score Market layer reads a provider inside its market: its position, and how deep its integrations go. Depth is only comparable within a position. Provisional and unweighted: not part of the Kin Score or agent readiness.

Market	Position	Depth	Registered MCP server	Declares compatibility
Agent Skills (SKILL.md packages)	builds-on	17.2 (thin)	-	1
Stripe App Marketplace and Partner Ecosystem (builders on Stripe)	builds-on	17.2 (thin)	-	1

Registered MCP server and declares compatibility are report only — not weighted. Undeclared means we found nothing we can read, so there is no number: we never infer integrations.

Standards implemented 1

Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.

OpenAPI

measured — observed by APIs.io (published)

APIs 4

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

Steel Files API

Manage files inside a session's browser context.

Steel Quick Actions API

Stateless one-off scrape, screenshot, PDF, and search.

Steel Session Actions API

Scrape, screenshot, and PDF the page in a running session.

Steel Sessions API

Launch, inspect, and release cloud browser sessions.

Open Collections 5

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

Steel Files API

OPEN COLLECTION

Steel Files Quick Actions API

OPEN COLLECTION

Steel Files Session Actions API

OPEN COLLECTION

Steel Files Sessions API

OPEN COLLECTION

Steel API

OPEN COLLECTION

Steel API pricing

Not yet checked against Steel's own pricing page. Compiled by API Evangelist on 2026-06-20 from steel.dev/pricing; confirm before you rely on a figure. A free plan or tier is listed.

Plan	Price
Hobby free	—
Starter paid	—
Developers paid	—
Startups paid	—
Enterprise enterprise	—
Self-Hosted (Open Source) free	—

Plan details, limits and sources →

Rate limits

Concurrent Sessions: see provider documentation sessions
Browser Hours: see plan allotment browser hours
Proxy Bandwidth: see plan allotment gigabytes

Compiled by API Evangelist, not yet checked against Steel's documentation. All 5 limits →

Pricing Plans 1

Published pricing tiers and plan structures.

Steel Plans Pricing

6 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Steel Rate Limits

5 limits

RATE LIMITS

FinOps 1

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

Steel Finops

FINOPS

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs. Counts are the severity each rule declares, not results of running them.

Steel API Rules

54 rules · 51 error-severity 1 warn-severity 2 info-severity

SPECTRAL

Security Posture 2

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

Steel Authentication

apiKey · 1 scheme

SECURITY

Steel Domain Security

TLSv1.3 · HSTS

SECURITY

Agentic Access (API Evangelist recommendations) 1

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

Steel Agentic Access

17 operations · 10 acting

AGENTIC

Resources

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 2

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Authentication

Authentication

Operate 1

Status, limits, changes, and where to get help

RateLimits

RateLimits

Commercial 2

Pricing, plans, and the legal terms of use

Plans

Plans

FinOps

FinOps

Company 3

The organization behind the API

Blog

Blog

LinkedIn

Website

Website

Source (apis.yml)

aid: steel-dev
url: https://raw.githubusercontent.com/api-evangelist/steel-dev/refs/heads/main/apis.yml
name: Steel
kind: company
description: Steel is the open-source browser API for AI agents and apps. The Steel Cloud REST API (https://api.steel.dev/v1)
  launches and manages cloud browser sessions, runs stateless quick actions (scrape, screenshot, pdf, search), and exposes
  a live session viewer, while long-running automation connects to a per-session Chrome DevTools Protocol (CDP) WebSocket
  driven with Playwright, Puppeteer, or Selenium. The same surface ships self-hosted under Apache-2.0 as steel-browser.
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
  gated: none
  gated_source:
  - onboarding
  label: Freemium · Self-serve signup
  confidence: medium
  source:
  - plans
  - authentication
  - security
  generated: '2026-11-13'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/steel-dev.png
tags:
- Browser
- Browser Automation
- Web Scraping
- AI Agents
- Open Source
tags_raw:
- Browser
- Web Automation
- Scraping
- AI Agents
- Open Source
- Open-Source
- Browser Automation
created: '2026-06-20'
modified: '2026-10-06'
specificationVersion: '0.23'
apis:
- aid: steel-dev:steel-dev-files-api
  name: Steel Files API
  description: Manage files inside a session's browser context.
  humanURL: https://docs.steel.dev/overview/sessions-api
  baseURL: https://api.steel.dev/v1
  tags:
  - File
  tags_raw:
  - Files
  properties:
  - type: OpenAPI
    url: openapi/steel-dev-files-api-openapi.yml
  - type: Documentation
    url: https://docs.steel.dev/overview/sessions-api
  - type: APIReference
    url: https://docs.steel.dev/api-reference
  - type: PostmanCollection
    url: collections/steel-dev.postman_collection.json
  - type: OpenCollection
    url: collections/steel-dev.opencollection.json
  - type: Documentation
    url: https://docs.steel.dev/overview/quick-actions-api
  - type: Documentation
    url: https://docs.steel.dev/overview/guides/connect-with-playwright
  - type: Review
    url: review.yml
- aid: steel-dev:steel-dev-quick-actions-api
  name: Steel Quick Actions API
  description: Stateless one-off scrape, screenshot, PDF, and search.
  humanURL: https://docs.steel.dev/overview/sessions-api
  baseURL: https://api.steel.dev/v1
  tags:
  - Quick Actions
  properties:
  - type: OpenAPI
    url: openapi/steel-dev-quick-actions-api-openapi.yml
  - type: Documentation
    url: https://docs.steel.dev/overview/sessions-api
  - type: APIReference
    url: https://docs.steel.dev/api-reference
  - type: PostmanCollection
    url: collections/steel-dev.postman_collection.json
  - type: OpenCollection
    url: collections/steel-dev.opencollection.json
  - type: Documentation
    url: https://docs.steel.dev/overview/quick-actions-api
  - type: Documentation
    url: https://docs.steel.dev/overview/guides/connect-with-playwright
  - type: Review
    url: review.yml
- aid: steel-dev:steel-dev-session-actions-api
  name: Steel Session Actions API
  description: Scrape, screenshot, and PDF the page in a running session.
  humanURL: https://docs.steel.dev/overview/sessions-api
  baseURL: https://api.steel.dev/v1
  tags:
  - Session Actions
  properties:
  - type: OpenAPI
    url: openapi/steel-dev-session-actions-api-openapi.yml
  - type: Documentation
    url: https://docs.steel.dev/overview/sessions-api
  - type: APIReference
    url: https://docs.steel.dev/api-reference
  - type: PostmanCollection
    url: collections/steel-dev.postman_collection.json
  - type: OpenCollection
    url: collections/steel-dev.opencollection.json
  - type: Documentation
    url: https://docs.steel.dev/overview/quick-actions-api
  - type: Documentation
    url: https://docs.steel.dev/overview/guides/connect-with-playwright
  - type: Review
    url: review.yml
- aid: steel-dev:steel-dev-sessions-api
  name: Steel Sessions API
  description: Launch, inspect, and release cloud browser sessions.
  humanURL: https://docs.steel.dev/overview/sessions-api
  baseURL: https://api.steel.dev/v1
  tags:
  - Sessions
  properties:
  - type: OpenAPI
    url: openapi/steel-dev-sessions-api-openapi.yml
  - type: Documentation
    url: https://docs.steel.dev/overview/sessions-api
  - type: APIReference
    url: https://docs.steel.dev/api-reference
  - type: PostmanCollection
    url: collections/steel-dev.postman_collection.json
  - type: OpenCollection
    url: collections/steel-dev.opencollection.json
  - type: Documentation
    url: https://docs.steel.dev/overview/quick-actions-api
  - type: Documentation
    url: https://docs.steel.dev/overview/guides/connect-with-playwright
  - type: Review
    url: review.yml
common:
- url: https://steel.dev/blog
  type: Blog
- type: AgenticAccess
  url: agentic-access/steel-dev-agentic-access.yml
- type: DomainSecurity
  url: security/steel-dev-domain-security.yml
- type: Authentication
  url: authentication/steel-dev-authentication.yml
- type: GitHubOrganization
  url: https://github.com/steel-dev
- type: LinkedIn
  url: https://www.linkedin.com/company/steel-dev
- type: Website
  url: https://steel.dev
- type: Documentation
  url: https://docs.steel.dev
- type: Plans
  url: plans/steel-dev-plans-pricing.yml
- type: RateLimits
  url: rate-limits/steel-dev-rate-limits.yml
- type: FinOps
  url: finops/steel-dev-finops.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

Steel API — frequently asked questions

Does Steel have an API?

Yes. APIs.io lists 4 APIs from Steel, including Steel Files API, Steel Quick Actions API and Steel Session Actions API, and 1 more.

Is there an OpenAPI specification for the Steel API?

Yes. APIs.io indexes 4 OpenAPI specifications for Steel, each linked for download from this page.

How do I authenticate with the Steel API?

Steel uses bearer-token authentication (apiKey · 1 scheme). The details are profiled on APIs.io as Steel Authentication.

How much does the Steel API cost?

APIs.io lists 6 pricing plans for Steel, with each plan's price, limits and inclusions under Pricing on this page.

Is the Steel API ready for AI agents?

Steel has a Kin Score of 26.5 out of 100 (thin) and an Agent Readiness score of 19.0 (agent-aware), scored by API Evangelist on 2026-11-13.

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