AT Protocol

AT Protocol (Authenticated Transfer Protocol) is an open, federated social networking protocol developed by Bluesky Social PBC that powers the Bluesky social network and its 40M+ users. The protocol defines a public HTTP API surface via XRPC (cross-resolver protocol calls) organized under Lexicon schemas that cover identity (DIDs and handles), repository management, feed generation, labeling, and moderation. Developers can tap into a public firehose WebSocket event stream without API keys, and write operations use OAuth 2.0 or JWT bearer tokens for authentication. All data is stored in user-owned signed repositories and is 100% publicly accessible, making the protocol suitable for building social apps, feed generators, labelers, and bots.

AT Protocol publishes 8 APIs on the APIs.io network, including actor API, feed API, graph API, and 5 more. Tagged areas include Social Networking, Decentralized, Federated, Open Source, and Bluesky.

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

AT Protocol’s developer surface includes authentication, documentation, engineering blog, and 12 more developer resources.

🌐 Visit website 📡 Source on GitHub
52.2/100 developing ▬ flat Agent 31/100 agent aware Full breakdown ↓
scored 2026-07-28 · rubric v0.6
AccessFreeOpen⚡ Free to try
9 APIs
Social NetworkingDecentralizedFederatedOpen SourceBlueskyFediverseIdentityXRPCLexicon

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-07-28 · rubric v0.6
Composite quality — 52.2/100 · developing
Contract Quality 17.4 / 25
Developer Ergonomics 5.7 / 20
Commercial Clarity 7.9 / 20
Operational Transparency 6.8 / 13
Governance 7.0 / 12
Discoverability 7.4 / 10
Agent readiness — 31/100 · agent aware
Machine-Readable Contract 18 / 18
Agentic Access Contract 10 / 10
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
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/atproto: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 9

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

AT Protocol Firehose (Event Stream)

Public WebSocket event stream providing real-time access to all public activity on the AT Protocol network, including posts, likes, follows, and other repository events. No API ...

AT Protocol actor API

Actor (user) profile, search, and preference operations

AT Protocol feed API

Feed, post, timeline, and content operations

AT Protocol graph API

Graph operations — follows, blocks, lists, and mutes

AT Protocol identity API

DID and handle resolution, identity management

AT Protocol notification API

Notification management

AT Protocol repo API

Repository management, record CRUD operations

AT Protocol server API

Server management, session creation, account administration

AT Protocol sync API

Data synchronization, firehose, blob access

Scroll for all 9

Pricing Plans 1

Published pricing tiers and plan structures.

Atproto Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Atproto Rate Limits

17 limits

RATE LIMITS

FinOps 1

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

Atproto Finops

FINOPS

Semantic Vocabularies 1

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

Atproto Context

17 classes · 43 properties

JSON-LD

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

AT Protocol API Rules

5 rules · 3 warnings 2 info

SPECTRAL

JSON Schema 3

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

Bluesky Post (app.bsky.feed.post)

9 properties

JSON SCHEMA

Bluesky Profile View Detailed (app.bsky.actor.defs#profileViewDetailed)

14 properties

JSON SCHEMA

AT Protocol Session

10 properties

JSON SCHEMA

Examples 4

Example request and response payloads for these APIs.

Atproto Createrecord Example

4 fields

EXAMPLE

Atproto Createsession Example

4 fields

EXAMPLE

Atproto Getprofile Example

4 fields

EXAMPLE

Atproto Gettimeline Example

4 fields

EXAMPLE

Security Posture 2

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

Atproto Authentication

http · 1 scheme

SECURITY

Atproto Domain Security

TLSv1.3 · DMARC

SECURITY

Agentic Access 1

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

Atproto Agentic Access

37 operations · 11 acting

37 operations · 11 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 3

SDKs, sample code, and the tooling you integrate with

GitHubOrganization
GitHubOrganization
 SDKs
SDKs
 SDKs
SDKs

Access & Security 2

Authentication, authorization, and security posture

DomainSecurity
DomainSecurity
 Authentication
Authentication

Operate 2

Status, limits, changes, and where to get help

StatusPage
StatusPage
 RateLimits
RateLimits

Commercial 2

Pricing, plans, and the legal terms of use

Plans
Plans
 FinOps
FinOps

Company 3

The organization behind the API

Website
Website
 Blog
Blog
 LinkedIn
LinkedIn

Other 1

Properties that don't map to a standard resource type

X
X

Source (apis.yml)

apis.yml Raw ↑ 
aid: atproto
name: AT Protocol
description: AT Protocol (Authenticated Transfer Protocol) is an open, federated social networking protocol developed by Bluesky
  Social PBC that powers the Bluesky social network and its 40M+ users. The protocol defines a public HTTP API surface via
  XRPC (cross-resolver protocol calls) organized under Lexicon schemas that cover identity (DIDs and handles), repository
  management, feed generation, labeling, and moderation. Developers can tap into a public firehose WebSocket event stream
  without API keys, and write operations use OAuth 2.0 or JWT bearer tokens for authentication. All data is stored in user-owned
  signed repositories and is 100% publicly accessible, making the protocol suitable for building social apps, feed generators,
  labelers, and bots.
type: Index
accessModel:
  pricing: free
  onboarding: open
  trial: false
  try_now: true
  public: true
  label: Free · Open access
  confidence: high
  source:
  - plans
  - authentication
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/atproto.png
tags:
- Social Networking
- Decentralized
- Federated
- Open Source
- Bluesky
- Fediverse
- Identity
- XRPC
- Lexicon
url: https://raw.githubusercontent.com/api-evangelist/atproto/refs/heads/main/apis.yml
created: '2026-06-12'
modified: '2026-06-12'
specificationVersion: '0.19'
apis:
- aid: atproto:firehose
  name: AT Protocol Firehose (Event Stream)
  description: Public WebSocket event stream providing real-time access to all public activity on the AT Protocol network,
    including posts, likes, follows, and other repository events. No API key is required to subscribe. Useful for building
    feed generators, search engines, bots, and analytics tools.
  humanURL: https://atproto.com/specs/event-stream
  baseURL: wss://jetstream1.us-east.bsky.network/subscribe
  tags:
  - Firehose
  - WebSocket
  - Real-Time
  - Events
  - Streaming
  properties:
  - type: Documentation
    url: https://atproto.com/specs/event-stream
- aid: atproto:atproto-actor-api
  name: AT Protocol actor API
  description: Actor (user) profile, search, and preference operations
  humanURL: https://atproto.com/specs/xrpc
  baseURL: https://bsky.social/xrpc
  tags:
  - actor
  properties:
  - type: OpenAPI
    url: openapi/atproto-actor-api-openapi.yml
  - type: Documentation
    url: https://atproto.com/specs/xrpc
  - type: Documentation
    url: https://atproto.com/guides/overview
  - type: Documentation
    url: https://docs.bsky.app/docs/advanced-guides/atproto
  - type: Documentation
    url: https://endpoints.bsky.app/
- aid: atproto:atproto-feed-api
  name: AT Protocol feed API
  description: Feed, post, timeline, and content operations
  humanURL: https://atproto.com/specs/xrpc
  baseURL: https://bsky.social/xrpc
  tags:
  - feed
  properties:
  - type: OpenAPI
    url: openapi/atproto-feed-api-openapi.yml
  - type: Documentation
    url: https://atproto.com/specs/xrpc
  - type: Documentation
    url: https://atproto.com/guides/overview
  - type: Documentation
    url: https://docs.bsky.app/docs/advanced-guides/atproto
  - type: Documentation
    url: https://endpoints.bsky.app/
- aid: atproto:atproto-graph-api
  name: AT Protocol graph API
  description: Graph operations — follows, blocks, lists, and mutes
  humanURL: https://atproto.com/specs/xrpc
  baseURL: https://bsky.social/xrpc
  tags:
  - graph
  properties:
  - type: OpenAPI
    url: openapi/atproto-graph-api-openapi.yml
  - type: Documentation
    url: https://atproto.com/specs/xrpc
  - type: Documentation
    url: https://atproto.com/guides/overview
  - type: Documentation
    url: https://docs.bsky.app/docs/advanced-guides/atproto
  - type: Documentation
    url: https://endpoints.bsky.app/
- aid: atproto:atproto-identity-api
  name: AT Protocol identity API
  description: DID and handle resolution, identity management
  humanURL: https://atproto.com/specs/xrpc
  baseURL: https://bsky.social/xrpc
  tags:
  - identity
  properties:
  - type: OpenAPI
    url: openapi/atproto-identity-api-openapi.yml
  - type: Documentation
    url: https://atproto.com/specs/xrpc
  - type: Documentation
    url: https://atproto.com/guides/overview
  - type: Documentation
    url: https://docs.bsky.app/docs/advanced-guides/atproto
  - type: Documentation
    url: https://endpoints.bsky.app/
- aid: atproto:atproto-notification-api
  name: AT Protocol notification API
  description: Notification management
  humanURL: https://atproto.com/specs/xrpc
  baseURL: https://bsky.social/xrpc
  tags:
  - notification
  properties:
  - type: OpenAPI
    url: openapi/atproto-notification-api-openapi.yml
  - type: Documentation
    url: https://atproto.com/specs/xrpc
  - type: Documentation
    url: https://atproto.com/guides/overview
  - type: Documentation
    url: https://docs.bsky.app/docs/advanced-guides/atproto
  - type: Documentation
    url: https://endpoints.bsky.app/
- aid: atproto:atproto-repo-api
  name: AT Protocol repo API
  description: Repository management, record CRUD operations
  humanURL: https://atproto.com/specs/xrpc
  baseURL: https://bsky.social/xrpc
  tags:
  - repo
  properties:
  - type: OpenAPI
    url: openapi/atproto-repo-api-openapi.yml
  - type: Documentation
    url: https://atproto.com/specs/xrpc
  - type: Documentation
    url: https://atproto.com/guides/overview
  - type: Documentation
    url: https://docs.bsky.app/docs/advanced-guides/atproto
  - type: Documentation
    url: https://endpoints.bsky.app/
- aid: atproto:atproto-server-api
  name: AT Protocol server API
  description: Server management, session creation, account administration
  humanURL: https://atproto.com/specs/xrpc
  baseURL: https://bsky.social/xrpc
  tags:
  - server
  properties:
  - type: OpenAPI
    url: openapi/atproto-server-api-openapi.yml
  - type: Documentation
    url: https://atproto.com/specs/xrpc
  - type: Documentation
    url: https://atproto.com/guides/overview
  - type: Documentation
    url: https://docs.bsky.app/docs/advanced-guides/atproto
  - type: Documentation
    url: https://endpoints.bsky.app/
- aid: atproto:atproto-sync-api
  name: AT Protocol sync API
  description: Data synchronization, firehose, blob access
  humanURL: https://atproto.com/specs/xrpc
  baseURL: https://bsky.social/xrpc
  tags:
  - sync
  properties:
  - type: OpenAPI
    url: openapi/atproto-sync-api-openapi.yml
  - type: Documentation
    url: https://atproto.com/specs/xrpc
  - type: Documentation
    url: https://atproto.com/guides/overview
  - type: Documentation
    url: https://docs.bsky.app/docs/advanced-guides/atproto
  - type: Documentation
    url: https://endpoints.bsky.app/
common:
- type: AgenticAccess
  url: agentic-access/atproto-agentic-access.yml
- type: DomainSecurity
  url: security/atproto-domain-security.yml
- type: Authentication
  url: authentication/atproto-authentication.yml
- type: Website
  url: https://atproto.com/
- type: Documentation
  url: https://atproto.com/guides/overview
- type: Blog
  url: https://atproto.com/blog
- type: GitHubOrganization
  url: https://github.com/bluesky-social
- type: LinkedIn
  url: https://www.linkedin.com/company/bluesky-pbc
- type: X
  url: https://twitter.com/at_protocol
- type: StatusPage
  url: https://status.bsky.app/
- type: SDKs
  url: https://github.com/bluesky-social/atproto/tree/main/packages
- type: SDKs
  url: https://github.com/bluesky-social/indigo
- type: Plans
  url: plans/atproto-plans-pricing.yml
- type: RateLimits
  url: rate-limits/atproto-rate-limits.yml
- type: FinOps
  url: finops/atproto-finops.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com