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.
Real signal across most facets with visible, nameable gaps — the contract exists but is thin, or the portal is good while governance and commercial terms are absent.
API Evangelist profiles AT Protocol the way a machine reads it — 39 machine-readable artifacts across 2 APIs, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.
Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — AT Protocol scores 47.5/100 (developing), with a separate agent-readiness read of 24/100 (agent aware). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.
Kin Score
This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance. Every facet and dimension name is a link: it opens that measurement's page on APIs.io, where the rating runs across the whole catalog — the exact checks that feed it, how every profiled provider distributes on it, and who is at the top of it.
Kin Score
How this is scored →scored 2026-09-10 · rubric v0.20.0
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How we profile AT Protocol
Each block below is one kind of artifact we hold for AT Protocol. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.
APIs 15
Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.
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
AT Protocol XRPC API
XRPC is the AT Protocol's HTTP-based remote procedure call layer. All protocol interactions — querying records, writing records, subscribing to streams, resolving identity, mode...
AT Protocol Lexicon Schemas
Lexicon is the schema definition language for AT Protocol. Every record type, XRPC method, and event subscription on the network is described by a Lexicon document, which acts a...
Personal Data Server (PDS) API
The PDS hosts a user's repository of signed records and exposes the com.atproto.* XRPC methods for account creation, authentication, record CRUD, blob upload, and repository syn...
AT Protocol Relay & Firehose
The Relay aggregates the com.atproto.sync.subscribeRepos firehose across PDS hosts and re-broadcasts the combined event stream over WebSocket. AppViews and indexers subscribe to...
Bluesky AppView API
The Bluesky AppView indexes the firehose and exposes the app.bsky.* XRPC methods that the Bluesky client (and any compatible client) uses to render timelines, threads, profiles,...
AT Protocol Identity (DID & Handles)
Identity in AT Protocol is anchored in DIDs (did:plc or did:web), with human-readable handles resolved through DNS TXT records or well-known HTTP endpoints. The protocol specifi...
Scroll within the panel for all 15 ·
Open Collections 9
Open, tool-agnostic collections carry the same runnable value as Postman without locking you to one client — the portable, forkable form of the same exercise.
Open, tool-agnostic API collections (OpenAPI-derived and Bruno).
API Collection
OPEN COLLECTIONBluesky Application API (app.bsky) actor API
OPEN COLLECTIONBluesky Application API (app.bsky) actor feed API
OPEN COLLECTIONBluesky Application API (app.bsky) actor graph API
OPEN COLLECTIONBluesky Application API (app.bsky) actor identity API
OPEN COLLECTIONBluesky Application API (app.bsky) actor notification API
OPEN COLLECTIONBluesky Application API (app.bsky) actor repo API
OPEN COLLECTIONBluesky Application API (app.bsky) actor server API
OPEN COLLECTIONBluesky Application API (app.bsky) actor sync API
OPEN COLLECTIONScroll within the panel for all 9 ·
Pricing Plans 1
Pricing is part of the interface. Machine-readable plans tell you what a tier costs and includes before you commit — one of the things the Kin Score reads for access clarity — renamed from commercial clarity in rubric 0.12, because a free statutory interface has access terms and no commercial ones.
Published pricing tiers and plan structures.
Rate Limits 1
Rate limits are the difference between a demo that works and a production integration that doesn't fall over. Publishing them is an operational-transparency signal — and a hard requirement for any agent that plans its own throughput.
Documented rate limits and quota policies.
Atproto Rate Limits
RATE LIMITSFinOps 1
Cost, billing, and metering signals let a buyer model the financial operations of an API before it's live. We profile them for the same reason we profile pricing: the money is part of the contract.
Cost, billing, and metering signals for API financial operations.
Atproto Finops
FINOPSSemantic Vocabularies 1
JSON-LD contexts give the data shared meaning across APIs. We profile them because semantics are what let a machine reconcile 'customer' here with 'customer' somewhere else.
JSON-LD contexts and semantic vocabularies used across these APIs.
Atproto Context
JSON-LDSpectral Rules 1
Governance rulesets we run against this provider's specs — the automated checks behind parts of the score. Profiling them makes the quality bar explicit and re-runnable, not a matter of opinion.
AT Protocol API Rules
SPECTRALJSON Schema 3
Standalone JSON Schema definitions describe the data models behind the API. We profile them so the shapes are validatable on their own — useful long after a single request is forgotten.
Standalone JSON Schema definitions for this provider's data models.
Bluesky Post (app.bsky.feed.post)
JSON SCHEMAAT Protocol Session
JSON SCHEMAExamples 4
Real request and response payloads are what turn a spec from abstract into obvious — and they're one of the twelve things an agent needs to call an API correctly on the first try.
Example request and response payloads for these APIs.
Atproto Createrecord Example
EXAMPLEAtproto Getprofile Example
EXAMPLEAtproto Gettimeline Example
EXAMPLESecurity Posture 2
Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Agentic Access 1
An x-agentic-access contract marks which operations are safe for an agent to run on its own and which need a human in the loop. It is the difference between an API an agent can use and one it can use safely.
Recommended x-agentic-access execution contracts for AI agents.
Resources
Every other property we hold for AT Protocol — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.
Documentation 1
Reference material describing how the API behaves
Agent Surfaces 1
MCP servers, agent skills, and machine-readable catalogs
Build 3
SDKs, sample code, and the tooling you integrate with
Access & Security 2
Authentication, authorization, and security posture
Operate 2
Status, limits, changes, and where to get help
Commercial 2
Pricing, plans, and the legal terms of use
Company 3
The organization behind the API
Other 1
Properties that don't map to a standard resource type
← All providers · Data indexed from github.com/api-evangelist/atproto · machine-readable index on apis.io
This is an independent, third-party profile of AT Protocol, published by API Evangelist. We do not operate, host, resell, or support these APIs, and we are not affiliated with or endorsed by the company unless stated above. Everything here is built from publicly available information — the company's own site, developer portal, documentation, public repositories, and the specifications it publishes for public use. Nothing is obtained by breaching a system, defeating an access control, or using credentials.
The Kin Score and Agent Readiness rating are independently calculated assessments of a company's public API artifacts, scored against a published rubric. They are not certifications, endorsements, security assessments, or audits.
Corrections, re-scores, and removal are free — no partnership or purchase required, and you do not need to justify the request. A removed company is recorded as unrated, never scored zero for having asked. Acknowledgement within one business day; removal within two.
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