AT Protocol
The facts below are what the maker publishes about AT Protocol, checked and dated. Our editors have not written about it yet.
The facts
Each one read from AT Protocol's own pages, with the date it was checked.
Where it runs
- App passwords
- Accounts can create and revoke app passwords separately from their primary password.checked 7 Oct 2026
What it does
- Authentication
- Applications can use OAuth, while single-purpose apps such as bots or command-line tools may use password authentication.checked 7 Oct 2026
- Authorization
- OAuth is the primary mechanism for clients to make authorized requests to PDS instances, including mobile, browser, desktop, and web service clients.checked 7 Oct 2026
- Cryptography
- AT Protocol uses public key cryptography to authenticate public data; protocol-level data encryption is not used, though many components use TLS.checked 7 Oct 2026
- Data model
- Users publish JSON records into repositories, and changes to those records sync across the network to drive applications.checked 7 Oct 2026
- Developer support
- The official site links to tutorials, SDKs, a cookbook, deployment guidance, and community discussions on GitHub.checked 7 Oct 2026
- Developer use
- Developers can build feeds, bots, search engines, and applications using the public firehose, with no API key required.checked 7 Oct 2026
- Hosting limits
- Operating a relay is bandwidth intensive, while hosting an AppView is resource intensive.checked 7 Oct 2026
- Identity
- Usernames can be domains, and account portability is supported through signed data repositories and DIDs.checked 7 Oct 2026
- Intended users
- The protocol is aimed at developers building social applications, agents, custom feeds, and other services using shared network data.checked 7 Oct 2026
- Limited permissions
- OAuth lets developers request limited account access without requiring users to share their passwords.checked 7 Oct 2026
- Media
- Blobs include images, video, audio, or other files, and are stored separately from records.checked 7 Oct 2026
- Moderation
- Moderation uses labels, with Osprey for event-stream decisions and analysis and Ozone for labeling and moderation decisions.checked 7 Oct 2026
- OAuth safeguards
- The protocol's OAuth profile requires PKCE and DPoP, and does not use a client secret shared between servers and clients.checked 7 Oct 2026
- Public activity stream
- The public firehose provides a live stream of public activity for feeds, bots, search engines, and applications, with no API key required.checked 7 Oct 2026
- Purpose
- AT Protocol is an open social protocol for building high-scale social applications that are interoperable by default.checked 7 Oct 2026
- Schemas
- Lexicon schemas let separate teams define shared data and RPC formats for strongly typed APIs.checked 7 Oct 2026
- Schemas and APIs
- Lexicons describe schemas for data and RPC calls, and provide runtime correctness checks.checked 7 Oct 2026
- SDKs
- Bluesky Social PBC's reference SDKs are TypeScript and Go, and the TypeScript SDK works on Web, NodeJS, and React Native.checked 7 Oct 2026
- Self-hosting
- Operators can self-host components including a PDS, Relay, Tap, AppView, and Ozone; Relay hosting is bandwidth intensive and AppView hosting is resource intensive.checked 7 Oct 2026
- User identity
- User handles are DNS records, and user DIDs are permanent identifiers.checked 7 Oct 2026
The company
- Maker
- The site identifies Bluesky Social PBC as the copyright holder.checked 7 Oct 2026
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