Libraries & SDKs Overview

This page provides an overview of ActivityPub libraries available for different programming languages.

By Language

JavaScript/TypeScript

Library	Description	Status
Fedify	Modern TypeScript framework	Active
ActivityPub.js	General-purpose library	Maintenance
activitypub-express	Express.js middleware	Unmaintained

More JavaScript libraries →

Python

Library	Description	Status
bovine	ActivityPub library	Maintenance
little-boxes	ActivityPub toolkit	Maintenance
Federation	Protocol support	Active

More Python libraries →

Go

Library	Description	Status
go-fed/activity	Complete implementation	Active
go-ap	ActivityPub packages	Active
pub	WriteFreely's library	Maintenance

More Go libraries →

Rust

Library	Description	Status
activitypub-federation	Lemmy's library	Active
activitystreams	Types library	Active

More Rust libraries →

Ruby

Library	Description	Status
Mastodon source	Reference implementation	Active

More Ruby libraries →

PHP

Library	Description	Status
ActivityPub for WordPress	WordPress plugin	Active
Pixelfed source	Reference for PHP	Active

More PHP libraries →

Choosing a Library

For Quick Prototypes

• JavaScript: Fedify (well-documented, active)
• Python: bovine or little-boxes
• Go: go-ap, or go-fed/activity (complete but unmaintained since 2022)

For Production

• TypeScript: Fedify (modern, maintained)
• Rust: activitypub-federation (battle-tested)
• Go: go-fed/activity or GoToSocial's code

For Learning

• Study existing implementations:
  • GoToSocial (Go) - Clean, well-documented
  • Mastodon (Ruby) - Reference implementation
  • Lemmy (Rust) - Modern architecture

What Libraries Provide

Core Features

• JSON-LD context handling
• ActivityStreams type definitions
• Activity serialization/deserialization

Federation Features

• HTTP Signature signing/verification
• WebFinger client/server
• Inbox/Outbox handling
• Activity delivery

Optional Features

• Database integration
• Queue management
• Caching
• Rate limiting

Library Maturity Levels

Production Ready

• activitypub-federation (Rust)
• Fedify (TypeScript)

Stable

• bovine (Python)

Experimental

• Various new projects

Unmaintained

• activitypub-express (JavaScript) — no activity since early 2024
• go-fed/activity (Go) — no activity since 2022; feature-complete and still widely used

Building Without a Library

If no library fits your needs, you can implement from scratch:

1. Start simple: WebFinger + Actor endpoint
2. Add inbox: Receive activities
3. Add signing: HTTP Signatures
4. Add delivery: Send to other servers

See our implementation guides for step-by-step instructions.

Contributing to Libraries

Most libraries welcome contributions:

• Bug fixes and tests
• Documentation improvements
• Feature additions
• Compatibility fixes

Check each library's contribution guidelines.

See Also

• JavaScript Libraries - Detailed JS options
• Python Libraries - Python options
• Go Libraries - Go options
• Choosing Your Stack - Stack selection