ActivityPub

aid: activitypub
url: https://raw.githubusercontent.com/api-evangelist/activitypub/refs/heads/main/apis.yml
apis:
- aid: activitypub:activitypub-actors-api
  name: ActivityPub Actors API
  tags:
  - Actors
  - Profiles
  - Social Networks
  properties:
  - url: https://www.w3.org/TR/activitypub/#actors
    type: Documentation
  - url: https://www.w3.org/TR/activitypub/#actor-objects
    type: APIReference
  description: Actors are the primary objects in ActivityPub that represent entities capable of performing activities. Each
    actor has a unique IRI and exposes properties such as inbox, outbox, followers, following, and liked collections. Actor
    objects are retrieved via HTTP GET and served as JSON-LD using the ActivityStreams 2.0 vocabulary.
- aid: activitypub:activitypub-inbox-api
  name: ActivityPub Inbox API
  tags:
  - Inbox
  - Messages
  - Delivery
  - Social Networks
  properties:
  - url: https://www.w3.org/TR/activitypub/#inbox
    type: Documentation
  - url: https://www.w3.org/TR/activitypub/#server-to-server-interactions
    type: APIReference
  description: The inbox is an OrderedCollection endpoint on each actor that receives activities delivered by remote servers.
    Servers POST activities to an actor's inbox to federate content. The inbox also supports GET for authorized clients to
    retrieve received activities. ActivityPub uses HTTP Signatures for server-to-server authentication when delivering to
    inboxes.
- aid: activitypub:activitypub-outbox-api
  name: ActivityPub Outbox API
  tags:
  - Outbox
  - Publishing
  - Activities
  - Social Networks
  properties:
  - url: https://www.w3.org/TR/activitypub/#outbox
    type: Documentation
  - url: https://www.w3.org/TR/activitypub/#client-to-server-interactions
    type: APIReference
  description: The outbox is an OrderedCollection endpoint that stores activities published by an actor. Clients POST activities
    to an actor's outbox to create, update, delete, follow, like, and perform other social interactions. The server then federates
    these activities to the appropriate recipients. The outbox also supports GET for reading published activities.
- aid: activitypub:activitypub-followers-following-api
  name: ActivityPub Followers and Following API
  tags:
  - Followers
  - Following
  - Social Graph
  - Social Networks
  properties:
  - url: https://www.w3.org/TR/activitypub/#followers
    type: Documentation
  - url: https://www.w3.org/TR/activitypub/#following
    type: APIReference
  description: Actors expose followers and following as OrderedCollection or Collection endpoints. These endpoints enumerate
    the social graph connections for an actor. The Follow activity posted to the outbox initiates a follow relationship; the
    target actor can accept or reject via Accept or Reject activities. These collections are pageable via OrderedCollectionPage.
- aid: activitypub:activitypub-liked-api
  name: ActivityPub Liked Collection API
  tags:
  - Liked
  - Reactions
  - Activities
  - Social Networks
  properties:
  - url: https://www.w3.org/TR/activitypub/#liked
    type: Documentation
  description: The liked collection is an optional OrderedCollection endpoint on an actor listing all objects the actor has
    liked. Posting a Like activity to the actor's outbox adds the referenced object to this collection. It is publicly readable
    and supports pagination through the standard ActivityStreams 2.0 collection paging mechanism.
- aid: activitypub:activitypub-object-delivery-api
  name: ActivityPub Object and Activity Delivery API
  tags:
  - Activities
  - Objects
  - Delivery
  - Federation
  - Social Networks
  properties:
  - url: https://www.w3.org/TR/activitypub/#delivery
    type: Documentation
  - url: https://www.w3.org/TR/activitypub/#activity-types
    type: APIReference
  description: ActivityPub defines a server-to-server federation protocol for delivering activities between instances. Servers
    dereference actor inboxes from WebFinger or direct URLs, then HTTP POST signed Activity objects (Create, Update, Delete,
    Announce, Follow, Accept, Reject, Undo, Block, etc.) using JSON-LD with the ActivityStreams context. Delivery handles
    addressing via to, cc, bcc, and audience fields.
- aid: activitypub:activitypub-webfinger-api
  name: ActivityPub WebFinger Discovery API
  tags:
  - WebFinger
  - Discovery
  - Identity
  - Social Networks
  properties:
  - url: https://www.w3.org/TR/activitypub/#security-considerations
    type: Documentation
  - url: https://webfinger.net/
    type: APIReference
  - url: https://www.rfc-editor.org/rfc/rfc7033
    type: Documentation
  description: ActivityPub implementations commonly use WebFinger (RFC 7033) for actor discovery. A GET request to /.well-known/webfinger?resource=acct:user@example.com
    returns a JSON Resource Descriptor (JRD) linking to the actor's canonical ActivityPub profile URL. WebFinger enables cross-instance
    lookup of actors using familiar user@domain addressing across the Fediverse.
- aid: activitypub:activitypub-nodeinfo-api
  name: ActivityPub NodeInfo API
  tags:
  - NodeInfo
  - Discovery
  - Server Metadata
  - Social Networks
  properties:
  - url: https://nodeinfo.diaspora.software/
    type: Documentation
  - url: https://www.w3.org/TR/activitypub/#actor-objects
    type: APIReference
  description: NodeInfo is a complementary protocol used by ActivityPub servers to expose server capability metadata at /.well-known/nodeinfo.
    It describes the software name, version, supported protocols, usage statistics, and open registration status, enabling
    clients and crawlers to understand server capabilities without inspecting individual actors.
name: ActivityPub
tags:
- Open Standard
- Social Networks
- Federation
- Fediverse
- W3C
type: Index
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
access: 3rd-Party
created: '2026-06-13'
modified: '2026-06-13'
position: Consumer
description: ActivityPub is a W3C Recommendation that defines a decentralized social networking protocol and REST API standard
  for federated social interactions. It provides both a client-to-server API for creating and managing social content and
  a server-to-server federation protocol for distributing activities across instances. Built on ActivityStreams 2.0 and JSON-LD,
  it powers the Fediverse — including Mastodon, Pixelfed, PeerTube, and hundreds of other platforms — enabling interoperable
  social networking across independently operated servers.
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
specificationVersion: '0.19'
common:
- type: Website
  url: https://activitypub.rocks/
- type: Documentation
  url: https://www.w3.org/TR/activitypub/
- type: Specification
  url: https://www.w3.org/TR/activitypub/
- type: GettingStarted
  url: https://activitypub.rocks/
- type: Authentication
  url: https://www.w3.org/TR/activitypub/#authorization
- type: Security
  url: https://www.w3.org/TR/activitypub/#security-considerations
- type: UseCases
  url: https://www.w3.org/TR/activitypub/#overview
- type: GitHubOrganization
  url: https://github.com/w3c/activitypub
- type: GitHubRepository
  url: https://github.com/w3c/activitypub
- type: Forums
  url: https://socialhub.activitypub.rocks/
- type: ChangeLog
  url: https://www.w3.org/TR/activitypub/#change-log
- type: Vocabulary
  url: https://www.w3.org/TR/activitystreams-vocabulary/
- type: JSONSchema
  url: https://www.w3.org/TR/activitystreams-core/
- type: RateLimits
  url: rate-limits/activitypub-rate-limits.yml
- type: Plans
  url: plans/activitypub-plans.yml
- type: FinOps
  url: finops/activitypub-finops.yml