Farcaster

Farcaster is a decentralised social protocol built on Snapchain, an append-only state machine that stores casts, reactions, follows, and user profile data. The protocol publishes a Hub / Snapchain reference implementation, the Mini Apps SDK (formerly Frames) for distributing interactive apps inside Farcaster feeds, Sign In with Farcaster (SIWF) for authentication, and AuthKit for React-based sign-in. The Warpcast client (now rebranded Farcaster app at farcaster.xyz) is the primary consumer surface. Indexer providers such as Neynar host scaled Hub APIs and value-added read / write / webhook APIs at api.neynar.com.

Farcaster publishes 15 API contracts indexed on the APIs.io network, including Casts API, Events API, Info API, and 12 more. Tagged areas include Farcaster, Social, Decentralized, Protocol, and Mini Apps.

The Farcaster catalog on APIs.io includes 1 Spectral governance ruleset.

Farcaster’s developer surface includes engineering blog, documentation, GitHub presence, and 9 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

24.5/100 emerging ▬ flat Agent 18/100 agent aware Front door AI 1/6 silent Heartbeat 89/100 alive Full breakdown ↓
scored 2026-11-02 · rubric v0.26.0 · Show this score on your site →

AccessFree

1 published contract

Farcaster Social Decentralized Protocol Mini Apps Frames Authentication Web3 SDK

Kin Score

Kin Score How this is scored →
scored 2026-11-02 · rubric v0.26.0

Composite quality — 24.5/100 · emerging

Contract Quality 9.5 / 19

Developer Ergonomics 2.9 / 15

Access Clarity 0.8 / 15

Operational Transparency 1.0 / 10

Contract Governance 1.2 / 9

Discoverability 4.6 / 8

Regulatory Posture 0.9 / 15

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 18/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 0 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 7 / 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

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Pagination 5 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

Regulatory Posture applies to this provider. Its tags matched the Horizontal (data, software, accessibility, platform) regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

Create-or-Update Ergonomics applies to this provider. This API accepts writes, so it carries 10 points of the composite. It is scored from the published contracts themselves: whether a caller can create-or-update in one call, whether the write accepts a key the caller already holds, and whether the response says which branch ran. Without that, every write needs a search-and-branch in front of it, and the first time that check is skipped a duplicate record is created. Scored against the observed mean rather than raw — a provider at the catalog average is unchanged by this facet, not penalised by it.

The six quality facets above are damped to 75 points between them, because the conditional facet above carries the other 25. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 75% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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Agent readiness — checks not met, largest first (exact, from this profile):

MCP Server +12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship
Machine-Readable Auth +10 pts — a served openid-configuration/oauth-authorization-server carrying `issuer` (served), else the securitySchemes class in the provider OpenAPIs — bound (mutualTLS, DPoP, Signature) > negotiable (oauth2 authorizationCode/clientCredentials, openIdConnect) > bearer (http bearer, apiKey)
Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented)
Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Registration Without a Human +6 pts — a `registration_endpoint` in the served RFC 8414 / OIDC discovery document

9 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Access Clarity scores 5.3 — up to +18.9 composite points
Developer Ergonomics scores 19.0 — up to +16.2 composite points
Contract Quality scores 50.7 — up to +12.3 composite points

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from the provider profile at artifacts.apis.io/farcaster/apis.yml: open an issue on github.com/api-evangelist/farcaster to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Markets this provider is in provisional

The Kin Score Market layer reads a provider inside its market: its position, and how deep its integrations go. Depth is only comparable within a position. Provisional and unweighted: not part of the Kin Score or agent readiness.

Market	Position	Depth	Registered MCP server	Declares compatibility
Raycast Store Extensions (first-party publishers + community-wrapped products)	covered	26.8 (thin)	-	-

Registered MCP server and declares compatibility are report only — not weighted. Undeclared means we found nothing we can read, so there is no number: we never infer integrations.

Standards implemented 1

Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.

OpenAPI

measured — observed by APIs.io (published)

APIs 15

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

Snapchain / Hub API

Query interface for Farcaster's Snapchain network - read casts, reactions, follows, user data, and verifications by FID; submit signed messages; and run a Snapchain node for ful...

Farcaster Mini Apps SDK

JavaScript SDK for building Mini Apps (the evolution of Frames) that run inside Farcaster feeds and clients. Provides host bridge, context, wallet actions, notifications, and an...

Sign In with Farcaster (SIWF)

Authentication flow that lets users sign in to third-party apps with their Farcaster identity, returning a verified FID and optional profile data. Backed by EIP-4361-style signe...

Farcaster AuthKit (React)

React toolkit wrapping Sign In with Farcaster - provides hooks and components for the QR-code / deep-link handoff to a Farcaster client and returns the verified user context to ...

Neynar Hosted Farcaster API

Third-party indexer providing hosted Hub access, indexed read APIs (users, casts, channels, feeds), write APIs (publish casts, reactions, follows), webhooks for real-time events...

Warpcast / Farcaster Client API

Client-side API exposed by the Warpcast / Farcaster app for client-specific surfaces (channels, mentions, direct casts, mini-app contexts) layered above the Snapchain protocol A...

Farcaster Casts API

The Casts API from Farcaster — 4 operation(s) for casts.

Farcaster Events API

The Events API from Farcaster — 2 operation(s) for events.

Farcaster Info API

The Info API from Farcaster — 2 operation(s) for info.

Farcaster Links API

The Links API from Farcaster — 3 operation(s) for links.

Farcaster Reactions API

The Reactions API from Farcaster — 4 operation(s) for reactions.

Farcaster Submit API

The Submit API from Farcaster — 3 operation(s) for submit.

Farcaster Verifications API

The Verifications API from Farcaster — 1 operation(s) for verifications.

Farcaster On Chain API

The On Chain API from Farcaster — 4 operation(s) for on chain.

Farcaster User Data API

The User Data API from Farcaster — 4 operation(s) for user data.

Scroll for all 15

Open Collections 10

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

Farcaster Snapchain Hub HTTP Casts API

OPEN COLLECTION

Farcaster Snapchain Hub HTTP Casts Events API

OPEN COLLECTION

Farcaster Snapchain Hub HTTP Casts Info API

OPEN COLLECTION

Farcaster Snapchain Hub HTTP Casts Links API

OPEN COLLECTION

Farcaster Snapchain Hub HTTP Casts OnChain API

OPEN COLLECTION

Farcaster Snapchain Hub HTTP Casts Reactions API

OPEN COLLECTION

Farcaster Snapchain Hub HTTP Casts Submit API

OPEN COLLECTION

Farcaster Snapchain Hub HTTP Casts UserData API

OPEN COLLECTION

Farcaster Snapchain Hub HTTP Casts Verifications API

OPEN COLLECTION

Farcaster Snapchain Hub HTTP API

OPEN COLLECTION

Scroll for all 10

GraphQL 1

GraphQL schemas published by this provider.

Farcaster GraphQL Schema

title: Farcaster GraphQL Schema

GRAPHQL

Pricing Plans 1

Published pricing tiers and plan structures.

Farcaster Plans Pricing

1 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Farcaster Rate Limits

2 limits

RATE LIMITS

FinOps 1

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

Farcaster Finops

FINOPS

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Farcaster API Rules

43 rules · 39 errors 3 warnings 1 info

SPECTRAL

Security Posture 1

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

Farcaster Domain Security

TLSv1.3 · HSTS · DNSSEC · DMARC

SECURITY

Agentic Access 1

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

Farcaster Agentic Access

27 operations · 3 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 1

SDKs, sample code, and the tooling you integrate with

GitHub

GitHub

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Operate 1

Status, limits, changes, and where to get help

RateLimits

RateLimits

Commercial 2

Pricing, plans, and the legal terms of use

Plans

Plans

FinOps

FinOps

Company 2

The organization behind the API

Blog

Blog

Website

Website

Other 3

Properties that don't map to a standard resource type

Mini Apps

Mini Apps

Snapchain

Snapchain

Neynar

Neynar

Source (apis.yml)

aid: farcaster
name: Farcaster
description: Farcaster is a decentralised social protocol built on Snapchain, an append-only state machine that stores casts,
  reactions, follows, and user profile data. The protocol publishes a Hub / Snapchain reference implementation, the Mini Apps
  SDK (formerly Frames) for distributing interactive apps inside Farcaster feeds, Sign In with Farcaster (SIWF) for authentication,
  and AuthKit for React-based sign-in. The Warpcast client (now rebranded Farcaster app at farcaster.xyz) is the primary consumer
  surface. Indexer providers such as Neynar host scaled Hub APIs and value-added read / write / webhook APIs at api.neynar.com.
type: Index
deliveryModel:
  model: unknown
  open_source: false
  commercial: false
  callable_host: true
  label: Delivery model not determined — needs a product licence on record
  confidence: low
  source:
  - openapi
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: free
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Free
  confidence: low
  source:
  - plans
  - security
  generated: '2026-11-02'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/farcaster.png
access: 3rd-Party
position: Producing
created: '2026-05-23'
modified: '2026-10-06'
tags:
- Farcaster
- Social
- Decentralized
- Protocol
- Mini Apps
- Frames
- Authentication
- Web3
- SDK
tags_raw:
- Farcaster
- Social
- Decentralized
- Protocol
- Mini Apps
- Frames
- Authentication
- Web3
- SDKs
url: https://raw.githubusercontent.com/api-evangelist/farcaster/refs/heads/main/apis.yml
specificationVersion: '0.23'
apis:
- aid: farcaster:snapchain
  name: Snapchain / Hub API
  description: Query interface for Farcaster's Snapchain network - read casts, reactions, follows, user data, and verifications
    by FID; submit signed messages; and run a Snapchain node for full replication. Public reference endpoint is hosted at
    snapchain.farcaster.xyz.
  humanURL: https://snapchain.farcaster.xyz/
  baseURL: https://snapchain.farcaster.xyz
  tags:
  - Snapchain
  - Hub API
  - Reads
  - Writes
  properties:
  - type: Documentation
    url: https://snapchain.farcaster.xyz/
  - type: Reference
    url: https://snapchain.farcaster.xyz/reference
  - type: Run a Node
    url: https://snapchain.farcaster.xyz/guides/running-a-node
  - url: graphql/farcaster-graphql.md
    type: GraphQL
- aid: farcaster:mini-apps-sdk
  name: Farcaster Mini Apps SDK
  description: JavaScript SDK for building Mini Apps (the evolution of Frames) that run inside Farcaster feeds and clients.
    Provides host bridge, context, wallet actions, notifications, and analytics for permissionlessly distributed social apps.
  humanURL: https://miniapps.farcaster.xyz/
  baseURL: https://miniapps.farcaster.xyz/
  tags:
  - Mini Apps
  - Frames
  - SDK
  - Social
  properties:
  - type: Documentation
    url: https://miniapps.farcaster.xyz/
- aid: farcaster:siwf
  name: Sign In with Farcaster (SIWF)
  description: Authentication flow that lets users sign in to third-party apps with their Farcaster identity, returning a
    verified FID and optional profile data. Backed by EIP-4361-style signed messages.
  humanURL: https://docs.farcaster.xyz/developers/siwf
  baseURL: https://docs.farcaster.xyz/developers/siwf
  tags:
  - Authentication
  - SIWF
  - Identity
  properties:
  - type: Documentation
    url: https://docs.farcaster.xyz/developers/siwf
- aid: farcaster:auth-kit
  name: Farcaster AuthKit (React)
  description: React toolkit wrapping Sign In with Farcaster - provides hooks and components for the QR-code / deep-link handoff
    to a Farcaster client and returns the verified user context to the host app.
  humanURL: https://docs.farcaster.xyz/auth-kit/installation
  baseURL: https://docs.farcaster.xyz/auth-kit/installation
  tags:
  - SDK
  - React
  - Authentication
  properties:
  - type: Documentation
    url: https://docs.farcaster.xyz/auth-kit/installation
  - type: Examples
    url: https://docs.farcaster.xyz/auth-kit/examples
- aid: farcaster:neynar
  name: Neynar Hosted Farcaster API
  description: Third-party indexer providing hosted Hub access, indexed read APIs (users, casts, channels, feeds), write APIs
    (publish casts, reactions, follows), webhooks for real-time events, a Node.js SDK, and a Mini Apps framework with analytics.
    Most widely used scaled gateway to Farcaster data.
  humanURL: https://docs.neynar.com/
  baseURL: https://api.neynar.com
  tags:
  - Neynar
  - Indexer
  - Hosted Hub
  - Webhook
  tags_raw:
  - Neynar
  - Indexer
  - Hosted Hub
  - Webhooks
  properties:
  - type: Documentation
    url: https://docs.neynar.com/
  - type: Reference
    url: https://docs.neynar.com/reference
- aid: farcaster:warpcast-api
  name: Warpcast / Farcaster Client API
  description: Client-side API exposed by the Warpcast / Farcaster app for client-specific surfaces (channels, mentions, direct
    casts, mini-app contexts) layered above the Snapchain protocol APIs.
  humanURL: https://docs.farcaster.xyz/reference/warpcast/api
  baseURL: https://api.warpcast.com
  tags:
  - Warpcast
  - Client API
  - Channels
  properties:
  - type: Documentation
    url: https://docs.farcaster.xyz/reference/warpcast/api
- aid: farcaster:farcaster-casts-api
  name: Farcaster Casts API
  description: The Casts API from Farcaster — 4 operation(s) for casts.
  humanURL: https://snapchain.farcaster.xyz/
  baseURL: https://snapchain.farcaster.xyz
  tags:
  - Casts
  properties:
  - type: OpenAPI
    url: openapi/farcaster-casts-api-openapi.yml
- aid: farcaster:farcaster-events-api
  name: Farcaster Events API
  description: The Events API from Farcaster — 2 operation(s) for events.
  humanURL: https://snapchain.farcaster.xyz/
  baseURL: https://snapchain.farcaster.xyz
  tags:
  - Event
  tags_raw:
  - Events
  properties:
  - type: OpenAPI
    url: openapi/farcaster-events-api-openapi.yml
- aid: farcaster:farcaster-info-api
  name: Farcaster Info API
  description: The Info API from Farcaster — 2 operation(s) for info.
  humanURL: https://snapchain.farcaster.xyz/
  baseURL: https://snapchain.farcaster.xyz
  tags:
  - Info
  properties:
  - type: OpenAPI
    url: openapi/farcaster-info-api-openapi.yml
- aid: farcaster:farcaster-links-api
  name: Farcaster Links API
  description: The Links API from Farcaster — 3 operation(s) for links.
  humanURL: https://snapchain.farcaster.xyz/
  baseURL: https://snapchain.farcaster.xyz
  tags:
  - Links
  properties:
  - type: OpenAPI
    url: openapi/farcaster-links-api-openapi.yml
- aid: farcaster:farcaster-reactions-api
  name: Farcaster Reactions API
  description: The Reactions API from Farcaster — 4 operation(s) for reactions.
  humanURL: https://snapchain.farcaster.xyz/
  baseURL: https://snapchain.farcaster.xyz
  tags:
  - Reactions
  properties:
  - type: OpenAPI
    url: openapi/farcaster-reactions-api-openapi.yml
- aid: farcaster:farcaster-submit-api
  name: Farcaster Submit API
  description: The Submit API from Farcaster — 3 operation(s) for submit.
  humanURL: https://snapchain.farcaster.xyz/
  baseURL: https://snapchain.farcaster.xyz
  tags:
  - Submit
  properties:
  - type: OpenAPI
    url: openapi/farcaster-submit-api-openapi.yml
- aid: farcaster:farcaster-verifications-api
  name: Farcaster Verifications API
  description: The Verifications API from Farcaster — 1 operation(s) for verifications.
  humanURL: https://snapchain.farcaster.xyz/
  baseURL: https://snapchain.farcaster.xyz
  tags:
  - Verification
  tags_raw:
  - Verifications
  properties:
  - type: OpenAPI
    url: openapi/farcaster-verifications-api-openapi.yml
- aid: farcaster:farcaster-on-chain-api
  name: Farcaster On Chain API
  description: The On Chain API from Farcaster — 4 operation(s) for on chain.
  humanURL: https://snapchain.farcaster.xyz/
  baseURL: https://snapchain.farcaster.xyz
  tags:
  - Onchain
  tags_raw:
  - On Chain
  properties:
  - type: OpenAPI
    url: openapi/farcaster-on-chain-api-openapi.yml
- aid: farcaster:farcaster-user-data-api
  name: Farcaster User Data API
  description: The User Data API from Farcaster — 4 operation(s) for user data.
  humanURL: https://snapchain.farcaster.xyz/
  baseURL: https://snapchain.farcaster.xyz
  tags:
  - User Data
  properties:
  - type: OpenAPI
    url: openapi/farcaster-user-data-api-openapi.yml
common:
- type: Plans
  url: plans/farcaster-plans-pricing.yml
- type: RateLimits
  url: rate-limits/farcaster-rate-limits.yml
- type: FinOps
  url: finops/farcaster-finops.yml
- url: https://farcaster.xyz/blog/
  type: Blog
- type: AgenticAccess
  url: agentic-access/farcaster-agentic-access.yml
- type: DomainSecurity
  url: security/farcaster-domain-security.yml
- type: Website
  url: https://www.farcaster.xyz/
- type: Documentation
  url: https://docs.farcaster.xyz/
- type: Mini Apps
  url: https://miniapps.farcaster.xyz/
- type: Snapchain
  url: https://snapchain.farcaster.xyz/
- type: GitHub
  url: https://github.com/farcasterxyz
- type: Neynar
  url: https://neynar.com/
maintainers:
- FN: API Evangelist
  url: https://apievangelist.com

Farcaster API — frequently asked questions

Does Farcaster have an API?

Yes. APIs.io lists 15 APIs from Farcaster, including Snapchain / Hub API, Farcaster Mini Apps SDK and Sign In with Farcaster (SIWF), and 12 more.

Is there an OpenAPI specification for the Farcaster API?

Yes. APIs.io indexes 9 OpenAPI specifications for Farcaster, each linked for download from this page.

How much does the Farcaster API cost?

APIs.io lists 1 pricing plan for Farcaster, with each plan's price, limits and inclusions under Pricing Plans on this page.

Is the Farcaster API ready for AI agents?

Farcaster has a Kin Score of 24.5 out of 100 (emerging) and an Agent Readiness score of 18.4 (agent-aware), scored by API Evangelist on 2026-11-02.

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