Yearn Finance

Yearn Finance is a DeFi yield aggregator that automates yield farming strategies across EVM-compatible networks. It provides REST and GraphQL APIs for accessing vault data, APY rates, strategy information, user positions, TVL metrics, and protocol analytics across Ethereum, Optimism, Polygon, Fantom, Base, and Arbitrum.

Yearn Finance publishes 4 APIs on the APIs.io network, including Chains API, Info API, TVL API, and 1 more. Tagged areas include DeFi, Yield Aggregator, Vault, EVM, and Web3.

The Yearn Finance catalog on APIs.io includes 1 JSON-LD context and 1 Spectral governance ruleset.

🌐 Visit website 📡 Source on GitHub

29.3/100 thin ▬ flat Agent 23/100 agent aware self hosted · MIT Full breakdown ↓
scored 2026-09-14 · rubric v0.22.0

AccessFreeOpen⚡ Free to try

1 APIs

DeFiYield AggregatorVault EVM Web3 Blockchain Finance

Kin Score

Kin Score How this is scored →
scored 2026-09-14 · rubric v0.22.0

Composite quality — 29.3/100 · thin

Contract Quality 13.9 / 23

Developer Ergonomics 1.7 / 18

Access Clarity 5.2 / 18

Operational Transparency 0.6 / 12

Contract Governance 1.1 / 11

Discoverability 6.8 / 9

Open Source Surface 0.0 / 10

Agent readiness — 23/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 6 / 6

MCP Server 0 / 12

Machine-Readable Auth 0 / 10

Idempotency 9 / 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 4 / 4

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Open Source Surface applies to this provider. This product is open source and we read its repository directly, so Open Source Surface carries 10 points of the composite. It is scored from what the repository actually publishes — a security policy, a contribution guide, a release history, a code of conduct — read live from the provider rather than inferred from our own catalog pointers. This facet adds; nothing was taken away to make room for it. An open-source project is not excused from the commercial facets, because exemption would strip it of the points it does earn. If we have the wrong repository, or this product is not open source, say so on your provider repo and we will drop the facet rather than have you publish against it.

Create-or-Update Ergonomics does not apply to this provider. The published contracts declare no write operations, and a read-only API cannot create-or-update. The facet is excluded from this provider's denominator entirely — not scored zero. A reference or data API is not deficient for being unable to upsert.

The six quality facets above are damped to 90 points between them, because the conditional facet above carries the other 10. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 90% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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 github.com/api-evangelist/yearn: open an issue to ask a question, or submit a pull request to add artifacts. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

APIs 5

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

Kong GraphQL API

An integrated indexing service and GraphQL API providing comprehensive data on Yearn V2 and V3 vault ecosystems, including contract snapshots, event histories, vault-strategy re...

Yearn Finance Chains API

Supported blockchain network information

Yearn Finance Info API

Protocol information and metadata

Yearn Finance TVL API

Total Value Locked metrics

Yearn Finance Vaults API

Endpoints for querying Yearn vault data

Open Collections 5

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

API Collection

OPEN COLLECTION

Yearn Finance yDaemon REST Chains API

OPEN COLLECTION

Yearn Finance yDaemon REST Chains Info API

OPEN COLLECTION

Yearn Finance yDaemon REST Chains TVL API

OPEN COLLECTION

Yearn Finance yDaemon REST Chains Vaults API

OPEN COLLECTION

GraphQL 1

GraphQL schemas published by this provider.

Yearn Finance GraphQL API

Yearn Finance's Kong GraphQL API is an integrated indexing and querying service that provides comprehensive on-chain data for Yearn V2 and V3 vault ecosystems. It exposes vault ...

GRAPHQL

Pricing Plans 1

Published pricing tiers and plan structures.

Plans

1 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Rate Limits

0 limits

RATE LIMITS

FinOps 1

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

Finops

FINOPS

Semantic Vocabularies 1

JSON-LD contexts and semantic vocabularies used across these APIs.

context Context

37 classes · 11 properties

JSON-LD

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Yearn Finance API Rules

6 rules · 4 warnings 2 info

SPECTRAL

JSON Schema 1

Standalone JSON Schema definitions for this provider's data models.

Vault

22 properties

JSON SCHEMA

Security Posture 1

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

Yearn Domain Security

TLSv1.3 · HSTS · DNSSEC · DMARC

SECURITY

Agentic Access 1

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

Yearn Agentic Access

9 operations

9 operations · 0 acting

AGENTIC

Resources

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Operate 1

Status, limits, changes, and where to get help

IssueTracker

IssueTracker

Commercial 1

Pricing, plans, and the legal terms of use

License

License

Source (apis.yml)

name: Yearn Finance
description: Yearn Finance is a DeFi yield aggregator that automates yield farming strategies across EVM-compatible networks.
  It provides REST and GraphQL APIs for accessing vault data, APY rates, strategy information, user positions, TVL metrics,
  and protocol analytics across Ethereum, Optimism, Polygon, Fantom, Base, and Arbitrum.
deliveryModel:
  model: self-hosted
  license: MIT
  open_source: true
  commercial: false
  callable_host: true
  label: Self-hosted open source · you run it yourself
  confidence: high
  source:
  - license
  - openapi
  generated: '2026-08-28'
  method: derived
specificationVersion: '0.23'
accessModel:
  pricing: free
  onboarding: open
  trial: false
  try_now: true
  public: true
  label: Free · Open access
  confidence: medium
  source:
  - plans
  generated: '2026-07-22'
  method: derived
image: https://yearn.fi/logo.svg
tags:
- DeFi
- Yield Aggregator
- Vault
- EVM
- Web3
- Blockchain
- Finance
tags_raw:
- DeFi
- Yield Aggregator
- Vaults
- EVM
- Web3
- Blockchain
- Finance
url: https://yearn.fi
apis:
- name: Kong GraphQL API
  description: An integrated indexing service and GraphQL API providing comprehensive data on Yearn V2 and V3 vault ecosystems,
    including contract snapshots, event histories, vault-strategy relationships, fees, rewards, APY, and TVL timeseries data.
  humanURL: https://docs.yearn.fi/developers/data-services/yearn-data
  baseURL: https://kong.yearn.fi
  tags:
  - GraphQL
  - Vault
  - Analytics
  - Strategies
  - Event
  tags_raw:
  - GraphQL
  - Vaults
  - Analytics
  - Strategies
  - Events
  properties:
  - type: Documentation
    url: https://docs.yearn.fi/developers/data-services/yearn-data
  - type: GitHubRepository
    url: https://github.com/yearn/kong
  contact:
  - FN: Yearn Finance
    email: ''
    X-twitter: iearnfinance
  apis:
  - name: Kong GraphQL Query
    description: GraphQL endpoint for querying Yearn V2 and V3 vault ecosystem data including snapshots, events, APY timeseries,
      TVL, strategies, fees, rewards, and vault metadata.
    humanURL: https://docs.yearn.fi/developers/data-services/yearn-data
    baseURL: https://kong.yearn.fi
    path: /api/gql
    method: POST
    tags:
    - GraphQL
    - Vault
    - Analytics
    tags_raw:
    - GraphQL
    - Vaults
    - Analytics
    properties:
    - type: Documentation
      url: https://docs.yearn.fi/developers/data-services/yearn-data
- aid: yearn:yearn-chains-api
  name: Yearn Finance Chains API
  description: Supported blockchain network information
  humanURL: https://docs.yearn.fi/developers/data-services/yearn-data
  baseURL: https://ydaemon.yearn.fi
  tags:
  - Chains
  properties:
  - type: OpenAPI
    url: openapi/yearn-chains-api-openapi.yml
  - type: Documentation
    url: https://docs.yearn.fi/developers/data-services/yearn-data
  - type: GitHubRepository
    url: https://github.com/yearn/ydaemon
  - type: GraphQL
    url: graphql/yearn-graphql.md
- aid: yearn:yearn-info-api
  name: Yearn Finance Info API
  description: Protocol information and metadata
  humanURL: https://docs.yearn.fi/developers/data-services/yearn-data
  baseURL: https://ydaemon.yearn.fi
  tags:
  - Info
  properties:
  - type: OpenAPI
    url: openapi/yearn-info-api-openapi.yml
  - type: Documentation
    url: https://docs.yearn.fi/developers/data-services/yearn-data
  - type: GitHubRepository
    url: https://github.com/yearn/ydaemon
  - type: GraphQL
    url: graphql/yearn-graphql.md
- aid: yearn:yearn-tvl-api
  name: Yearn Finance TVL API
  description: Total Value Locked metrics
  humanURL: https://docs.yearn.fi/developers/data-services/yearn-data
  baseURL: https://ydaemon.yearn.fi
  tags:
  - TVL
  properties:
  - type: OpenAPI
    url: openapi/yearn-tvl-api-openapi.yml
  - type: Documentation
    url: https://docs.yearn.fi/developers/data-services/yearn-data
  - type: GitHubRepository
    url: https://github.com/yearn/ydaemon
  - type: GraphQL
    url: graphql/yearn-graphql.md
- aid: yearn:yearn-vaults-api
  name: Yearn Finance Vaults API
  description: Endpoints for querying Yearn vault data
  humanURL: https://docs.yearn.fi/developers/data-services/yearn-data
  baseURL: https://ydaemon.yearn.fi
  tags:
  - Vault
  tags_raw:
  - Vaults
  properties:
  - type: OpenAPI
    url: openapi/yearn-vaults-api-openapi.yml
  - type: Documentation
    url: https://docs.yearn.fi/developers/data-services/yearn-data
  - type: GitHubRepository
    url: https://github.com/yearn/ydaemon
  - type: GraphQL
    url: graphql/yearn-graphql.md
modified: 2026-06-13
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
common:
- type: IssueTracker
  url: https://github.com/yearn/kong/issues
- type: License
  name: MIT
  url: https://github.com/yearn/kong/blob/main/LICENSE
- type: AgenticAccess
  url: agentic-access/yearn-agentic-access.yml
- type: DomainSecurity
  url: security/yearn-domain-security.yml

Work with this as data

Every provider here is available over the APIs.io API and to AI agents over MCP.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for providers

9 MCP tools reach this

find_providersBrowse and filter every provider in the catalog.
get_provider_artifactsEvery artifact this provider publishes, grouped by type.
get_provider_operationsEvery operation across all of their OpenAPIs — one call instead of parsing every spec.
get_provider_toolsEvery MCP tool they ship, with the operation each wraps.
get_provider_evidenceHow each part of their score was established. Free — the basis for a claim should not sit behind it.
get_provider_ratingPRO — composite, band, trend and facet scores.
apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
resolveTurn a domain, URL or GitHub org into the provider it belongs to.
find_cohortsEvery scored population of providers in the catalog.

All 92 tools →

Call it yourself

curl for this page

This provider

curl "https://apis.io/api/v1/providers/yearn"

All providers

curl "https://apis.io/api/v1/providers?limit=25"

Every operation they expose

curl "https://apis.io/api/v1/providers/yearn/operations?limit=25"

How their score was established

curl "https://apis.io/api/v1/providers/yearn/evidence"

Discovery needs no key. Ratings and market analysis are Pro.

Get an API key

Free tier, no form to fill in. Signing in shares your email address with us — we store it to create your key and to recognise you if you sign in with another provider. See our Privacy Policy and Terms.

GitHub Google LinkedIn

A second provider on the same verified email joins the account you already have.