Yearn Finance Chains API

openapi: 3.1.0
info:
  title: Yearn Finance yDaemon REST Chains API
  description: The primary REST API for Yearn Finance, providing access to vault data, APY calculations, TVL metrics, strategy information, and protocol analytics across all supported EVM networks including Ethereum, Optimism, Polygon, Fantom, Base, and Arbitrum. Used by the production Yearn frontends.
  version: 1.0.0
  contact:
    name: Yearn Finance
    url: https://yearn.fi
  license:
    name: GNU Affero General Public License v3.0
    url: https://github.com/yearn/ydaemon/blob/main/LICENSE
  x-twitter: iearnfinance
servers:
- url: https://ydaemon.yearn.fi
  description: Production yDaemon API
tags:
- name: Chains
  description: Supported blockchain network information
paths:
  /info/chains:
    get:
      operationId: getSupportedChains
      summary: Get supported chains
      description: Returns the list of blockchain networks supported by the yDaemon API, including Ethereum, Optimism, Polygon, Fantom, Base, and Arbitrum, along with their RPC and contract configuration data.
      tags:
      - Chains
      responses:
        '200':
          description: An object mapping chain IDs to chain configuration data.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ChainsResponse'
components:
  schemas:
    ChainInfo:
      type: object
      description: Configuration and metadata for a supported EVM chain.
      properties:
        ID:
          type: integer
          description: EVM chain ID.
          example: 1
        RpcURI:
          type: string
          format: uri
          description: RPC endpoint URI for the chain.
        SubgraphURI:
          type: string
          format: uri
          description: The Graph subgraph URI for the chain.
        EtherscanURI:
          type: string
          format: uri
          description: Etherscan-compatible API URI.
        MaxBlockRange:
          type: integer
          description: Maximum block range for log queries.
        MaxBatchSize:
          type: integer
          description: Maximum batch size for multicall requests.
        AvgBlocksPerDay:
          type: integer
          description: Average number of blocks per day on this chain.
        CanUseWebsocket:
          type: boolean
          description: Whether WebSocket connections are supported.
        LensContract:
          $ref: '#/components/schemas/ChainContract'
        MulticallContract:
          $ref: '#/components/schemas/ChainContract'
        YBribeV3Contract:
          $ref: '#/components/schemas/ChainContract'
    ChainContract:
      type: object
      description: A smart contract deployed on a chain.
      properties:
        Address:
          type: string
          pattern: ^0x[a-fA-F0-9]{40}$
          description: Contract address.
        Block:
          type: integer
          description: Block number at which the contract was deployed.
        Version:
          type: integer
          description: Contract version number.
        Tag:
          type: string
          description: Optional tag label for the contract.
        Label:
          type: string
          description: Optional human-readable label.
    ChainsResponse:
      type: object
      description: Map of chain IDs to chain configuration objects.
      properties:
        chains:
          type: object
          description: An object where each key is a chain ID string and the value is a ChainInfo object.
          additionalProperties:
            $ref: '#/components/schemas/ChainInfo'
externalDocs:
  description: Yearn Finance Developer Documentation
  url: https://docs.yearn.fi/developers/data-services/yearn-data