openapi: 3.1.0
info:
  title: Yearn Finance yDaemon REST Chains TVL 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: TVL
  description: Total Value Locked metrics
paths:
  /{chainID}/vaults/tvl:
    get:
      operationId: getVaultsTVL
      summary: Get total TVL for a chain
      description: Returns the Total Value Locked (in USD) aggregated across all vaults on the specified chain.
      tags:
      - TVL
      parameters:
      - $ref: '#/components/parameters/chainID'
      responses:
        '200':
          description: Total Value Locked as a numeric USD value.
          content:
            application/json:
              schema:
                type: number
                format: double
                description: Total Value Locked in USD across all vaults on the chain.
                example: 181230031.34
        '400':
          $ref: '#/components/responses/BadRequest'
        '404':
          $ref: '#/components/responses/NotFound'
components:
  responses:
    BadRequest:
      description: Bad Request - invalid parameters.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    NotFound:
      description: Not Found - the requested resource does not exist.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
  parameters:
    chainID:
      name: chainID
      in: path
      required: true
      description: 'The EVM chain ID. Supported values: 1 (Ethereum), 10 (Optimism), 137 (Polygon), 250 (Fantom), 8453 (Base), 42161 (Arbitrum).'
      schema:
        type: integer
        example: 1
        enum:
        - 1
        - 10
        - 137
        - 250
        - 8453
        - 42161
  schemas:
    Error:
      type: object
      properties:
        error:
          type: string
          description: A human-readable error message.
          example: not found
externalDocs:
  description: Yearn Finance Developer Documentation
  url: https://docs.yearn.fi/developers/data-services/yearn-data