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OpenAPI Specification

openapi: 3.2.0
info:
  title: FlexYield Data API
  version: 1.0.0
  description: 'One API key, one bill, every provider. JSON-RPC relay across 6 chains, the toolbox, the data API and account statements. Weighted metering (standard 1 · heavy 2 · data 10 · toolbox 1 · cache hit 0); every error carries data.request_id and data.support. Agents: the same capabilities are MCP tools at https://flexyield.io/mcp.'
  contact:
    email: hello@flexyield.io
    url: https://flexyield.io/support
  termsOfService: https://flexyield.io/terms
servers:
- url: https://flexyield.io
tags:
- name: Data
paths:
  /data/{chain}/balances/{address}:
    get:
      summary: Native + token balances (paid tiers, 10 units)
      security:
      - bearer: []
      parameters:
      - name: chain
        in: path
        required: true
        schema:
          type: string
          enum:
          - eth_mainnet
          - base_mainnet
          - arbitrum_one
          - optimism_mainnet
          - polygon_pos
          - solana_mainnet
      - name: address
        in: path
        required: true
        schema:
          type: string
          pattern: ^0x[0-9a-fA-F]{40}$
      responses:
        '200':
          description: OK
          content:
            application/json:
              schema:
                type: object
        '401':
          description: Invalid or missing API key (-32001)
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '429':
          description: Rate window, key budget, plan quota or service cap reached (-32005/-32006/-32007/-32014) — the body says what to do next
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '403':
          description: Service switched off for this account/key (-32012) or account suspended (-32009)
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
      tags:
      - Data
      operationId: getDataByChainBalancesByAddress
      x-operation-id-source: derived
  /data/{chain}/history/{address}:
    get:
      summary: Transfer history (paid tiers, 10 units)
      security:
      - bearer: []
      parameters:
      - name: chain
        in: path
        required: true
        schema:
          type: string
          enum:
          - eth_mainnet
          - base_mainnet
          - arbitrum_one
          - optimism_mainnet
          - polygon_pos
          - solana_mainnet
      - name: address
        in: path
        required: true
        schema:
          type: string
          pattern: ^0x[0-9a-fA-F]{40}$
      responses:
        '200':
          description: OK
          content:
            application/json:
              schema:
                type: object
        '401':
          description: Invalid or missing API key (-32001)
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '429':
          description: Rate window, key budget, plan quota or service cap reached (-32005/-32006/-32007/-32014) — the body says what to do next
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '403':
          description: Service switched off for this account/key (-32012) or account suspended (-32009)
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
      tags:
      - Data
      operationId: getDataByChainHistoryByAddress
      x-operation-id-source: derived
components:
  schemas:
    Error:
      type: object
      properties:
        error:
          type: object
          properties:
            code:
              type: integer
              description: JSON-RPC style code, e.g. -32005 rate window
            message:
              type: string
            data:
              type: object
              properties:
                request_id:
                  type: string
                  format: uuid
                support:
                  type: string
                  description: Path to file this call as a ticket
  securitySchemes:
    bearer:
      type: http
      scheme: bearer
      description: Your FlexYield API key (fy_…). Free tier at https://flexyield.io/registration/new
    x402:
      type: apiKey
      in: header
      name: X-PAYMENT
      description: 'x402 lane: the one-time credential (fyx_…) returned by POST https://flexyield.io/x402/redeem after a payment against the menu at https://flexyield.io/x402 (base); the redeem needs an EIP-191 signature by the paying wallet — the tx hash alone is public and is not a credential'
externalDocs:
  url: https://flexyield.io/docs
  description: Developer docs
x-pricing:
  rule: 'Price per unit falls with commitment, never with identity: more volume committed per month → lower USD per 1M units; yearly < monthly; per call is the dearest lane; no pack undercuts the yearly tier; a subscription is cheapest per unit at its included volume.'
  unit: USD per 1,000,000 standard units (standard 1 · heavy 2 · data 10 · cache hit 0), net — VAT is added where it applies on every lane, incl. per call (by the payer's location)
  tierMultipliers:
    cheap: 0.5
    balanced: 1.0
    fast: 2.0
  lanes:
  - key: scale_yearly
    label: Scale (yearly)
    kind: subscription
    commitmentUsd: 2990.0
    priceUsd: 249.17
    units: 60000000
    usdPerMillionUnits: 4.15
    supply: premium
    fastShare: 0.25
    live: true
  - key: growth_yearly
    label: Growth (yearly)
    kind: subscription
    commitmentUsd: 8990.0
    priceUsd: 749.17
    units: 200000000
    usdPerMillionUnits: 3.75
    supply: premium
    fastShare: 0.2
    live: true
  - key: pro_yearly
    label: Pro (yearly)
    kind: subscription
    commitmentUsd: 990.0
    priceUsd: 82.5
    units: 15000000
    usdPerMillionUnits: 5.5
    supply: premium
    fastShare: 0.3
    live: true
  - key: scale_monthly
    label: Scale
    kind: subscription
    commitmentUsd: 299.0
    priceUsd: 299.0
    units: 60000000
    usdPerMillionUnits: 4.98
    supply: premium
    fastShare: 0.25
    live: true
  - key: growth_monthly
    label: Growth
    kind: subscription
    commitmentUsd: 899.0
    priceUsd: 899.0
    units: 200000000
    usdPerMillionUnits: 4.5
    supply: premium
    fastShare: 0.2
    live: true
  - key: pack_l
    label: Pack L
    kind: pack
    commitmentUsd: 200.0
    priceUsd: 200.0
    units: 32000000
    usdPerMillionUnits: 6.25
    supply: premium
    fastShare: 0.0
    live: true
  - key: pro_monthly
    label: Pro
    kind: subscription
    commitmentUsd: 99.0
    priceUsd: 99.0
    units: 15000000
    usdPerMillionUnits: 6.6
    supply: premium
    fastShare: 0.3
    live: true
  - key: pack_m
    label: Pack M
    kind: pack
    commitmentUsd: 50.0
    priceUsd: 50.0
    units: 7000000
    usdPerMillionUnits: 7.14
    supply: premium
    fastShare: 0.0
    live: true
  - key: pack_s
    label: Pack S
    kind: pack
    commitmentUsd: 10.0
    priceUsd: 10.0
    units: 1200000
    usdPerMillionUnits: 8.33
    supply: premium
    fastShare: 0.0
    live: true
  - key: per_call
    label: Per call (x402) / PAYG
    kind: per_call
    commitmentUsd: 0.0
    priceUsd: 9.0
    units: 1000000
    usdPerMillionUnits: 9.0
    supply: premium
    fastShare: 1.0
    live: true
  - key: builder
    label: Builder
    kind: flat
    commitmentUsd: 12.0
    priceUsd: 12.0
    units: 20000000
    usdPerMillionUnits: 0.6
    supply: public
    fastShare: 0.0
    live: true
  - key: free
    label: Free
    kind: free
    commitmentUsd: 0.0
    priceUsd: 0.0
    units: 1000000
    usdPerMillionUnits: 0.0
    supply: public
    fastShare: 0.0
    live: true
  - key: door1
    label: Anonymous key (door 1)
    kind: free
    commitmentUsd: 0.0
    priceUsd: 0.0
    units: 300000
    usdPerMillionUnits: 0.0
    supply: public
    fastShare: 0.0
    live: false
  - key: founding
    label: Founding (Pro locked 12 months; until 2026-12-05 or while seats last)
    kind: subscription
    commitmentUsd: 79.0
    priceUsd: 79.0
    units: 15000000
    usdPerMillionUnits: 5.27
    supply: premium
    fastShare: 0.3
    live: true