> ## Documentation Index
> Fetch the complete documentation index at: https://docs.hypedexer.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Raw fills absorbed by the backstop of a dex

> Paginated stream of fills executed against the backstop address of a HIP-3 dex. These are positions absorbed by the backstop strategy following liquidations not covered by the order book.

**Pagination.** `has_more` is set to `true` when `len(data) >= limit` (heuristic, no `COUNT(*)`). Use `offset` to walk the stream.

**Latency.** ~170 ms.



## OpenAPI

````yaml /evm/openapi-rest.json get /evm/hip3/backstop/{dex}/fills
openapi: 3.0.3
info:
  title: 'Hypedexer API: EVM'
  version: 1.0.0
  description: >-
    EVM blockchain data: blocks, transactions, event logs, ledger transfers,
    bridge events.
servers:
  - url: https://api.hypedexer.com
    description: Production, routed to the nearest region (EU or JP)
security:
  - ApiKeyAuth: []
tags:
  - name: EVM
    description: >-
      EVM blockchain data: blocks, transactions, logs, ledger transfers, bridge
      events.
  - name: HIP-3 Backstop
    description: >-
      Principal flows (`hip3LiquidatorTransfer`) and on-chain activity of HIP-3
      backstop addresses (`0x4000…00 + dex_index`). Combines deployer-side
      principal injections with observed fills absorbed by the backstop.
paths:
  /evm/hip3/backstop/{dex}/fills:
    get:
      tags:
        - HIP-3 Backstop
      summary: Raw fills absorbed by the backstop of a dex
      description: >-
        Paginated stream of fills executed against the backstop address of a
        HIP-3 dex. These are positions absorbed by the backstop strategy
        following liquidations not covered by the order book.


        **Pagination.** `has_more` is set to `true` when `len(data) >= limit`
        (heuristic, no `COUNT(*)`). Use `offset` to walk the stream.


        **Latency.** ~170 ms.
      parameters:
        - name: dex
          in: path
          required: true
          description: Dex identifier
          schema:
            type: string
        - name: coin
          in: query
          description: Filter by coin (e.g. `km:BTC`, `xyz:NVDA`)
          schema:
            type: string
        - name: side
          in: query
          description: Filter by side (`B` = buy, `A` = sell)
          schema:
            type: string
            enum:
              - B
              - A
        - name: start_time
          in: query
          description: Start of window (UTC)
          schema:
            type: string
            format: date-time
        - name: end_time
          in: query
          description: End of window (UTC)
          schema:
            type: string
            format: date-time
        - name: limit
          in: query
          schema:
            type: integer
            default: 100
            minimum: 1
            maximum: 1000
        - name: offset
          in: query
          schema:
            type: integer
            default: 0
        - name: X-API-Key
          in: header
          schema:
            type: string
      responses:
        '200':
          description: OK
          content:
            application/json:
              schema:
                allOf:
                  - $ref: '#/components/schemas/APIResponse'
                  - type: object
                    properties:
                      data:
                        type: array
                        items:
                          $ref: '#/components/schemas/Hip3BackstopFill'
              example:
                success: true
                message: Fetched 2 backstop fills
                data:
                  - time: '2026-04-10T22:10:27.052000'
                    dex_id: km
                    coin: km:SMALL2000
                    side: B
                    px: 262.44
                    sz: 0.003
                    notional: 0.78732
                    fee: 0.000063
                    is_liquidation: 0
                    hash: 0x0328...
                total_count: null
                execution_time_ms: 172.7
                next_cursor: null
                has_more: true
components:
  schemas:
    APIResponse:
      type: object
      description: Standard response envelope used by every route.
      properties:
        success:
          type: boolean
          default: true
        message:
          type: string
        data: {}
        total_count:
          type: integer
          nullable: true
        execution_time_ms:
          type: number
          description: Server-side execution time in milliseconds.
        next_cursor:
          type: string
          nullable: true
        has_more:
          type: boolean
    Hip3BackstopFill:
      type: object
      description: Single fill executed against a HIP-3 backstop address.
      properties:
        time:
          type: string
          format: date-time
          description: UTC timestamp (millisecond precision).
        dex_id:
          type: string
        coin:
          type: string
          description: Symbol prefixed by `dex_id` (e.g. `km:BTC`).
        side:
          type: string
          enum:
            - B
            - A
          description: '`B` = buy, `A` = sell.'
        px:
          type: number
          format: float
          description: Execution price.
        sz:
          type: number
          format: float
          description: Size (contract unit).
        notional:
          type: number
          format: float
          description: '`px × sz` (USDC).'
        fee:
          type: number
          format: float
          description: Fee paid by the backstop (USDC).
        is_liquidation:
          type: integer
          description: >-
            1 if the fill resulted from a liquidation (in practice always 1 for
            the backstop).
        hash:
          type: string
          description: Transaction hash.
  securitySchemes:
    ApiKeyAuth:
      type: apiKey
      in: header
      name: X-API-Key
      description: >-
        Your Hypedexer API key. Create one in the console at
        https://app.hypedexer.com. `Authorization: Bearer <key>` and the
        `api_key` query parameter are accepted as well.

````

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