> ## 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.

# Backstop health for a single dex

> Combined principal flow and observed on-chain activity for a single HIP-3 dex backstop. Returns 404 if no backstop activity has ever been observed for this dex (its address has never appeared in `hip3_fills`).

**Latency.** ~170 ms (one remote `hip3_fills` query plus one local `hip3_liquidator_transfers` query).



## OpenAPI

````yaml /evm/openapi-rest.json get /evm/hip3/backstop/{dex}/health
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}/health:
    get:
      tags:
        - HIP-3 Backstop
      summary: Backstop health for a single dex
      description: >-
        Combined principal flow and observed on-chain activity for a single
        HIP-3 dex backstop. Returns 404 if no backstop activity has ever been
        observed for this dex (its address has never appeared in `hip3_fills`).


        **Latency.** ~170 ms (one remote `hip3_fills` query plus one local
        `hip3_liquidator_transfers` query).
      parameters:
        - name: dex
          in: path
          required: true
          description: Dex identifier (e.g. `km`, `xyz`, `cash`)
          schema:
            type: string
        - 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:
                        $ref: '#/components/schemas/Hip3BackstopHealth'
              example:
                success: true
                message: Backstop health for km
                data:
                  dex_id: km
                  backstop_address: '0x4000000000000000000000000000000000000005'
                  dex_index: 5
                  principal_deposited_usdc: 0
                  principal_withdrawn_usdc: 0
                  net_principal_usdc: 0
                  fill_count: 1812
                  notional_traded: 1399890.76
                  fees_paid: 56.17
                  fills_last_24h: 0
                  last_fill_time: '2026-04-10T22:10:27.052000'
                  first_fill_time: '2026-03-23T11:10:32.434000'
                  coins_active: 1
                total_count: null
                execution_time_ms: 172.7
                next_cursor: null
                has_more: false
        '404':
          description: No backstop activity has ever been observed for this dex.
          content:
            application/json:
              schema:
                type: object
                properties:
                  detail:
                    type: string
              example:
                detail: >-
                  No backstop activity recorded for dex 'xxx' (address never
                  observed in fills)
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
    Hip3BackstopHealth:
      type: object
      description: Combined principal flow + observed activity for a single HIP-3 backstop.
      properties:
        dex_id:
          type: string
          description: Dex identifier (e.g. `km`, `xyz`).
        backstop_address:
          type: string
          description: On-chain backstop address (`0x4000…00 + dex_index`).
        dex_index:
          type: integer
          description: Derived from the last byte of `backstop_address`.
        principal_deposited_usdc:
          type: number
          format: float
          description: >-
            Total principal deposited by the deployer (sum of
            `hip3LiquidatorTransfer` deposits).
        principal_withdrawn_usdc:
          type: number
          format: float
          description: >-
            Total principal withdrawn. Note: PnL is non-withdrawable by protocol
            constraint.
        net_principal_usdc:
          type: number
          format: float
          description: '`principal_deposited_usdc − principal_withdrawn_usdc`.'
        fill_count:
          type: integer
          description: Total number of fills absorbed by the backstop.
        notional_traded:
          type: number
          format: float
          description: Sum of fill notionals (USDC).
        fees_paid:
          type: number
          format: float
          description: Sum of fees paid by the backstop (USDC).
        fills_last_24h:
          type: integer
          description: Number of fills in the last 24 hours.
        last_fill_time:
          type: string
          format: date-time
          nullable: true
          description: Timestamp of the most recent fill.
        first_fill_time:
          type: string
          format: date-time
          nullable: true
          description: Timestamp of the first observed fill.
        coins_active:
          type: integer
          description: Number of distinct coins touched by the backstop.
  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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