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

# Ping

> Returns `pong`. No API key needed. Use it to open and keep warm a connection before sending.



## OpenAPI

````yaml /openapi.json get /ping
openapi: 3.0.3
info:
  description: >-
    REST API for the Archer Exchange — a high-performance Solana-based order
    book exchange.


    All monetary values (prices, sizes, fees) are returned as decimal strings
    for precision.


    ### Rate Limiting

    All endpoints are rate-limited via a token-bucket algorithm. When the limit
    is exceeded, the API returns `429 Too Many Requests`.


    ### Error Format

    All errors follow a consistent JSON format:

    ```json

    {
      "error": "ERROR_CODE",
      "message": "Human-readable description"
    }

    ```


    ### Handling errors

    Every error falls into one of five actions. REST errors come back as
    `{"error": CODE, "message"}`. A transaction that fails on-chain reports
    `{"InstructionError": [index, {"Custom": code}]}`; codes are the `errors`
    list of the program IDL (`archer-sdk/idl/archer_v1.json`). When a build
    endpoint's preflight catches an on-chain error first, it returns `400
    INVALID_PARAMS` with the reason in `message`.


    | Action | REST | On-chain (code) |

    |---|---|---|

    | **Retry as is**, with backoff | `RATE_LIMITED` (429),
    `SERVICE_UNAVAILABLE` (503), `INTERNAL_ERROR` (500); relay `OVERLOADED`,
    `PREFLIGHT_UNAVAILABLE`. Keep backing off on 429: 50 of them within a minute
    from one IP returns `BANNED` (403) for 10 minutes | none |

    | **Refetch, rebuild, retry**: the book or registry changed under you | |
    `LevelSizeMismatch` (527), `StaleSequenceNumber` (509),
    `SequenceNumberTooFarAhead` (522), `RegistryBooksMismatch` (525),
    `IncompleteMakerBooks` (513), `NoMatchingLiquidity` (507); relay status
    `expired` (re-sign with a fresh blockhash) |

    | **Reprice** | `CROSSES_SPREAD`, `SLIPPAGE_EXCEEDED` | `PostOnlyWouldCross`
    (524), `CrossingOrderLevels` (505), `InvalidPrice` (503),
    `SlippageToleranceExceeded` (703) |

    | **Resize** | `INSUFFICIENT_LIQUIDITY` (the body's `availableSize` is what
    fits) | `MakerBookSideFull` (528: cancel a level first),
    `InvalidSizeAtLevel` (506), `InsufficientBalance` (402) and SPL Token `1`
    (fund the account or shrink), `ZeroSwapAmount` (702) |

    | **Stop**: fix the request or the setup; retrying cannot help |
    `INVALID_PARAMS`, `MISSING_API_KEY` / `INVALID_API_KEY` (401), `FORBIDDEN`,
    `NOT_FOUND`, `MARKET_NOT_FOUND`, `METHOD_NOT_ALLOWED`; `MARKET_PAUSED` /
    `MARKET_FROZEN` until the market resumes |
    `UnauthorizedArcherAccountDelegate` (1001), `BuilderFeeExceedsAccountCap`
    (1003), `UnauthorizedMaker` (502), `MakerNotRegistered` (512),
    `PostOnlyRequiresLimitOrderBook` (526), `MarketNotActive` (107),
    `MarketFrozen` (114); any 200–399 code (wrong account wiring, a bug to
    report) |
  title: Archer Exchange API
  version: 1.0.0
servers:
  - description: Production
    url: https://api.archer.exchange
  - description: Staging
    url: https://api-staging.archer.exchange
  - description: Local
    url: http://localhost:8080
security:
  - apiKey: []
tags:
  - description: Discover and inspect available trading markets
    name: Markets
  - description: Token metadata for every mint Archer lists
    name: Tokens
  - description: Get price quotes before placing an order
    name: Quote
  - description: Build unsigned Solana transactions for swaps
    name: Orders
  - description: Build unsigned Solana transactions for limit orders
    name: Limit Orders
  - description: >-
      ArcherAccount — a wallet's delegated trading identity. Collateral sits in
      token accounts owned by the account PDA; an authorized delegate can trade
      and quote as the account but never withdraw.
    name: Account
  - description: Read a maker book — balances and resting levels — by PDA or by owner
    name: Maker Books
  - description: Deposit / withdraw / close — fund movement for a maker book
    name: Maker Funds
  - description: Public protocol-wide aggregate statistics
    name: Stats
  - description: >-
      Submit signed Solana transactions and let Archer land them. Hosted at
      `https://send.archer.exchange`, separate from the REST API, using the same
      API key.
    name: Transaction Relay
paths:
  /ping:
    servers:
      - description: Transaction relay
        url: https://send.archer.exchange
    get:
      tags:
        - Transaction Relay
      summary: Ping
      description: >-
        Returns `pong`. No API key needed. Use it to open and keep warm a
        connection before sending.
      operationId: relayPing
      responses:
        '200':
          content:
            text/plain:
              schema:
                example: pong
                type: string
          description: '`pong`'
      security: []
components:
  securitySchemes:
    apiKey:
      in: header
      name: X-API-Key
      type: apiKey

````

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