> ## 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. # Send a transaction > Accepts a fully signed transaction and lands it. Returns the signature as soon as it is accepted (after preflight, unless `skipPreflight`), before it lands; track it with `GET /v1/send/{signature}`. Send JSON, or raw bytes with `Content-Type: application/octet-stream`. With raw bytes, pass the options as query parameters: `?commitment=confirmed&maxRetries=3&skipPreflight=true`. In JSON, body fields take precedence over query parameters. Re-submitting an already-accepted transaction returns the same signature and does not re-send it. ## OpenAPI ````yaml /openapi.json post /v1/send 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: /v1/send: servers: - description: Transaction relay url: https://send.archer.exchange post: tags: - Transaction Relay summary: Send a transaction description: >- Accepts a fully signed transaction and lands it. Returns the signature as soon as it is accepted (after preflight, unless `skipPreflight`), before it lands; track it with `GET /v1/send/{signature}`. Send JSON, or raw bytes with `Content-Type: application/octet-stream`. With raw bytes, pass the options as query parameters: `?commitment=confirmed&maxRetries=3&skipPreflight=true`. In JSON, body fields take precedence over query parameters. Re-submitting an already-accepted transaction returns the same signature and does not re-send it. operationId: relaySendTransaction parameters: - description: Same as the JSON field. Use with a raw-bytes body. in: query name: commitment required: false schema: default: processed enum: - processed - confirmed - finalized type: string - description: Same as the JSON field. Use with a raw-bytes body. in: query name: maxRetries required: false schema: default: 1 minimum: 0 type: integer - description: Same as the JSON field. Use with a raw-bytes body. in: query name: skipPreflight required: false schema: default: false type: boolean requestBody: content: application/json: schema: $ref: '#/components/schemas/SendTransactionRequest' application/octet-stream: schema: description: >- The serialized signed transaction, in any message format: legacy, v0 or v1 (max 1232 bytes for legacy and v0, 4096 bytes for v1). format: binary type: string required: true responses: '200': content: application/json: schema: $ref: '#/components/schemas/SendTransactionResponse' description: Accepted (or already accepted). The relay is now landing it. '400': content: application/json: examples: invalidOption: summary: Invalid option value: error: INVALID_REQUEST message: commitment must be "processed", "confirmed" or "finalized" invalidTransaction: summary: Invalid transaction value: error: INVALID_TRANSACTION message: transaction signature verification failed preflightFailed: summary: Preflight failed value: err: InstructionError: - 2 - Custom: 1 error: PREFLIGHT_FAILED logs: - Program 11111111111111111111111111111111 invoke [1] - 'Transfer: insufficient lamports 0, need 1' - >- Program 11111111111111111111111111111111 failed: custom program error: 0x1 message: >- Transaction simulation failed: {"InstructionError":[2,{"Custom":1}]} reason: code: 1 instruction: 2 name: ResultWithNegativeLamports program: '11111111111111111111111111111111' programName: System Program schema: $ref: '#/components/schemas/RelayErrorResponse' description: >- Rejected: invalid body/options/transaction, or the preflight simulation failed. '401': $ref: '#/components/responses/RelayUnauthorized' '429': $ref: '#/components/responses/RelayRateLimited' '503': content: application/json: examples: overloaded: summary: Overloaded value: error: OVERLOADED message: Too many pending transactions; retry shortly. preflightUnavailable: summary: Preflight unavailable value: error: PREFLIGHT_UNAVAILABLE message: >- Preflight simulation is unavailable right now; retry, or send with skipPreflight=true. schema: $ref: '#/components/schemas/RelayErrorResponse' description: >- Too many transactions in flight across the relay, or preflight simulation is temporarily unavailable. Retry shortly (or send with `skipPreflight=true`). security: - apiKey: [] - apiKeyQuery: [] components: schemas: SendTransactionRequest: additionalProperties: false properties: commitment: default: processed description: >- Commitment at which the transaction counts as landed (and re-sending stops). Also the commitment preflight simulates at. enum: - processed - confirmed - finalized type: string encoding: default: base64 description: Encoding of `transaction`. enum: - base64 - base58 type: string maxRetries: default: 1 description: >- Re-sends after the first send, ~400 ms apart, while it hasn't landed. Capped at 149. minimum: 0 type: integer skipPreflight: default: false description: Skip simulating the transaction before sending it. type: boolean transaction: description: >- The fully signed transaction (legacy or v0), serialized and encoded as `encoding`. example: AQAAAA...base64... type: string required: - transaction type: object SendTransactionResponse: properties: signature: description: >- The transaction's first signature (base58). Returned as soon as the transaction is accepted, before it lands. example: >- 5r5Zb67VfBe3cGp27z53XVcQbF7oTmf9N4q2WoqDxWL716mSq8uttuZeABVksZRQPa28fTfJvDYiDcCYN685bDRr type: string required: - signature type: object RelayErrorResponse: properties: err: description: >- `PREFLIGHT_FAILED` only: the simulation error as Solana RPC returns it, a string (e.g. `"AccountNotFound"`) or an object (e.g. `{"InstructionError": [0, {"Custom": 1}]}`). error: description: Machine-readable error code. enum: - MISSING_API_KEY - INVALID_API_KEY - RATE_LIMITED - INVALID_REQUEST - INVALID_TRANSACTION - PREFLIGHT_FAILED - PREFLIGHT_UNAVAILABLE - INVALID_SIGNATURE - NOT_FOUND - OVERLOADED type: string logs: description: '`PREFLIGHT_FAILED` only: program logs from the simulation.' items: type: string type: array message: description: Human-readable error description. type: string reason: allOf: - $ref: '#/components/schemas/RelayFailureReason' description: '`PREFLIGHT_FAILED` only: the simulation error explained.' required: - error - message type: object RelayFailureReason: description: >- Names the error behind a failed or expired transaction. Solana's error variants are passed through as-is; a custom program error code is mapped to that program's variant name (Archer, System, Token, Token-2022, Associated Token Account; any other program stays `Custom`). The program is taken from the logs, so a failure inside a router's call (e.g. Jupiter calling Archer) is attributed to the program that actually raised it. properties: code: description: >- The program's own error code, for custom program errors (Archer's codes are listed in its IDL). example: 703 nullable: true type: integer instruction: description: Index of the top-level instruction the error is attributed to. example: 2 nullable: true type: integer name: description: >- The error's variant name: the program's for a custom error (e.g. `InvalidMakerBook`, `SlippageToleranceExceeded`, `InsufficientFunds`), otherwise Solana's (e.g. `BlockhashNotFound`, `MissingRequiredSignature`); `Custom` for an unrecognised program's code; `BlockhashExpired` or `NotLanded` for an expired transaction. example: SlippageToleranceExceeded type: string program: description: >- Program that raised the error (base58). `null` for errors outside any instruction (fees, blockhash, account loading, expiry). example: Archer8kgiavM61GyusMzaaS2ft5sALtNsD1HxkUPMhy nullable: true type: string programName: description: >- Well-known name of `program`, when known (e.g. `Archer`, `Token Program`). example: Archer nullable: true type: string required: - name - program - programName - instruction - code type: object responses: RelayUnauthorized: content: application/json: example: error: MISSING_API_KEY message: >- An API key is required. Pass it via the X-API-Key header or ?api-key=. schema: $ref: '#/components/schemas/RelayErrorResponse' description: Missing or unknown API key. RelayRateLimited: content: application/json: example: error: RATE_LIMITED message: Rate limit exceeded for this API key. schema: $ref: '#/components/schemas/RelayErrorResponse' description: >- Rate limit exceeded for this API key: 10/s (burst 20) for sending, and separately 10/s (burst 20) for status lookups. securitySchemes: apiKey: in: header name: X-API-Key type: apiKey apiKeyQuery: description: >- Same key as `X-API-Key`, as a query parameter (`?api-key=YOUR_KEY`). Transaction relay only. in: query name: api-key type: apiKey ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.