--- updatedAt: 2026-05-20T16:41:48.000Z --- Fetch the complete documentation index at: https://docs.blockdaemon.com/llms.txt. Use this file to discover all available pages before exploring further. Append .md to any documentation page URL to get its markdown version. # Compile an Unsigned Transaction Takes an unsigned transaction and a signature and returns a signed transaction. ### **Compute Unit Value**: `5` (fixed) *** > 👍 START HERE! > > Click **Try It!** to test the endpoint with the default values or customize your request by following these steps: > > 1. Enter your API key in the **Header: token** text box (top right). > * You can **[get a free API key here](https://docs.blockdaemon.com/docs/quick-start-blockdaemon-api-suite)** . > 2. Enter the parameters available below. > 3. Click **Try It!**. *** {`

Supported Protocols & Networks

Protocol Network Path Parameter
Avalanche Mainnet-c avalanche-mainnet-c
Testnet-c avalanche-testnet-c
Bitcoin Mainnet bitcoin-mainnet
Testnet bitcoin-testnet
Testnet4 bitcoin-testnet4
Bitcoincash Mainnet bitcoincash-mainnet
Testnet bitcoincash-testnet
Cosmos Mainnet cosmos-mainnet
Ethereum Mainnet ethereum-mainnet
Sepolia ethereum-sepolia
Hoodi ethereum-hoodi
Litecoin Mainnet litecoin-mainnet
Testnet litecoin-testnet
Near Mainnet near-mainnet
Testnet near-testnet
Polkadot Mainnet polkadot-mainnet
Westend polkadot-westend
Assethub Mainnet polkadot-assethub-mainnet
Assethub Westend polkadot-assethub-westend
Polygon Mainnet polygon-mainnet
Amoy polygon-amoy
Solana Mainnet solana-mainnet
Testnet solana-testnet
Devnet solana-devnet
Stellar Mainnet stellar-mainnet
Testnet stellar-testnet
Tron Mainnet tron-mainnet
Nile tron-nile
`} # OpenAPI definition ```json { "openapi": "3.0.3", "info": { "title": "Transaction API", "version": "1.0.0", "description": "Blockdaemon transaction API to create, compile, send and verify transactions for supported blockchains.", "contact": { "name": "Blockdaemon", "email": "info@blockdaemon.com", "url": "https://blockdaemon.com" }, "x-logo": { "url": "https://storage.googleapis.com/blockdaemon-app-static-images/marketing/PNG/dark-logo.png", "altText": "Blockdaemon logo" } }, "servers": [ { "url": "https://svc.blockdaemon.com/tx/v1", "description": "Blockdaemon transaction API" } ], "security": [ { "apiKeyAuthHeader": [] }, { "bearerAuth": [] } ], "paths": { "/{blockchain_id}/compile": { "parameters": [ { "$ref": "#/components/parameters/blockchain_id" } ], "post": { "summary": "Compile an Unsigned Transaction", "description": "Takes an unsigned transaction and a signature and returns a signed transaction.", "operationId": "TxCompile", "requestBody": { "required": true, "content": { "application/json": { "schema": { "$ref": "#/components/schemas/ApiTxCompileRequest" }, "examples": { "evm": { "summary": "EVM example", "value": { "unsigned_tx": "e909843b9aca008252089481b7e08f65bdf5648606c89998a9cc81643976478601d1a94a200080808080", "address": "b9aca008252089481b7e08f65bdf5648606c8", "signature": "", "public_key": "" } }, "btc_single_signature": { "summary": "Bitcoin P2PKH example with a single signature for a single UTxO", "value": { "unsigned_tx": "010000000131da247ea6672d26661559a06d677cf1756feebc2b8fb299a36125b68047d2050000000000ffffffff0210270000000000001976a91417e036c0c8b9e59c99cf1e2d6b7d0a4864a336f988ac729a0000000000001976a914b3d049ba9f8947c29b491cb14ddea70241ba353e88ac00000000", "signatures": [ { "signature": "3045022100e4db442039a65eb2a0043647a5f88c5211dd3dcc39d4eba379301c87940587190220764dd4609b7efac2be539bdca148072ad172f53314ff68e9f8801f4b1ea754b0", "address": "mwuimViRhJ5nMJDFiS3ZTQ73hmBH1NUjZA", "public_key": "0x027513c263c79dc1acde054bbb754616b67612924b98893efa73708f73441bccdb" } ] } }, "btc_multiple_signatures": { "summary": "Bitcoin P2WPKH example with multiple signatures for each UTxO", "value": { "unsigned_tx": "01000000039c9aa424d4db36156a86245dccf4fe0be6feb5c51372d116358e8b5c0a47fd480200000000ffffffffc74f6e194d162b3b80e7e66f8eab7b31ea870d58a0eecaaafb4e29464d77f69c0900000000ffffffffad95de94df324097b0820d24caaeb82aa52ddcd5a07aff62161c33b23cc28bf20800000000ffffffff016c020000000000001600148dd7608be98d6bd93368f24d45b1165b74cb913700000000", "signatures": [ { "signature": "30440220428fc6fd5cff7b5023699f1e32694c8cab3f8de2dc841d886f9235b2658c0ef4022059e344ea9d5a2434c416ad2164e445aa44d87daaba507bc8f8fde198ab9a5b57", "address": "tb1q3htkpzlf344ajvmg7fx5tvgktd6vhyfhlq9urn", "public_key": "025dafb4159e25323eb2c7c684bec7de6bb5a3d17b1adc66a0025563e4081adf3f" }, { "signature": "304402207ed5e14b8fff54138b1f1e7e3d19c7f7d670c783b5aa157edca7d433eb55e4e5022067ebd3f41b788ecb109d0fb053ae895dfa172ee0556c94bdc1ab798d59753714", "address": "tb1q3htkpzlf344ajvmg7fx5tvgktd6vhyfhlq9urn", "public_key": "025dafb4159e25323eb2c7c684bec7de6bb5a3d17b1adc66a0025563e4081adf3f" }, { "signature": "3045022100a3a2082e864caf7b3645d942a96c68da7aed2bccffbdddf5d11456440f3c960a022073ee6723e6ff1a99f78ced51a04669947f4799fdb55900ddfa4747b9eb5ec4be", "address": "tb1q3htkpzlf344ajvmg7fx5tvgktd6vhyfhlq9urn", "public_key": "025dafb4159e25323eb2c7c684bec7de6bb5a3d17b1adc66a0025563e4081adf3f" } ] } } } } } }, "responses": { "200": { "description": "OK", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/ApiTxSigned" } } } }, "401": { "$ref": "#/components/responses/ErrorUnauthorized" }, "429": { "$ref": "#/components/responses/ErrorTooManyRequests" }, "500": { "$ref": "#/components/responses/ErrorInternal" }, "501": { "$ref": "#/components/responses/ErrorNotImplemented" }, "503": { "$ref": "#/components/responses/ErrorServiceUnavailable" } } } } }, "components": { "securitySchemes": { "apiKeyAuthHeader": { "type": "apiKey", "in": "header", "name": "X-API-Key", "description": "Unlock higher TPS - Create your own API key in the [Blockdaemon App](https://app.blockdaemon.com).\n", "x-default": "2go1YqUcuAr4WZ2-3WgSD3c7qpatZqQuNWhTVBldKZnTSUtw" }, "bearerAuth": { "type": "http", "scheme": "bearer", "bearerFormat": "Opaque", "description": "[Legacy Auth] Unlock higher TPS - Create your own API key in the [Blockdaemon App](https://app.blockdaemon.com).\n", "x-default": "2go1YqUcuAr4WZ2-3WgSD3c7qpatZqQuNWhTVBldKZnTSUtw" } }, "parameters": { "blockchain_id": { "name": "blockchain_id", "in": "path", "required": true, "description": "Either a hyphen seperated protocol-network pair like `ethereum-mainnet` or the `chain-id`", "schema": { "type": "string", "default": "ethereum-mainnet" } } }, "responses": { "ErrorTooManyRequests": { "description": "Rate limit exceeded", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/error" }, "example": { "type": "too-many-requests", "title": "Too Many Requests", "status": 429, "detail": "Request rate limits have been exceeded. Try again after a few seconds." } } } }, "ErrorUnauthorized": { "description": "Invalid or expired token", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/error" }, "example": { "type": "unauthorized", "title": "Invalid Token", "status": 401 } } } }, "ErrorInternal": { "description": "An internal server error happened", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/error" }, "example": { "type": "internal-server-error", "title": "Internal Server Error", "status": 500 } } } }, "ErrorServiceUnavailable": { "description": "The resource you are trying to access is currently unavailable", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/error" }, "example": { "type": "unavailable", "title": "Unavailable", "status": 503 } } } }, "ErrorNotImplemented": { "description": "The request endpoint is not implemented", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/error" }, "example": { "type": "not-implemented", "title": "Not implemented", "status": 501 } } } } }, "schemas": { "StellarSignature": { "type": "object", "properties": { "signature": { "type": "string", "description": "A hex encoded string of the cryptographic signature.", "example": "0x..", "x-oapi-codegen-extra-tags": { "validate": "required" } }, "public_key": { "type": "string", "description": "A hex encoded string which is the public key for the address.", "example": "0x..", "x-oapi-codegen-extra-tags": { "validate": "required" } } }, "required": [ "signature", "public_key" ] }, "SolanaSignature": { "type": "object", "properties": { "signature": { "type": "string", "description": "A base58 encoded string of the cryptographic signature.", "example": "2A3yw9TAUm55Ka7EnJDM6vZPrtsjmek9bMhGBdiUGgW8aQugNp5CdyLqMNbahbJXMnQ9h2SMFHhbk2R39RSzsSef", "x-oapi-codegen-extra-tags": { "validate": "required" } } }, "required": [ "signature" ] }, "signature": { "type": "object", "properties": { "address": { "type": "string", "description": "The hex address.", "example": "0x31c129468975e4ef41135a405000e6428a399a03d023b6627eed4cb95faf19ca", "x-oapi-codegen-extra-tags": { "validate": "required" } }, "signature": { "type": "string", "description": "A hex encoded string of the cryptographic signature. ECDSA secp256k1 signatures are expected to be ASN1 encoded.", "example": "0x..", "x-oapi-codegen-extra-tags": { "validate": "required" } }, "public_key": { "type": "string", "description": "A hex encoded string which is the public key for the address.", "example": "0x..", "x-oapi-codegen-extra-tags": { "validate": "required" } } }, "required": [ "address", "signature", "public_key" ] }, "ApiTxCompileRequest": { "anyOf": [ { "$ref": "#/components/schemas/ApiTxCompileRequestEVM" }, { "$ref": "#/components/schemas/ApiTxCompileRequestStellar" }, { "$ref": "#/components/schemas/ApiTxCompileRequestSubstrate" }, { "$ref": "#/components/schemas/ApiTxCompileRequestBTC" }, { "$ref": "#/components/schemas/ApiTxCompileRequestTron" }, { "$ref": "#/components/schemas/ApiTxCompileRequestSolana" }, { "$ref": "#/components/schemas/ApiTxCompileRequestNear" }, { "$ref": "#/components/schemas/ApiTxCompileRequestCosmos" } ] }, "ApiTxCompileRequestEVM": { "title": "Api Tx Compile Request EVM", "type": "object", "properties": { "unsigned_tx": { "type": "string", "description": "The unsigned transaction. This transaction is hex RLP encoded and should be encoded wihout the R, S and V values (this is diffrent from what the /create endpoint returns)", "example": "02ed82426880840c1a97ac847e881fdc82520894057cbbc4d1568530991088108ee48fd8b949167f843b9aca0080c0", "x-oapi-codegen-extra-tags": { "validate": "required" } }, "address": { "type": "string", "description": "The hex address.", "example": "0x31c129468975e4ef41135a405000e6428a399a03d023b6627eed4cb95faf19ca" }, "signature": { "type": "string", "description": "A hex encoded string of the cryptographic signature. This should include the R and S values of the signature in ASN1 encoding.", "example": "0x..", "x-oapi-codegen-extra-tags": { "validate": "required" } }, "public_key": { "type": "string", "description": "A hex encoded string of the sender's public key in the 32 byte compressed format.", "example": "0x..", "x-oapi-codegen-extra-tags": { "validate": "required" } } }, "required": [ "unsigned_tx", "signature", "public_key" ] }, "ApiTxCompileRequestBTC": { "title": "Api Tx Compile Request BTC", "type": "object", "properties": { "unsigned_tx": { "type": "string", "description": "The transaction data needed to sign.", "example": "02f86f0180834c4b40852096a4848082cde49495ad61b0a150d79219dcf64e1e6cc01f0b64c4ce80b844a9059cbb000000000000000000000000e6026f60efc3d0e714f1b89c596aa484ffbd25c800000000000000000000000000000000000000000303b6ae12d00504a8ed8000c0808080", "x-oapi-codegen-extra-tags": { "validate": "required" } }, "signatures": { "type": "array", "items": { "$ref": "#/components/schemas/signature" }, "x-oapi-codegen-extra-tags": { "validate": "required,dive" }, "example": [ { "address": "0x31c129468975e4ef41135a405000e6428a399a03d023b6627eed4cb95faf19ca", "signature": "0x..", "public_key": "0x.." } ] } }, "required": [ "unsigned_tx", "signatures" ] }, "ApiTxCompileRequestStellar": { "title": "Api Tx Compile Request Stellar", "type": "object", "properties": { "unsigned_tx": { "type": "string", "description": "The base64 encoded transaction", "x-oapi-codegen-extra-tags": { "validate": "required" } }, "signatures": { "type": "array", "items": { "$ref": "#/components/schemas/StellarSignature" }, "x-oapi-codegen-extra-tags": { "validate": "required,dive" } }, "replace_signatures": { "type": "boolean", "x-go-type-skip-optional-pointer": true } }, "required": [ "unsigned_tx", "signatures" ] }, "ApiTxCompileRequestSubstrate": { "title": "Api Tx Compile Request Substrate", "type": "object", "properties": { "unsigned_tx": { "type": "string", "description": "The hex encoded unsigned extrinsic", "x-oapi-codegen-extra-tags": { "validate": "required" } }, "signature": { "type": "string", "description": "A hex encoded string of the cryptographic signature.", "x-oapi-codegen-extra-tags": { "validate": "required" } }, "public_key": { "type": "string", "description": "The hex encoded public key", "x-oapi-codegen-extra-tags": { "validate": "required" } }, "signature_scheme": { "type": "string", "enum": [ "ed25519", "sr25519" ], "default": "ed25519" } }, "required": [ "unsigned_tx", "signature", "public_key", "signature_scheme" ] }, "ApiTxCompileRequestTron": { "title": "Api Tx Compile Request Tron", "type": "object", "properties": { "unsigned_tx": { "type": "string", "description": "The protobuf hex encoded tron transaction", "x-oapi-codegen-extra-tags": { "validate": "required" } }, "signature": { "type": "string", "description": "A hex encoded string of the cryptographic signature.", "x-oapi-codegen-extra-tags": { "validate": "required" } }, "public_key": { "type": "string", "description": "The hex encoded public key of the signer", "x-oapi-codegen-extra-tags": { "validate": "required" } } }, "required": [ "unsigned_tx", "signature", "public_key" ] }, "ApiTxCompileRequestSolana": { "title": "Api Tx Compile Request Solana", "type": "object", "properties": { "unsigned_tx": { "type": "string", "description": "The transaction data needed to sign.", "example": "AAEAAwYqxtWdFTb3/xrAW77tXSxoksrUwfWFAj5zub2JojTbnAnmeRNLj9i/bnMMVMh6QF5AP37ejGou8zrK1/IjTymqfYQGW/wgxXxux6CxGpqQkEbj0ZY3LYwYJuNSvOf8i/0Gp9UXGSxWjuCKhF9z0peIzwNcMUWyGrNE2AYuqUAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAwZGb+UhFzL/7K26csOb57yM5bvF9xJrLEObOkAAAACSA/HmJql7hyAMci43hBLdOCK44yJ2YmFxfit5l1C6ngMEAwEDAAQEAAAABAIAAgwCAAAAAOH1BQAAAAAFAAkDiBMAAAAAAAA=", "x-oapi-codegen-extra-tags": { "validate": "required" } }, "signatures": { "type": "array", "items": { "$ref": "#/components/schemas/SolanaSignature" }, "x-oapi-codegen-extra-tags": { "validate": "required" }, "example": [ { "signature": "4STXcD6nnpdPqM2AsJgxr4Wfbz4ihS7xQ5eCiQw2FUMTG7vqdr4TqomTrWsos4ZAjZbAr4vceEccUKTVWCn3jSs" } ] } }, "required": [ "unsigned_tx", "signatures" ] }, "ApiTxCompileRequestNear": { "title": "Api Tx Compile Request Near", "type": "object", "properties": { "unsigned_tx": { "type": "string", "description": "The unsigned transaction in base64 encoding.", "x-oapi-codegen-extra-tags": { "validate": "required" } }, "signature": { "type": "string", "description": "The signature hex encoded", "x-oapi-codegen-extra-tags": { "validate": "required" } } }, "required": [ "unsigned_tx", "signature" ] }, "CosmosSignature": { "type": "object", "properties": { "sequence": { "type": "integer", "x-go-type": "uint64", "x-go-type-skip-optional-pointer": true }, "signature": { "type": "string", "x-oapi-codegen-extra-tags": { "validate": "required" } }, "sign_mode": { "x-go-type": "int32", "type": "string", "x-go-type-skip-optional-pointer": true }, "public_key": { "type": "string" } }, "required": [ "sequence", "sign_mode", "signature", "public_key" ] }, "ApiTxCompileRequestCosmos": { "title": "Api Tx Compile Request Cosmos", "type": "object", "properties": { "unsigned_tx": { "type": "string", "description": "The transaction data needed to sign.", "x-oapi-codegen-extra-tags": { "validate": "required" } }, "signatures": { "type": "array", "items": { "$ref": "#/components/schemas/CosmosSignature" }, "x-oapi-codegen-extra-tags": { "validate": "required,dive" } } }, "required": [ "unsigned_tx", "signatures" ] }, "ApiTxSigned": { "type": "object", "properties": { "tx": { "type": "string", "description": "The signed TX.", "example": "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", "x-oapi-codegen-extra-tags": { "validate": "required" } } }, "required": [ "tx" ] }, "error": { "type": "object", "properties": { "type": { "type": "string", "description": "The HTTP error type.", "example": "bad-request" }, "code": { "type": "integer", "description": "The numeric error code.", "example": 16384 }, "title": { "type": "string", "description": "The short error description.", "example": "Invalid Address" }, "status": { "type": "integer", "description": "The HTTP status of the error.", "example": 400 }, "detail": { "type": "string", "description": "Long error description", "example": "The requested address is invalid on this protocol." } } } } } } ```