decode_tx
Decode Bitcoin transaction hex to reveal details like inputs, outputs, and amounts for blockchain analysis and verification.
Instructions
Decode a Bitcoin transaction
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| rawHex | Yes | Transaction hex |
Implementation Reference
- src/server/tools.ts:107-128 (handler)MCP handler function for the decode_tx tool. Validates input schema and delegates to BitcoinService.decodeTx, then formats the response.
export async function handleDecodeTx( bitcoinService: BitcoinService, args: unknown ) { const result = DecodeTxSchema.safeParse(args); if (!result.success) { throw new McpError( ErrorCode.InvalidParams, `Invalid parameters: ${result.error.message}` ); } const tx = bitcoinService.decodeTx(result.data.rawHex); return { content: [ { type: "text", text: `Decoded transaction:\nTXID: ${tx.txid}\nVersion: ${tx.version}\nInputs: ${tx.inputs.length}\nOutputs: ${tx.outputs.length}\nLocktime: ${tx.locktime}`, }, ] as TextContent[], }; } - src/types.ts:122-124 (schema)Zod schema for validating input to decode_tx tool: requires rawHex string.
export const DecodeTxSchema = z.object({ rawHex: z.string().min(1, "Raw transaction hex is required"), }); - src/server/base.ts:136-145 (registration)Tool registration in listToolsRequestHandler: defines name, description, and inputSchema for decode_tx.
name: "decode_tx", description: "Decode a Bitcoin transaction", inputSchema: { type: "object", properties: { rawHex: { type: "string", description: "Transaction hex" }, }, required: ["rawHex"], }, } as Tool, - src/server/base.ts:206-207 (registration)Tool call handler registration: switch case dispatches decode_tx calls to handleDecodeTx.
case "decode_tx": { return handleDecodeTx(this.bitcoinService, args); - src/services/bitcoin.ts:137-163 (helper)Core implementation of transaction decoding using bitcoinjs-lib Transaction.fromHex, extracts txid, inputs, outputs, etc.
decodeTx(rawHex: string): DecodedTx { try { const tx = bitcoin.Transaction.fromHex(rawHex); return { txid: tx.getId(), version: tx.version, inputs: tx.ins.map((input) => ({ txid: Buffer.from(input.hash).reverse().toString("hex"), vout: input.index, sequence: input.sequence, })), outputs: tx.outs.map((output) => ({ value: output.value, scriptPubKey: output.script.toString("hex"), address: this.tryGetAddress(output.script), })), locktime: tx.locktime, }; } catch (error) { logger.error({ error, rawHex }, "Failed to decode transaction"); throw new BitcoinError( "Failed to decode transaction", BitcoinErrorCode.DECODE_ERROR ); } }