arbdebug_validationInputsAt
Retrieve validation inputs for specific messages on Arbitrum networks to debug and verify transaction processing using debug APIs.
Instructions
Get validation inputs at a specific message (requires debug API)
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| rpcUrl | No | The RPC URL of the Arbitrum node (optional if default is set) | |
| chainName | No | Chain name (e.g., 'Xai', 'Arbitrum One') - will auto-resolve to RPC URL | |
| msgNum | Yes | Message number to get validation inputs for | |
| target | No | Target for validation inputs |
Implementation Reference
- src/index.ts:633-650 (handler)MCP tool handler for 'arbdebug_validationInputsAt': resolves RPC URL from args or chainName, instantiates NitroNodeClient, calls getValidationInputsAt(msgNum, target), returns JSON-formatted result.
case "arbdebug_validationInputsAt": { const rpcUrl = await this.resolveRpcUrl( (args.rpcUrl as string) || (args.chainName as string) ); const nodeClient = new NitroNodeClient(rpcUrl); const result = await nodeClient.getValidationInputsAt( args.msgNum as number, args.target as string ); return { content: [ { type: "text", text: JSON.stringify(result, null, 2), }, ], }; } - src/index.ts:1435-1462 (registration)Tool registration in getAvailableTools(): defines name, description, and inputSchema (rpcUrl optional, chainName optional, msgNum required, target optional). Returned by ListTools handler.
name: "arbdebug_validationInputsAt", description: "Get validation inputs at a specific message (requires debug API)", inputSchema: { type: "object" as const, properties: { rpcUrl: { type: "string", description: "The RPC URL of the Arbitrum node (optional if default is set)", }, chainName: { type: "string", description: "Chain name (e.g., 'Xai', 'Arbitrum One') - will auto-resolve to RPC URL", }, msgNum: { type: "number", description: "Message number to get validation inputs for", }, target: { type: "string", description: "Target for validation inputs", }, }, required: ["msgNum"], }, }, - src/index.ts:1439-1461 (schema)Input schema definition for the tool: object with optional rpcUrl/chainName, required msgNum (number), optional target (string).
type: "object" as const, properties: { rpcUrl: { type: "string", description: "The RPC URL of the Arbitrum node (optional if default is set)", }, chainName: { type: "string", description: "Chain name (e.g., 'Xai', 'Arbitrum One') - will auto-resolve to RPC URL", }, msgNum: { type: "number", description: "Message number to get validation inputs for", }, target: { type: "string", description: "Target for validation inputs", }, }, required: ["msgNum"], }, - Helper method in NitroNodeClient: converts msgNum to hex, optionally adds target, calls RPC 'arbdebug_validationInputsAt', returns inputs or error.
async getValidationInputsAt( msgNum: number, target?: string ): Promise<ValidationInputs> { try { const params = [`0x${msgNum.toString(16)}`]; if (target) { params.push(target); } const inputs = await this.makeRpcCall( "arbdebug_validationInputsAt", params ); return { inputs }; } catch (error) { return { inputs: null, error: `Validation inputs not supported on this RPC endpoint: ${ (error as Error).message }`, }; }