helius_get_latest_blockhash
Retrieve the current blockhash from Solana for constructing transactions.
Instructions
Get the latest blockhash from the Solana blockchain
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| commitment | No |
Implementation Reference
- src/handlers/helius.ts:128-135 (handler)Handler function that calls connection.getLatestBlockhash() and returns the blockhash and last valid block height.
export const getLatestBlockhashHandler = async (input: GetLatestBlockhashInput): Promise<ToolResultSchema> => { try { const { blockhash, lastValidBlockHeight } = await (helius as any as Helius).connection.getLatestBlockhash(input.commitment); return createSuccessResponse(`Latest blockhash: ${blockhash}, Last valid block height: ${lastValidBlockHeight}`); } catch (error) { return createErrorResponse(`Error getting latest blockhash: ${error instanceof Error ? error.message : String(error)}`); } } - src/handlers/helius.types.ts:56-63 (schema)Type definitions for GetLatestBlockhashInput (optional commitment) and GetLatestBlockhashOutput (blockhash + lastValidBlockHeight).
export type GetLatestBlockhashInput = { commitment?: "confirmed" | "finalized" | "processed"; } export type GetLatestBlockhashOutput = { blockhash: string; lastValidBlockHeight: number; } - src/tools.ts:91-101 (registration)Tool registration defining the name, description, and input schema for helius_get_latest_blockhash.
{ name: "helius_get_latest_blockhash", description: "Get the latest blockhash from the Solana blockchain", inputSchema: { type: "object", properties: { commitment: { type: "string", enum: ["confirmed", "finalized", "processed"] } }, required: [] } }, - src/tools.ts:555-555 (registration)Mapping the tool name string to its handler function in the handlers dictionary.
"helius_get_latest_blockhash": getLatestBlockhashHandler, - src/handlers/utils.ts:38-59 (helper)Utility functions createSuccessResponse and createErrorResponse used by the handler to format responses.
export const createSuccessResponse = (message: string): ToolResultSchema => { return { content: [{ type: "text", text: message }], isError: false }; }; /** * Utility function to validate a public key and return an error response if invalid * @param publicKeyString The public key string to validate * @returns Either a PublicKey object or a ToolResultSchema with an error message */ export const validatePublicKey = (publicKeyString: string): PublicKey | ToolResultSchema => { const { publicKey, error } = createPublicKey(publicKeyString); if (error) { return createErrorResponse(error); } return publicKey!; };