run_graphql_query
Execute read-only GraphQL queries on a Hasura endpoint, providing a query string and optional variables to retrieve data efficiently.
Instructions
Executes a read-only GraphQL query against the Hasura endpoint...
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| query | Yes | The GraphQL query string (must be a read-only operation). | |
| variables | No | Optional. An object containing variables... |
Implementation Reference
- src/index.ts:130-142 (handler)The main execution logic for the 'run_graphql_query' tool: logs execution, checks for mutation, executes the query using makeGqlRequest helper, returns formatted JSON result or throws error.
async ({ query, variables }) => { console.log(`[INFO] Executing tool 'run_graphql_query'`); if (query.trim().toLowerCase().startsWith('mutation')) { throw new Error("This tool only supports read-only queries..."); } try { const result = await makeGqlRequest(query, variables); return { content: [{ type: "text", text: JSON.stringify(result, null, 2) }] }; } catch (error: any) { console.error(`[ERROR] Tool 'run_graphql_query' failed: ${error.message}`); throw error; } } - src/index.ts:126-129 (schema)Zod input schema defining the tool parameters: required 'query' (string) and optional 'variables' (object).
{ query: z.string().describe("The GraphQL query string (must be a read-only operation)."), variables: z.record(z.unknown()).optional().describe("Optional. An object containing variables..."), }, - src/index.ts:123-143 (registration)The MCP server.tool() registration call for 'run_graphql_query', including description, input schema, and inline handler function.
server.tool( "run_graphql_query", "Executes a read-only GraphQL query against the Hasura endpoint...", { query: z.string().describe("The GraphQL query string (must be a read-only operation)."), variables: z.record(z.unknown()).optional().describe("Optional. An object containing variables..."), }, async ({ query, variables }) => { console.log(`[INFO] Executing tool 'run_graphql_query'`); if (query.trim().toLowerCase().startsWith('mutation')) { throw new Error("This tool only supports read-only queries..."); } try { const result = await makeGqlRequest(query, variables); return { content: [{ type: "text", text: JSON.stringify(result, null, 2) }] }; } catch (error: any) { console.error(`[ERROR] Tool 'run_graphql_query' failed: ${error.message}`); throw error; } } ); - src/index.ts:54-74 (helper)Supporting utility function that performs the actual GraphQL request using GraphQLClient, merges headers (including admin secret), and handles ClientError with GraphQL-specific error messages.
async function makeGqlRequest< T = any, V extends Record<string, any> = Record<string, any> >( query: string, variables?: V, requestHeaders?: Record<string, string> ): Promise<T> { try { const combinedHeaders = { ...headers, ...requestHeaders }; return await gqlClient.request<T>(query, variables, combinedHeaders); } catch (error) { if (error instanceof ClientError) { const gqlErrors = error.response?.errors?.map(e => e.message).join(', ') || 'Unknown GraphQL error'; console.error(`[ERROR] GraphQL Request Failed: ${gqlErrors}`, error.response); throw new Error(`GraphQL operation failed: ${gqlErrors}`); } console.error("[ERROR] Unexpected error during GraphQL request:", error); throw error; } }