OpenTofu MCP Server

Instructions

Implementation Reference

• src/servers/registry/index.ts:117-125 (handler)

  The tool handler function for 'get-resource-docs', which calls RegistryClient.getResourceDocs and returns the documentation as text, with error handling.

  server.tool("get-resource-docs", "Get detailed documentation for a specific OpenTofu resource by provider namespace, provider name, and resource name.", resourceDocsSchema, async (params) => {
    try {
      const resourceDocs = await client.getResourceDocs(params.namespace, params.name, params.resource, params.version);
      return textResult(resourceDocs);
    } catch (error: unknown) {
      const errorMessage = error instanceof Error ? error.message : "Resource documentation not found";
      return textResult(`Failed to get documentation for resource ${params.name}_${params.resource}: ${errorMessage}`);
    }
  });

• src/servers/registry/index.ts:23-28 (schema)

  Input schema/validation for the get-resource-docs tool using Zod.

  const resourceDocsSchema = {
    namespace: z.string().min(1).describe("Provider namespace (e.g., 'hashicorp', 'opentofu')"),
    name: z.string().min(1).describe("Provider name WITHOUT 'terraform-provider-' prefix (e.g., 'aws', 'kubernetes')"),
    resource: z.string().min(1).describe("Resource name WITHOUT provider prefix (e.g., 's3_bucket', 'instance')"),
    version: z.string().optional().describe("Provider version (e.g., 'v4.0.0'). If not specified, latest version will be used"),
  };

• src/registry/index.ts:118-120 (helper)

  RegistryClient method that retrieves resource documentation by delegating to fetchMarkdownDoc.

  async getResourceDocs(namespace: string, name: string, target: string, version?: string): Promise<string> {
    return await this.fetchMarkdownDoc("resource", namespace, name, target, version);
  }

• src/registry/index.ts:126-139 (helper)

  Core helper function that resolves the provider version if needed and fetches the markdown documentation from the OpenTofu Registry API.

    private async fetchMarkdownDoc(docType: DocType, namespace: string, name: string, docName: string, version?: string): Promise<string> {
      let targetVersion = version;
      if (!targetVersion) {
        targetVersion = await this.getLatestProviderVersion(namespace, name);
        if (!targetVersion) {
          throw new Error(`Could not determine latest version for provider ${namespace}/${name}`);
        }
      }
  
      const path = `/registry/docs/providers/${namespace}/${name}/${targetVersion}/${docType}s/${docName}.md`;
      console.error(`Fetching ${path}`);
      return this.fetchFromApi<string>(path, {}, "text");
    }
  }