send_draft

Instructions

Implementation Reference

• src/index.ts:371-386 (registration)

  Registers the 'send_draft' MCP tool, including input schema (draft ID) and handler that calls Gmail API to send the draft.

  server.tool("send_draft",
    "Send an existing draft",
    {
      id: z.string().describe("The ID of the draft to send")
    },
    async (params) => {
      return handleTool(config, async (gmail: gmail_v1.Gmail) => {
        try {
          const { data } = await gmail.users.drafts.send({ userId: 'me', requestBody: { id: params.id } })
          return formatResponse(data)
        } catch (error) {
          return formatResponse({ error: 'Error sending draft, are you sure you have at least one recipient?' })
        }
      })
    }
  )

• src/index.ts:376-385 (handler)

  Inline handler function for 'send_draft' tool that uses handleTool to authenticate and execute gmail.users.drafts.send API call.

  async (params) => {
    return handleTool(config, async (gmail: gmail_v1.Gmail) => {
      try {
        const { data } = await gmail.users.drafts.send({ userId: 'me', requestBody: { id: params.id } })
        return formatResponse(data)
      } catch (error) {
        return formatResponse({ error: 'Error sending draft, are you sure you have at least one recipient?' })
      }
    })
  }

• src/index.ts:373-375 (schema)

  Zod schema defining input parameters for 'send_draft' tool: requires 'id' as string (draft ID).

  {
    id: z.string().describe("The ID of the draft to send")
  },

• src/index.ts:50-80 (helper)

  Shared helper function 'handleTool' used by 'send_draft' (and other tools) to handle OAuth2 authentication, credential validation, Gmail client creation, and API execution with error handling.

  const handleTool = async (queryConfig: Record<string, any> | undefined, apiCall: (gmail: gmail_v1.Gmail) => Promise<any>) => {
    try {
      const oauth2Client = queryConfig ? createOAuth2Client(queryConfig) : defaultOAuth2Client
      if (!oauth2Client) throw new Error('OAuth2 client could not be created, please check your credentials')
  
      const credentialsAreValid = await validateCredentials(oauth2Client)
      if (!credentialsAreValid) throw new Error('OAuth2 credentials are invalid, please re-authenticate')
  
      const gmailClient = queryConfig ? google.gmail({ version: 'v1', auth: oauth2Client }) : defaultGmailClient
      if (!gmailClient) throw new Error('Gmail client could not be created, please check your credentials')
  
      const result = await apiCall(gmailClient)
      return result
    } catch (error: any) {
      // Check for specific authentication errors
      if (
        error.message?.includes("invalid_grant") ||
        error.message?.includes("refresh_token") ||
        error.message?.includes("invalid_client") ||
        error.message?.includes("unauthorized_client") ||
        error.code === 401 ||
        error.code === 403
      ) {
        return formatResponse({
          error: `Authentication failed: ${error.message}. Please re-authenticate by running: npx @shinzolabs/gmail-mcp auth`,
        });
      }
  
      return formatResponse({ error: `Tool execution failed: ${error.message}` });
    }
  }