How to integrate Gmail MCP with OpenCode

Trusted by teams at
AWS
Glean
Zoom
Airtable

30 min · no commitment · see it on your stack

Gmail logo
OpenCode logo
divider

How to integrate Gmail MCP with OpenCode

This guide explains how to connect Gmail MCP to OpenCode using Composio Connect, which simplifies OAuth, API changes, and reliability concerns.

There are two ways to set this up:

Also integrate Gmail with

Why use Composio?

Composio provides a single MCP server or CLI tool that exposes a set of meta-tools, allowing you to:

  • Connect to 1,000+ apps with on-demand tool loading, so you do not fill your LLM context window with unnecessary tool definitions.
  • Use programmatic tool calling through a remote Bash tool, letting LLMs write their own code to handle complex tool chaining. This reduces back-and-forth for frequent tool calls.
  • Handle large tool responses outside the LLM context to keep conversations lean.

Connect Gmail with OpenCode

Option 1: Using Composio CLI

1. Install Composio CLI

Install the Composio CLI, authenticate, and initialize your project:

bash
# Install the Composio CLI
curl -fsSL https://composio.dev/install | bash

# Authenticate with Composio
composio login

During login, you will be redirected to the sign-in page. Finish the flow and you are all set.

Composio CLI authorization screen

2. Authorize Gmail

Once the CLI is installed, it is essentially done. Give OpenCode access to your apps with these steps:

  1. Launch OpenCode.
  2. Prompt it to "Authenticate with Gmail Composio".
  3. Complete the authentication and authorization flow, and your Gmail integration is all set.
  4. Start asking anything you want.

Option 2: Using Composio MCP

You can also connect Gmail to OpenCode by adding Composio as an MCP server through the OpenCode CLI.

1. Add the Composio MCP server

bash
opencode mcp add

This launches an interactive prompt.

2. Fill in the fields

FieldValue
Namecomposio
Typeremote
URLhttps://connect.composio.dev/mcp
Require OAuthYes
Have client IDNo
OpenCode MCP server interactive prompt for Composio

Alternatively, you can skip the interactive prompt and paste the configuration directly into your OpenCode config file.

Open your global OpenCode config:

bash
open ~/.config/opencode/opencode.json

Add this under the mcp key and save the file.

bash
{
  "mcp": {
    "composio": {
      "type": "remote",
      "url": "https://connect.composio.dev/mcp",
      "enabled": true
    }
  }
}

3. Authenticate

Authenticate the Composio MCP server you just added:

bash
opencode mcp auth composio

This opens a browser session. Authorize Composio and you are done.

Composio browser authorization for OpenCode MCP

4. Verify installation

bash
opencode mcp list

5. Connect Gmail with OpenCode

Now, in the chat, ask the agent to connect to Gmail or give it any Gmail-related task.

For example, ask it to:

  • "Summarize unread emails from this morning"
  • "Create draft replies to urgent messages"
  • "Fetch contact details for recent senders"

It will prompt you to authenticate and authorize access to Gmail.

That is it. Composio tools are now available in OpenCode, and your Gmail account is ready to use.

Supported Tools & Triggers

Tools
Triggers
Modify email labelsAdds and/or removes specified gmail labels for a message; ensure `message id` and all `label ids` are valid (use 'listlabels' for custom label ids).
Create email draftCreates a gmail email draft, supporting to/cc/bcc, subject, plain/html body (ensure `is html=true` for html), attachments, and threading.
Create labelCreates a new label with a unique name in the specified user's gmail account.
Delete DraftPermanently deletes a specific gmail draft using its id; ensure the draft exists and the user has necessary permissions for the given `user id`.
Delete messagePermanently deletes a specific email message by its id from a gmail mailbox; for `user id`, use 'me' for the authenticated user or an email address to which the authenticated user has delegated access.
Fetch emailsFetches a list of email messages from a gmail account, supporting filtering, pagination, and optional full content retrieval.
Fetch message by message IDFetches a specific email message by its id, provided the `message id` exists and is accessible to the authenticated `user id`.
Fetch Message by Thread IDRetrieves messages from a gmail thread using its `thread id`, where the thread must be accessible by the specified `user id`.
Get Gmail attachmentRetrieves a specific attachment by id from a message in a user's gmail mailbox, requiring valid message and attachment ids.
Get contactsFetches contacts (connections) for the authenticated google account, allowing selection of specific data fields and pagination.
Get PeopleRetrieves either a specific person's details (using `resource name`) or lists 'other contacts' (if `other contacts` is true), with `person fields` specifying the data to return.
Get ProfileRetrieves key gmail profile information (email address, message/thread totals, history id) for a user.
List draftsRetrieves a paginated list of email drafts from a user's gmail account.
List Gmail labelsRetrieves a list of all system and user-created labels for the specified gmail account.
List threadsRetrieves a list of email threads from a gmail account, identified by `user id` (email address or 'me'), supporting filtering and pagination.
Modify thread labelsAdds or removes specified existing label ids from a gmail thread, affecting all its messages; ensure the thread id is valid.
Move to TrashMoves an existing, non-deleted email message to the trash for the specified user.
Patch LabelPatches the specified label.
Remove labelPermanently deletes a specific, existing user-created gmail label by its id for a user; cannot delete system labels.
Reply to email threadSends a reply within a specific gmail thread using the original thread's subject, requiring a valid `thread id` and correctly formatted email addresses.
Search PeopleSearches contacts by matching the query against names, nicknames, emails, phone numbers, and organizations, optionally including 'other contacts'.
Send DraftSends the specified, existing draft to the recipients in the to, cc, and bcc headers.
Send EmailSends an email via gmail api using the authenticated user's google profile display name, requiring `is html=true` if the body contains html and valid `s3key`, `mimetype`, `name` for any attachment.

Way Forward

Now that Gmail is connected, extend your setup by connecting the other apps you already use every day, so your agent can run true cross-app workflows end to end.

  • Connect Calendar to turn threads into scheduled meetings automatically.
  • Connect Slack or Teams to post summaries, approvals, and alerts where your team works.
  • Connect Notion, Linear, Jira, or Asana to convert requests into tickets, tasks, and docs.
  • Connect Drive, Dropbox, or OneDrive to fetch, file, and share attachments without manual steps.

Start with one workflow you do repeatedly, then keep adding apps as you find new handoffs. With everything behind a single MCP endpoint, your agent can coordinate multiple tools safely and reliably in one conversation.

How to build Gmail MCP Agent with another framework

FAQ

What are the differences in Tool Router MCP and Gmail MCP?

With a standalone Gmail MCP server, the agents and LLMs can only access a fixed set of Gmail tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from Gmail and many other apps based on the task at hand, all through a single MCP endpoint.

Can I use Tool Router MCP with OpenCode?

Yes, you can. OpenCode fully supports MCP integration. You get structured tool calling, message history handling, and model orchestration while Tool Router takes care of discovering and serving the right Gmail tools.

Can I manage the permissions and scopes for Gmail while using Tool Router?

Yes, absolutely. You can configure which Gmail scopes and actions are allowed when connecting your account to Composio. You can also bring your own OAuth credentials or API configuration so you keep full control over what the agent can do.

How safe is my data with Composio Tool Router?

All sensitive data such as tokens, keys, and configuration is fully encrypted at rest and in transit. Composio is SOC 2 Type 2 compliant and follows strict security practices so your Gmail data and credentials are handled as safely as possible.

Used by agents from

Context
Letta
glean
HubSpot
Agent.ai
Altera
DataStax
Entelligence
Rolai
Context
Letta
glean
HubSpot
Agent.ai
Altera
DataStax
Entelligence
Rolai
Context
Letta
glean
HubSpot
Agent.ai
Altera
DataStax
Entelligence
Rolai

Never worry about agent reliability

We handle tool reliability, observability, and security so you never have to second-guess an agent action.