How to integrate Basecamp MCP with DeepSeek Harness

Connect DeepSeek Harness to Basecamp MCP. Create a new project for client onboarding, add a to-do item to the marketing team, and more using natural language, with authentication handled for you.

Get started for free Get a demo

Basecamp

Oauth2

Basecamp is a project management and team collaboration tool by 37signals. It helps teams organize tasks, share files, and communicate efficiently in one place.

Managed auth

Connect Basecamp without auth hassles

We manage OAuth, API keys, token refresh, and scopes — you just build.

Book a call

Explore the MCP Gateway

Introduction

DeepSeek Harness (dsh) is an open-source agent runtime from DeepSeek AI, and every part of it is a plugin, so you can swap out the model adapter, the tool registry, or the agent loop. It runs on the Cordis framework and comes with a local Web UI, a headless CLI runner, and a Python SDK. You can point it at DeepSeek V4-Pro and V4-Flash, or at Anthropic, OpenAI, and other OpenAI-compatible providers. It is MIT licensed and still in developer preview.

This guide shows how to connect your Basecamp account to DeepSeek Harness, and you can do it with either the Composio Connect CLI or the Composio Connect MCP. The dsh-base bundle gives shell execution as a first-class tool, so the CLI is the easiest path for personal use. It is quick to set up and needs no server config, and the MCP path works well too, since the harness comes with a built-in MCP client.

What is Composio Connect?

Composio Connect lets anyone plug 1,000+ applications directly into their agent harness, including DeepSeek Harness, through a single hosted MCP endpoint. Each task runs as a session, a scoped runtime that ties together the user, the available toolkits, authentication, and execution state. It can:

Discover and load tools on-demand. A small set of meta tools lets the agent search for the right tool at runtime, so you never load hundreds of tool definitions into context.
Chain tools in a sandboxed remote workbench. Multi-step workflows run server-side, passing outputs between tools and working with files in the session's sandbox, so long chains finish without a lot of back-and-forth with the LLM.
Manage authentication end-to-end. Managed OAuth, per-user connected accounts, and account isolation are all handled for you, so you never wire up auth yourself.

Connect Basecamp to DeepSeek Harness with Composio

Prerequisites: Install DeepSeek Harness

DeepSeek Harness needs Node.js (20 or 22) and pnpm. Build it from source. This is also what the MCP path in Option 2 requires, since the built-in MCP client resolves its dependencies from the checkout:

bash

git clone https://github.com/deepseek-ai/deepseek-harness.git
cd deepseek-harness
pnpm install
pnpm run build
pnpm dsh web

The Web UI listens on http://127.0.0.1:3080 by default. Open that address to confirm it is up.

Then configure your model route. In the Web UI, open Settings → Models: the built-in DeepSeek card accepts a DeepSeek API key, and the same page supports Anthropic, OpenAI, and custom OpenAI-compatible endpoints. Full first-run details are in the DeepSeek Harness docs.

Option 1: Composio CLI (recommended)

DeepSeek Harness runs shell commands as a first-class tool through its dsh-base bundle, so the Composio Universal CLI fits well. There is no MCP server to configure, and multi-step tool chaining is reliable. Install and authenticate:

bash

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

# Log in to Composio
composio login

Connect to Basecamp

Ask DeepSeek Harness to connect to Basecamp, or just request any Basecamp-related task. Under the hood the agent calls Composio commands like any other shell tool:

bash

composio search "what can I do with Basecamp?"
composio link basecamp

On the first Basecamp call, composio link basecamp opens an OAuth prompt so you can authorize access. After that, every Basecamp command works with your stored credentials automatically, so you just talk to the agent and it will search, execute, and chain Basecamp tools as needed.

Option 2: Composio MCP

DeepSeek Harness bridges MCP through its built-in @deepseek-ai/dsh-mcp-client plugin. You register one server as a plugin row, and its tools appear under server-qualified names (mcp__<serverName>__<rawName>), the same shape Claude Code and Codex use.

MCP requires the source build. The built-in client depends on the harness's own internal packages (cordis, dsh-llm, dsh-tools, dsh-invariants, dsh-subprocess), which resolve from the git checkout you built in the prerequisites. Run everything below from that checkout with pnpm dsh. For a route that avoids editing config files, see the community plugin at the end of this section.

Auth note: The built-in client passes static headers only and has no OAuth flow, so authenticate to Composio Connect with the x-consumer-api-key header. For Composio's OAuth flow, use the community plugin below.

1. Register the Composio server

The web profile's user patch layer is $DSH_HOME/profiles/web/cordis.patch.yml ($DSH_HOME defaults to ~/.dsh). This is a patch file, so a new plugin goes under an insert: entry. A bare - id: row instead targets an existing entry and fails to boot with patch: entry "…" not found. Add:

bash

- insert:
    - id: mcp-composio
      name: '@deepseek-ai/dsh-mcp-client'
      config:
        serverName: composio
        transport: streamable-http
        url: https://connect.composio.dev/mcp
        headers:
          x-consumer-api-key: !!js process.env.COMPOSIO_API_KEY

2. Set the API key and launch

The header value must resolve to a string at load time. Export your Composio consumer API key (ck_...), which is on the Connect → Settings → Sessions page of the Composio dashboard, in the shell you launch from. If it is unset, process.env.COMPOSIO_API_KEY is undefined and the config fails validation:

bash

export COMPOSIO_API_KEY=ck_your_key
pnpm dsh web

3. Done!

Open http://127.0.0.1:3080 and start a session on Standard or Code mode. (Minimal mode exposes only bash and str_replace_editor, so it hides MCP tools.) Composio's tools register as mcp__composio__*. Ask DeepSeek Harness to connect to Basecamp or request any Basecamp-related task, and Composio authorizes Basecamp on demand on the first call.

The dsh-mcp-client config schema (transport, serverName, url, headers, plus reconnect.* and toolCallTimeoutMs) is the current developer-preview interface and may change between releases.

Alternative: OAuth via the community plugin

To use Composio Connect's OAuth flow instead of a static key, or to skip editing cordis.patch.yml by hand, use the community dsh-mcp-manager plugin. It installs as a self-contained external plugin, ships a bundle patch so it auto-mounts, and adds a Settings → MCP page plus OAuth (authorization code + PKCE, RFC 7591 dynamic client registration, and refresh-token rotation). It needs the web profile and Node.js ^22.19 or >=24, with pnpm on your PATH.

Install it from your source checkout, then restart pnpm dsh web and refresh:

bash

pnpm dsh plugin --profile web add github:hyqhyq3/dsh-mcp-manager

Open Settings → MCP → ＋ Add MCP server, choose HTTP, set the name to composio, the URL to https://connect.composio.dev/mcp, and the auth mode to OAuth. Click Authenticate, and Composio's login and consent screen opens in the browser, then redirects back and registers the tools as mcp__composio__*. The row should read connected (N tools).

The plugin catches the OAuth code on a loopback redirect (http://127.0.0.1:<port>/mcp-manager/callback/<id>), so Composio's OAuth provider must allow that loopback URL. Server configs and tokens persist at ~/.dsh/mcp-manager.json, so treat that file as a secret. Being a community plugin on a preview harness, its commands may change, so check the plugin repo if a step drifts.

What is the Basecamp MCP server, and what's possible with it?

The Basecamp MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Basecamp account. It provides structured and secure access so your agent can perform Basecamp operations on your behalf.

Way Forward

With Basecamp connected, DeepSeek Harness can now act on your behalf whenever you ask it to.

From here, you can extend the harness further:

Connect more apps: Calendar, Slack, Notion, Linear, and hundreds of others are available through the same Composio Connect setup, and each new integration adds to what your agent can do for you.
Build workflows across tools: Once multiple apps are connected, DeepSeek Harness can chain actions together, so it can turn an email into a calendar invite, a Slack message into a Linear ticket, or a meeting note into a follow-up draft.
Use the plugin system: Wrap common Basecamp flows as dsh plugins or prompt templates so recurring tasks become one-line commands, and bundle your most-used Basecamp tools into a named profile you can boot on demand.

If you run into trouble or want to share what you've built, join the community or check out the Docs for more configuration options.

FRAMEWORKS

How to build Basecamp MCP Agent with another framework

ChatGPT Work

Use Basecamp MCP with ChatGPT Work

Antigravity

Use Basecamp MCP with Antigravity

OpenAI Agents SDK

Use Basecamp MCP with OpenAI Agents SDK

Claude Agent SDK

Use Basecamp MCP with Claude Agent SDK

Claude Code

Use Basecamp MCP with Claude Code

Claude Cowork

Use Basecamp MCP with Claude Cowork

Codex

Use Basecamp MCP with Codex

Grok Build

Use Basecamp MCP with Grok Build

Cursor

Use Basecamp MCP with Cursor

VS Code

Use Basecamp MCP with VS Code

OpenCode

Use Basecamp MCP with OpenCode

OpenClaw

Use Basecamp MCP with OpenClaw

Hermes

Use Basecamp MCP with Hermes

Pi

Use Basecamp MCP with Pi

Google ADK

Use Basecamp MCP with Google ADK

LangChain

Use Basecamp MCP with LangChain

Vercel AI SDK

Use Basecamp MCP with Vercel AI SDK

Mastra AI

Use Basecamp MCP with Mastra AI

LlamaIndex

Use Basecamp MCP with LlamaIndex

CrewAI

Use Basecamp MCP with CrewAI

Pydantic AI

Use Basecamp MCP with Pydantic AI

AutoGen

Use Basecamp MCP with AutoGen

MORE TOOLKITS

Explore Other Toolkits

Toolkit marketplace

Gmail

Oauth2

Gmail is Google's email service with powerful spam protection, search, and G Suite integration. It keeps your inbox organized and makes communication fast and reliable.

Outlook

Oauth2S2s Oauth2

Outlook is Microsoft's email and calendaring platform for unified communications and scheduling. It helps users stay organized with powerful email, contacts, and calendar management.

Google Sheets

Oauth2

Google Sheets is a cloud-based spreadsheet tool for real-time collaboration and data analysis. It lets teams work together from anywhere, updating information instantly.

Notion

Oauth2Api Key

Notion is a collaborative workspace for notes, docs, wikis, and tasks. It streamlines team knowledge, project tracking, and workflow customization in one place.

FAQ

Frequently asked questions

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

Yes, you can. DeepSeek Harness 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 Basecamp tools.

Yes, absolutely. You can configure which Basecamp 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.

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 Basecamp data and credentials are handled as safely as possible.

Start with Basecamp.It takes 30 seconds.

Managed auth, hosted MCP servers, and every Basecamp tool your agent needs.Free to start.

Start building

How to integrate Basecamp MCP with DeepSeek Harness

Connect Basecamp without auth hassles

Introduction

Also integrate Basecamp with

What is Composio Connect?

Connect Basecamp to DeepSeek Harness with Composio

Prerequisites: Install DeepSeek Harness

Option 1: Composio CLI (recommended)

Connect to Basecamp

Option 2: Composio MCP

1. Register the Composio server

2. Set the API key and launch

3. Done!

Alternative: OAuth via the community plugin

What is the Basecamp MCP server, and what's possible with it?

Way Forward

How to build Basecamp MCP Agent with another framework

ChatGPT Work

Antigravity

OpenAI Agents SDK

Claude Agent SDK

Claude Code

Claude Cowork

Codex

Grok Build

Cursor

VS Code

OpenCode

OpenClaw

Hermes

Pi

Google ADK

LangChain

Vercel AI SDK

Mastra AI

LlamaIndex

CrewAI

Pydantic AI

AutoGen

Explore Other Toolkits

Gmail

Outlook

Google Sheets

Notion

Frequently asked questions

What are the differences in Tool Router MCP and Basecamp MCP?+

Can I use Tool Router MCP with DeepSeek Harness?+

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

How safe is my data with Composio Tool Router?+

Start with Basecamp.It takes 30 seconds.