DeepSeek Harness Guide

DeepSeek Harness (dsh) is DeepSeek's open-source agent harness, and Maritime runs it as a managed, always-on agent with one command.

Overview

DeepSeek Harness (dsh) is DeepSeek's open-source agent harness, released in August 2026. Everything in it is a plugin: models, tools, skills, sessions, sandboxes, and the web workbench itself. Every run is recorded in append-only session logs you can resume, fork, and replay from the workbench.

Upstream is an early developer preview that promises breaking changes between releases, so Maritime pins the exact dsh version in its template image and upgrades deliberately after testing each release.

Docker Image

Image: ghcr.io/maritime-sh/dsh-agent:0.1.0-rc.7

A first-party Maritime image: Node 22, dsh pinned to the tag version, the web workbench on port3080 behind a per-agent auth layer, and agent state under /data/.dsh so sessions survive restarts and upgrades.

How It Works

The upstream web workbench ships without authentication, so the Maritime image runs it loopback-only behind a small auth shim that requires a per-agent token on every request. The Maritime dashboard injects that token for you: click Harness Workbench on the agent page and you are in. The default model routes through the metered Maritime LLM proxy, so a fresh agent works with no API key at all. Chat messages from Telegram, the CLI, and share links run one-shot headless turns inside the agent's own container.

# The container runs with:
DSH_HEADLESS=true
DSH_PORT=3080
DSH_GATEWAY_TOKEN=<auto-generated>
DSH_MODEL=gpt-5-mini
DSH_HOME=/data/.dsh (baked in the image)

Environment Variables

If you don't supply OPENAI_API_KEY, Maritime injects a per-agent proxy token pointed athttps://api.maritime.sh/api/llm/v1. Set DSH_MODEL to change the default model (any model the proxy serves). You can also add your own providers, including DeepSeek's API, in the workbench under Settings > Models; keys you add there are stored inside your agent's volume, never on Maritime's control plane.

How do I host DeepSeek Harness on Maritime?

One command with the Maritime CLI:

maritime create -n my-agent -t dsh && maritime deploy my-agent

Or select Template > DeepSeek Harness in the Create Agent modal. New here? The quickstart covers accounts and the Templates guide covers cloning and sharing agents.

Talk to it

Open Harness Workbench from the agent page for the full experience: sessions, plan mode, tool approvals, session replay, and plugin management. Or chat from the terminal:

maritime chat my-agent "clone my repo and run the tests"

Terminal and channel chats are one-shot headless runs: each message boots the harness, runs the task to completion with tools enabled, and returns the final answer. Recent conversation context carries over between messages; long-lived interactive sessions live in the workbench.