DeepSeek Harness

Add persistent memory to the DeepSeek Harness with @mem0/deepseek-plugin. The plugin recalls relevant context before a model request, captures completed turns, and provides explicit Mem0 tools when the agent needs them.

Current package version: 0.3.0.

Sidekick is available only in the Claude Code plugin.

Overview

The plugin provides automatic memory plus two agent-callable tools:

Capability	What it does
Automatic recall	Searches with the latest human prompt and adds unseen results to the model context
Automatic capture	Stores the human and assistant messages from each completed turn
`search_memory`	Recall facts from Mem0 relevant to a query
`add_memory`	Store a fact in Mem0 for future sessions

Unlike file-based memory plugins, Mem0 is a managed backend: server-side extraction, semantic dedup, and conflict resolution, with memories reusable by integrations that use compatible user identities and search filters.

How it works

A Cordis plugin is a module exporting apply(ctx, config). This plugin waits for the Harness tool and system-prompt services, then uses their native extension points:

system-prompt/assemble recalls memory before a model request.
session/event captures only completed turns from the durable event stream.
ctx.tools.register(...) exposes explicit search and add tools.

Cordis removes the listeners and tools when the plugin unmounts. Memory failures are fail-open, so a Mem0 outage does not stop the agent from completing its normal work. DeepSeek Harness provides subagents through separate host-composition packages. This Mem0 package does not register a named Sidekick or claim child filesystem isolation. A Harness child uses Mem0 only when its own agent preset includes the Mem0 plugin.

Prerequisites

A Mem0 Platform account and API key:
- Sign up at app.mem0.ai
- Get your API key (starts with m0-)
The DeepSeek Harness installed.
Your API key exported in your shell:

echo 'export MEM0_API_KEY="m0-your-api-key"' >> ~/.zshrc
source ~/.zshrc

echo 'export MEM0_API_KEY="m0-your-api-key"' >> ~/.bashrc
source ~/.bashrc

Try it locally

Build and pack the plugin:

cd integrations/deepseek-plugin
pnpm install --frozen-lockfile
pnpm build
mkdir -p /tmp/mem0-deepseek-plugin
pnpm pack --pack-destination /tmp/mem0-deepseek-plugin

Install it into a disposable Harness profile so Harness supplies its peer dependencies:

DSH_HOME=/tmp/mem0-dsh-dev pnpm dlx @deepseek-ai/dsh@0.1.1-rc.2 \
  plugin --profile headless add /tmp/mem0-deepseek-plugin/mem0-deepseek-plugin-0.3.0.tgz

Copy cordis.example.yml, set its installed package path and your userId, then load it with the same profile:

DSH_HOME=/tmp/mem0-dsh-dev pnpm dlx @deepseek-ai/dsh@0.1.1-rc.2 \
  web --patch ./integrations/deepseek-plugin/cordis.example.yml

Open the web UI and ask the agent to remember something, then recall it in a later turn.

The cordis.yml entry looks like this:

- name: "@deepseek-ai/dsh-system-prompt"
- name: "@deepseek-ai/dsh-tools"
- insert:
    - id: mem0
      name: "/tmp/mem0-dsh-dev/profiles/headless/node_modules/@mem0/deepseek-plugin/dist/index.js"
      config:
        # apiKey is read from MEM0_API_KEY when omitted here.
        userId: "your-user-id"
        autoRecall: true
        autoCapture: true
        # host: "https://your-onprem.mem0.ai"   # optional: Platform on-prem / dedicated base URL

For a Mem0 Platform on-prem or dedicated deployment, point config.host at that base URL (defaults to api.mem0.ai). host is a Platform base-URL override, not a switch to self-hosted Mem0 OSS.

Configuration

Field	Required	Default	Notes
`apiKey`	no	`$MEM0_API_KEY`	Mem0 platform API key
`userId`	yes		Default entity that owns the memories
`allowUserOverride`	no	`false`	Permit model-selected access to a different user only in a trusted multi-user deployment
`host`	no	`api.mem0.ai`	Platform base URL (on-prem / dedicated)
`autoRecall`	no	`true`	Recall relevant memory before model requests
`autoCapture`	no	`true`	Store completed human and assistant turns

Both tools also accept optional per-call userId, agentId, and runId params so a single install can partition memory by entity, agent, or session; userId defaults to the configured user, while agentId and runId are omitted unless supplied. Automatic recall and capture use the configured user without an agent, repository, or session filter. Automatic capture preserves full redacted user and assistant message text without a per-message character cutoff.

Telemetry

Writes are tagged source="DEEPSEEK_HARNESS" so Mem0 can attribute usage to this integration. Usage events include operation names, durations, result counts, and coarse failure kinds. They are not anonymous: when an API key is configured they are sent under your Mem0 account email, the same way the SDK attributes its own. Queries, memory text, entity IDs, and API keys are never included. Set MEM0_TELEMETRY=false to opt out.

This plugin is a developer preview and tracks the evolving DeepSeek Harness plugin API.

Troubleshooting

MISSING_CREDENTIAL for deepseek-official: Configure DEEPSEEK_API_KEY through Harness’s Models page or export it in the shell that launches Harness.
EMFILE: too many open files, watch on macOS: Launch Harness with CHOKIDAR_USEPOLLING=1.
Mem0 tools do not appear: Run Harness with --dump-config and confirm the final composition contains the mem0 row and the installed dist/index.js path.

Per-call userId overrides are rejected unless the operator enables allowUserOverride: true. Automatic recall and capture always use the configured user.

Coding Agents

Agent Harness

DeepSeek Harness

Overview

How it works

Prerequisites

Try it locally

Configuration

Telemetry

Troubleshooting

​Overview

​How it works

​Prerequisites

​Try it locally

​Configuration

​Telemetry

​Troubleshooting

Overview

How it works

Prerequisites

Try it locally

Configuration

Telemetry

Troubleshooting