mem0/docs/integrations/deepseek-plugin.mdx

---
title: DeepSeek Harness
description: "Add persistent memory to DeepSeek Harness with automatic recall, automatic capture, and two native Mem0 tools."
---

Add persistent memory to the [**DeepSeek Harness**](https://github.com/deepseek-ai/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.

<Info>Current package version: `0.3.1`.</Info>

Sidekick is available only in the [Claude Code plugin](/integrations/claude-code#sidekick-agent).

## 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. Memory availability in children depends on the Harness composition and service scope.

## Prerequisites

1. A Mem0 Platform account and API key:
   - <a href="https://app.mem0.ai?utm_source=oss&utm_medium=integration-deepseek-plugin">Sign up at app.mem0.ai</a>
   - <a href="https://app.mem0.ai/dashboard/api-keys?utm_source=oss&utm_medium=integration-deepseek-plugin">Get your API key</a> (starts with `m0-`)

2. The DeepSeek Harness installed and a funded model-provider credential (`DEEPSEEK_API_KEY` for the official DeepSeek provider). This is separate from your Mem0 key.

3. Your Mem0 key and a stable user identity exported in the shell that launches Harness:

<CodeGroup>
```bash zsh
echo 'export MEM0_API_KEY="m0-your-api-key"' >> ~/.zshrc
echo 'export MEM0_USER_ID="your-user-id"' >> ~/.zshrc
source ~/.zshrc
```

```bash bash
echo 'export MEM0_API_KEY="m0-your-api-key"' >> ~/.bashrc
echo 'export MEM0_USER_ID="your-user-id"' >> ~/.bashrc
source ~/.bashrc
```
</CodeGroup>

## Try it locally

1. Build and pack the plugin from the full repository (the source imports the sibling shared core):
   ```sh
   cd integrations/deepseek-plugin
   pnpm install --frozen-lockfile
   pnpm build
   mkdir -p /tmp/mem0-deepseek-plugin
   pnpm pack --pack-destination /tmp/mem0-deepseek-plugin
   ```

2. Install it into a disposable Harness profile so Harness supplies its peer dependencies:
   ```sh
   DSH_HOME=/tmp/mem0-dsh-dev pnpm dlx @deepseek-ai/dsh@0.1.1-rc.2 \
     plugin --profile web add /tmp/mem0-deepseek-plugin/mem0-deepseek-plugin-0.3.1.tgz
   ```

3. Launch the same profile. The package's `dsh.bundle` activates Mem0 automatically:
   ```sh
   DSH_HOME=/tmp/mem0-dsh-dev pnpm dlx @deepseek-ai/dsh@0.1.1-rc.2 \
     web
   ```

4. Open the web UI, select a workspace, and state a synthetic preference without mentioning Mem0. Allow extraction to finish, start a fresh session, and ask for that preference without tools. Inspect the `mem0:recall` context to confirm automatic recall.

`pnpm pack` builds the package automatically and ships its activation patch. To customize it, copy `cordis.example.yml` and launch with `web --patch /absolute/path/to/cordis.yml`. The override updates the existing bundle row:

```yaml
- id: mem0
  config:
    # A config override replaces the whole config, so restate userId.
    userId: !!js process.env.MEM0_USER_ID
    memoryScope: workspace
    autoRecall: true
    autoCapture: true
    # host: "https://your-onprem.mem0.ai"   # optional: Platform dedicated base URL
```

When upgrading from a manual installation, remove the old patch that inserts a `mem0` row; the bundle now inserts it. Keep custom settings as an override by `id`.

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 |
| `memoryScope` | no | `user` | `user` shares memory across workspaces; `workspace` isolates automatic and explicit memory operations |
| `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 capture preserves full redacted user and assistant message text without a per-message character cutoff.

## Workspace scope

By default, automatic capture and recall use the configured user across all workspaces. This is intentional compatibility behavior. To isolate workspaces, set `memoryScope: workspace` as shown above. All writes then attach an `appId` derived from the canonical absolute session workspace path; all searches require its matching `app_id`. The model cannot override that workspace filter.

Symlink aliases share a scope. Different directories, clones, or worktrees have different scopes; moving a directory changes its scope. Missing or invalid workspace paths skip automatic memory operations and reject explicit tools without falling back to user-wide access. Existing user-only memories are not migrated into workspace scopes.

User scope searches all memories belonging to the user, including workspace-tagged memories. Workspace isolation applies only when workspace scope is configured; it is application filtering, not a separate Mem0 account or credential.

## Extraction and recall limits

Capture sends the full redacted turn to Mem0 for asynchronous extraction. A queued write, or even an initially nonempty memory list, does not mean every extracted fact is ready. Allow processing to finish and inspect stored memories before diagnosing lost preferences or missing filenames and numeric constraints. Exact extraction remains model-dependent; a one-off request should not automatically become a standing preference.

Automatic recall is a shallow first pass: up to five results, 4,000 context characters, and a two-second wait. The explicit `search_memory` tool can use a more focused query and returns up to ten results by default.

## Telemetry

Writes are tagged `source="DEEPSEEK_HARNESS"` so Mem0 can attribute usage to this integration. Anonymous usage events include operation names, durations, result counts, and coarse failure kinds. Queries, memory text, entity IDs, and API keys are never included. Set `MEM0_TELEMETRY=false` to opt out.

<Note>
  This plugin is a developer preview and tracks the evolving DeepSeek Harness plugin API.
</Note>

## 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` for the same profile used at installation and confirm it contains a `mem0` row naming `@mem0/deepseek-plugin`. Export `MEM0_USER_ID` and `MEM0_API_KEY` before launching.

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