> ## Documentation Index
> Fetch the complete documentation index at: https://docs.replicas.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# DeepSeek Harness

> Run OpenRouter-backed DeepSeek Harness agents in Replicas workspaces.

Replicas supports [DeepSeek Harness](https://github.com/deepseek-ai/DeepSeek-Harness) as a coding agent. The official DSH runtime runs inside the workspace and uses OpenRouter for inference.

## Setup

1. Create a key on the [OpenRouter keys page](https://openrouter.ai/keys).
2. Paste it under **DeepSeek Harness → OpenRouter API Key** in [Organization → Coding Agents](https://app.replicas.dev/dashboard/agents).
3. Set an organization credential for the team, or add a personal key under **Personal** to override it.

The OpenRouter key and enabled-model selection are shared with [Opencode](/features/coding-agents/opencode) and [Pi](/features/coding-agents/pi). See [Credentials](/admin/credentials) for credential scope and fallback behavior.

## Models

Organization admins choose models under **DeepSeek Harness → OpenRouter models** in [Coding Agents settings](https://app.replicas.dev/dashboard/agents). Until changed, Replicas enables:

| Model ID                        | Label            | Notes                        |
| ------------------------------- | ---------------- | ---------------------------- |
| `deepseek/deepseek-v4-pro-0813` | DeepSeek V4 Pro  | Default                      |
| `z-ai/glm-5.3`                  | GLM 5.3          | General agentic coding       |
| `moonshotai/kimi-k3`            | Kimi K3          | Multimodal coding model      |
| `google/gemini-3.8-flash`       | Gemini 3.8 Flash | Fast multimodal Google model |

Enable additional models under **OpenRouter models** in [Coding Agents settings](https://app.replicas.dev/dashboard/agents). Saved organization selections take precedence over these defaults.

Choose an organization default under [Defaults](/admin/defaults), a personal default in account preferences, or a model for the active chat from the workspace composer.

## Using DeepSeek Harness in Workspaces

Choose **DeepSeek Harness** from the composer's agent picker. It can:

* Read, write, and edit repository files
* Run shell commands and show tool activity in chat
* Accept image attachments
* Ask questions in the composer
* Use [Plan Mode](/features/workspaces/plan-mode)
* Discover skills and expose them as slash commands
* Persist sessions, tool history, jobs, and context usage across turns
* Steer a queued message into the active turn
* Interrupt an active turn

DeepSeek Harness runs with full workspace access and does not request approval before using tools. Before each tool runs, Replicas applies your organization's security policies and returns any block reason to the agent.

DeepSeek Harness does not support Fast Mode or Codex goal mode.

## Programmatic Use

Select DeepSeek Harness anywhere Replicas accepts a coding agent:

| Surface                              | How to choose DeepSeek Harness                                              |
| ------------------------------------ | --------------------------------------------------------------------------- |
| [CLI](/features/cli)                 | `-a deepseek` on `replicas create` and `replicas send`                      |
| [API](/features/api)                 | `"coding_agent": "deepseek"` on create and message requests                 |
| [MCP](/features/mcp)                 | `"coding_agent": "deepseek"` on `create_replica` and `send_replica_message` |
| [Automations](/features/automations) | Set **Coding agent** to DeepSeek Harness                                    |
| [Defaults](/admin/defaults)          | Select DeepSeek Harness as the organization or personal default             |

```bash theme={null}
replicas create fix-tests \
  -e backend \
  -a deepseek \
  -m "Inspect the repository and fix the failing tests"

replicas send REPLICA_ID \
  -a deepseek \
  -m "Run the tests and address any remaining failures"
```

```bash theme={null}
curl -X POST "https://api.replicas.dev/v1/replica" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "fix-tests",
    "environment_id": "ENVIRONMENT_UUID",
    "message": "Inspect the repository and fix the failing tests",
    "coding_agent": "deepseek",
    "model": "deepseek/deepseek-v4-pro-0813"
  }'
```