DeepSeek Harness

DeepSeek’s coding agent (dsh) runs named profiles, such as tui, web, and headless, under $DSH_HOME, which defaults to ~/.dsh. Restart dsh after changing a profile. Generally available OpenAI Chat Completions Nexus Auto

Quick start

Install and sign in

curl -fsSL https://nexus.fireworks.ai/install.sh | bash

You need Node.js 22 or later, git, and bash. On Windows, run the installer from Git Bash. PowerShell breaks the script’s line endings.

nexus login

Connect DeepSeek Harness

nexus deepseek
nexus deepseek status

Restart and pick a model

Restart dsh. It starts on auto and goes straight to Fireworks, with no DeepSeek key prompt. To change the default, run nexus deepseek --model glm-latest.

nexus deepseek status shows the provider, where the key comes from, and the configured model.

Use Nexus Auto

Nexus Auto (auto) is supported on the Chat Completions API.

Anthropic and OpenAI model turns: save a key with nexus auto --anthropic-api-key or --openai-api-key (each prompts for the key), then run nexus deepseek again. Nexus CLI adds the saved key to the fireworks provider headers. Or connect a Provider Key, which needs nothing saved locally.
Environment keys: Nexus CLI never sends ANTHROPIC_API_KEY or OPENAI_API_KEY from your environment.
Manual setup: send x-anthropic-api-key and x-openai-api-key headers yourself. See Manual setup (advanced).

MCP and tools

Nexus CLI doesn’t touch MCP. Set up servers in dsh as usual. Nexus CLI does not add web search to DeepSeek Harness. See Web Search.

Microsoft Foundry

Nexus CLI doesn’t connect DeepSeek Harness to Microsoft Foundry. For other options, see Nexus for Microsoft Foundry.

Troubleshooting

See Nexus Auto for issues that affect every harness. Upgrading from an earlier version? See Upgrading from earlier versions.

Manual setup (advanced)

Create the profile folder once, then add a patch to it. Repeat for each profile you use. On dsh 0.2 and later, you can put the same patch in ~/.dsh/cordis.patch.yml instead to cover every profile.

dsh --profile tui --dump-config > /dev/null

~/.dsh/profiles/tui/cordis.patch.yml

- id: llm-pi-ai
  name: "@deepseek-ai/dsh-llm-pi-ai"
  config:
    providers:
      fireworks:
        displayName: Fireworks
        apiKeyEnv: FIREWORKS_API_KEY
        api: openai-completions
        baseURL: https://api.fireworks.ai/inference/v1
        models:
          - id: glm-latest
            name: GLM (Latest)
            reasoning: true
            contextWindow: 1048576
            maxTokens: 131072
- id: agent-default-model
  name: "@deepseek-ai/dsh-agent-default-model"
  config:
    provider: fireworks
    model: glm-latest

export FIREWORKS_API_KEY="fw_..."
dsh tui

To use Nexus Auto with Anthropic or OpenAI model turns, add headers to the provider, such as x-anthropic-api-key: sk-ant-..., and use auto as the model. The harness setup generates the full patch. See what changes without the Nexus CLI.

What the Nexus CLI writes

Nexus CLI writes the fireworks provider and default model to three layers, so every dsh version picks them up:

~/.dsh/settings.yaml
~/.dsh/cordis.patch.yml, the home-level patch that dsh 0.2 and later apply to every profile, including new ones
Each existing profile’s cordis.patch.yml, which dsh 0.1.7 and later read

Your key goes to ~/.dsh/.credentials.yaml as FIREWORKS_API_KEY.

~/.dsh

settings.yaml

cordis.patch.yml

.credentials.yaml

profiles/<profile>

cordis.patch.yml

See what Nexus CLI writes

~/.dsh/settings.yaml

llm-pi-ai:
  providers:
    fireworks:
      displayName: Fireworks
      apiKeyEnv: FIREWORKS_API_KEY
      api: openai-completions
      baseURL: https://api.fireworks.ai/inference/v1
      headers:
        x-anthropic-api-key: sk-ant-...
      models:
        - id: auto
          name: Auto
          reasoning: true
          input: [text, image]
          contextWindow: 1048575
          maxTokens: 131072
agent-default-model:
  provider: fireworks
  model: auto

~/.dsh/.credentials.yaml

FIREWORKS_API_KEY: fw_...

The patch files carry the same provider and model as llm-pi-ai and agent-default-model entries. The x-anthropic-api-key and x-openai-api-key headers appear only for keys you saved with nexus auto. Nexus CLI also adds its own attribution headers.Every file is saved with mode 0600. off restores each one byte-for-byte from the snapshot under ~/.nexus/deepseek/, and deletes the ones Nexus CLI created. Use --config-path for a settings.yaml stored elsewhere. Nexus CLI then keeps the credentials file and patches in that folder.

Get started

Nexus CLI

Model Orchestration

Harness Support

Nexus settings

More

Quick start

Use Nexus Auto

MCP and tools

Microsoft Foundry

Troubleshooting

Manual setup (advanced)

What the Nexus CLI writes

​Quick start

​Use Nexus Auto

​MCP and tools

​Microsoft Foundry

​Troubleshooting

​Manual setup (advanced)

​What the Nexus CLI writes

Quick start

Use Nexus Auto

MCP and tools

Microsoft Foundry

Troubleshooting

Manual setup (advanced)

What the Nexus CLI writes