DeepSeek Harness

DeepSeek Harness (dsh) is an open-source coding agent from DeepSeek. Within the working folder you select, dsh can read files, edit code, run shell commands, and complete multi-step tasks—via the web interface, headless mode, SDK, or ACP. dsh uses the Anthropic Messages protocol. Hostlinku provides it at POST /v1/messages, so dsh can be directed to Hostlinku with just two environment variables—no proxy, no additional plugins.

Before you begin

Latest Node.js LTS (node --version). The dsh package pulls in hundreds of dependencies, so the initial installation may take 1–3 minutes.
Hostlinku API key sk-… from console.hostlinku.com → API Keys.
Balance or sufficient spending limit for that key.
Secure test folder. The folder where you run dsh becomes its default workspace. Do not run it directly from your home directory or a folder containing sensitive data.

Recommended model

The model field can be populated with any slug from the catalog that supports tool calls. The list of active models for your key is available at GET /v1/models.

Requirements	Slug	Notes
Daily default, fast, and affordable	`deepseek-v4-1-flash`	Context: 1M, reasoning, tool calling.
Image input required (screenshots, diagrams)	`deepseek-v4-1-flash`	Support the vision.
Major task / major refactor	`deepseek-v4-1-flash-hyper`	Context 1M, deeper reasoning.
Open-weight alternative	`kimi-k2-7-code`, `glm-5-3`	Tool calling and reasoning.

Security

While the task is running, prompts, code snippets, file contents, and tool outputs are sent to Hostlinku for inference. Do not run dsh on projects containing trade secrets or personal data without permission.
Use a separate API key specifically for dsh with a spending limit, so it can be easily revoked if compromised. See Authentication.
Do not write the API key directly in cordis.patch.yml. apiKeyEnv only stores the name of the variable; the key value is still read from the environment.

Troubleshooting

Symptoms	Causes & Solutions
`INVALID_REQUEST: max_tokens (256000) exceeds the output limit of model …`	`maxTokens` has not been set. Add `maxTokens: 32000` in the `llm-deepseek` block.
`startup failed … $.provider missing required value`	The `agent-default-model` block in the patch does not include `provider`. Rewrite it completely as shown in the example above.
`MISSING_CREDENTIAL`	`DEEPSEEK_API_KEY` has not been exported in the shell where `dsh` is running.
`401` / invalid API key	The key is incorrect, revoked, or expired. Create a new key in the console.
`404 model not found`	The slug is incorrect or is still `deepseek-flash`. Copy the slug from `GET /v1/models`.
Image attachment failed	`dsh` first attempts to upload an image via `/v1/files`, then automatically resends the image inline. Ensure the selected model supports vision (e.g., `deepseek-v4-1-flash`).

Full details on plugin options are available in the DeepSeek Harness repository. Related guides: Claude Code · CC Switch · Anthropic Messages.

Start

Models & Features

API

Account

Help

Before you begin

Recommended model

Security

Troubleshooting