Claude Code DeepSeek setup

What Claude Code DeepSeek actually is

Claude Code is the agent shell: it edits files, runs the terminal, and understands slash commands. DeepSeek V4 Pro / Flash is the model. DeepSeek documents https://api.deepseek.com/anthropic so Claude Code can keep sending Anthropic-style requests without rewriting the tool. You install @anthropic-ai/claude-code, then point ANTHROPIC_BASE_URL at DeepSeek and ANTHROPIC_AUTH_TOKEN at your DeepSeek API key.

This is not a new DeepSeek model, and it is not DeepSeek Harness. Harness is DeepSeek’s own agent runtime (npx @deepseek-ai/dsh web). Claude Code DeepSeek is “Claude Code as the harness, DeepSeek as the brain.” Deep Code is a different free OSS coding CLI. All three default to the hosted DeepSeek API — you do not download Hugging Face weights for this setup.

When to use this setup

Reach for Claude Code DeepSeek when the shell you already know is Claude Code:

• You want Claude Code’s files/terminal/slash-command UX, billed at DeepSeek token rates.
• Your team already has Claude Code muscle memory and only needs a cheaper or open-weight-friendly brain.
• You map Opus-class work to deepseek-v4-pro and Haiku/subagents to deepseek-v4-flash.
• You can use the CLI or the VS Code extension with ~/.claude/settings.json.

What this is not

Do not confuse the shell with the model or with DeepSeek’s own runtime:

• Not a new model ID. You still call deepseek-v4-pro or deepseek-v4-flash.
• Not DeepSeek Harness and not Deep Code.
• Not an Anthropic-supported backend swap. Preview features that need Anthropic’s own backend may fail.
• Not Claude Desktop OAuth. Desktop login does not read these env vars the same way — use CLI or VS Code.

At a glance

Shell

Claude Code (npm i -g @anthropic-ai/claude-code)

Endpoint

https://api.deepseek.com/anthropic

Opus-class →

deepseek-v4-pro

Haiku / subagent →

deepseek-v4-flash

GPU

Not required (hosted API)

Keys

Official DeepSeek platform — not this site

Install, env, settings.json

Need Node.js 18+. Windows also needs Git for Windows. Then install, set variables, or write settings.json so new terminals keep the mapping.

1. Install: npm install -g @anthropic-ai/claude-code
2. Check: claude --version
3. Set ANTHROPIC_BASE_URL=https://api.deepseek.com/anthropic and ANTHROPIC_AUTH_TOKEN to your DeepSeek API key.
4. Map Opus/Sonnet-class names to deepseek-v4-pro[1m]; Haiku and CLAUDE_CODE_SUBAGENT_MODEL to deepseek-v4-flash.
5. For persistence, write ~/.claude/settings.json (Windows: %USERPROFILE%\.claude\settings.json).

export ANTHROPIC_BASE_URL=https://api.deepseek.com/anthropic
export ANTHROPIC_AUTH_TOKEN=<your DeepSeek API Key>
export ANTHROPIC_MODEL=deepseek-v4-pro[1m]
export ANTHROPIC_DEFAULT_OPUS_MODEL=deepseek-v4-pro[1m]
export ANTHROPIC_DEFAULT_SONNET_MODEL=deepseek-v4-pro[1m]
export ANTHROPIC_DEFAULT_HAIKU_MODEL=deepseek-v4-flash
export CLAUDE_CODE_SUBAGENT_MODEL=deepseek-v4-flash
export CLAUDE_CODE_EFFORT_LEVEL=max

$env:ANTHROPIC_BASE_URL="https://api.deepseek.com/anthropic"
$env:ANTHROPIC_AUTH_TOKEN="<your DeepSeek API Key>"
$env:ANTHROPIC_MODEL="deepseek-v4-pro[1m]"
$env:ANTHROPIC_DEFAULT_OPUS_MODEL="deepseek-v4-pro[1m]"
$env:ANTHROPIC_DEFAULT_SONNET_MODEL="deepseek-v4-pro[1m]"
$env:ANTHROPIC_DEFAULT_HAIKU_MODEL="deepseek-v4-flash"
$env:CLAUDE_CODE_SUBAGENT_MODEL="deepseek-v4-flash"
$env:CLAUDE_CODE_EFFORT_LEVEL="max"

{
  "env": {
    "ANTHROPIC_BASE_URL": "https://api.deepseek.com/anthropic",
    "ANTHROPIC_AUTH_TOKEN": "<your DeepSeek API Key>",
    "ANTHROPIC_MODEL": "deepseek-v4-pro[1m]",
    "ANTHROPIC_DEFAULT_OPUS_MODEL": "deepseek-v4-pro[1m]",
    "ANTHROPIC_DEFAULT_SONNET_MODEL": "deepseek-v4-pro[1m]",
    "ANTHROPIC_DEFAULT_HAIKU_MODEL": "deepseek-v4-flash",
    "CLAUDE_CODE_SUBAGENT_MODEL": "deepseek-v4-flash",
    "CLAUDE_CODE_EFFORT_LEVEL": "max"
  }
}

Claude Code vs Harness vs Deep Code

Same DeepSeek API, different shells:

Limits to know

• Claude Desktop OAuth will not pick up these variables like the CLI does.
• Web Search inside Claude Code can add extra DeepSeek token cost.
• If you leave default claude-opus / claude-haiku names, DeepSeek maps them — but explicit deepseek-v4-* IDs are clearer.
• Model IDs such as deepseek-v4-pro[1m] follow current official docs; they can change.
• This site does not issue API keys. Get them on the official platform.