Run Claude Code Through DeepSeek on Windows PowerShell

2. Set DeepSeek for this terminal only

Use a current PowerShell session first. That keeps the blast radius small while you prove the routing works.

Replace the placeholder with your own DeepSeek API key:

$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"

Do not paste your real key into chat, commits, .env.example, logs, screenshots, or tutorial snippets. A setup that works by leaking a credential is not working.

3. Launch inside the project

For a project like PixelBoats:

cd B:\Dev\PixelBoats
claude

Start with a low-risk prompt:

Read the repo structure only. Do not edit files. Summarize the main app entrypoints, package manager, and likely verification commands.

That first prompt tells you whether the CLI launches, whether the model responds, and whether the agent can inspect the repo without immediately changing anything.

4. Make a launcher script instead

Once the terminal-session test works, move the setup into a local launcher script. This avoids changing your normal shell profile and makes the DeepSeek route an intentional choice.

Create:

notepad B:\Dev\launch-claude-deepseek.ps1

Paste:

param(
  [string]$Project = "B:\Dev\PixelBoats"
)
 
if (-not $env:DEEPSEEK_API_KEY) {
  Write-Error "Missing DEEPSEEK_API_KEY. Set it first in your user environment or current shell."
  exit 1
}
 
$env:ANTHROPIC_BASE_URL="https://api.deepseek.com/anthropic"
$env:ANTHROPIC_AUTH_TOKEN=$env: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"
 
Set-Location $Project
claude

Then set the key once for your Windows user:

[Environment]::SetEnvironmentVariable("DEEPSEEK_API_KEY", "YOUR_DEEPSEEK_API_KEY", "User")

Open a new PowerShell window and run:

B:\Dev\launch-claude-deepseek.ps1

The difference is important: your key lives in the user environment, while the Anthropic-compatible routing only exists for the launched Claude Code process.

5. Temporary one-liner

For a throwaway test, the one-liner version is fine:

$env:ANTHROPIC_BASE_URL="https://api.deepseek.com/anthropic"; $env:ANTHROPIC_AUTH_TOKEN=$env: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"; cd B:\Dev\PixelBoats; claude

I would not make that the everyday workflow. It is useful for proving the route, not for operating a tool you expect to trust.

Compatibility notes

DeepSeek says Claude Code web search is supported through their API. Treat that as a paid path: search-triggered calls can add token usage because retrieved content still has to be summarized by the model.

DeepSeek's Anthropic API guide also documents model-name mapping. Claude model names starting with claude-opus map to deepseek-v4-pro, while claude-haiku and claude-sonnet map to deepseek-v4-flash.

That mapping is useful when compatibility gets weird, but for Claude Code I would start with the explicit environment variables from the integration docs. It is clearer, easier to audit, and less likely to hide a routing mistake behind automatic mapping.

The operating rule

Keep the key separate from the launcher. Keep the launcher separate from your default Claude setup. Start each new project with a read-only smoke test.

That gives you the benefit of the DeepSeek route without turning your normal coding environment into a mystery box.