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Use Claude Code with DeepSeek, Ollama or other models

Point Claude Code at a vendor's Anthropic-compatible endpoint with ANTHROPIC_BASE_URL and ANTHROPIC_AUTH_TOKEN, and name the vendor's models in ANTHROPIC_MODEL and the ANTHROPIC_DEFAULT_*_MODEL variables. It works, but Anthropic does not support it, one session talks to one vendor, and features such as prompt caching can be silently ignored.

Updated

How it works

Claude Code sends every request in Anthropic's Messages format to whatever ANTHROPIC_BASE_URL names. A vendor that serves that format can stand in for Anthropic, and Claude Code cannot tell the difference until a request uses something the vendor has not implemented. Anthropic's gateway documentation is explicit that this is unsupported: it "doesn't support routing Claude Code to non-Claude models through any gateway."

Endpoints that work with it

VendorANTHROPIC_BASE_URLNotes
DeepSeekhttps://api.deepseek.com/anthropicOfficial guide. claude-opus* names map to V4 Pro, everything else to V4 Flash
Ollama (local)http://localhost:11434Official integration from Ollama 0.14; ollama launch claude sets it up
Kimi (Moonshot)https://api.moonshot.ai/anthropicOfficial guide; kimi-k2.7-code needs thinking switched on
Z.ai GLMhttps://api.z.ai/api/anthropicOfficial guide
Alibaba Coding Planhttps://coding-intl.dashscope.aliyuncs.com/apps/anthropicOfficial guide; pay-as-you-go endpoints are per region
OpenRouterhttps://openrouter.ai/apiOnly guaranteed with Anthropic as the upstream provider; set ANTHROPIC_API_KEY to an empty string
LM Studio (local)http://localhost:1234Official integration page

Example: DeepSeek

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

These are the values from DeepSeek's own Claude Code page. Set every tier, not just ANTHROPIC_MODEL: a tier left unset still sends a Claude model name, which the endpoint does not know, and the background tasks and subagents that use it fail.

Example: a local model with Ollama

ollama launch claude

That configures Claude Code for you. By hand, it is three variables and a model that supports tool calling:

export ANTHROPIC_BASE_URL=http://localhost:11434
export ANTHROPIC_AUTH_TOKEN=ollama
export ANTHROPIC_API_KEY=""
claude --model qwen3.5

Ollama recommends a context window of 64K tokens or more for larger repositories; a coding agent re-sends the conversation on every turn and a small window fills fast.

What breaks

  • Prompt caching markers. DeepSeek and Ollama ignore Anthropic's cache_control, and Kimi honours it only at the top level. Nothing errors; whether you still get cache pricing depends on the vendor's own caching.
  • Switching vendors. Claude Code reads one ANTHROPIC_BASE_URL, so moving from DeepSeek to Claude means restarting with different settings, not a /model command.
  • Web search. Claude Code's WebSearch tool runs on Anthropic's servers. DeepSeek says its endpoint supports it; Ollama says hosted web search is not fully supported.
  • Unknown request fields. Claude Code treats an unrecognised model name as a current Claude model and sends thinking and effort fields that some endpoints reject with a 400. CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS=1 strips beta fields, at the cost of MCP tool search.
  • Account features. Remote Control and voice dictation are unavailable while a gateway credential is set.
  • Stale credentials. A leftover ANTHROPIC_API_KEY, a saved login or old env values in settings.json can override the setup; /status shows which one is in use.

When a model-agnostic agent fits better

If you want one vendor at a time and already work in Claude Code, the settings above are enough. If you want Claude, DeepSeek and a local model inside the same task, OHarness does that natively: each provider is built in, the conversation is stored in a vendor-neutral format, and /model switches across vendors without a restart. OHarness vs Claude Code compares the two directly.

npm install -g oharness
oharness -m deepseek/deepseek-v4-flash

Then, mid-session, /model anthropic/claude-sonnet-5 for the step that needs it, and back again.

Sources

Common questions

Can Claude Code use DeepSeek models?

Yes, unofficially. DeepSeek serves an Anthropic-compatible endpoint at https://api.deepseek.com/anthropic: set ANTHROPIC_BASE_URL to it, ANTHROPIC_AUTH_TOKEN to a DeepSeek API key, and the model variables to DeepSeek's model names. Anthropic does not support non-Claude models in Claude Code.

Can Claude Code run a local model with Ollama?

Yes. Ollama 0.14 and later serve the Anthropic Messages format, and `ollama launch claude` configures Claude Code to use it. Pick a model that supports tool calling and give it a context window of 64K tokens or more.

Can Claude Code switch between Claude and DeepSeek in one session?

No. Claude Code reads a single ANTHROPIC_BASE_URL, so one Claude Code session talks to one vendor. OHarness switches between Anthropic, DeepSeek, OpenAI, Gemini and local models mid-session with /model.

Why does Claude Code return 400 errors with another vendor's endpoint?

Claude Code assumes an unrecognised model is a current Claude model and sends fields such as adaptive thinking and effort that some endpoints reject. Setting every ANTHROPIC_DEFAULT_*_MODEL variable to the vendor's names, and CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS=1, removes most of them.

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