Claude Alias Patch

Add custom model aliases to Claude Code. Use Gemini, GPT, or any model as a subagent — Claude sees them as selectable options alongside Sonnet, Opus, and Haiku.

How it works

Claude Code hardcodes its model aliases to sonnet, opus, and haiku. This patch extends that list by scanning for ANTHROPIC_DEFAULT_*_MODEL environment variables in your ~/.claude/settings.json.

For example, setting ANTHROPIC_DEFAULT_GEMINI_MODEL registers gemini as a model alias. Claude can then select it when spawning subagents via the Task tool, in the model picker, and in agent definitions.

If you don't set any custom env vars, the patch does nothing — Claude Code works exactly like normal.

You'll need an API proxy that accepts Anthropic-format API calls and routes them to the correct provider. LiteLLM, OpenRouter, and similar tools work.

Install

curl -fsSL https://raw.githubusercontent.com/East-rayyy/claude-alias-patch/main/linux-apply.sh | bash

Prerequisites: Node.js >= 18, npm, python3.

The installer downloads Claude Code from npm, patches it, backs up your existing claude binary, and installs a wrapper script. Works whether you originally installed Claude Code via npm, the native binary, or a package manager.

Configure

Add your custom models to ~/.claude/settings.json. These env vars are completely optional — only add the ones you need:

{
  "env": {
    "ANTHROPIC_BASE_URL": "http://localhost:PORT/v1",
    "ANTHROPIC_DEFAULT_GEMINI_MODEL": "google/gemini-2.5-pro",
    "ANTHROPIC_DEFAULT_GPT_MODEL": "openai/gpt-4o",
    "ANTHROPIC_DEFAULT_DEEPSEEK_MODEL": "deepseek/deepseek-r1"
  }
}

The naming convention is ANTHROPIC_DEFAULT_{ALIAS}_MODEL. The alias comes from the middle part:

• ANTHROPIC_DEFAULT_GEMINI_MODEL → alias gemini
• ANTHROPIC_DEFAULT_GPT_MODEL → alias gpt
• ANTHROPIC_DEFAULT_DEEP_SEEK_MODEL → alias deep-seek (underscores become hyphens)

Restart Claude Code after changing your env vars. Your custom aliases show up automatically in the model picker, the Task tool, and agent definitions.

Update

claude update

The wrapper intercepts the update command, pulls the latest patcher from GitHub, fetches the latest Claude Code from npm, re-patches it, and self-updates the wrapper script. Everything stays current automatically.

Uninstall

curl -fsSL https://raw.githubusercontent.com/East-rayyy/claude-alias-patch/main/linux-remove.sh | bash

Restores your original Claude Code binary and removes the cache.

What it patches

6 locations in Claude Code's cli.js. Patches 1–5 use literal string matching; Patch 6 uses regex to handle obfuscated function names that change between builds:

#	What	Why
1	Zod enum → string	Accept any model alias, not just sonnet/opus/haiku
2	Env var whitelist	Allow custom env vars through the settings.json loader
3	Model picker fallback	Include custom aliases in the fallback list
4	Tool description	List available aliases in the Task tool's model parameter description
5	Model picker UI	Show custom models in the model selection interface
6	Alias resolver fallback	Resolve custom aliases to their model ID at runtime

All patches are idempotent — running the patcher twice produces the same result.

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If you run into issues, open an issue or start a discussion.