> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/badrisnarayanan/antigravity-claude-proxy/llms.txt
> Use this file to discover all available pages before exploring further.
# Available Models
> Claude and Gemini models supported by Antigravity Claude Proxy
Antigravity Claude Proxy provides access to both Claude and Gemini models through a unified Anthropic-compatible API.
## Claude Models
Claude models are accessed through the proxy using Anthropic's API format. All Claude models support extended thinking capabilities.
**Most Capable Model**
Claude Opus 4.6 with extended thinking capabilities. Best for complex reasoning tasks and challenging problems.
* Extended thinking output
* Highest capability tier
* Best for multi-step reasoning
**Balanced Performance**
Claude Sonnet 4.5 with extended thinking. Excellent balance of speed and capability.
* Extended thinking output
* Fast response times
* Ideal for general coding tasks
**Standard Model**
Claude Sonnet 4.5 without thinking output. Fastest response times for straightforward tasks.
* No thinking blocks
* Maximum speed
* Best for simple operations
### Claude Thinking Models
Claude thinking models include an internal reasoning process before generating their final response:
* **signature field**: Claude uses the `signature` field on thinking blocks for multi-turn conversations
* **Thinking blocks**: Extended reasoning is included in the response as separate content blocks
* **Cache support**: Thinking signatures are cached for conversation continuity
## Gemini Models
Gemini models provide high-performance alternatives with Google's latest AI technology. All Gemini models version 3+ include thinking capabilities.
**High Performance Tier**
Gemini 3.1 Pro High with advanced thinking. Best for demanding workloads.
* Extended thinking via `thoughtSignature`
* High quota allocation
* Best for production use
**Balanced Tier**
Gemini 3.1 Pro Low with thinking support. Good balance of performance and quota.
* Extended thinking support
* Moderate quota allocation
* General purpose use
**Fast Responses**
Gemini 3 Flash with thinking. Optimized for speed and efficiency.
* Quick response times
* Extended thinking included
* Ideal for rapid iteration
### Gemini Thinking Models
Gemini models (version 3 and higher) support thinking capabilities:
* **thoughtSignature field**: Gemini uses the `thoughtSignature` field on `functionCall` parts
* **Automatic detection**: Models with "thinking" in the name or version 3+ are treated as thinking models
* **Signature caching**: `thoughtSignature` values are cached for 2 hours
* **Fallback handling**: If Claude Code strips the signature, the proxy restores it from cache or uses a sentinel value
## Model Selection in Claude Code
Configure your Claude Code CLI to use specific models:
Edit `~/.claude/settings.json`:
```json theme={null}
{
"ANTHROPIC_BASE_URL": "http://localhost:8080",
"ANTHROPIC_AUTH_TOKEN": "test",
"ANTHROPIC_MODEL": "claude-opus-4-6-thinking",
"ANTHROPIC_DEFAULT_OPUS_MODEL": "claude-opus-4-6-thinking",
"ANTHROPIC_DEFAULT_SONNET_MODEL": "claude-sonnet-4-5-thinking",
"ANTHROPIC_DEFAULT_HAIKU_MODEL": "claude-sonnet-4-5"
}
```
Set environment variables before launching Claude Code:
```bash theme={null}
export ANTHROPIC_BASE_URL="http://localhost:8080"
export ANTHROPIC_AUTH_TOKEN="test"
export ANTHROPIC_MODEL="gemini-3.1-pro-high"
claude
```
Use the Web Console to generate pre-configured settings:
1. Open the WebUI at `http://localhost:8080`
2. Navigate to **Settings → Claude CLI**
3. Select a preset (Claude Thinking or Gemini 1M)
4. Click **Save to \~/.claude/settings.json**
## Model Naming Conventions
The proxy uses consistent naming patterns for model identification:
### Thinking vs Non-Thinking
| Pattern | Type | Example |
| ------------------------------------ | -------------- | ---------------------------- |
| Contains `thinking` | Thinking model | `claude-sonnet-4-5-thinking` |
| Version 3+ (Gemini) | Thinking model | `gemini-3-flash` |
| No `thinking` + version 2.x or older | Standard model | `claude-sonnet-4-5` |
### Model Family Detection
The proxy automatically detects model families:
* **Claude family**: Model name contains `claude`
* **Gemini family**: Model name contains `gemini`
```javascript theme={null}
// Example model family detection
getModelFamily('claude-opus-4-6-thinking') // Returns 'claude'
getModelFamily('gemini-3-flash') // Returns 'gemini'
```
## Context Window Limits
Gemini models have a maximum output token limit of **16,384 tokens**. The proxy automatically enforces this limit.
### Quota and Rate Limits
Each model has different quota allocations based on your subscription tier:
* **Ultra tier**: Highest quota limits across all models
* **Pro tier**: Moderate quota limits
* **Free tier**: Basic quota limits
Check your current quota in the Web Console under **Models** or via the `/account-limits` API endpoint.
## Cross-Model Conversations
When switching between Claude and Gemini models mid-conversation, thinking signatures may be incompatible and will be dropped automatically.
The proxy handles cross-model scenarios:
1. **Signature validation**: Checks if cached signatures match the target model family
2. **Automatic cleanup**: Drops incompatible signatures when switching families
3. **Recovery mechanism**: Injects synthetic messages to close interrupted tool loops
### Best Practices
* **Stick to one family**: Use either Claude or Gemini for the entire conversation
* **Use fallback strategically**: Enable fallback only when needed to maintain signature compatibility
* **Monitor model switches**: Check logs for signature cleanup warnings
## Testing Models
The proxy includes test utilities for each model family:
```bash theme={null}
# Test Claude models
npm run test:signatures
# Test Gemini models
npm run test:crossmodel
# Test all models
npm test
```
Default test models:
* **Claude**: `claude-sonnet-4-5-thinking`
* **Gemini**: `gemini-3-flash`