LLM Configuration
Settings for controlling how LambChat interacts with language models.
Model Provider Keys
These are consumed by the underlying LLM SDK libraries directly (not by the Settings class):
| Variable | Description |
|---|---|
LLM_API_KEY | Default LLM API key (consumed by LiteLLM) |
LLM_API_BASE | Default LLM API base URL (consumed by LiteLLM) |
LLM_MODEL | Default LLM model name, e.g. anthropic/claude-sonnet-4-6 |
ANTHROPIC_API_KEY | Anthropic API key (consumed by langchain-anthropic) |
ANTHROPIC_BASE_URL | Anthropic-compatible API base URL |
TIP
LambChat supports multi-model management through the UI. The env vars above set the default provider. Users can add additional providers and models at runtime through the settings panel.
Retry & Cache Settings
| Variable | Default | Description |
|---|---|---|
DEFAULT_MODEL_ID | (empty) | Admin model configuration ID used as the default for new sessions and background jobs. Empty = first enabled model. |
LLM_MAX_RETRIES | 3 | Retries after the initial call for timeout, network, rate-limit, and 5xx failures. 3 means up to 4 attempts. |
LLM_RETRY_DELAY | 1.0 | Initial retry delay in seconds (exponential backoff). |
LLM_REQUEST_TIMEOUT | 0 | Total seconds allowed for a complete non-streaming response. 0 or a negative value disables LambChat's non-streaming total timeout, so non-streaming waits indefinitely by default. |
LLM_FIRST_EVENT_TIMEOUT | 30 | Seconds allowed for the first provider event of a streaming response. 0 or a negative value disables this deadline. After the first event, LambChat applies no total duration limit or chunk idle timeout. |
LLM_MODEL_CACHE_SIZE | 50 | Model instance cache size. Prevents memory leaks from repeated instantiation. |
LLM_REQUEST_HEADERS | (empty) | JSON object of request headers merged over the built-in anti-ban defaults (Claude Code style User-Agent/x-app for Anthropic protocol, opencode style User-Agent for OpenAI-compatible). Example: {"User-Agent": "my-agent/1.0"}. Per-model header overrides take precedence; Google protocol is not supported. |
LLM_MAX_INPUT_TOKENS | (none) | Optional: context window size for DeepAgent auto-summarization. |
LLM_TEMPERATURE | (none) | Optional: default temperature for LLM calls. |
LLM_MAX_TOKENS | (none) | Optional: max output tokens for LLM calls. |
DeepAgent Context Settings
| Variable | Default | Description |
|---|---|---|
DEEPAGENT_DEFAULT_MAX_INPUT_TOKENS | 64000 | Default max input tokens for DeepAgent. |
Example
bash
# .env
LLM_API_KEY=sk-your-api-key
LLM_API_BASE=https://api.openai.com/v1
LLM_MODEL=gpt-4o
LLM_MAX_RETRIES=3
LLM_RETRY_DELAY=1.0
LLM_REQUEST_TIMEOUT=0
LLM_FIRST_EVENT_TIMEOUT=30
LLM_MODEL_CACHE_SIZE=50