Caching Features
Langfuse includes built-in caching capabilities for API keys and prompts to improve performance and reduce database load. These features are enabled by default and can be configured or disabled as needed (starting with v3.81.0).
Overview
Caching in Langfuse helps optimize performance by storing frequently accessed data in Redis, reducing the need for repeated database queries. This is particularly beneficial for:
- API key validation: Reduces database lookups for every API request
- Prompt retrieval: Speeds up prompt fetching for applications that frequently access the same prompts
API Key Caching
API key caching stores validated API keys in Redis to avoid repeated database lookups during authentication. This significantly improves response times for ingestion requests. API keys are never stored in plaintext; only their hashed values are cached.
Default Behavior
- Status: Enabled by default
- TTL: 300 seconds (5 minutes)
- Scope: All API key validations
Configuration
| Variable | Default | Description |
|---|---|---|
LANGFUSE_CACHE_API_KEY_ENABLED | true | Enable or disable API key caching |
LANGFUSE_CACHE_API_KEY_TTL_SECONDS | 300 | Time-to-live for cached API keys in seconds |
Disabling API Key Caching
To disable API key caching, set the following environment variable:
LANGFUSE_CACHE_API_KEY_ENABLED=falsePrompt Caching
Prompt caching stores frequently accessed prompts in Redis to improve retrieval performance for applications that regularly fetch the same prompts.
Default Behavior
- Status: Enabled by default
- TTL: 300 seconds (5 minutes)
- Scope: All prompt retrievals via API
Configuration
| Variable | Default | Description |
|---|---|---|
LANGFUSE_CACHE_PROMPT_ENABLED | true | Enable or disable prompt caching |
LANGFUSE_CACHE_PROMPT_TTL_SECONDS | 300 | Time-to-live for cached prompts in seconds |
Disabling Prompt Caching
To disable prompt caching, set the following environment variable:
LANGFUSE_CACHE_PROMPT_ENABLED=falseCache Invalidation
Langfuse automatically handles cache invalidation to ensure data consistency:
- API keys: Cached API keys are invalidated when the key is deleted, disabled, or its permissions change
- Prompts: Cached prompts are invalidated when a prompt is updated, deleted, or a new version is published
Migration from Previous Versions
If you’re upgrading from a previous version of Langfuse, these caching features will be automatically enabled with default settings. No additional configuration is required unless you want to customize the behavior.