fetch_observations
Retrieve Langfuse observations by type, time range, and filters like name or user ID for debugging and analysis of LLM applications.
Instructions
Get observations filtered by type and other criteria.
Args:
ctx: Context object containing lifespan context with Langfuse client
type: The observation type to filter by (SPAN, GENERATION, or EVENT)
age: Minutes ago to start looking (e.g., 1440 for 24 hours)
name: Optional name filter (string pattern to match)
user_id: Optional user ID filter (exact match)
trace_id: Optional trace ID filter (exact match)
parent_observation_id: Optional parent observation ID filter (exact match)
page: Page number for pagination (starts at 1)
limit: Maximum number of observations to return per page
output_mode: Controls the output format and detail level
Returns:
Based on output_mode:
- compact: List of summarized observation objects
- full_json_string: String containing the full JSON response
- full_json_file: List of summarized observation objects with file save infoInput Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| type | No | The observation type to filter by ('SPAN', 'GENERATION', or 'EVENT') | |
| age | Yes | Minutes ago to start looking (e.g., 1440 for 24 hours) | |
| name | No | Optional name filter (string pattern to match) | |
| user_id | No | Optional user ID filter (exact match) | |
| trace_id | No | Optional trace ID filter (exact match) | |
| parent_observation_id | No | Optional parent observation ID filter (exact match) | |
| page | No | Page number for pagination (starts at 1) | |
| limit | No | Maximum number of observations to return per page | |
| output_mode | No | Controls the output format and action. 'compact' (default): Returns a summarized JSON object optimized for direct agent consumption. 'full_json_string': Returns the complete, raw JSON data serialized as a string. 'full_json_file': Returns a summarized JSON object AND saves the complete data to a file. | compact |
Output Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |