Langfuse MCP Server
Server Configuration
Describes the environment variables required to run the server.
| Name | Required | Description | Default |
|---|---|---|---|
| LANGFUSE_HOST | No | Langfuse instance URL. For self-hosted instances use your own instance URL. Defaults to https://cloud.langfuse.com. | https://cloud.langfuse.com |
| LANGFUSE_PUBLIC_KEY | No | Langfuse public API key (e.g. pk-...). Precedence: CLI flags (--public-key) > environment variables > the selected profile > defaults. | |
| LANGFUSE_SECRET_KEY | No | Langfuse secret API key (e.g. sk-...). Precedence: CLI flags (--secret-key) > environment variables > the selected profile > defaults. | |
| LANGFUSE_MCP_PROFILE | No | Profile to load from the profiles file; same as the --profile flag. Selects a Langfuse project's credentials from the profiles file. | |
| LANGFUSE_MAX_AGE_DAYS | No | Caps the lookback window for time-based tools (fetch_traces, fetch_observations, etc.). Set to match your Langfuse instance's data retention, e.g. 30 if retention is 30 days. | 7 |
| LANGFUSE_MCP_READ_ONLY | No | Set to true to disable all write operations for safer read-only access (disables create/update/delete tools for prompts, datasets, and annotation queues). Equivalent to the --read-only flag. | false |
| LANGFUSE_MCP_PROFILES_FILE | No | Path of the TOML profiles file; same as the --profiles-file flag. Defaults to $XDG_CONFIG_HOME/langfuse-mcp/profiles.toml (or ~/.config/langfuse-mcp/profiles.toml when XDG_CONFIG_HOME is not set). | $XDG_CONFIG_HOME/langfuse-mcp/profiles.toml |
| LANGFUSE_MCP_DEFAULT_OUTPUT_MODE | No | Sets the MCP-exposed default output_mode so clients that omit the parameter automatically use your preferred mode. Supported values: compact, full_json_string, full_json_file. Equivalent to the --default-output-mode flag. Clients can still override it per call by passing output_mode explicitly. | |
| LANGFUSE_MCP_TRACE_TIMEOUT_SECONDS | No | Per-request read timeout in seconds for single-trace fetches (fetch_trace). Raise it if large traces with include_observations=True time out. Must be a positive integer. | 120 |
Instructions
Guidance the server publishes about itself, which clients place ahead of the tool catalog so the model reads it before choosing anything.
This server publishes no instructions, or was last inspected before Glama recorded them.
Capabilities
Server capabilities have not been inspected yet.
Tools
Functions exposed to the LLM to take actions
| Name | Description |
|---|---|
No tools | |
Prompts
Interactive templates invoked by user choice
| Name | Description |
|---|---|
No prompts | |
Resources
Contextual data attached and managed by the client
| Name | Description |
|---|---|
No resources | |
This server cannot be deployed
Maintenance
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