---
title: telemetry
sidebarTitle: telemetry
---

# `fastmcp.telemetry`


OpenTelemetry instrumentation for FastMCP.

This module provides native OpenTelemetry integration for FastMCP servers and clients.
It uses only the opentelemetry-api package, so telemetry is a no-op unless the user
installs an OpenTelemetry SDK and configures exporters.

Example usage with SDK:
    ```python
    from opentelemetry import trace
    from opentelemetry.sdk.trace import TracerProvider
    from opentelemetry.sdk.trace.export import ConsoleSpanExporter, SimpleSpanProcessor

    # Configure the SDK (user responsibility)
    provider = TracerProvider()
    provider.add_span_processor(SimpleSpanProcessor(ConsoleSpanExporter()))
    trace.set_tracer_provider(provider)

    # Now FastMCP will emit traces
    from fastmcp import FastMCP
    mcp = FastMCP("my-server")
    ```


## Functions

### `get_tracer` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/fastmcp_slim/fastmcp/telemetry.py#L38" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
get_tracer(version: str | None = None) -> Tracer
```


Get the FastMCP tracer for creating spans.

**Args:**
- `version`: Optional version string for the instrumentation

**Returns:**
- A tracer instance. Returns a no-op tracer if no SDK is configured.


### `inject_trace_context` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/fastmcp_slim/fastmcp/telemetry.py#L50" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
inject_trace_context(meta: dict[str, Any] | None = None) -> dict[str, Any] | None
```


Inject current trace context into a meta dict for MCP request propagation.

**Args:**
- `meta`: Optional existing meta dict to merge with trace context

**Returns:**
- A new dict containing the original meta (if any) plus trace context keys,
- or None if no trace context to inject and meta was None


### `record_span_error` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/fastmcp_slim/fastmcp/telemetry.py#L76" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
record_span_error(span: Span, exception: BaseException) -> None
```


Record an exception on a span and set error status.


### `extract_trace_context` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/fastmcp_slim/fastmcp/telemetry.py#L82" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
extract_trace_context(meta: dict[str, Any] | None) -> Context
```


Extract trace context from an MCP request meta dict.

If already in a valid trace (e.g., from HTTP propagation), the existing
trace context is preserved and meta is not used.

**Args:**
- `meta`: The meta dict from an MCP request (ctx.request_context.meta)

**Returns:**
- An OpenTelemetry Context with the extracted trace context,
- or the current context if no trace context found or already in a trace

