> ## Documentation Index
> Fetch the complete documentation index at: https://gofastmcp.com/llms.txt
> Use this file to discover all available pages before exploring further.

# 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 theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
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 theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
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 theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
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 theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
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 theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
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