Environment Variables

Node.js

@pydantic/logfire-node reads these variables:

Variable	Purpose
`LOGFIRE_TOKEN`	Write token used to send traces, metrics, and logs to Logfire.
`LOGFIRE_API_KEY`	API key for platform APIs such as remote managed variables.
`LOGFIRE_SERVICE_NAME`	Service name resource metadata.
`LOGFIRE_SERVICE_VERSION`	Service version resource metadata.
`LOGFIRE_ENVIRONMENT`	Deployment environment resource metadata.
`LOGFIRE_CONSOLE`	Set to `true` to also print spans to the console. Boolean-only.
`LOGFIRE_MIN_LEVEL`	Minimum manual Logfire level to emit.
`LOGFIRE_SEND_TO_LOGFIRE`	Set sending behavior. `if-token-present` sends only when a token exists.
`LOGFIRE_DISTRIBUTED_TRACING`	Set to `false` to suppress extraction of incoming trace context.
`LOGFIRE_TRACE_SAMPLE_RATE`	Head sampling rate from `0` to `1`.
`LOGFIRE_BASE_URL`	Override the Logfire API base URL.
`LOGFIRE_CREDENTIALS_DIR`	Directory containing `logfire_credentials.json` for local Node projects.
`OTEL_SERVICE_NAME`	Service name fallback when `LOGFIRE_SERVICE_NAME` is unset.
`OTEL_SERVICE_VERSION`	Service version fallback when `LOGFIRE_SERVICE_VERSION` is unset.

For service metadata, precedence is code configuration, then LOGFIRE_*, then OTEL_*.

LOGFIRE_MIN_LEVEL accepts trace, debug, info, notice, warning, error, or fatal. Values are matched case-insensitively. Numeric strings are not accepted. Invalid values warn with console.warn and are ignored.

LOGFIRE_CONSOLE=true enables Node console output with the default console minimum level of info. Object-style console options such as console.minLevel, console.includeTags, and console.includeTimestamps are available only through code configuration.

When LOGFIRE_TOKEN is unset and no code token is passed, Node.js also checks for .logfire/logfire_credentials.json in the current working directory. LOGFIRE_CREDENTIALS_DIR changes that directory. These local credentials are written by npx logfire projects use/new and are not read by browser code.

Cloudflare Workers

@pydantic/logfire-cf-workers reads Worker environment values:

Variable	Purpose
`LOGFIRE_TOKEN`	Write token used by the Worker exporter.
`LOGFIRE_ENVIRONMENT`	Deployment environment metadata.
`LOGFIRE_BASE_URL`	Override the Logfire API base URL.

Store production values as Worker secrets.

Browser

@pydantic/logfire-browser does not read Logfire credentials from environment variables. Configure a traceUrl that points at your backend proxy.

Generic OpenTelemetry

Platforms such as Deno and Vercel’s OpenTelemetry integration use standard OTLP environment variables:

Variable	Purpose
`OTEL_EXPORTER_OTLP_ENDPOINT`	Base OTLP endpoint, such as `https://logfire-api.pydantic.dev`.
`OTEL_EXPORTER_OTLP_TRACES_ENDPOINT`	Trace endpoint, such as `https://logfire-api.pydantic.dev/v1/traces`.
`OTEL_EXPORTER_OTLP_METRICS_ENDPOINT`	Metric endpoint, such as `https://logfire-api.pydantic.dev/v1/metrics`.
`OTEL_EXPORTER_OTLP_HEADERS`	Headers for OTLP export, including `Authorization=your-write-token`.