Environment variables¶

These variables configure the implemented Go utilities. The behavioral baseline is TypeScript v2.35.0; Go-specific OTel settings are explicit extensions. Configure variables before constructing utilities. Do not mutate process environment as request-local state in concurrent handlers.

Logging, tracing and metrics¶

Variable	Purpose and precedence	Details
`POWERTOOLS_SERVICE_NAME`	Shared service fallback; utility-specific explicit options take precedence	Logger, Tracer, Metrics
`POWERTOOLS_DEV`	Readable Logger output; disables default tracing and Metrics emission	A valid explicit metrics-disabled setting can override the Metrics development fallback
`POWERTOOLS_LOG_LEVEL` / `LOG_LEVEL`	Configured Logger threshold fallback; default INFO	ALC has precedence; Logger configuration
`AWS_LAMBDA_LOG_LEVEL`	Lambda advanced logging threshold; also affects default router debug diagnostics	Configure through Lambda logging settings
`POWERTOOLS_LOGGER_SAMPLE_RATE`	Debug sampling probability; default zero	Construction/first/warm invocation decisions are distinct
`POWERTOOLS_LOGGER_LOG_EVENT`	Opt-in event logging; default disabled	Emits input data, separately from business messages
`TZ`	Logger timestamp timezone	UTC default; timezone validation is utility-specific
`POWERTOOLS_TRACE_ENABLED`	Disable tracing with false; local enablement remains explicit	Tracer configuration
`POWERTOOLS_TRACER_CAPTURE_RESPONSE` / `POWERTOOLS_TRACER_CAPTURE_ERROR`	False vetoes automatic capture	Explicit application decisions; response defaults differ from the quickstart's opt-out
`POWERTOOLS_TRACER_CAPTURE_HTTPS_REQUESTS`	HTTP tracing capture switch	Instrument a client explicitly
`OTEL_EXPORTER_OTLP_ENDPOINT` / `OTEL_EXPORTER_OTLP_TRACES_ENDPOINT`	OTLP collector base or traces URL	Does not install/start a collector
`OTEL_TRACES_SAMPLER` / `OTEL_TRACES_SAMPLER_ARG`	Default OTel provider sampler settings	Unset default is parent-based always-on
`POWERTOOLS_METRICS_NAMESPACE`	Metrics namespace fallback	Missing namespace emits `default_namespace` with a warning
`POWERTOOLS_METRICS_FUNCTION_NAME`	Optional cold-start function dimension	Name precedence
`POWERTOOLS_METRICS_DISABLED`	Explicit enable/disable; validated before options	Invalid/present-empty values return a construction error
`AWS_LAMBDA_INITIALIZATION_TYPE`	Metrics ColdStart requires on-demand initialization	Runtime-owned; provisioned/unknown differs

Configuration, persistence and metadata¶

Variable	Purpose	Details
`POWERTOOLS_PARAMETERS_MAX_AGE`	Ordinary parameter cache TTL seconds; default five	Cache policy; named batches have separate reference quirks
`POWERTOOLS_PARAMETERS_SSM_DECRYPT`	SSM decryption fallback	Explicit per-call flag, then SDK input, then environment
`AWS_APPCONFIG_EXTENSION_HTTP_PORT`	AppConfig Agent port; default 2772	Agent extension must be installed separately
`POWERTOOLS_APPCONFIG_AGENT_RETURN_VALUE`	Agent helper's outside-Lambda development value	Provider behavior
`POWERTOOLS_IDEMPOTENCY_DISABLED`	Disable Idempotency at construction	Lifecycle/configuration
`AWS_LAMBDA_METADATA_API` / `AWS_LAMBDA_METADATA_TOKEN`	Default LMDS endpoint and bearer token	Metadata; outside-Lambda default makes no request

Signer's default credentials provider reads AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY and optional AWS_SESSION_TOKEN for each operation; AWS_REGION is the default region. Inject a provider for another credential source. Other AWS SDK clients use their supplied configuration; this table does not replace SDK configuration or required service permissions.

Lambda function name, memory size, request identity and trace headers enrich telemetry when invocation context is available. Prefer wrapper-provided runtime context. Applications should not forge runtime variables to turn local execution into service acceptance.

Parsing and scope¶

Boolean, numeric and whitespace parsing is utility-specific. Commons exposes strict/extended modes; Metrics explicitly validates its disabled variable, while Logger retains its own fallback behavior. Refer to each utility's configuration table rather than assuming an identical parser everywhere.

Construct reusable objects once. Root configuration and caches survive warm invocations, but Logger/Metrics request state belongs to the wrapper-created scope. Usage patterns explains this lifecycle and how method errors differ from business errors.