NestJS Request and Workflow Telemetry

Implementation evidence

NestJS Request and Workflow Telemetry: from boundary to verified row

Use NestJS Request and Workflow Telemetry at a controlled application boundary, keep the event contract small, and verify a known outcome before building aggregate views.

1
Choose the outcome
NestJS API monitoring
2
Define the contract
request_id, controller, handler, route_template, and method
3
Instrument the boundary
Apply an interceptor at the narrowest useful scope and derive route_template from framework metadata rather than req.originalUrl.
4
Verify the evidence
Exercise a known fixture, then inspect api_request_completed for one correctly typed terminal row.

Before you start

Prerequisites and boundaries

telemetry-sh initialized in a server-only NestJS provider or module
A route-template resolver that avoids raw URLs and path identifiers
An exception taxonomy and a policy for non-blocking versus durable delivery

Delivery setup

Install and initialize server-side

Import telemetry-sh in server-only code and initialize it once with process.env.TELEMETRY_API_KEY. Keep ingestion credentials out of browser bundles, client-visible environment variables, source control, logs, and exception messages.

nestjs-install

npm installation

bash

npm install telemetry-sh

1Prepare one reusable server-side delivery client with bounded network behavior.
2Add the outcome event at the success, failure, retry, or timeout boundary.
3Send controlled fixtures and inspect the stored rows before enabling an alert.

Snippet

Start with one structured event

Add this shape where the workflow completes, fails, or retries. Then build the dashboard from real fields.

nestjs

NestJS Request and Workflow Telemetry event

javascript

@Injectable()
export class OutcomeInterceptor implements NestInterceptor {
  intercept(context: ExecutionContext, next: CallHandler) {
    const request = context.switchToHttp().getRequest();
    const response = context.switchToHttp().getResponse();
    const startedAt = performance.now();
    let errorType: string | undefined;

    return next.handle().pipe(
      catchError((error) => {
        errorType = classifyError(error);
        throw error;
      }),
      finalize(() => {
        const statusCode = response.statusCode;
        void telemetry.log("api_request_completed", {
          request_id: request.id,
          controller: context.getClass().name,
          handler: context.getHandler().name,
          route_template: resolveRouteTemplate(context),
          method: request.method,
          status_code: statusCode,
          status: statusCode >= 500 ? "failed" : "success",
          latency_ms: Math.round(performance.now() - startedAt),
          error_type: errorType,
          release: process.env.APP_RELEASE,
        }).catch(recordTelemetryFailure);
      }),
    );
  }
}

Event contract

request_id, controller, handler, route_template, and method

status, status_code, latency_ms, error_type, and release

tenant_id, plan, or feature only when explicitly approved

Implementation checkpoints

Checkpoint 1

Apply an interceptor at the narrowest useful scope and derive route_template from framework metadata rather than req.originalUrl.

Checkpoint 2

The example accounts for the delivery promise but does not delay the HTTP response; use an application-owned outbox when the event is compliance or billing critical.

Checkpoint 3

Keep exception objects, request bodies, authorization headers, cookies, query strings, and raw path parameters out of the payload.

Verification

Prove the event arrived

Run this after exercising known success and failure cases. Replace the fallback table name if your final event contract differs from the snippet.

nestjs-verification

NestJS Request and Workflow Telemetry verification query

sql

SELECT *
FROM api_request_completed
ORDER BY timestamp_utc DESC
LIMIT 20;

Confirm one terminal row per logical outcome, with the expected status, identifiers, units, and UTC time.

Inspect the inferred schema and verify that retries do not change field types or generate a new logical event ID.

Search the stored fields for credentials, raw payloads, prompts, private content, and unbounded error messages.

Exercise a provider timeout, ingestion rejection, and process shutdown before treating the dashboard as complete.

Implementation references

Review the event contract, data-safety guidance, and upstream primary documentation before enabling a new production path.

JavaScript SDK API reliability guide Delivery and idempotency NestJS interceptors NestJS request lifecycle

Production boundary

Keep the outcome event small and recoverable

This pattern provides

A bounded, SQL-ready outcome beside the upstream workflow.
Stable fields for dashboards, alerts, and cross-event correlation.
A fixture-driven path for validating success, failure, retry, and timeout behavior.

This pattern does not provide

An OTLP exporter, automatic collection pipeline, or replacement for detailed traces and diagnostic logs.
Exactly-once delivery merely because the payload contains an event ID.
Permission to collect raw provider payloads, user content, credentials, or regulated data.

Delivery and idempotency Batching and shutdown Troubleshoot ingestion

Event schema starting points

Review the row grain, emit boundary, required types, privacy classes, example payload, and validation checklist before adapting a query or snippet to production.

API reliability10 fields