custom-collector

name	custom-collector
description	Write a custom @eleven-labs/nest-profiler collector, or a context adapter for a non-HTTP protocol, when no official @eleven-labs/nest-profiler-* package instruments the integration. Use when a user wants a profiler panel for a library/subsystem that has no ready-made collector, or wants to profile a transport (gRPC, WebSockets, a custom queue) the profiler doesn't know yet.

Write a custom collector or context adapter

When an integration has no @eleven-labs/nest-profiler-* package, don't invent one — implement the public contract in the consumer's app. Two distinct extension points:

• Collector — adds a panel with data you gather during a request (a third-party client, a domain metric). Implement IProfilerCollector.
• Context adapter — teaches the profiler a non-HTTP protocol (gRPC, WebSockets, a custom message queue) so executions of that kind get profiled. Implement IContextAdapter.

First confirm the core profiler is set up (setup-nest-profiler otherwise). Then pick the right extension point above from what the user is instrumenting.

Collector (IProfilerCollector)

Decorate a provider with @ProfilerCollector() and implement collect(profile). Key fields: name, label, icon, scope ('profile' default, or 'global' for once-per-list-page data like config), and optional getBadgeValue / getTemplatePath. Append entries with appendCollectorEntry(profile, name, entry) and read them back with getCollectorEntries. For query-style collectors, extend AbstractQueryCollector / AbstractSqlQueryCollector; for a home-page schema panel, AbstractSchemaCollector. To feed the performance-tagging engine, implement TaggableCollector (see the interpret-performance-tags skill).

import { Injectable } from '@nestjs/common';
import {
  ProfilerCollector,
  appendCollectorEntry,
  getCollectorEntries,
  type IProfilerCollector,
  type Profile,
} from '@eleven-labs/nest-profiler';

@Injectable()
@ProfilerCollector()
export class WidgetCollector implements IProfilerCollector {
  readonly name = 'widget';
  readonly label = 'Widget';
  collect(profile: Profile) {
    return getCollectorEntries(profile, this.name);
  }
  record(profile: Profile, entry: unknown) {
    appendCollectorEntry(profile, this.name, entry);
  }
}

Provide the collector in a module gated the same way as the core, and register a template if you add a custom panel view.

Context adapter (IContextAdapter)

Implement contextType (e.g. 'rpc', 'ws'), recoverProfile(ctx) (read back the profile the middleware created), and enrichProfile(profile, ctx) (attach protocol metadata). Optionally enrichHttpResponse / getRequest. Register it imperatively from your module's onModuleInit:

const core = this.moduleRef.get(ProfilerCoreService, { strict: false });
core.registerContextAdapter(new MyRpcContextAdapter());

Resolve ProfilerCoreService with { strict: false } because the core is a dynamic/global module — this imperative registration is the single supported mechanism.

Verify

Exercise the instrumented path, open a fresh profile at /_profiler, and confirm the new panel (collector) or the newly-profiled execution (context adapter) appears with the expected data. Confirm the app still boots with profiling disabled.

Docs: https://nest-profiler.eleven-labs.com/docs/tutorials/custom-collector · context adapters: https://nest-profiler.eleven-labs.com/docs/packages/nest-profiler/context-adapters