Storage backends

Profiles have to live somewhere between the request that produces them and the moment you open the UI. Three options are available, controlled by the storageType or storage options.

Memory (default)

Profiles are kept in an in-memory LRU map and are lost on restart.

ProfilerModule.forRoot({
  storageType: 'memory', // default — no need to specify
  maxProfiles: 100,
  ttl: 3600,
});

File system

Profiles are stored as individual JSON files and survive restarts. Inspired by Symfony's file profiler.

ProfilerModule.forRoot({
  storageType: 'file',
  storagePath: '.profiler', // relative to cwd, default: '.profiler'
  maxProfiles: 200,
  ttl: 86400, // 24h
});

Each profile is written to {storagePath}/{token}.json. The directory is created automatically. Add .profiler/ to .gitignore.

The in-memory index is reconstructed from disk on startup — expired profiles are cleaned up automatically.

For fast list rendering, parsed profiles are also cached in memory and validated against each file's mtime, so steady-state memory grows with maxProfiles × average profile size — keep maxProfiles reasonable when collectBody is enabled. Profiles returned by the storage are shared with this cache: treat them as read-only.

Custom adapter

Implement IProfilerStorageAdapter to plug in any backend (Redis, database, …):

import type {
  IProfilerStorageAdapter,
  StorageFindOptions,
  Profile,
} from '@eleven-labs/nest-profiler';

export class RedisStorageAdapter implements IProfilerStorageAdapter {
  async save(profile: Profile): Promise<void> {
    /* ... */
  }
  async findAll(options?: StorageFindOptions): Promise<Profile[]> {
    /* ... */
  }
  async findOne(token: string): Promise<Profile | undefined> {
    /* ... */
  }
  async clear(): Promise<void> {
    /* ... */
  }
}

ProfilerModule.forRoot({
  storage: new RedisStorageAdapter(redisClient), // takes precedence over storageType
});

Step-by-step tutorial — File-based profile storage shows persistent profiles in action, including CLI command profiles that survive the process that created them.