Deepgram Observability

Overview

Full observability stack for Deepgram: Prometheus metrics (request counts, latency histograms, audio processed, cost tracking), OpenTelemetry distributed tracing, structured JSON logging with Pino, Grafana dashboard JSON, and AlertManager rules.

Four Pillars

Pillar	Tool	What It Tracks
Metrics	Prometheus	Request rate, latency, error rate, audio minutes, estimated cost
Traces	OpenTelemetry	End-to-end request flow, Deepgram API span timing
Logs	Pino (JSON)	Request details, errors, audit trail
Alerts	AlertManager	Error rate >5%, P95 latency >10s, rate limit hits

Instructions

Step 1: Prometheus Metrics Definition

import { Counter, Histogram, Gauge, Registry, collectDefaultMetrics } from 'prom-client';

const registry = new Registry();
collectDefaultMetrics({ register: registry });

// Request metrics
const requestsTotal = new Counter({
  name: 'deepgram_requests_total',
  help: 'Total Deepgram API requests',
  labelNames: ['method', 'model', 'status'] as const,
  registers: [registry],
});

const latencyHistogram = new Histogram({
  name: 'deepgram_request_duration_seconds',
  help: 'Deepgram API request duration',
  labelNames: ['method', 'model'] as const,
  buckets: [0.1, 0.5, 1, 2, 5, 10, 30, 60],
  registers: [registry],
});

// Usage metrics
const audioProcessedSeconds = new Counter({
  name: 'deepgram_audio_processed_seconds_total',
  help: 'Total audio seconds processed',
  labelNames: ['model'] as const,
  registers: [registry],
});

const estimatedCostDollars = new Counter({
  name: 'deepgram_estimated_cost_dollars_total',
  help: 'Estimated cost in USD',
  labelNames: ['model', 'method'] as const,
  registers: [registry],
});

// Operational metrics
const activeConnections = new Gauge({
  name: 'deepgram_active_websocket_connections',
  help: 'Currently active WebSocket connections',
  registers: [registry],
});

const rateLimitHits = new Counter({
  name: 'deepgram_rate_limit_hits_total',
  help: 'Number of 429 rate limit responses',
  registers: [registry],
});

export { registry, requestsTotal, latencyHistogram, audioProcessedSeconds,
         estimatedCostDollars, activeConnections, rateLimitHits };

Step 2: Instrumented Deepgram Client

import { createClient, DeepgramClient } from '@deepgram/sdk';

class InstrumentedDeepgram {
  private client: DeepgramClient;
  private costPerMinute: Record<string, number> = {
    'nova-3': 0.0043, 'nova-2': 0.0043, 'base': 0.0048, 'whisper-large': 0.0048,
  };

  constructor(apiKey: string) {
    this.client = createClient(apiKey);
  }

  async transcribeUrl(url: string, options: Record<string, any> = {}) {
    const model = options.model ?? 'nova-3';
    const timer = latencyHistogram.startTimer({ method: 'prerecorded', model });

    try {
      const { result, error } = await this.client.listen.prerecorded.transcribeUrl(
        { url }, { model, smart_format: true, ...options }
      );

      const status = error ? 'error' : 'success';
      timer();
      requestsTotal.inc({ method: 'prerecorded', model, status });

      if (error) {
        if ((error as any).status === 429) rateLimitHits.inc();
        throw error;
      }

      // Track usage
      const duration = result.metadata.duration;
      audioProcessedSeconds.inc({ model }, duration);
      estimatedCostDollars.inc(
        { model, method: 'prerecorded' },
        (duration / 60) * (this.costPerMinute[model] ?? 0.0043)
      );

      return result;
    } catch (err) {
      timer();
      requestsTotal.inc({ method: 'prerecorded', model, status: 'error' });
      throw err;
    }
  }

  // Live transcription with connection tracking
  connectLive(options: Record<string, any>) {
    const model = options.model ?? 'nova-3';
    activeConnections.inc();

    const connection = this.client.listen.live(options);

    const originalFinish = connection.finish.bind(connection);
    connection.finish = () => {
      activeConnections.dec();
      return originalFinish();
    };

    return connection;
  }
}

Step 3: OpenTelemetry Tracing

import { NodeSDK } from '@opentelemetry/sdk-node';
import { OTLPTraceExporter } from '@opentelemetry/exporter-trace-otlp-http';
import { getNodeAutoInstrumentations } from '@opentelemetry/auto-instrumentations-node';
import { Resource } from '@opentelemetry/resources';
import { SEMRESATTRS_SERVICE_NAME } from '@opentelemetry/semantic-conventions';
import { trace } from '@opentelemetry/api';

const sdk = new NodeSDK({
  resource: new Resource({
    [SEMRESATTRS_SERVICE_NAME]: 'deepgram-service',
    'deployment.environment': process.env.NODE_ENV ?? 'development',
  }),
  traceExporter: new OTLPTraceExporter({
    url: process.env.OTEL_EXPORTER_OTLP_ENDPOINT ?? 'http://localhost:4318/v1/traces',
  }),
  instrumentations: [
    getNodeAutoInstrumentations({
      '@opentelemetry/instrumentation-http': {
        ignoreIncomingPaths: ['/health', '/metrics'],
      },
    }),
  ],
});

sdk.start();

// Add custom spans for Deepgram operations
const tracer = trace.getTracer('deepgram');

async function tracedTranscribe(url: string, model: string) {
  return tracer.startActiveSpan('deepgram.transcribe', async (span) => {
    span.setAttribute('deepgram.model', model);
    span.setAttribute('deepgram.audio_url', url.substring(0, 100));

    try {
      const instrumented = new InstrumentedDeepgram(process.env.DEEPGRAM_API_KEY!);
      const result = await instrumented.transcribeUrl(url, { model });

      span.setAttribute('deepgram.duration_seconds', result.metadata.duration);
      span.setAttribute('deepgram.request_id', result.metadata.request_id);
      span.setAttribute('deepgram.confidence',
        result.results.channels[0].alternatives[0].confidence);

      return result;
    } catch (err: any) {
      span.recordException(err);
      span.setStatus({ code: 2, message: err.message });
      throw err;
    } finally {
      span.end();
    }
  });
}

Step 4: Structured Logging with Pino

import pino from 'pino';

const logger = pino({
  level: process.env.LOG_LEVEL ?? 'info',
  formatters: {
    level: (label) => ({ level: label }),
  },
  timestamp: pino.stdTimeFunctions.isoTime,
  base: {
    service: 'deepgram-integration',
    env: process.env.NODE_ENV,
  },
});

// Child loggers per component
const transcriptionLog = logger.child({ component: 'transcription' });
const metricsLog = logger.child({ component: 'metrics' });

// Usage:
transcriptionLog.info({
  action: 'transcribe',
  model: 'nova-3',
  audioUrl: url.substring(0, 100),
  requestId: result.metadata.request_id,
  duration: result.metadata.duration,
  confidence: result.results.channels[0].alternatives[0].confidence,
}, 'Transcription completed');

transcriptionLog.error({
  action: 'transcribe',
  model: 'nova-3',
  error: err.message,
  statusCode: err.status,
}, 'Transcription failed');

Step 5: Grafana Dashboard Panels

{
  "title": "Deepgram Observability",
  "panels": [
    {
      "title": "Request Rate",
      "type": "timeseries",
      "targets": [{ "expr": "rate(deepgram_requests_total[5m])" }]
    },
    {
      "title": "P95 Latency",
      "type": "gauge",
      "targets": [{ "expr": "histogram_quantile(0.95, rate(deepgram_request_duration_seconds_bucket[5m]))" }]
    },
    {
      "title": "Error Rate %",
      "type": "stat",
      "targets": [{ "expr": "rate(deepgram_requests_total{status='error'}[5m]) / rate(deepgram_requests_total[5m]) * 100" }]
    },
    {
      "title": "Audio Processed (min/hr)",
      "type": "timeseries",
      "targets": [{ "expr": "rate(deepgram_audio_processed_seconds_total[1h]) / 60" }]
    },
    {
      "title": "Estimated Daily Cost",
      "type": "stat",
      "targets": [{ "expr": "increase(deepgram_estimated_cost_dollars_total[24h])" }]
    },
    {
      "title": "Active WebSocket Connections",
      "type": "gauge",
      "targets": [{ "expr": "deepgram_active_websocket_connections" }]
    }
  ]
}

Step 6: AlertManager Rules

groups:
  - name: deepgram-alerts
    rules:
      - alert: DeepgramHighErrorRate
        expr: >
          rate(deepgram_requests_total{status="error"}[5m])
          / rate(deepgram_requests_total[5m]) > 0.05
        for: 5m
        labels: { severity: critical }
        annotations:
          summary: "Deepgram error rate > 5% for 5 minutes"

      - alert: DeepgramHighLatency
        expr: >
          histogram_quantile(0.95,
            rate(deepgram_request_duration_seconds_bucket[5m])
          ) > 10
        for: 5m
        labels: { severity: warning }
        annotations:
          summary: "Deepgram P95 latency > 10 seconds"

      - alert: DeepgramRateLimited
        expr: rate(deepgram_rate_limit_hits_total[1h]) > 10
        for: 10m
        labels: { severity: warning }
        annotations:
          summary: "Deepgram rate limit hits > 10/hour"

      - alert: DeepgramCostSpike
        expr: >
          increase(deepgram_estimated_cost_dollars_total[24h])
          > 2 * increase(deepgram_estimated_cost_dollars_total[24h] offset 1d)
        for: 30m
        labels: { severity: warning }
        annotations:
          summary: "Deepgram daily cost > 2x yesterday"

      - alert: DeepgramZeroRequests
        expr: rate(deepgram_requests_total[15m]) == 0
        for: 15m
        labels: { severity: warning }
        annotations:
          summary: "No Deepgram requests for 15 minutes"

Metrics Endpoint

import express from 'express';
const app = express();

app.get('/metrics', async (req, res) => {
  res.set('Content-Type', registry.contentType);
  res.send(await registry.metrics());
});

Output

• Prometheus metrics (6 metrics covering requests, latency, usage, cost)
• Instrumented Deepgram client with auto-tracking
• OpenTelemetry distributed tracing with custom spans
• Structured JSON logging (Pino)
• Grafana dashboard panel definitions
• AlertManager rules (5 alerts)

Error Handling

Issue	Cause	Solution
Metrics not appearing	Registry not exported	Check /metrics endpoint
High cardinality	Too many label values	Limit labels to known set
Alert storms	Thresholds too sensitive	Add for: duration, tune values
Missing traces	OTEL exporter not configured	Set OTEL_EXPORTER_OTLP_ENDPOINT

Resources

• Prometheus Client
• OpenTelemetry Node.js
• Pino Logger
• Grafana Dashboards