APM Integrations

dd-trace-js provides automatic tracing for 100+ third-party libraries. Each integration consists of two decoupled layers communicating via Node.js diagnostic channels.

Architecture

┌──────────────────────────┐     diagnostic channels      ┌─────────────────────────┐
│     Instrumentation      │ ──────────────────────────▶  │        Plugin           │
│ datadog-instrumentations │    apm:<name>:<op>:start     │  datadog-plugin-<name>  │
│                          │    apm:<name>:<op>:finish    │                         │
│ Hooks into library       │    apm:<name>:<op>:error     │ Creates spans, sets     │
│ methods, emits events    │                              │ tags, handles errors    │
└──────────────────────────┘                              └─────────────────────────┘

Instrumentation (packages/datadog-instrumentations/src/): Hooks into a library's internals and publishes events with context data to named diagnostic channels. Has zero knowledge of tracing — only emits events.