FAQ

Hud currently supports Python and Node.js.
For the full requirements, visit the Hud Support Matrix:

• Compatibility Matrix for Node.js
• Compatibility Matrix for Python

Hud currently supports VSCode, Cursor, Webstorm, PyCharm, and IntelliJ IDEA.\

Multiple reasons might cause this:

• The wrong environment might be selected – try choosing the correct one in the top-right dropdown of the screen.
• Hud might not be running – check your application’s stdout to better understand why.
  • Data is on the way - make sure to trigger your functions and wait up to 5 minutes for the data to arrive.

Hud’s SDK is designed to be safe even if its backend is unavailable. It:

• Aggregates metrics into a cyclic in-memory buffer.
• Avoids memory or storage overload.
• Prevents any impact on the main application.

• Data is sent from a separate worker thread to isolate memory, CPU, and event loop usage.
• You can disable instrumentation via the HUD_ENABLE environment variable, ensuring opt-out without code changes.
• Hud self-monitors and can auto-disable if anomalies are detected.
• The SDK is under continuous internal monitoring (memory, CPU, ELU, etc.).

Hud is tested to work seamlessly with:

• Datadog
• NewRelic
• Opentelemetry
• Sentry

Have another APM? Let us know — we’re happy to include it in our test suite.

Hud actively monitors all customer pipelines.
If data flow is interrupted:

• You’ll receive detailed updates about the impact (e.g., data loss or lag) and resolution steps.

When Javascript code is bundled or transpiled, Hud uses sourcemaps to map the running code back to the original source code.
This enables accurate diagnostics and observability.

In Hud, we use metrics like P90 duration.
To understand what P90 duration means and why it matters, check out this quick explainer:
Understanding p90 duration