Amplitude

Enable it

npx klaridian generate --spec ./api.yaml --out ./my-server --plugin amplitude

Every tool call sends an Amplitude event with the tool name, how long it took, and whether it succeeded. This tells you which tools get used—OpenTelemetry tells you if a call is slow or broken, but not whether anyone's calling it.

Configure it

AMPLITUDE_API_KEY=... \
AMPLITUDE_SERVER_ZONE=US \
node dist/src/index.js

AMPLITUDE_API_KEY is your Amplitude project API key and is required. AMPLITUDE_SERVER_ZONE picks the data region—US or EU—and defaults to the value you chose at generation time (US unless you set it otherwise).

Why this is a separate plugin from OTel

Tracing has one open standard—OpenTelemetry—so one otel plugin works with every backend. Product analytics doesn't have that: PostHog, Amplitude, and Mixpanel each need their own integration. amplitude works the same way as posthog and mixpanel.

One plugin at a time

Today you can pick one plugin per server—otel, or one of the analytics plugins, not both together. Combining an engineering plugin and a product plugin on the same server is planned, not built yet.

Python and TypeScript

The amplitude plugin supports both target languages. With --language python it ships a vendored instrumentation/amplitude.py built on the Amplitude Python SDK; the default TypeScript target ships src/instrumentation/amplitude.ts on @amplitude/analytics-node. Both wrap tool dispatch the same way and read the same AMPLITUDE_API_KEY and AMPLITUDE_SERVER_ZONE environment variables.