Skip to main content

Phoenix tracing

Arize Phoenix is a free, open-source LLM observability tool that consumes OpenTelemetry spans and renders them with first-class support for the OpenInference span-kind convention. memledger's spans land in Phoenix natively — no custom integration required.

Phoenix is the reference observability target for memledger because it's free and OpenInference-aware. Any OTEL-supported backend works equally well; see OpenTelemetry integration for the full list.

Setup​

Point memledger's OTLP exporter at your Phoenix collector:

export PHOENIX_BASE_URL=http://phoenix:6006
export OTEL_EXPORTER_OTLP_ENDPOINT=http://phoenix:4317

memledger detects these env vars at startup and registers Phoenix as an annotation target.

What you'll see​

Phoenix renders memledger spans under three categories via openinference.span.kind:

  • RETRIEVER — memledger.add / memledger.search / memledger.get
  • EVALUATOR — evaluators.mai_*
  • default — internal operations

Span list​

Phoenix span list with memledger.* attributes

Phoenix span list with memledger.* attributes — every memory operation is a traceable span.

Sessions view​

Phoenix Sessions view filtered by service.name

Filter the Sessions view by service.name to see all memory operations from a single agent run.

Why Phoenix specifically​

  • Free + open source — Apache 2.0; deployable in your cluster
  • OpenInference span recognition — eval annotations render with rubric scores and pass/fail status without custom code
  • Sessions view — agent-run-level traces map cleanly to service.name per agent
  • Self-hostable — runs in your Kubernetes cluster as a sidecar; no SaaS lock-in

For non-Phoenix backends, see OpenTelemetry integration for the OTLP wiring.

The full Phoenix setup guide — Helm chart deployment, dashboard template, span retention — ships in a future release.