Akari — 灯¶
A high-performance PHP APM extension.
Automatic distributed tracing — exported as OpenTelemetry.
Work in progress
This project is still a work in progress and is not yet ready for production use. APIs, configuration, and internals may change at any time.
Akari (灯, "light") is a PHP C extension that illuminates your
application's behavior. It hooks into the Zend Engine via the official
zend_observer API to capture database queries, HTTP requests, cache and
messaging calls, framework internals, and exceptions — all exported as
standard OpenTelemetry traces to any OTLP-compatible collector (Jaeger,
Grafana Tempo, Honeycomb, etc.).
Key design goals¶
-
Zero-config
Drop in, get traces. Sensible defaults cover 90% of use cases.
-
Near-zero overhead
Fire-and-forget UDP export, frame deduplication, and per-hook thresholds keep the hot path at roughly ~1μs.
-
No vendor lock-in
Standard OTLP protocol — point it at any collector you already run.
-
Broad coverage
Databases, caches, HTTP clients, messaging, and the major PHP frameworks are instrumented out of the box.
How it works¶
graph LR
A["PHP-FPM / CLI<br>akari extension"] -- "UDP / msgpack<br>fire & forget (~1μs)" --> B["akari-forwarder<br>(Go)"]
B -- "OTLP / HTTP" --> C["Collector<br>Jaeger · Tempo · …"]Spans are serialized as compact msgpack and sent via UDP to a local Go
forwarder, which batches and forwards them to your OTLP collector. Log records
emitted with Akari\log() travel the same UDP path and are forwarded to the
collector's /v1/logs endpoint (spans go to /v1/traces).
Where to next¶
-
Get traces flowing in a few minutes with Docker.
-
Build the extension and forwarder from source.
-
Every INI setting and recommended profiles.
-
How the extension, forwarder, and collector fit together.
Requirements¶
- PHP 8.2+
- macOS or Linux
- Go 1.26+ (for the forwarder)
License¶
Akari is released under the MIT License.