Otelot

Export your Elixir app's metrics and logs to any OpenTelemetry backend over OTLP — without rewriting your instrumentation.

• Metrics: reuse the Telemetry.Metrics definitions you already have (Phoenix, Ecto, Oban, your own :telemetry events). Otelot aggregates them in-process and exports them as OTel sums, gauges and histograms.
• Logs: a :logger handler that batches log events and ships them as OTel log records, with trace/span correlation when the official tracing SDK is in use.

Installation

def deps do
  [
    {:otelot, "~> 0.5"}
  ]
end

Quickstart

Point Otelot at an OTLP/HTTP endpoint:

# config/runtime.exs
config :otelot,
  otlp_endpoint: "http://localhost:4318",
  resource: %{service: %{name: "my_app"}}

Export metrics by adding the exporter to your supervision tree, e.g. in the Telemetry module that Phoenix generates:

children = [
  {Otelot.MetricExporter, metrics: metrics(), export_period: :timer.seconds(30)}
]

Export logs by registering the handler:

# config/config.exs
config :my_app, :logger, [
  {:handler, :otel, Otelot.LogHandler, %{config: %{metadata: [:request_id]}}}
]

# lib/my_app/application.ex, in start/2
Logger.add_handlers(:my_app)

The standard OTEL_EXPORTER_OTLP_*, OTEL_SERVICE_NAME and OTEL_RESOURCE_ATTRIBUTES environment variables are honoured too.

Documentation

• Getting started — full setup, a local collector for experimenting, troubleshooting.
• Metrics — how Telemetry.Metrics types map to OTel, export semantics, differences from the official SDK.
• Configuration — all options and environment variables.

How it differs from the official OpenTelemetry SDK

Otelot trades API compliance for fitting into the existing Elixir ecosystem:

• Metrics are defined with Telemetry.Metrics, not the OTel Metrics API.
• summary metrics and OTel's ExponentialHistogram are not supported.
• Transport is OTLP over HTTP with protobuf encoding; gRPC and HTTP/JSON are not supported.
• To create and export OTel spans, use opentelemetry. The two work fine side by side.

Compatibility

Otelot requires Elixir 1.17+ and is tested in CI against:

Elixir	Erlang/OTP
1.17	27
1.19	28
1.20	29

It works with any OTLP/HTTP receiver: the OpenTelemetry Collector, Grafana Cloud, Honeycomb, Datadog, etc.

Development

mix deps.get
mix test
mix format --check-formatted

See CONTRIBUTING.md before opening an issue or a pull request.

Maintenance

Otelot is maintained by Oleksii Sholik on a best-effort basis. It follows semantic versioning; while it is on 0.x, minor releases may contain breaking changes, which are always called out in the changelog.

License

Copyright 2026 Oleksii Sholik

Otelot is derived from otel_metric_exporter, copyright 2024–2026 its contributors, which was used in production at Electric. It has been modified since the fork. Both are licensed under the Apache License, Version 2.0 (the "License"); you may not use this software except in compliance with the License. You may obtain a copy of the License in LICENSE or at http://www.apache.org/licenses/LICENSE-2.0.

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.