Otel Generic Style

Generic OTel Style

Use this skill for any language that does not have its own otel-*-style companion (Go, Java/Kotlin, Ruby, Rust, .NET/C#, PHP, Elixir, plain Node/TypeScript without Next.js or Expo, etc.). Read otel-onboarding-style first for the cross-language rules; this skill is the language-agnostic translation of that guidance.

If a language-specific skill exists for the runtime in front of you (otel-python-style, otel-fastapi-style, otel-livekit-style, otel-nextjs-style, otel-expo-style, otel-supabase-edge-style), prefer that one — it overrides this skill.

Use the language's official OTel SDK

Pull the SDK and exporters from the OpenTelemetry project for that language. Do not invent helper APIs around it. Examples:

• Go: go.opentelemetry.io/otel, otel/sdk, otel/exporters/otlp/otlptrace/otlptracehttp
• Java/Kotlin: io.opentelemetry:opentelemetry-sdk + opentelemetry-exporter-otlp (or the Java agent for auto-instrumentation)
• Ruby: opentelemetry-sdk, opentelemetry-exporter-otlp, opentelemetry-instrumentation-all
• Rust: opentelemetry, opentelemetry_sdk, opentelemetry-otlp
• .NET/C#: OpenTelemetry, OpenTelemetry.Exporter.OpenTelemetryProtocol, framework OpenTelemetry.Instrumentation.* packages
• PHP: open-telemetry/sdk, open-telemetry/exporter-otlp
• Elixir: :opentelemetry, :opentelemetry_api, :opentelemetry_exporter
• Plain Node/TS: @opentelemetry/sdk-node + @opentelemetry/auto-instrumentations-node (use @vercel/otel for Next.js — see otel-nextjs-style)

Use HTTP OTLP exporters, not gRPC. gRPC pulls in native bindings that break bundlers, slim containers, and serverless cold starts.

Acquire tracers/meters once, at module/package scope

Whatever the idiomatic "module top" is in that language — package-level vars in Go, static fields in Java/.NET, top-of-file constants in Ruby/Node, @moduledoc-level attributes in Elixir. Don't construct a fresh tracer or meter on every call.

// Go
var (
    tracer = otel.Tracer("mugline.api")
    meter  = otel.Meter("mugline.api")
    ordersSubmitted, _ = meter.Int64Counter("orders.submitted")
)

// Java
private static final Tracer TRACER = GlobalOpenTelemetry.getTracer("mugline.api");
private static final Meter METER = GlobalOpenTelemetry.getMeter("mugline.api");
private static final LongCounter ORDERS_SUBMITTED =
    METER.counterBuilder("orders.submitted").build();

Bounded work

For any function with clear start/end boundaries, open a span that covers the whole operation and ends automatically. Use the language's built-in construct — defer span.End(), try-with-resources, using, with, block form, etc. Do not start a span in one place and end it manually somewhere else for bounded work.

ctx, span := tracer.Start(ctx, "order.submit")
defer span.End()
span.SetAttributes(
    attribute.String("tenant.id", tenantID),
    attribute.String("order.id", orderID),
)

using var activity = ActivitySource.StartActivity("order.submit");
activity?.SetTag("tenant.id", tenantId);
activity?.SetTag("order.id", orderId);

Span names are conventional and low-cardinality: domain.verb (order.submit, payment.charge, voice.session, llm.generate_copy).

Error paths

Record the exception and set the span status to error on the active span, then re-raise so the caller still sees the failure.

if err != nil {
    span.RecordError(err)
    span.SetStatus(codes.Error, err.Error())
    return err
}

rescue => e
  span = OpenTelemetry::Trace.current_span
  span.record_exception(e)
  span.status = OpenTelemetry::Trace::Status.error(e.message)
  raise
end

Logs

If logs are claimed as OTLP-forwarded, install the OTel log bridge for that language so existing log calls carry trace_id / span_id automatically. Keep the existing logger (log/slog, Logback, Logger, Serilog, Logger.Logger, etc.) — just add an OTLP handler/processor underneath.

Do not replace the project's structured logger with a bespoke one.

Init behavior

Use the source-level public Superlog configuration pattern from otel-onboarding-style in the telemetry init area. The public project token is write-only and belongs with the endpoint in one setup block, like a PostHog project token or Sentry DSN.

If init can run more than once (test reloads, framework restarts, multiple entrypoints), guard provider/exporter setup so duplicate processors aren't installed.

Resource attributes

Set on the OTel resource for every service:

• service.name
• service.version (when available)
• deployment.environment.name
• vcs.repository.url.full — canonical https URL of the repo
• vcs.ref.head.revision — best-effort commit SHA from build env (GITHUB_SHA, VERCEL_GIT_COMMIT_SHA, RAILWAY_GIT_COMMIT_SHA, SOURCE_COMMIT, GIT_COMMIT, HEROKU_SLUG_COMMIT, …)

Do not shell out to git from the running process. Use the OTel semantic-convention keys exactly — do not invent git.repo / app.repo_url.

Metrics

Counters for additive totals: requests, events, jobs, errors, business state transitions. Histograms for distributions: duration, latency, payload size, queue depth.

Low-cardinality attributes only — tenant/org/project, operation/use case, provider/model, outcome. Do not put raw user IDs or request IDs in metric tags.

For LLM token/cost telemetry, follow the gen_ai.* / app.gen_ai.* convention from otel-onboarding-style. Do not add app-side llm.cost_usd metrics — Superlog computes cost centrally.

When no OTel SDK exists

Some runtimes have no usable OpenTelemetry SDK — older languages (Perl, Bash/shell, Lua, Crystal, Nim, Zig), niche runtimes, restricted edge environments, or languages whose "SDK" is abandoned/pre-alpha and would be worse than rolling your own. In that case, emit OTLP/HTTP JSON directly. The wire format is stable, documented, and small.

Rules for a hand-rolled OTLP emitter:

• Speak OTLP/HTTP+JSON, not a vendor format. POST to https://intake.superlog.sh/v1/traces, /v1/metrics, /v1/logs with Content-Type: application/json and the public project token in the x-api-key header (x-api-key: sl_public_...). Ingest reads only x-api-key or Authorization: Bearer <token> (literal Bearer prefix) — any other header name 401s on every request even when the token is valid. Body shape follows the OTLP proto-to-JSON mapping (resourceSpans / resourceMetrics / resourceLogs → scopeSpans → spans, with traceId/spanId as lowercase hex).
• Keep the shim tiny and OTel-shaped. Expose names a future SDK port could drop into: startSpan(name), setAttributes, recordException, endSpan, counter.add, histogram.record. Don't invent sendSuperlogEvent or recordCounter — those are exactly what the style forbids elsewhere.
• Generate IDs correctly. 16-byte trace IDs and 8-byte span IDs as lowercase hex; use the runtime's CSPRNG. Timestamps are nanoseconds since Unix epoch (time.UnixNano() equivalent — beware language defaults that give ms or µs).
• Batch and flush. Buffer spans/metrics/logs in memory, flush on a small interval (a few seconds) and on process exit. Drop on overflow rather than blocking the hot path. For a CLI or short-lived script, do a final synchronous flush before exit.
• Resource attributes still apply. Set service.name, service.version, deployment.environment.name, vcs.repository.url.full, vcs.ref.head.revision once on the resource and reuse it on every export envelope.
• Use the same public config as SDK-based services. Keep the endpoint and public project token in one setup block, and set resource attributes on every export envelope. If signup is still in progress, initialize cleanly and note that ingest may reject the generated token until the browser flow claims it.
• Trace context propagation uses W3C traceparent. Read it from inbound HTTP headers if the runtime is a server; emit it on outbound requests as traceparent: 00-<trace-id>-<span-id>-01.

For shell scripts and one-shot tools, even a single curl POST to /v1/traces with a hand-built JSON body is acceptable — that's still OTLP, and it composes with everything else in the user's pipeline.

If the language does have an SDK but it doesn't load in this particular runtime (bundler, edge, restricted FFI), the same shim approach applies. The Supabase Edge skill is one worked example.

Auto-instrumentation

Where the language has a packaged auto-instrumentation story, use it as the floor:

• Java: the OpenTelemetry Java agent (-javaagent:opentelemetry-javaagent.jar)
• .NET: OpenTelemetry.Instrumentation.AspNetCore / Http / SqlClient etc.
• Ruby: opentelemetry-instrumentation-all
• Node: @opentelemetry/auto-instrumentations-node
• Go: framework-specific otelhttp, otelgin, otelpgx, otelsql wrappers (Go has no global agent)
• PHP: the open-telemetry/opentelemetry-auto-* extensions
• Elixir: :opentelemetry_phoenix, :opentelemetry_ecto, :opentelemetry_cowboy

Then add custom spans, metrics, and logs around business operations the auto-instrumentation can't see — the operations a human operator would actually want to inspect when something looks wrong.