Maple Effect style

For Effect apps, use @maple-dev/effect-sdk — Maple's first-class Effect SDK. It wraps Effect's built-in Otlp.layerJson exporter and handles batching, shutdown, and resource attributes for you.

Install

npm install @maple-dev/effect-sdk effect

For Effect 3, use @maple-dev/effect-sdk@effect-v3 instead. Same API, different peer ranges.

Bootstrap

Pick the entry point per runtime — they have different lifecycle requirements:

• Server (Node.js, Bun, Deno): background-export fiber, env-var auto-detection, graceful shutdown.
• Browser: explicit config (no env vars), browser metadata baked in.
• Cloudflare Workers: manual flush() in ctx.waitUntil, lazy env resolution, in-isolate buffering.

Server

import { Maple } from "@maple-dev/effect-sdk"
import { Effect, Layer } from "effect"

const TracerLive = Maple.layer({
	serviceName: "orders-api",
	endpoint: "https://ingest.maple.dev",
	ingestKey: "MAPLE_TEST", // set by maple-onboard skill on pairing
	attributes: {
		"vcs.repository.url.full": "https://github.com/acme/orders-api",
	},
})

const program = Effect.gen(function* () {
	yield* Effect.log("Order received")
}).pipe(Effect.withSpan("order.submit"))

Effect.runPromise(program.pipe(Effect.provide(TracerLive)))

The default import resolves to the server build under Node.js. Import @maple-dev/effect-sdk/server explicitly when needed.

If endpoint is omitted, the server layer auto-detects it from MAPLE_ENDPOINT (falling back to OTEL_EXPORTER_OTLP_ENDPOINT). When MAPLE_ENDPOINT is unset, the layer is a no-op — local dev runs without exporting. Inline the endpoint when you want telemetry to flow regardless of env (matches the rest of the maple-onboard inline-key pattern).

The server layer also auto-fills vcs.ref.head.revision from COMMIT_SHA / RAILWAY_GIT_COMMIT_SHA / VERCEL_GIT_COMMIT_SHA / CF_PAGES_COMMIT_SHA / RENDER_GIT_COMMIT (first match wins). You should still set vcs.repository.url.full in attributes since no env var carries it.

Cloudflare Workers

import { Maple } from "@maple-dev/effect-sdk/cloudflare"
import { Effect } from "effect"

export default {
	async fetch(req: Request, env: Env, ctx: ExecutionContext) {
		const TracerLive = Maple.layer({
			serviceName: "orders-edge",
			endpoint: "https://ingest.maple.dev",
			ingestKey: "MAPLE_TEST",
		})

		const program = Effect.gen(function* () {
			yield* Effect.log("edge request")
			return new Response("ok")
		}).pipe(Effect.withSpan("edge.handle"))

		const response = await Effect.runPromise(program.pipe(Effect.provide(TracerLive)))
		ctx.waitUntil(Maple.flush())
		return response
	},
}

The Cloudflare entry point requires ctx.waitUntil(Maple.flush()) so telemetry survives the isolate exit. Forgetting this is the most common reason traces don't show up from Workers.

Browser

import { Maple } from "@maple-dev/effect-sdk/browser"

const TracerLive = Maple.layer({
	serviceName: "web-client",
	endpoint: "https://ingest.maple.dev",
	ingestKey: "MAPLE_TEST",
})

No env-var fallback in the browser entry point — config is always explicit.

Custom spans

Use Effect.withSpan to trace operations and Effect.annotateCurrentSpan for attributes — don't reach for the raw @opentelemetry/api tracer when an Effect-native primitive is available.

const processOrder = (orderId: string) =>
	Effect.gen(function* () {
		yield* Effect.annotateCurrentSpan("order.id", orderId)
		yield* Effect.annotateCurrentSpan("peer.service", "payment-api")
		const result = yield* chargePayment(orderId)
		return result
	}).pipe(Effect.withSpan("order.process"))

Setting peer.service on outgoing calls makes them visible on Maple's service map.

Effect.fail and uncaught defects are recorded as exceptions and set the span status to ERROR automatically — you don't need to wrap with try / catch / finally.

@maple/otel-helpers withSpan is for non-Effect TypeScript code; in Effect code prefer the Effect-native span primitives.

Logs

Effect.log automatically includes trace context when called inside a span — no additional setup needed:

const program = Effect.gen(function* () {
	yield* Effect.log("Processing started")
	yield* doWork()
	yield* Effect.log("Processing complete")
}).pipe(Effect.withSpan("process"))

Logs emitted inside spans are correlated with the active trace in the Maple dashboard.

Coexistence

If the project already uses @effect/opentelemetry or Otlp.layerJson with a custom exporter (e.g. for Honeycomb, Datadog), keep it. Maple.layer() can compose alongside via Layer.merge:

const TracerLive = Layer.merge(
	Maple.layer({ serviceName: "api", endpoint: "https://ingest.maple.dev", ingestKey: "MAPLE_TEST" }),
	HoneycombLayer,
)

Both vendors receive the same spans.