feat(effect-sdk): span options on Maple.layer, subtree drops, error predicates

.changeset/effect-sdk-span-options.md

@@ -0,0 +1,5 @@
+---
+"@maple-dev/effect-sdk": minor
+---
+
+`Maple.layer` takes the same span options as `MapleFlush.make` and the Cloudflare `make`, and all three classify spans the same way. New on every preset: `dropSpanSubtrees` drops a span and everything under it, `dropSpan` drops a finished span by predicate, and `isAnticipatedError` is the predicate form of `anticipatedErrorIdentifiers`. A server span that answered 5xx stays an error even when its failure is anticipated. On `Maple.layer`, unmatched-route 404 spans are now dropped and server spans that rendered a 5xx are recorded as errors, which can surface new error groups.

apps/landing/src/content/changelog/2026-10-16-effect-sdk-span-options.md

@@ -0,0 +1,31 @@
+---
+title: "Drop noisy spans and expected errors from Maple.layer"
+description: "Maple.layer now takes the same span options as MapleFlush.make, plus subtree drops and predicates for both."
+date: 2026-10-16
+category: sdk
+authors: [makisuo]
+---
+
+`Maple.layer`, the long-running preset in `@maple-dev/effect-sdk`, now accepts the span options
+that were only on `MapleFlush.make` and the Cloudflare `make`. All three presets take the same
+options and classify spans the same way.
+
+- `dropSpanNames` drops spans by name prefix, as before. Only the matching span goes.
+- `dropSpanSubtrees` drops a span and every span under it, so an idle polling loop and the
+  queries it runs stop exporting. Outgoing calls under a dropped span carry an unsampled
+  `traceparent`, and errors inside it are not tracked, so keep real work outside it.
+- `dropSpan` takes a predicate on the finished span (name, kind, attributes, exit), for example
+  to drop only polls that found nothing.
+- `anticipatedErrorIdentifiers` marks expected failures (a duplicate, a not-found) as `Ok` with
+  no exception, so they stop creating error groups. `isAnticipatedError` is its predicate form,
+  for driver errors that are only expected in one case.
+- `excludeLogSpans` is now available on `Maple.layer` too.
+
+A few behaviour changes come with it:
+
+- A server span that answered 5xx stays an error even when its failure is listed as anticipated.
+- On `Maple.layer`, spans for unmatched-route 404s are dropped, and server spans that rendered a
+  5xx response are recorded as errors, matching the other presets. That can surface new error
+  groups for crashes that used to export as `Ok`.
+
+Upgrade to `@maple-dev/effect-sdk` 0.11.0.

apps/landing/src/content/docs/sdks/effect-cloudflare.md

@@ -56,22 +56,17 @@ A flush fails when the request throws (for example a network error) or the inges
 
 ## Cloudflare-specific config
 
-`make()` accepts the [common options](/docs/sdks/effect#configuration-reference) marked for Cloudflare (`serviceName`, `region`, `endpoint`, `ingestKey`, `serviceVersion`, `serviceNamespace`, `environment`, `repositoryUrl`, `attributes`), plus these:
+`make()` accepts the [common options](/docs/sdks/effect#configuration-reference) marked for Cloudflare (`serviceName`, `region`, `endpoint`, `ingestKey`, `serviceVersion`, `serviceNamespace`, `environment`, `repositoryUrl`, `attributes`), the [span options](/docs/sdks/effect#dropping-spans) (`excludeLogSpans`, `dropSpanNames`, `dropSpanSubtrees`, `dropSpan`, `anticipatedErrorIdentifiers`, `isAnticipatedError`), plus these:
 
-| Option                        | Type                    | Default       | Description                                                                                            |
-| ----------------------------- | ----------------------- | ------------- | ------------------------------------------------------------------------------------------------------ |
-| `excludeLogSpans`             | `boolean`               | `false`       | Skip Effect log spans in OTLP log attributes                                                           |
-| `dropSpanNames`               | `ReadonlyArray<string>` | none          | Drop spans whose name starts with any prefix in this list                                              |
-| `anticipatedErrorIdentifiers` | `ReadonlyArray<string>` | none          | `_tag` / `Error.name` values of expected 4xx failures. Spans export as `Ok`, with no `exception` event |
-| `tracesPath`                  | `string`                | `/v1/traces`  | OTLP traces path appended to `endpoint`                                                                |
-| `logsPath`                    | `string`                | `/v1/logs`    | OTLP logs path appended to `endpoint`                                                                  |
-| `metricsPath`                 | `string`                | `/v1/metrics` | OTLP metrics path appended to `endpoint`                                                               |
-
-`anticipatedErrorIdentifiers` keeps expected rejections (a 404, a 401) visible as traces without counting them as errors. A span still exports as `Error` if its cause contains any defect.
+| Option        | Type     | Default       | Description                              |
+| ------------- | -------- | ------------- | ---------------------------------------- |
+| `tracesPath`  | `string` | `/v1/traces`  | OTLP traces path appended to `endpoint`  |
+| `logsPath`    | `string` | `/v1/logs`    | OTLP logs path appended to `endpoint`    |
+| `metricsPath` | `string` | `/v1/metrics` | OTLP metrics path appended to `endpoint` |
 
 An error that crossed an HTTP boundary is a decoded body rather than the class that raised it, so a failure shaped `{ error: { _tag } }` (the envelope convention many APIs use) is matched on the body's `_tag`. Client-side spans classify the same as the server-side ones they mirror, with no separate identifiers to configure.
 
-`dropSpanNames` suppresses protocol-level chatter. For example, `["McpServer/Notifications."]` drops MCP notification spans without dropping handler spans.
+`dropSpanNames` suppresses protocol-level chatter. For example, `["McpServer/Notifications."]` drops MCP notification spans without dropping handler spans. Use `dropSpanSubtrees` instead when the children should go too.
 
 ## Endpoint resolution