---
title: Submission observations
description: Observe minimal starting and settled sender-call facts without capturing private payloads.
---

Use `observedEmailSenderLayer` from `@corven/email-sdk/observations` around an `EmailSender`, then build the common `Email` service:

```ts
import { Effect, Layer } from "effect";
import { Email, emailLayer } from "@corven/email-sdk";
import type { EmailMessageInput } from "@corven/email-sdk";
import {
  EmailSubmissionObservations,
  observedEmailSenderLayer,
} from "@corven/email-sdk/observations";
import type {
  EmailSubmissionObserver,
  EmailSubmissionStartingObserver,
} from "@corven/email-sdk/observations";
import { recordingSenderLayer } from "@corven/email-sdk/testing";

export const submitAndInspectSyntheticEmail = Effect.fnUntraced(
  function* submitAndInspectSyntheticEmail(message: EmailMessageInput) {
    const email = yield* Email;
    const observations = yield* EmailSubmissionObservations;
    const receipt = yield* email.send(message);
    const snapshot = yield* observations.snapshot;

    return { receipt, snapshot };
  },
);

export const observedSyntheticEmailLayer = (
  observer: EmailSubmissionObserver,
  startingObserver?: EmailSubmissionStartingObserver,
) =>
  emailLayer().pipe(
    Layer.provideMerge(
      observedEmailSenderLayer(recordingSenderLayer, { capacity: 10 }, observer, startingObserver),
    ),
  );
```

`Layer.provideMerge` keeps the observation query service available alongside sending. Acquire both from the same composed Layer.

## Read the view

`EmailSubmissionObservations.snapshot` returns retained observations and `truncated`. Settled cases are `Receipt`, `Rejected` and `Unknown`. A receipt observation includes only its kind and provider; it does not retain recipients, message content, keys or original private causes.

The optional starting callback describes a sender invocation. It is a separate event from settled history, not evidence that the provider accepted a message.

## Choose the correct unit

A sender call is not necessarily a whole logical workflow, an audience or a lifetime delivery count. Local validation can fail before this observation boundary. For complete prepared-operation outcomes, use [operation observations](/composition/operations); for Loops/Iterable use [native instrumentation](/composition/native-instrumentation).

Callbacks are awaited Effects. A callback failure can stop the caller's workflow, but cannot roll back a provider acknowledgment or authorize retry/fallback. Treat missing data and truncated history as incomplete evidence.