---
summary: "Outbound message lifecycle API for channel plugins: adapters, receipts, durable sends, live preview, and reply pipeline helpers"
title: "Channel outbound API"
read_when:
  - You are building or refactoring a messaging channel plugin send path
  - You need durable final reply delivery, receipts, live preview finalization, or receive acknowledgement policy
  - You are migrating from channel-message, channel-message-runtime, or legacy reply dispatch helpers
---

Channel plugins expose outbound message behavior from
`openclaw/plugin-sdk/channel-outbound`. Use
`openclaw/plugin-sdk/channel-inbound` for receive/context/dispatch
orchestration.

Core owns queueing, durability, generic retry policy, hooks, receipts, and
the shared `message` tool. The plugin owns native send/edit/delete calls,
target normalization, platform threading, selected quotes, notification
flags, account state, and platform-specific side effects.

## Adapter

Most plugins define one `message` adapter:

```ts
import {
  defineChannelMessageAdapter,
  createMessageReceiptFromOutboundResults,
} from "openclaw/plugin-sdk/channel-outbound";

export const demoMessageAdapter = defineChannelMessageAdapter({
  id: "demo",
  durableFinal: {
    capabilities: {
      text: true,
      replyTo: true,
      thread: true,
      messageSendingHooks: true,
    },
  },
  send: {
    text: async ({ cfg, to, text, accountId, replyToId, threadId, signal }) => {
      const sent = await sendDemoMessage({
        cfg,
        to,
        text,
        accountId: accountId ?? undefined,
        replyToId: replyToId ?? undefined,
        threadId: threadId == null ? undefined : String(threadId),
        signal,
      });

      return {
        receipt: createMessageReceiptFromOutboundResults({
          results: [{ channel: "demo", messageId: sent.id, conversationId: to }],
          kind: "text",
          threadId: threadId == null ? undefined : String(threadId),
          replyToId: replyToId ?? undefined,
        }),
      };
    },
  },
});
```

Only declare capabilities the native transport actually preserves. Cover
each declared send, receipt, live-preview, and receive-ack capability with
the contract helpers exported from this subpath.

## Plain-text sanitization

Use `sanitizeForPlainText(...)` when an outbound adapter needs to convert the
supported HTML formatting tags into lightweight text markup. The default keeps
the existing chat-style bold and strikethrough markers. Pass
`{ style: "markdown" }` only when the channel reparses the result as Markdown:

```ts
import { sanitizeForPlainText } from "openclaw/plugin-sdk/channel-outbound";

const chatText = sanitizeForPlainText(text);
const markdownText = sanitizeForPlainText(text, { style: "markdown" });
```

The Markdown style uses `**bold**` and `~~strikethrough~~`; italic and inline
code keep `_italic_` and backtick markers in both styles. Select the style at
the channel boundary instead of rewriting marker text after sanitization.

## Delivery Evidence

A `MessageReceipt` records the result returned by a channel adapter. Concrete
platform message identifiers show that the platform send path accepted the
message; they do not prove that a recipient's device displayed or read it.
Receipts without platform message identifiers are local receipt metadata only.
Channels with read receipts or device-delivery state should track those facts
through a separate channel-specific path.

If a channel adapter can prove that retrying a failure cannot duplicate a
recipient-visible send and no finalization-capable call began, throw
`new PlatformMessageNotDispatchedError("...", { cause: error })` from
`openclaw/plugin-sdk/error-runtime`. Core can then clear stale send-attempt
evidence and safely retry the queued intent. Only the adapter that owns the
final dispatch boundary may make this assertion. Never use the marker after a
finalization/send call begins or returns an ambiguous result; false marking can
duplicate messages.

## Existing outbound adapters

If the channel already has a compatible `outbound` adapter, derive the
message adapter instead of duplicating send code:

```ts
import { createChannelMessageAdapterFromOutbound } from "openclaw/plugin-sdk/channel-outbound";

export const messageAdapter = createChannelMessageAdapterFromOutbound({
  id: "demo",
  outbound,
  durableFinal: {
    capabilities: {
      text: true,
      media: true,
    },
  },
});
```

## Durable sends

Runtime send helpers also live on `channel-outbound`:

- `sendDurableMessageBatch(...)`
- `withDurableMessageSendContext(...)`
- `deliverInboundReplyWithMessageSendContext(...)`
- draft streaming/progress helpers such as `resolveChannelDraftStreamingChunking(...)`

`sendDurableMessageBatch(...)` returns one explicit outcome:

| Outcome          | Meaning                                                                                 |
| ---------------- | --------------------------------------------------------------------------------------- |
| `sent`           | at least one visible platform message was accepted by the platform send path            |
| `suppressed`     | no platform message should be treated as missing                                        |
| `partial_failed` | at least one platform message was accepted before a later payload or side effect failed |
| `failed`         | no platform receipt was produced                                                        |

Use `payloadOutcomes` when a batch mixes sent, suppressed, and failed
payloads. Do not infer hook cancellation from an empty legacy
direct-delivery result.

## Deferred delivery admission

Use `message.durableFinal.admitDeferredDelivery(...)` when a resolved account
cannot safely accept core-managed outbound or deferred delivery. Core calls
this hook synchronously before live outbound work, including paths that skip
queue persistence, and again before replaying a recovered intent. The context
includes `cfg`, `channel`, `to`, `accountId`, and a `phase` of `live` or
`recovery`.

Return `{ status: "allowed" }` to continue. Return
`{ status: "permanent_rejection", reason }` when the delivery must not be
persisted, sent directly, or replayed. A live rejection fails before queue
creation, message hooks, or platform work. A recovery rejection marks the
queued record failed and skips reconciliation and replay. Omitting the hook
means allowed.

The hook is a synchronous admission decision, not a send path. Read only
already-loaded config or runtime state; do not perform network, filesystem, or
other asynchronous I/O. Contract tests should exercise both phases and both
result variants through `ChannelMessageDurableFinalAdapter` from
`openclaw/plugin-sdk/channel-outbound`.

## Compatibility dispatch

Assemble inbound reply dispatch through `dispatchChannelInboundReply(...)`
from `channel-inbound`. Keep platform delivery in the delivery adapter; use
`channel-outbound` for message adapters, durable sends, receipts, live
preview, and reply pipeline options.