openclaw/docs/plugins/sdk-channel-outbound.md

summary, title, read_when

summary	title	read_when
Outbound message lifecycle API for channel plugins: adapters, receipts, durable sends, live preview, and reply pipeline helpers	Channel outbound API	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:

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:

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:

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.