Chunk delivery

Chat platforms cap message length, so WednesdayAI splits long outbound replies into multiple messages before sending. Channel adapters and reply-shaping plugins control the split through per-channel config and the SDK resolvers in src/auto-reply/chunk.ts — resolveChunkDelivery, resolveTextChunkLimit (both re-exported from openclaw/plugin-sdk).

Config surface

Per channel (and per account within a channel):

// ~/.openclaw/openclaw.json
{
  channels: {
    telegram: {
      textChunkLimit: 4000,          // chars; Telegram default 4000, Discord default 2000
      chunkMode: "paragraph",        // "length" (default) | "newline" | "paragraph"
      accounts: {
        "<accountId>": {             // per-account overrides win over the channel level
          chunkMode: "newline",
        },
      },
    },
  },
}

Key	Values	Default	Effect
`textChunkLimit`	positive int	4000 (Telegram/generic), 2000 (Discord)	Hard per-message character cap
`chunkMode`	`"length" \| "newline" \| "paragraph"`	`"length"`	Split policy — see below
`chunkNewlinePacking`	boolean	`true`	Deprecated. With `"newline"`: pack paragraphs up to the limit (`false` = one message per paragraph). Use `chunkMode: "paragraph"` instead

Modes

chunkMode resolves to a runtime boundary mode plus a pack flag (ResolvedChunkDelivery):

`chunkMode`	Resolves to	Behaviour
`"length"` (default)	`{ mode: "length", pack: true }`	Split only when a message would exceed `textChunkLimit`. Newlines stay inside chunks; boundaries prefer safe break points
`"newline"`	`{ mode: "newline", pack: true }`	Split on paragraph/line boundaries; consecutive paragraphs are packed into one message up to the limit
`"paragraph"`	`{ mode: "newline", pack: false }`	One message per paragraph — no packing. Config-facing alias; the runtime never reports mode `"paragraph"`

Split safety, all modes: code fences are never split mid-fence — a forced split at the limit closes and reopens the fence so Markdown stays valid — and breaks avoid splitting a surrogate pair mid-emoji.

The deprecated packing key

chunkNewlinePacking still parses but logs a deprecation warning (once per channel:account):

Situation	Warning
Set with `chunkMode: "length"`	Only applies with `"newline"`/`"paragraph"`; remove the key
Set to `false` with `"newline"`	Use `chunkMode: "paragraph"` for one message per paragraph
Set to `true` with `"newline"`	Remove the key — newline mode packs by default

Migration: chunkNewlinePacking: false → chunkMode: "paragraph"; any other use → delete the key.

Using the resolvers

import {
  resolveChunkDelivery,
  resolveTextChunkLimit,
} from "openclaw/plugin-sdk";

// In a channel adapter / reply pipeline, with the loaded config:
const limit = resolveTextChunkLimit(cfg, "telegram", accountId);
// → channels.telegram.textChunkLimit (account override first), else the channel default

const delivery = resolveChunkDelivery(cfg, "telegram", accountId);
// → { mode: "length" | "newline", pack: boolean }
//   "paragraph" never appears here — it resolves to { mode: "newline", pack: false }

resolveChunkDelivery(cfg, provider, accountId?) — merge order: account override → channel config → defaults. Returns { mode: "length", pack: true } for the internal message channel (INTERNAL_MESSAGE_CHANNEL) and unknown providers.
resolveChunkMode(...) — convenience: resolveChunkDelivery(...).mode.
resolveChunkNewlinePacking(...) — deprecated; returns .pack.
resolveTextChunkLimit(cfg, provider, accountId?, { fallbackLimit? }) — caller-supplied fallback (e.g. a dock’s outbound.textChunkLimit) when no config key exists; the hard fallback is 4000.

Interaction with block streaming

When block streaming is on, stream chunk sizes are clamped to textChunkLimit, and the resolved delivery controls flush behaviour: with mode: "newline" and pack: false (i.e. chunkMode: "paragraph"), blocks flush eagerly per paragraph; with packing on, the outbound packer composes larger messages. See Streaming.

What not to do

// ❌ treat "paragraph" as a runtime mode
if (resolveChunkDelivery(cfg, "telegram").mode === "paragraph") { /* unreachable */ }

// ❌ new code reading chunkNewlinePacking
if (resolveChunkNewlinePacking(cfg, "telegram") === false) { /* deprecated — use mode+pack */ }

// ❌ assume a fixed 4000 default for every channel
const limit = 4000; // Discord caps at 2000 by default — call resolveTextChunkLimit

Streaming — block and preview streaming
Auto-reply pipeline — where chunking sits in the reply path
Channel adapters — building a channel plugin

Getting started

Extension points

Channel references

SDK reference

Contributing

Core concepts (developer)

More plugins

Developer reference

Prompt templates

Shohin

Chunk delivery

Chunk delivery

Config surface

Modes

The deprecated packing key

Using the resolvers

Interaction with block streaming

What not to do

​Chunk delivery

​Config surface

​Modes

​The deprecated packing key

​Using the resolvers

​Interaction with block streaming

​What not to do

​Related

Chunk delivery

Config surface

Modes

The deprecated packing key

Using the resolvers

Interaction with block streaming

What not to do

Related