---
summary: "Forum threads, history and context limits, subagent thread sessions, and ACP channel bindings"
read_when:
  - Posting to a Discord forum or media channel
  - Working out which session a Discord thread maps to
  - Binding a Discord channel to a subagent or ACP agent
title: "Discord threads and sessions"
sidebarTitle: "Threads and sessions"
---

How Discord threads, forums, and channels map onto OpenClaw sessions.

## Forum channels

Discord forum and media channels only accept thread posts. OpenClaw supports two ways to create them:

- Send a message to the forum parent (`channel:<forumId>`) to auto-create a thread. The thread title is the first non-empty line of the message (truncated to Discord's 100-character thread-name limit).
- Use `openclaw message thread create` to create a thread directly. Do not pass `--message-id` for forum channels.

Send to the forum parent to create a thread:

```bash
openclaw message send --channel discord --target channel:<forumId> \
  --message "Topic title\nBody of the post"
```

Create a forum thread explicitly:

```bash
openclaw message thread create --channel discord --target channel:<forumId> \
  --thread-name "Topic title" --message "Body of the post"
```

Forum parents do not accept Discord components. If you need components, send to the thread itself (`channel:<threadId>`).

## Session and thread behavior

<AccordionGroup>
  <Accordion title="History, context, and thread behavior">
    Guild history context:

    - `channels.discord.historyLimit` default `20`
    - fallback: `messages.groupChat.historyLimit`
    - `0` disables

    DM history controls:

    - `channels.discord.dmHistoryLimit`
    - `channels.discord.dms["<user_id>"].historyLimit`

    Thread behavior:

    - Discord threads route as channel sessions and inherit parent channel config unless overridden.
    - Thread sessions inherit the parent channel's session-level `/model` selection as a model-only fallback; thread-local `/model` selections take precedence, and parent transcript history is not copied unless transcript inheritance is enabled.
    - `channels.discord.thread.inheritParent` (default `false`) opts new auto-threads into seeding from the parent transcript. Per-account override: `channels.discord.accounts.<id>.thread.inheritParent`.
    - Message-tool reactions can resolve `user:<id>` DM targets.
    - `guilds.<guild>.channels.<channel>.requireMention: false` is preserved during reply-stage activation fallback.

    Channel topics are injected as **untrusted** context. Allowlists gate who can trigger the agent, not a full supplemental-context redaction boundary.

  </Accordion>

  <Accordion title="Thread-bound sessions for subagents">
    Discord can bind a thread to a session target so follow-up messages in that thread keep routing to the same session (including subagent sessions).

    Commands:

    - `/session unbind` remove the current thread binding without closing its agent session
    - `/agents` show active runs and binding state
    - `/session idle <duration|off>` inspect/update inactivity expiry for the current binding
    - `/session max-age <duration|off>` inspect/update hard max age for the current binding

    Config:

```json5
{
  session: {
    threadBindings: {
      enabled: true,
      idleHours: 24,
      maxAgeHours: 0,
      spawnSessions: true,
      defaultSpawnContext: "fork",
    },
  },
}
```

    Notes:

    - `session.threadBindings.*` is the canonical policy for Discord and Telegram.
    - `spawnSessions` controls auto-create/bind threads for `sessions_spawn({ thread: true })` and ACP thread spawns. Default: `true`.
    - `defaultSpawnContext` controls native subagent context for thread-bound spawns. Default: `"fork"`.
    - Deprecated `spawnSubagentSessions`/`spawnAcpSessions` keys are migrated by `openclaw doctor --fix`.
    - If thread bindings are disabled, thread-bound spawns are unavailable.

    See [Sub-agents](/tools/subagents), [ACP Agents](/tools/acp-agents), and [Configuration Reference](/gateway/configuration-reference).

  </Accordion>

  <Accordion title="Persistent ACP channel bindings">
    For stable "always-on" ACP workspaces, configure top-level typed ACP bindings targeting Discord conversations.

    Config path: `bindings[]` with `type: "acp"` and `match.channel: "discord"`.

```json5
{
  agents: {
    entries: {
      codex: {
        runtime: {
          type: "acp",
          acp: {
            agent: "codex",
            backend: "acpx",
            mode: "persistent",
            cwd: "/workspace/openclaw",
          },
        },
      },
    },
  },
  bindings: [
    {
      type: "acp",
      agentId: "codex",
      match: {
        channel: "discord",
        accountId: "default",
        peer: { kind: "channel", id: "222222222222222222" },
      },
      acp: { label: "codex-main" },
    },
  ],
  channels: {
    discord: {
      guilds: {
        "111111111111111111": {
          channels: {
            "222222222222222222": {
              requireMention: false,
            },
          },
        },
      },
    },
  },
}
```

    Notes:

    - `/acp spawn codex --bind here` binds the current channel or thread in place and keeps future messages on the same ACP session. Thread messages inherit the parent channel binding.
    - In a bound channel or thread, `/new` and `/reset` reset the same ACP session in place. Temporary thread bindings can override target resolution while active.
    - `spawnSessions` gates child thread creation/binding via `--thread auto|here`.

    See [ACP Agents](/tools/acp-agents) for binding behavior details.

  </Accordion>
</AccordionGroup>