Channel sessions and sub-agent delegation

Arka provides channel sessions and sub-agent delegation — patterns inspired by Hermes Agent, not a separate product integration. They add per-channel conversation continuity, webhook session handoff, and isolated background sub-agents.

Features

Concept	Arka feature
Per-chat session store	`arka session` — keyed by `channel:chat_id`
Cross-platform continuity	Webhook + `arka ask` share the same session when `channel`/`chat_id` match
Silence tokens	`[SILENT]`, `NO_REPLY` suppress webhook outbound delivery
Sub-agent delegation	`subagent spawn` — isolated background agent tasks

Arka does not ship full gateway adapters (Telegram, Discord, etc.). Use webhook ingress and channel bridges, then attach channel sessions on top.

Message sessions

Per-channel conversation turns stored under ~/.config/arka/message-sessions/:

arka session push cli default user "Start the deploy checklist"
arka session push cli default assistant "Step 1: run tests"
arka session context cli default
arka session resume cli default
arka session list
arka session reset telegram 123456789
arka session status

Sessions are keyed as channel:chat_id (e.g. webhook:slack, cli:default, telegram:987654321).

CLI continuity

When MESSAGE_SESSIONS=1 (default), arka ask and the chat engine automatically read and write the cli:default session (override with MESSAGE_SESSION_CHANNEL and MESSAGE_SESSION_CHAT_ID). Start a thread in the terminal, continue via webhook with the same channel and chat ID, or vice versa.

Webhook continuity

When WEBHOOK_ENABLED=1, inbound POST bodies can include:

{
  "text": "What's the deploy status?",
  "channel": "telegram",
  "chat_id": "123456789"
}

Arka appends the user turn, injects prior session context into the agent prompt, stores the assistant reply, and returns chat_id in the response.

Silence tokens

Explicit silence tokens let group chats and automations store a turn without sending outbound text:

[SILENT]
SILENT
NO_REPLY
NO REPLY

When the agent’s final response is exactly one of these (case-insensitive), the webhook returns "silent": true and an empty output field. The turn is still stored in the session transcript. External MCP clients can check the same tokens with arka_sessions action silence_check (returns { "silent": true|false, "tokens": [...] }).

Environment variables

Variable	Default	Purpose
`MESSAGE_SESSIONS`	`1`	Enable (`0` to disable)
`MESSAGE_SESSIONS_DIR`	`~/.config/arka/message-sessions`	Storage root
`MESSAGE_SESSION_IDLE_MINUTES`	`0`	Auto-reset after idle minutes (`0` = never)
`MESSAGE_SESSION_MAX_TURNS`	`40`	Max turns kept per session
`MESSAGE_SESSION_CHANNEL`	`cli`	Default channel for CLI chat
`MESSAGE_SESSION_CHAT_ID`	`default`	Default chat ID for CLI chat

Legacy HERMES_SESSIONS* variables remain supported as aliases. Inbound turns are sanitized — injection patterns and unsafe content are blocked before storage.

Sub-agent delegation

Spawn isolated background agents for parallel workstreams:

subagent spawn "Summarize today's git log"
subagent list
subagent resume abc123def4
subagent status

Each sub-agent runs via the Python chat engine (with fish agent fallback). Task records live under ~/.cache/fish-agent/subagents/.

Security gates

Gate	Blocks when
`SUBAGENT_SECURITY=1`	Task fails `SECURITY_LLM` prompt verification
`SUBAGENT_MAX`	Concurrent running agents exceed limit
`SUBAGENT_MAX_CHARS`	Task text too long

Set SUBAGENT_SYNC=1 to run synchronously (used in tests).

Environment variables

Variable	Default	Purpose
`SUBAGENT_ENABLED`	`1`	Enable (`0` to disable)
`SUBAGENT_DIR`	`~/.cache/fish-agent/subagents`	Storage root
`SUBAGENT_MAX`	`3`	Max concurrent background agents
`SUBAGENT_TIMEOUT`	`600`	Per-agent timeout (seconds)
`SUBAGENT_SECURITY`	`1`	Apply security gates to spawn tasks

Legacy HERMES_SUBAGENT* variables remain supported as aliases. Sub-agents can attach to a message session via --session-channel and --session-chat-id.

Background process status

Use arka background processes when you want one place to see what Arka currently has active:

arka background processes
arka background processes --json

The report includes active sub-agent tasks, enabled routines, webhook status, configured MCP servers, and live OS processes that look Arka-owned such as arka mcp serve. The legacy command arka background agent tasks still works as an alias. This command is read-only. It does not stop or restart agents, routines, or servers.

Skill manifest gates

Plugin gates use metadata.openclaw, metadata.arka, or metadata.hermes — all merged the same way. See OpenClaw-inspired gates for details.

Heartbeat integration

heartbeat status reports channel session and sub-agent counts:

heartbeat status

Context layers — how memory, session notes, and channel turns fit together
Session memory — long-term markdown notes (MEMORY.md)
Webhooks — verified external ingress
Security — global SECURITY, SECURITY_LLM, and SECURITY_ACTIONS flags

Routing & CLI

Agent & memory

Developer tools

Models & inference

Media & documents

Integrations

Finance & data

Workflows & productivity

More

Channel sessions and sub-agent delegation

Features

Message sessions

CLI continuity

Webhook continuity

Silence tokens

Environment variables

Sub-agent delegation

Security gates

Environment variables

Background process status

Skill manifest gates

Heartbeat integration

​Features

​Message sessions

​CLI continuity

​Webhook continuity

​Silence tokens

​Environment variables

​Sub-agent delegation

​Security gates

​Environment variables

​Background process status

​Skill manifest gates

​Heartbeat integration

​Related features

Features

Message sessions

CLI continuity

Webhook continuity

Silence tokens

Environment variables

Sub-agent delegation

Security gates

Environment variables

Background process status

Skill manifest gates

Heartbeat integration

Related features