# Zylos AI Zylos Core Comm Bridge

> Communication Bridge (C4)

- Skill: `tomevault-io/zylos-ai-zylos-core-comm-bridge` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add tomevault-io/zylos-ai-zylos-core-comm-bridge`
- Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/zylos-ai-zylos-core-comm-bridge/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: tomevault-io (https://skillmd.com/u/tomevault-io)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/tomevault-io/zylos-ai-zylos-core-comm-bridge

---


# Communication Bridge (C4)

Central message hub - ALL communication with Claude goes through C4.

## Architecture

```
Web Console ──┐
Telegram    ───┼──► C4 Bridge ◄──► Claude
Lark        ───┘
```

## Components

| Script | Purpose | Reference |
|--------|---------|-----------|
| `c4-receive.js` | External → Claude (queue incoming messages) | [c4-receive](references/c4-receive.md) |
| `c4-send.js` | Claude → External (route outgoing messages) | [c4-send](references/c4-send.md) |
| `c4-control.js` | System control plane (heartbeat, maintenance) | [c4-control](references/c4-control.md) |
| `c4-dispatcher.js` | PM2 daemon: polls pending queue, delivers to tmux | — |
| `c4-session-init.js` | Hook (session start): context + Memory Sync trigger | [hooks](references/hooks.md) |
| `c4-fetch.js` | Fetch conversations by id range | [c4-fetch](references/c4-fetch.md) |
| `c4-db.js` | Database module and CLI for querying conversations and checkpoints | [c4-db](references/c4-db.md) |
| `c4-checkpoint.js` | Create/query checkpoints (sync boundaries) | [c4-checkpoint](references/c4-checkpoint.md) |

## Sending Messages

```bash
# Send to Telegram DM
cat <<'EOF' | node ~/zylos/.claude/skills/comm-bridge/scripts/c4-send.js telegram 8101553026
Hello! Quotes, $vars, **markdown** — all safe via stdin.
EOF

# Send to Lark group thread
cat <<'EOF' | node ~/zylos/.claude/skills/comm-bridge/scripts/c4-send.js lark "chat_xxx|type:group|root:msg_yyy"
Report ready.
EOF
```

Always pipe messages via stdin heredoc — never pass as CLI arguments. See [c4-send](references/c4-send.md) for full reference.
Treat the heredoc wrapper as fixed shell syntax: only the message body goes between the start line and the closing terminator line, and the terminator itself must never be copied into the actual outgoing message.

## Database

SQLite at `~/zylos/comm-bridge/c4.db`:
- `conversations`: All messages (in/out) with priority, status, retry tracking
- `checkpoints`: Recovery points with conversation id ranges
- `control_queue`: System control messages (heartbeat, maintenance) with priority, ack deadlines, and status lifecycle

## Health & Status

The activity monitor writes `~/zylos/activity-monitor/agent-status.json` which includes a `health` field:

| Value | Meaning |
|-------|---------|
| `ok` | System healthy, messages accepted normally |
| `recovering` | Liveness check failed, automatic recovery in progress |
| `down` | Max recovery attempts exhausted, manual intervention required |

**Fail-open semantics**: If the status file is missing or malformed, health is assumed `ok` — intake is never blocked by a read failure.

When health is not `ok`, `c4-receive.js` rejects incoming messages and records the channel/endpoint in `~/zylos/activity-monitor/pending-channels.jsonl`. Once health returns to `ok`, the activity monitor sends recovery notifications to all pending channels.

## Keystroke Delivery

The dispatcher supports `[KEYSTROKE]` control messages for sending raw keystrokes to the tmux session. This is an **ops-level capability** — no source gating is applied.

When a control message content starts with `[KEYSTROKE]`, the dispatcher:
- Extracts the key name (e.g., `Enter`, `Tab`, `Escape`)
- Sends it directly via `tmux send-keys` (no buffer paste, no "Meanwhile" prefix, no verification)
- Auto-acks the control immediately after delivery

Example: the permission auto-approve hook enqueues `[KEYSTROKE]Enter` at priority 0 with bypass-state to auto-confirm Claude Code's permission prompts.

Any process with access to `c4-control.js` can enqueue keystroke controls. This mirrors the existing reality that any process can call `tmux send-keys` directly — the C4 queue adds priority ordering and delivery guarantees, not access control.

## Service Management

```bash
pm2 status c4-dispatcher
pm2 logs c4-dispatcher
pm2 restart c4-dispatcher
```

---
> Converted and distributed by [TomeVault](https://tomevault.io/claim/zylos-ai) — claim your Tome and manage your conversions.
<!-- tomevault:4.0:skill_md:2026-04-11 -->