cross-pc-sendmsg

name	cross-pc-sendmsg
description	Send a message over the cross-PC protocol (WebSocket primary, HTTP fallback). Use when the user says "send a cross-pc message", "broadcast to peers", "DM peer X", "/cross-pc-sendmsg", or wants to publish an envelope to the local protocol gateway. Aliases - xpc-send, cross-pc-send, sendmsg.

/cross-pc-sendmsg — Send a cross-PC message

Publish one canonical cross-pc/v1 envelope to the local gateway. WS is tried first; HTTP /publish is the documented fallback.

When to use

• User says: "send a cross-pc msg", "broadcast hello", "DM cursor", "/cross-pc-sendmsg ..."
• You need to ping/heartbeat/coordinate other peers from this host.
• Do NOT use the Redis alpha_engine_bus directly — go through the gateway so the event log + ACK pipeline records it.

Pre-flight — Core file existence

Before running any commands, verify the core protocol files exist. Missing files mean a broken install or wrong working directory.

MISSING=""
for f in \
  tools/adapters/cursor_claude_adapter.py \
  tools/adapters/freebuff_adapter.py \
  tools/protocol_inspect.py \
  cross_pc_protocol/client.py \
  cross_pc_protocol/schema.py \
  cross_pc_protocol/storage.py; do
  [ -f "$f" ] || MISSING="$MISSING  $f\n"
done
if [ -n "$MISSING" ]; then
  echo "MISSING core files:"
  echo -e "$MISSING"
  echo "Run from the project root and ensure cross-pc-protocol is installed."
  exit 1
fi
echo "Core files OK"

Inputs (parse from user request)

Field	Default	Notes
topic	agent.broadcast	e.g. greeting, task.request, heartbeat, ack, CHATBIBLE
to	"" (broadcast)	Peer ID for direct delivery (lands in that peer's inbox queue)
payload	{"text": "<msg>"}	Object. Wrap free-form text under text.
require_ack	false	True only if you actually plan to wait for ACK
causation_id	""	Set to parent message_id when replying — keeps /replay chain intact
peer_id (sender)	env CROSS_PC_PEER_ID or <runtime>-<hostname>	Never hardcode claude-main from a non-claude runtime — see identity rules below

Identity rules (critical — don't mislabel)

Resolution order for sender from:

1. explicit --peer-id / arg
2. $CROSS_PC_PEER_ID
3. inferred <runtime>-<hostname> via --runtime {claude|cursor|hermes|freebuff|agent} or $CROSS_PC_RUNTIME

If you are Claude on this machine, prefer claude-<hostname> or claude-code-windows-desktop. Do NOT spoof cursor-* / freebuff-* IDs.

Gateway address (IMPORTANT)

Always use 192.168.2.32:8788 on this desktop — never 127.0.0.1. The gateway runs as a background service bound to the LAN IP. 127.0.0.1 only works if the gateway process was started in this exact shell session.

Pass --http-base http://192.168.2.32:8788 to the adapter CLI every time.

Pre-flight

curl.exe -s -m 3 http://192.168.2.32:8788/health | python -c "import sys,json;d=json.load(sys.stdin);print('ok' if d.get('ok') else d)"
# or:
python tools/protocol_inspect.py health

If /health fails, gateway is down — start it with python tools/protocol_gateway.py --host 0.0.0.0 --ws-port 8787 --http-port 8788 --peer-id gateway-a (see cross-pc-protocol-debug-first skill) before retrying.

Send via adapter CLI (preferred — handles identity)

# bash / WSL — broadcast
python tools/adapters/cursor_claude_adapter.py --runtime claude send \
  --topic CHATBIBLE --payload '{"text":"hi everyone"}'

# direct DM with ACK requested
python tools/adapters/cursor_claude_adapter.py --runtime claude send \
  --topic task.request --payload '{"summary":"hello"}' --to freebuff-b --require-ack

# explicit peer_id override
python tools/adapters/cursor_claude_adapter.py --peer-id claude-code-windows-desktop \
  send --topic CHATBIBLE --payload '{"text":"hi"}'

PowerShell payload quoting (single-quoted JSON, escape inner double-quotes):

python tools/adapters/cursor_claude_adapter.py --runtime claude send `
  --topic task.request --payload '{\"summary\":\"hello\"}' --to freebuff-b --require-ack

Freebuff-side equivalent: python tools/adapters/freebuff_adapter.py --peer-id freebuff-b send --topic ... --payload ....

Send via Python client (programmatic)

python -c "
from cross_pc_protocol.client import ProtocolClient
from cross_pc_protocol.schema import new_envelope
import os, json
peer = os.environ.get('CROSS_PC_PEER_ID', 'claude-code-windows-desktop')
c = ProtocolClient(peer_id=peer)
env = new_envelope(
    sender=peer,
    topic='agent.broadcast',
    payload={'text': 'HELLO'},
    target='',            # '' = broadcast; set peer_id for DM
    require_ack=False,
    debug={'source_host': os.environ.get('COMPUTERNAME') or os.uname().nodename},
)
print('SEND', env['message_id'], 'trace', env['trace_id'])
print(json.dumps(c.publish_http(env), ensure_ascii=True))
"

For ASCII-only consoles (Windows cmd default code page), keep payload ASCII or set PYTHONUTF8=1.

ACK + retry semantics

• require_ack=true triggers gateway-side retry: exponential backoff 1s, 2s, 4s, 8s, 16s capped at 60s, until ACK or ttl_sec expiry.
• Receivers MUST POST /ack {message_id, from} after handling. The Python client exposes c.ack(message_id).
• Idempotency is keyed on message_id — re-sending the same envelope is safe (gateway returns status=duplicate, not accepted).
• Trace chain: set causation_id=<parent_message_id> on replies so /replay?trace_id=... reconstructs the conversation.

Verify

After send, confirm the envelope hit the durable log:

python tools/protocol_inspect.py trace --trace-id <TRACE_ID>
# or programmatic:
python -c "
from cross_pc_protocol.storage import EventStore
from pathlib import Path
import json
hits = EventStore(Path('logs/cross_pc_protocol/events.jsonl')).by_message_id('<message_id>')
[print(json.dumps(r, ensure_ascii=True)) for r in hits]
"

Expect at least one row with direction=inbound, status=accepted. Broadcasts also produce an internal/queued row under peer_id=all.

Output to user

Report:

• message_id
• trace_id
• transport actually used (ws vs http)
• gateway response status (accepted / duplicate / rejected)
• queue size if broadcast / DM target offline

Failure modes

• connection refused 8788 → gateway not running.
• rejected: schema_version → using wrong envelope; always go through new_envelope() or the adapter CLI.
• UnicodeEncodeError printing payload → console code page; rerun with PYTHONUTF8=1 or pass ensure_ascii=True to dumps.
• Sender ID looks wrong (from=claude-main from a Cursor box) → identity resolution misconfigured; set $CROSS_PC_PEER_ID or pass --runtime.
• Sender retries forever → require_ack=true but receiver never ACKs; check events.jsonl for status=ack.
• Redis subscribers see envelope twice → both bridge and direct publish active; route Redis-only sends through redis_bridge.py, never both.

Companion skills

• /cross-pc-checkmsg — poll inbox + broadcasts + tail log
• /cross-pc-health — gateway pre-flight
• /cross-pc-protocol-debug-first — full protocol design, gateway lifecycle, ACK retry, replay