blemees 0.5.0

Headless agent daemon exposing `claude -p` over a Unix socket.

blemeesd — Headless agent daemon

Version: 0.1 Language: Python 3.11+, stdlib only (no runtime deps). Type-hinted. Target OS: Linux, macOS. Windows not supported.

This document is both the README and the authoritative protocol spec. Machine-readable JSON Schemas live under schemas/.

---

0. Install

Python 3.11+. No runtime dependencies outside the standard library. The claude binary must be on $PATH (or pass --claude).

PyPI is the canonical source — every channel below pulls the same wheel from there.

# pip (any environment):
pip install blemees

# uv (isolated CLI tool, fast):
uv tool install blemees

# pipx (isolated CLI tool, classic):
pipx install blemees

# Homebrew (macOS / Linux):
brew tap blemees/tap
brew install blemees

From source for development:

git clone https://github.com/blemees/blemees-daemon
cd blemees-daemon
uv pip install -e ".[dev]"      # or: pip install -e ".[dev]"

Run in the foreground:

blemeesd                          # socket at $XDG_RUNTIME_DIR/blemeesd.sock
blemeesd --socket /tmp/blemeesd.sock
blemeesd --log-level debug

Socket permissions are 0600. Anyone who can connect() the socket has full access to your Claude subscription, so guard it like an SSH agent.

systemd (Linux user unit)

mkdir -p ~/.config/systemd/user/
cp packaging/blemeesd/blemeesd.service ~/.config/systemd/user/
systemctl --user daemon-reload
systemctl --user enable --now blemeesd
journalctl --user -u blemeesd -f

launchd (macOS)

cp packaging/blemeesd/com.blemees.blemeesd.plist ~/Library/LaunchAgents/
launchctl load ~/Library/LaunchAgents/com.blemees.blemeesd.plist

brew services (after brew install)

brew services start blemees

The Homebrew formula ships a service stanza so the daemon runs at login without you touching launchd by hand.

---

1. Overview

blemeesd is a per-user daemon that exposes the Claude Code CLI (claude -p) as a long-running, multi-session backend over a Unix domain socket. It is a thin, general-purpose wrapper: clients get a headless agent they can reach from any language, any process.

The daemon is pass-through by design. It does not inject a system prompt, does not implement a tool protocol, does not filter events. It:

1. Listens on a Unix socket.
2. Lets clients open, drive, interrupt, resume, and close Claude Code sessions.
3. Forwards Claude Code's stream-json events to the client with a session field added.
4. Manages subprocess lifecycle (spawn, kill, respawn via --resume).

---

2. Goals and Non-Goals

Goals (v0.1)

• Expose claude -p over a local Unix socket, multiplexing multiple sessions.
• Support the full claude -p flag surface relevant to non-interactive use (§6.1). Clients control their own system prompt, tools, model, effort, cwd, MCP config, etc.
• Session resume across client disconnects and daemon restarts via --resume <session-id>.
• Interrupt: kill the in-flight turn cleanly and allow continuation.
• Sub-second warm first-event latency; ~1 s cold start.
• Be neutral — no client-specific assumptions, no built-in prompts, no tool protocols, no post-processing of events beyond session tagging.

Non-goals (v0.1)

• Inventing a tool protocol. Clients either use Claude Code's native tools (via --tools, --mcp-config, etc.) or implement their own protocol in their own system prompt. The daemon does not parse assistant output.
• Multi-user daemons. One blemeesd per OS user. Socket perms (0600) are the only access control.
• Remote access (TCP/TLS). Use SSH socket forwarding if needed.
• Running claude interactively (without -p).
• Token refresh. If OAuth expires, surface the error and let the user run claude auth manually.
• Prompt caching control, token accounting, GUI/admin interface.

---

3. Architecture

┌──────────────────────────────────────────────────────┐
│ blemeesd (single asyncio event loop)                  │
│                                                      │
│   UnixServer  listens on $XDG_RUNTIME_DIR/blemeesd.sock
│      │                                               │
│      ├─ Connection 1                                 │
│      │    ├─ Session s_abc  → Subprocess A (sonnet) │
│      │    └─ Session s_def  → Subprocess B (opus)   │
│      │                                               │
│      └─ Connection 2                                 │
│           └─ Session s_xyz  → Subprocess C (haiku)  │
│                                                      │
│   SubprocessManager                                  │
│     - spawns/kills/respawns `claude -p` children     │
│                                                      │
│   SessionTable                                       │
│     - session_id → (connection_id?, subprocess, cwd)│
│     - reaps orphans after IDLE_TIMEOUT              │
└──────────────────────────────────────────────────────┘

• Single asyncio event loop. asyncio.subprocess handles stdio.
• One claude -p subprocess per open session.
• Sessions outlive client connections (reattach via resume: true).
• Unattached sessions reaped after IDLE_TIMEOUT (default 900 s).

---

4. File Layout

blemees/
  __init__.py
  __main__.py       # python -m blemees → daemon entry point
  daemon.py         # UnixServer + connection dispatcher
  protocol.py       # wire protocol codec, message dataclasses
  session.py        # SessionTable
  subprocess.py     # ClaudeSubprocess wrapper (spawn, stream, kill, resume)
  config.py         # config loading (file + env + CLI)
  errors.py         # typed exceptions
  logging.py        # structured logging helpers
  client.py         # reference Python client (~200 lines, stdlib only)
tests/blemees/
  test_protocol.py
  test_session.py
  test_subprocess.py
  test_daemon_mock.py  # mock `claude` stub
  test_daemon_e2e.py   # requires real `claude`, gated

Package is self-contained (no external imports outside stdlib). A console script blemeesd in pyproject.toml maps to python -m blemees.

---

5. Wire Protocol

Machine-readable JSON Schemas for every frame in this section live under schemas/ (Draft 2020-12). See schemas/README.md for layout and usage. This prose is the human-facing spec; the schemas are the contract.

5.1 Framing

• Transport: AF_UNIX stream socket.
• Framing: UTF-8 newline-delimited JSON. Exactly one JSON object per line.
• Max line size: 16 MiB (configurable). Oversize → connection closed with an error frame.
• Full duplex. Neither side should block on write (see §9.3).

Client socket resolution

Clients using BlemeesClient.connect() (and the daemon itself for its own default) resolve the socket path in this order of precedence, stopping at the first match:

1. $BLEMEESD_SOCKET — explicit override, wins everywhere.
2. $XDG_RUNTIME_DIR/blemeesd.sock — typical on Linux user sessions.
3. /tmp/blemeesd-<uid>.sock — macOS and Linux without XDG.

Only set BLEMEESD_SOCKET in the client's environment when the daemon was started with a non-default path (e.g. via blemeesd --socket …).

5.2 Message namespacing

Every type on the wire carries an explicit namespace prefix:

Prefix	Emitted by	Purpose
blemeesd.*	client → daemon, daemon → client	Session lifecycle and daemon operations: hello, hello_ack, open, opened, close, closed, interrupt, interrupted, error, stderr, replay_gap, list_sessions, sessions.
claude.*	client → daemon, daemon → client	Conversation messages. Inbound (claude.user) is the client's user turn, which the daemon translates to claude -p stream-json stdin. Outbound is everything the daemon forwards from CC's stdout, namespaced by prepending claude. to the native type (e.g. claude.system, claude.stream_event, claude.assistant, claude.user, claude.result, claude.partial_assistant). Inner payloads (e.g. the event field of a stream event) are not rewritten.

Rationale: two stable namespaces — one for session lifecycle, one for the conversation stream in either direction. Clients can switch-case on type without worrying about collisions, and a claude.user sent and a claude.user echoed back live in the same namespace because they are the same conceptual thing.

5.3 Handshake

Client opens the connection and sends:

{"type":"blemeesd.hello","client":"your-tool/0.1","protocol":"blemees/1"}

Daemon replies:

{"type":"blemeesd.hello_ack","daemon":"blemeesd/0.1","protocol":"blemees/1","pid":12345,"claude_version":"2.1.118"}

If protocol does not match, daemon sends blemeesd.error (code protocol_mismatch) and closes.

5.4 Session open

Client supplies whichever claude -p flags it wants. All fields except session are OPTIONAL; the daemon omits corresponding flags when unset, letting Claude Code apply its defaults.

{
  "type": "blemeesd.open",
  "id": "req_001",
  "session_id": "s_abc",

  "model": "sonnet",
  "system_prompt": "...",
  "append_system_prompt": "...",
  "tools": "default",
  "disallowed_tools": [],
  "permission_mode": "default",
  "cwd": "/home/u/proj",
  "add_dir": ["/home/u/proj/vendored"],
  "effort": "medium",
  "agent": null,
  "agents": null,
  "mcp_config": [],
  "strict_mcp_config": false,
  "settings": null,
  "setting_sources": null,
  "plugin_dir": [],
  "betas": [],
  "exclude_dynamic_system_prompt_sections": false,
  "max_budget_usd": null,
  "json_schema": null,
  "fallback_model": null,
  "session_name": null,
  "session_persistence": true,
  "include_partial_messages": true,
  "replay_user_messages": false,

  "resume": false
}

Daemon flag mapping (only fields set by the client produce a flag; unset fields are omitted):

Field	CLI flag
model	--model <v>
system_prompt	--system-prompt <v>
append_system_prompt	--append-system-prompt <v>
tools	--tools <v> (use "" to disable all)
disallowed_tools	--disallowedTools <v...>
permission_mode	--permission-mode <v>
cwd	chdir() before spawn
add_dir	--add-dir <v...>
effort	--effort <v>
agent	--agent <v>
agents	--agents <json>
mcp_config	--mcp-config <v...>
strict_mcp_config	--strict-mcp-config
settings	--settings <v>
setting_sources	--setting-sources <v>
plugin_dir	--plugin-dir <v> (repeated)
betas	--betas <v...>
exclude_dynamic_system_prompt_sections	--exclude-dynamic-system-prompt-sections
max_budget_usd	--max-budget-usd <v>
json_schema	--json-schema <v>
fallback_model	--fallback-model <v>
session_name	-n <v>
session_persistence	--no-session-persistence when false
include_partial_messages	--include-partial-messages
replay_user_messages	--replay-user-messages
session + resume:true	--resume <session>
session + resume:false	--session-id <session>

Flags the daemon refuses to pass (always rejected with unsafe_flag): --dangerously-skip-permissions, --allow-dangerously-skip-permissions, --bare (see note), --continue, --from-pr. Clients that need bypassPermissions should pass "permission_mode":"bypassPermissions" explicitly — the daemon allows that, it just refuses the legacy kill switch.

--bare note: bare mode disables OAuth/keychain auth and requires ANTHROPIC_API_KEY. Incompatible with the daemon's typical auth assumption. v0.1 does not support it.

Daemon always enforces --verbose (required when --output-format stream-json is used with -p). Clients cannot override.

Fields the daemon owns and refuses to accept from clients (rejected with invalid_message on open): input_format, output_format. Both are fixed to stream-json; the event multiplexer requires it, so they are not client-tunable knobs.

Daemon reply on success:

{"type":"blemeesd.opened","id":"req_001","session_id":"s_abc","subprocess_pid":54321}

On failure:

{"type":"blemeesd.error","id":"req_001","session_id":"s_abc","code":"spawn_failed","message":"..."}

5.5 User message

Client sends a new user turn to an open session. The message field is passed through verbatim to claude -p's stream-json stdin — the daemon only rewrites the envelope (claude.user → user, session → session_id).

Simple text:

{"type":"claude.user","session_id":"s_abc","message":{"role":"user","content":"Hello"}}

Multimodal: content may be an array of CC stream-json blocks:

{"type":"claude.user","session_id":"s_abc","message":{"role":"user","content":[{"type":"text","text":"What is in this image?"},{"type":"image","source":{"type":"base64","media_type":"image/png","data":"..."}}]}}

message.role must be "user". message.content must be a string or an array of CC content blocks. Any additional fields CC may add to message in the future will pass through unchanged; the daemon does not validate them.

No id required. Responses stream as events until the turn ends.

5.6 Event stream (daemon → client)

The daemon reads each line of claude -p stdout, parses as JSON, injects "session_id":"<id>", and prepends claude. to the native type before forwarding. Clients see CC event shapes under a stable namespace (claude.system, claude.stream_event, claude.assistant, claude.user, claude.result, claude.partial_assistant, etc.). The inner payload (e.g. the event field of a stream_event) is untouched.

Example (abridged):

{"session_id":"s_abc","type":"claude.system","subtype":"init","model":"claude-sonnet-4-6","tools":["Bash","Read","Edit"]}
{"session_id":"s_abc","type":"claude.stream_event","event":{"type":"content_block_delta","delta":{"type":"text_delta","text":"Hel"}}}
{"session_id":"s_abc","type":"claude.stream_event","event":{"type":"content_block_delta","delta":{"type":"text_delta","text":"lo"}}}
{"session_id":"s_abc","type":"claude.assistant","message":{"role":"assistant","content":[{"type":"text","text":"Hello"}]}}
{"session_id":"s_abc","type":"claude.result","subtype":"success","duration_ms":1254,"num_turns":1}

The daemon does NOT translate, filter, deduplicate, or re-shape these events. Clients that only want streaming deltas should ignore the final assistant echo to avoid double-counting.

Events that arrive on the subprocess's stderr are wrapped and forwarded as well (for visibility into CC warnings / auth errors):

{"session_id":"s_abc","type":"blemeesd.stderr","line":"..."}

These are rate-limited to prevent a broken subprocess from flooding the client. Default cap: 50 lines per 10 s; excess dropped with a counter.

5.7 Interrupt

Client cancels the in-flight turn:

{"type":"blemeesd.interrupt","session_id":"s_abc"}

Daemon:

1. Sends SIGTERM to the subprocess. After 500 ms, SIGKILL if still alive.
2. Emits blemeesd.interrupted:

   {"type":"blemeesd.interrupted","session_id":"s_abc"}
   

3. Respawns the subprocess immediately with --resume <session> (all other flags identical to the original open), so the next claude.user works without further ceremony.

Any CC events emitted before the kill are forwarded as normal. Already-sent deltas are NOT retracted.

Interrupt is a no-op (returns blemeesd.interrupted with was_idle: true) if no turn is in flight.

5.8 Close

Explicit session close:

{"type":"blemeesd.close","id":"req_099","session_id":"s_abc","delete":true}

• delete: true → daemon removes the CC session file from disk after kill.
• delete: false (default) → session file retained for later resume: true.

Daemon replies:

{"type":"blemeesd.closed","id":"req_099","session_id":"s_abc"}

5.9 Connection close

When the socket is closed from the client side without explicit close messages (soft detach):

1. The writer attached to each session is unhooked immediately so no more frames are pushed to the dead socket.
2. If a turn is in flight, the subprocess is not killed — it keeps running to completion and the session is marked "finishing". Events continue to accumulate in the session's ring buffer (§5.11) and in the durable log if enabled, so a client that reconnects can replay them via last_seen_seq. When the subprocess next emits claude.result, the daemon gracefully terminates it.
3. If no turn is in flight, the subprocess is terminated immediately (SIGTERM → 500 ms → SIGKILL).
4. Either way, the session record is detached, not deleted: connection_id = None, detached_at = now(). It is reapable after IDLE_TIMEOUT (during which a late-finishing turn will be torn down along with the session).
5. A new connection may reattach by opening the same session with resume: true, optionally passing last_seen_seq to catch up on anything it missed while disconnected.

Rationale: a hard kill mid-turn left Claude Code's on-disk transcript in whatever partially-flushed state the SIGTERM grace allowed, silently diverging the model's conversation state from what the client last saw. Letting the turn complete closes the transcript cleanly and makes mid- stream reconnects a replay problem, not a consistency problem.

5.9.1 Session takeover

A second connection may open a session that is currently owned by another live connection (via resume: true). The daemon allows the takeover and notifies the previous owner before switching the writer:

{"type":"blemeesd.session_taken","session_id":"s_abc","by_peer_pid":12345}

After this frame the previous connection stops receiving events for that session; its other sessions (if any) are unaffected and its socket stays open. by_peer_pid reflects the new owner's peer PID from SO_PEERCRED when available, for debugging/audit; it is absent when the kernel or platform does not expose it.

If the ex-owner wants the session back, it may itself send open with resume: true — which will in turn notify the current owner. Ping-pong is the clients' problem; the daemon does not arbitrate.

The new owner's subsequent replay (via last_seen_seq) works as usual — the ring buffer is session-local, not connection-local, so frames emitted while the ex-owner held the writer are still available to the new owner.

5.10 Errors

Errors are blemeesd.error frames with a machine-readable code. The daemon never crashes the process on a per-session error.

{"type":"blemeesd.error","id":"req_001","session_id":"s_abc","code":"claude_crashed","message":"stderr tail: ..."}

Error codes the client must handle:

Code	Meaning	Fatal to connection?
protocol_mismatch	Incompatible protocol version.	Yes.
invalid_message	Malformed JSON or bad field.	No.
unknown_message	Unknown blemeesd.* type.	No.
unsafe_flag	Client requested a refused flag.	No.
session_unknown	No such session.	No.
session_exists	Session id collides on open.	No.
session_busy	Another turn in flight.	No.
spawn_failed	claude binary missing or launch failed.	No.
claude_crashed	Subprocess exited unexpectedly mid-turn.	No.
oauth_expired	OAuth token expired (stderr-detected).	No.
oversize_message	Inbound frame too large.	Yes.
slow_consumer	Per-connection queue stalled.	Yes.
daemon_shutdown	Daemon shutting down.	Yes.
internal	Unexpected daemon error.	No.

5.11 Event stream durability (seq, ring buffer, replay)

Every outbound frame the daemon emits for a session — both forwarded claude.* events and synthetic blemeesd.* frames — carries a monotonic integer seq, assigned by the session and starting at 1. blemeesd.opened additionally carries last_seq so a reconnecting client knows the highest seq the session has produced.

Recent frames are retained in two places:

• In-memory ring buffer, per session, bounded (default 1024; BLEMEESD_RING_BUFFER_SIZE). Always on. Survives client disconnects but not daemon restarts.
• Durable event log, per session, opt-in (BLEMEESD_EVENT_LOG_DIR). Append-only JSONL at <dir>/<session>.jsonl. On session reopen the ring is seeded from the log's tail, so replay survives daemon restarts. close {delete:true} unlinks the log.

On reconnect, the client may request replay:

{"type":"blemeesd.open","id":"r1","session_id":"s1","resume":true,"last_seen_seq":42}

The daemon delivers, in order:

1. blemeesd.opened (with last_seq), then
2. every buffered frame with seq > last_seen_seq, then
3. live frames.

If the buffer has rolled over past last_seen_seq + 1, a one-shot blemeesd.replay_gap{since_seq, first_available_seq} frame is emitted before the replay so the client can detect the loss:

{"type":"blemeesd.replay_gap","session_id":"s1","since_seq":42,"first_available_seq":71}

Omitting last_seen_seq on reattach replays whatever is currently in the ring. Passing last_seen_seq equal to the session's current seq skips replay and goes straight to live delivery.

5.12 Liveness (ping / pong)

Client:

{"type":"blemeesd.ping","id":"req_1","data":"anything"}

Daemon:

{"type":"blemeesd.pong","id":"req_1","data":"anything"}

data is opaque and echoed verbatim. id is recommended for round-trip correlation. Both fields are optional.

5.13 Status introspection

Client:

{"type":"blemeesd.status","id":"req_2"}

Daemon:

{
  "type":"blemeesd.status_reply","id":"req_2",
  "daemon":"blemeesd/0.1.0","protocol":"blemees/1","pid":12345,
  "claude_version":"2.1.118","uptime_s":127.3,
  "socket_path":"/run/user/1000/blemeesd.sock",
  "connections":3,
  "sessions":{"total":5,"attached":4,"detached":1,"active_turns":2},
  "config":{
    "ring_buffer_size":1024,"event_log_enabled":false,
    "idle_timeout_s":900,"shutdown_grace_s":30,
    "max_concurrent_sessions":64,"max_line_bytes":16777216
  }
}

No side effects. Forward-compatible: new fields may be added inside sessions / config, and new top-level keys may appear.

5.14 Watch (subscribe-only observer)

A second connection may subscribe to an existing session's event stream without taking ownership. The owner keeps driving the session; watchers receive the same claude.* events, blemeesd.stderr, blemeesd.error{claude_crashed,oauth_expired}, and blemeesd.replay_gap frames the owner does, plus an optional replay on subscribe.

Client:

{"type":"blemeesd.watch","id":"req_3","session_id":"s_abc","last_seen_seq":0}

Daemon (ack, then event stream):

{"type":"blemeesd.watching","id":"req_3","session_id":"s_abc","last_seq":42}

Unknown session → blemeesd.error{code:"session_unknown"}. Multiple connections may watch the same session. Watchers cannot drive: claude.user, blemeesd.interrupt, blemeesd.close, and blemeesd.session_taken remain connection-scoped to the owner.

Unsubscribe:

{"type":"blemeesd.unwatch","id":"req_4","session_id":"s_abc"}

Reply:

{"type":"blemeesd.unwatched","id":"req_4","session_id":"s_abc","was_watching":true}

Watchers are also automatically removed when the connection closes.

5.15 Session info (usage + turn counters)

Query a session's cumulative token usage, turn count, and last-turn snapshot. Side-effect-free.

Client:

{"type":"blemeesd.session_info","id":"req_5","session_id":"s_abc"}

Daemon:

{
  "type":"blemeesd.session_info_reply","id":"req_5","session_id":"s_abc",
  "model":"claude-sonnet-4-6","cwd":"/home/u/proj",
  "turns":5,
  "last_turn_at_ms":1745000000000,
  "last_turn_usage":{
    "input_tokens":500,"output_tokens":200,
    "cache_read_input_tokens":14000,"cache_creation_input_tokens":0
  },
  "cumulative_usage":{
    "input_tokens":3000,"output_tokens":1200,
    "cache_read_input_tokens":70000,"cache_creation_input_tokens":100
  },
  "context_tokens":14500,
  "attached":true,"subprocess_running":true,
  "last_seq":42
}

The accumulator is maintained from each claude.result event's usage block (fields pass through verbatim; future Anthropic-added keys appear automatically). context_tokens is the sum of the last turn's input-side tokens (fresh + cache_read + cache_creation) — compare to the model's context window to gauge headroom.

Persistence: when event_log_dir is enabled, the counters are written to <event_log_dir>/<session>.usage.json on every turn (atomic rename) and reloaded on session reopen, so they survive daemon restarts. Without the durable log they are in-memory only and reset to zero on restart. blemeesd.close {delete:true} also unlinks the sidecar.

---

6. Subprocess Management

6.1 Launch invocation

Construct argv dynamically from the open message's fields (§5.4). Always included:

claude -p
  --verbose
  --session-id <s>    OR    --resume <s>
  --input-format  stream-json   # fixed by the daemon; not client-settable
  --output-format stream-json   # fixed by the daemon; not client-settable
  [all other flags per §5.4 mapping, only when set]

Spawn context:

• cwd = open.cwd or daemon cwd. Do a real chdir in the child (use asyncio.create_subprocess_exec(cwd=...)).
• Inherit daemon env (carries ANTHROPIC_TOKEN / CLAUDE_CODE_OAUTH_TOKEN / ~/.claude/.credentials.json access).
• stdin/stdout/stderr = asyncio.subprocess.PIPE.

6.2 stdin — feeding user messages

Each client claude.user becomes one line on the subprocess stdin, in Claude Code's stream-json input shape. Canonical form for simple text:

{"type":"user","message":{"role":"user","content":"<text>"},"session_id":"<session>"}

For content arrays, the daemon passes them through:

{"type":"user","message":{"role":"user","content":[...content blocks...]},"session_id":"<session>"}

Flush after each line.

Writes to stdin must be queued: only one turn in flight at a time per session. If the client sends another claude.user while the subprocess has not yet emitted a result event, the daemon replies with error{code:"session_busy"} and drops the message.

6.3 stdout — event pass-through

The daemon reads stdout line-by-line, parses each line as JSON, injects "session_id":"<id>" at the top level, and forwards as one JSON line to the client. Non-JSON stdout is logged and dropped (should not occur; indicates a CC bug).

The daemon tracks result events to know when the turn has ended and the session is ready for the next message.

6.4 Interrupt mechanism

Per §5.7. Implementation notes:

• Use subprocess.send_signal(SIGTERM). On macOS and Linux, that's equivalent to proc.terminate().
• After 500 ms, if proc.returncode is None, proc.kill().
• Await proc.wait() before respawn.
• Respawn uses the same stored launch argv from the original open, but with --session-id X replaced by --resume X.

6.5 Session file management

Claude Code stores session state at ~/.claude/projects/<cwd-hash>/<session-id>.jsonl. The daemon does not parse these files. On close with delete: true, it removes the specific file.

Optional startup housekeeping: remove session files older than SESSION_RETENTION_DAYS (default 7). Opt-in via config.

---

7. Security

• Socket path: $XDG_RUNTIME_DIR/blemeesd.sock on Linux. On macOS, which lacks $XDG_RUNTIME_DIR, use /tmp/blemeesd-$UID.sock. Configurable via --socket.
• Permissions: socket created with mode 0600. If the path exists on startup and is not owned by the current UID, refuse to start.
• No authentication beyond socket perms. Anyone who can connect() the socket gets full access to the user's Claude subscription.
• No remote access. No TCP listener. For remote use, forward via SSH.
• Peer identity: the daemon captures SO_PEERCRED (Linux) / LOCAL_PEERCRED (macOS) at connect time and logs peer PID/UID. Informational only; no enforcement in v0.1.
• Secret handling: system_prompt, claude.user content, and event deltas are never logged at INFO+. At DEBUG, bodies are redacted to <redacted N chars>. OAuth tokens are never logged.

---

8. Configuration

Config file (optional): ~/.config/blemeesd/config.toml. CLI flags and env vars override. Env prefix: BLEMEESD_.

Key	CLI flag	Env var	Default
socket_path	--socket	BLEMEESD_SOCKET	$XDG_RUNTIME_DIR/blemeesd.sock
claude_bin	--claude	BLEMEESD_CLAUDE	claude on PATH
log_level	--log-level	BLEMEESD_LOG_LEVEL	info
log_file	--log-file	BLEMEESD_LOG_FILE	stderr
max_line_bytes	—	BLEMEESD_MAX_LINE	16777216
idle_timeout_s	—	BLEMEESD_IDLE_TIMEOUT	900
session_retention_days	—	—	7 (0 disables)
max_sessions_per_connection	—	—	32
max_concurrent_sessions	—	—	64
stderr_rate_lines	—	—	50
stderr_rate_window_s	—	—	10

CLI:

blemeesd [--socket PATH] [--claude PATH] [--log-level LEVEL] [--log-file PATH]
        [--config FILE] [--version]

v0.1 runs in the foreground only. Use systemd/launchd for background.

8.1 systemd user unit (ship in packaging/blemeesd/blemeesd.service)

[Unit]
Description=Headless agent daemon
After=default.target

[Service]
ExecStart=%h/.local/bin/blemeesd
Restart=on-failure
RestartSec=2s

[Install]
WantedBy=default.target

8.2 launchd plist (ship in packaging/blemeesd/com.blemees.blemeesd.plist)

Standard KeepAlive-on-crash plist with ThrottleInterval=5.

8.3 Service lifecycle

blemeesd is a per-user daemon by design — one instance per UID, one Claude account per instance, socket pinned to that UID. Every install path above registers it with a per-user service manager, not a system one.

macOS — LaunchAgent. brew services start blemees writes ~/Library/LaunchAgents/homebrew.mxcl.blemees.plist and loads it into your GUI session via launchctl. Manual install writes ~/Library/LaunchAgents/com.blemees.blemeesd.plist. Either way it:

• starts at login, restarts on crash (KeepAlive),
• stops at logout (a power cycle with no login leaves it off),
• runs as you, so ~/.claude/ creds and session logs are yours.

Socket: /tmp/blemeesd-<uid>.sock. Inspect: brew services list, launchctl list | grep blemees, tail -f "$(brew --prefix)/var/log/blemees/blemeesd.err.log".

Linux — systemd --user unit. brew services start blemees writes ~/.config/systemd/user/homebrew.blemees.service. Manual install writes ~/.config/systemd/user/blemeesd.service. Either way it:

• starts when your user manager starts (first login after boot),
• stops when your last session ends (SSH out, logout),
• runs as you.

Socket: $XDG_RUNTIME_DIR/blemeesd.sock (= /run/user/<uid>/blemeesd.sock). Inspect: systemctl --user status blemeesd, journalctl --user -u blemeesd -f.

Running at boot

You probably do not want this — claude runs with whatever privileges the daemon has, and a broader trust boundary means a bigger blast radius. If you need it anyway (e.g. headless server, unattended box), these are the supported paths. Both keep the daemon running as one named user; do not run it as root.

Linux — loginctl enable-linger. Single flag, no code or unit changes:

sudo loginctl enable-linger "$USER"

systemd starts your user manager at boot and keeps your --user units alive regardless of login state. Undo with disable-linger.

macOS — hand-rolled LaunchDaemon with UserName. There is no enable-linger equivalent. sudo brew services start blemees does produce a LaunchDaemon, but it runs as root — do not use it. Instead, stop the user-scope service and install a LaunchDaemon that drops to your user at launch:

brew services stop blemees

Write /Library/LaunchDaemons/com.blemees.blemeesd.plist (owned root:wheel, mode 0644):

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN"
  "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
  <key>Label</key>            <string>com.blemees.blemeesd</string>
  <key>UserName</key>         <string>YOUR_USERNAME</string>
  <key>ProgramArguments</key>
  <array>
    <string>/opt/homebrew/bin/blemeesd</string>
  </array>
  <key>EnvironmentVariables</key>
  <dict>
    <key>HOME</key> <string>/Users/YOUR_USERNAME</string>
    <key>PATH</key> <string>/opt/homebrew/bin:/usr/bin:/bin:/usr/sbin:/sbin</string>
  </dict>
  <key>RunAtLoad</key>        <true/>
  <key>KeepAlive</key>        <true/>
  <key>StandardOutPath</key>  <string>/Users/YOUR_USERNAME/Library/Logs/blemees/blemeesd.out.log</string>
  <key>StandardErrorPath</key><string>/Users/YOUR_USERNAME/Library/Logs/blemees/blemeesd.err.log</string>
</dict>
</plist>

Load and unload:

sudo launchctl bootstrap system /Library/LaunchDaemons/com.blemees.blemeesd.plist
sudo launchctl bootout   system /Library/LaunchDaemons/com.blemees.blemeesd.plist

Gotchas:

• HOME must be set in EnvironmentVariables; LaunchDaemons start with an empty env and ~/.claude/ lookups will fail otherwise.
• On FileVault-encrypted disks, "at boot" actually means "at first unlock of the disk at boot" — not truly pre-login.
• Intel Macs: use /usr/local/bin instead of /opt/homebrew/bin.

---

9. Error Handling and Recovery

9.1 Subprocess crash mid-turn

On EOF on stdout or non-zero exit during a turn:

{"type":"blemeesd.error","session_id":"s_abc","code":"claude_crashed","message":"<stderr tail>"}

Session remains open. Next claude.user respawns via --resume.

9.2 OAuth expired

Detect patterns in stderr: 401, OAuth token expired, Please run claude auth, Session authentication failed. Emit:

{"type":"blemeesd.error","session_id":"s_abc","code":"oauth_expired","message":"Run `claude auth` to re-authenticate."}

Do not retry automatically. Subsequent user messages repeat the error until the user re-auths and the daemon sees a successful spawn.

9.3 Backpressure

Bounded per-connection event queue (default 1024). When full, pause reading from the subprocess until the queue drains. If blocked > 30 s, emit error{code:"slow_consumer"} and close the connection. Sessions stay alive, detached, subject to idle timeout.

9.4 Malformed client message

Reply error{code:"invalid_message"}, continue connection. Do not kill sessions.

9.5 Daemon shutdown (SIGINT/SIGTERM)

Shutdown applies the same soft-detach policy as a client disconnect (§5.9): sessions with an in-flight turn are allowed to run to the next claude.result before being terminated, so their transcripts close cleanly.

1. Stop accepting new connections.
2. Emit error{code:"daemon_shutdown"} on every live connection.
3. For every session with turn_active=True, set _finishing=True. Events continue to accumulate in the ring buffer and (if enabled) durable log, so a client that reconnects to a restarted daemon can replay them via last_seen_seq.
4. Wait up to shutdown_grace_s seconds (default 30) for finishing subprocesses to reach their next claude.result and self-terminate. Idle sessions (no turn in flight) are not subject to this wait.
5. Force phase: SIGTERM every remaining child, 500 ms grace, then SIGKILL stragglers. Bounded by a 5 s budget.
6. Close sockets, unlink socket file.
7. Exit 0.

Overall wall-clock budget is therefore shutdown_grace_s + 5 s. Past that, the daemon force-exits 1.

Set shutdown_grace_s=0 (via BLEMEESD_SHUTDOWN_GRACE env or config) to disable the graceful phase and hard-kill immediately.

9.6 Stale socket file on startup

• connect() succeeds → another daemon is running; exit 1 with message.
• connect() fails → stale; unlink and continue.

---

10. Logging

• Structured JSON logs, one object per line, to stderr by default.
• Every line has ts, level, event, plus connection_id / session_id where applicable.
• Never log system_prompt, user.text, user.content, event deltas, or stderr subprocess output bodies at INFO+. At DEBUG, redact to <redacted N chars>.
• INFO events to include:
  • daemon start/stop (socket path, claude version, pid)
  • connection open/close (peer pid, uid)
  • session open/close (model, resume flag — NOT prompts)
  • subprocess spawn/exit (pid, exit code)
  • error frames emitted
  • interrupt received

---

11. Testing Requirements

11.1 Unit (no claude required)

• test_protocol.py: encode/decode every message type; malformed inputs; oversize frames; UTF-8 edge cases (surrogate pairs, NUL bytes).
• test_session.py: session table lifecycle; idle-timeout reaper; reattach by session id; delete-on-close.

11.2 Mock-claude tests

Provide a Python stub claude script that reads stream-json on stdin and emits scripted stream-json events on stdout. Tests:

• Full turn → result event → claude.user works again.
• Crash mid-turn → claude_crashed, next turn respawns.
• Interrupt → SIGTERM observed, respawn with --resume, continues.
• Concurrent sessions (3 parallel) do not interfere.
• --session-id vs --resume flag mapping is correct.
• Unsafe flags (e.g. --dangerously-skip-permissions) are rejected at the blemeesd.open stage.

11.3 End-to-end tests (requires_claude pytest mark)

Skipped unless the real claude CLI is installed and authenticated.

• Turn → text response, result event seen.
• Context preserved across two turns in one connection.
• Close → reattach from new connection with resume: true → context intact.
• Interrupt mid-generation → respawn → continuation works.

11.4 Latency benchmarks (python -m blemees.bench)

Acceptance targets on an ordinary dev machine:

• Cold open → first event ≤ 1.5 s.
• Warm user → first event ≤ 0.5 s.
• Resume open → first event ≤ 1.5 s.

---

12. Versioning

• Protocol: blemees/1 in v0.1. Breaking changes bump to blemees/2. Daemons MAY support multiple protocol versions; clients MUST request one.
• Daemon: semver. 0.x unstable; breaking changes allowed pre-1.0.

---

Appendix A: Reference client example

import asyncio, uuid
from blemees.client import BlemeesClient

async def main():
    async with BlemeesClient.connect() as c:
        async with c.open_session(
            session_id=str(uuid.uuid4()),
            model="sonnet",
            system_prompt="You are a terse assistant. Answer in one sentence.",
            tools="",                       # client wants pure inference
            permission_mode="bypassPermissions",
            cwd="/home/u/proj",
        ) as sess:
            await sess.send_user("What is 2+2?")
            async for event in sess.events():
                t = event.get("type")
                if t == "claude.stream_event":
                    inner = event.get("event", {})
                    if inner.get("type") == "content_block_delta":
                        delta = inner.get("delta", {})
                        if delta.get("type") == "text_delta":
                            print(delta["text"], end="", flush=True)
                elif t == "claude.result":
                    print()
                    break
                elif t == "blemeesd.error":
                    raise RuntimeError(event["message"])

asyncio.run(main())