feat(lease): add single-turn Claude promotion trigger

2026-08-11 20:51:03 -05:00
parent 3676180ae8
commit 77edb0dea2
10 changed files with 1304 additions and 6 deletions
@@ -0,0 +1,333 @@
+#!/usr/bin/env python3
+"""Claude UserPromptSubmit hook for operator-triggered lease promotion."""
+
+from __future__ import annotations
+
+import fcntl
+import json
+import os
+import secrets
+import stat
+import subprocess
+import sys
+import time
+from collections.abc import Callable, Mapping
+from pathlib import Path
+from typing import Final, TextIO
+
+_MODULE_DIRECTORY = str(Path(__file__).resolve().parent)
+if _MODULE_DIRECTORY not in sys.path:
+    sys.path.insert(0, _MODULE_DIRECTORY)
+
+from receipt_challenge import receipt_for  # noqa: E402
+
+MAX_FRAME: Final = 64 * 1024
+PENDING_MAX_AGE_SECONDS: Final = 60 * 60
+PROMOTER_TIMEOUT_SECONDS: Final = 10.0
+PROMOTION_PROMPT: Final = "/mosaic-promote"
+PROMOTER: Final = Path(__file__).resolve().with_name("lease_promote.py")
+PENDING_DIRECTORY: Final = "mosaic-lease"
+LOCK_FILE: Final = "promotion.lock"
+EXPECTED_BEGIN_KEYS: Final = frozenset(
+    {"ok", "state", "receipt_challenge", "receipt", "binding"}
+)
+EXPECTED_BINDING_KEYS: Final = frozenset(
+    {
+        "compaction_epoch",
+        "request_epoch",
+        "h_source",
+        "h_payload",
+        "runtime_generation",
+        "schema_version",
+    }
+)
+
+
+class PromotionAlreadyInProgress(RuntimeError):
+    pass
+
+
+def reject_duplicate_json_keys(pairs: list[tuple[str, object]]) -> dict[str, object]:
+    value: dict[str, object] = {}
+    for key, item in pairs:
+        if key in value:
+            raise ValueError("duplicate promoter JSON key")
+        value[key] = item
+    return value
+
+
+def read_hook_input(stream: object) -> dict[str, object]:
+    raw = getattr(stream, "buffer", stream).read(MAX_FRAME + 1)
+    if not isinstance(raw, bytes) or len(raw) > MAX_FRAME:
+        raise ValueError("invalid UserPromptSubmit input")
+    value = json.loads(raw, object_pairs_hook=reject_duplicate_json_keys)
+    if not isinstance(value, dict):
+        raise ValueError("invalid UserPromptSubmit input")
+    return value
+
+
+def emit_context(stream: TextIO, message: str) -> None:
+    json.dump(
+        {
+            "hookSpecificOutput": {
+                "hookEventName": "UserPromptSubmit",
+                "additionalContext": message,
+            }
+        },
+        stream,
+        separators=(",", ":"),
+    )
+    stream.write("\n")
+
+
+def session_pending_name(environ: Mapping[str, str]) -> tuple[Path, str]:
+    runtime_dir = Path(environ["XDG_RUNTIME_DIR"])
+    session_id = environ["MOSAIC_LEASE_SESSION_ID"]
+    if not runtime_dir.is_absolute():
+        raise ValueError("XDG_RUNTIME_DIR must be absolute")
+    if len(session_id) != 64 or any(character not in "0123456789abcdef" for character in session_id):
+        raise ValueError("invalid lease session id")
+    return runtime_dir, f"pending-{session_id}"
+
+
+def open_pending_directory(runtime_dir: Path) -> int:
+    directory_flags = (
+        os.O_RDONLY
+        | getattr(os, "O_CLOEXEC", 0)
+        | getattr(os, "O_DIRECTORY", 0)
+        | getattr(os, "O_NOFOLLOW", 0)
+    )
+    runtime_descriptor = os.open(runtime_dir, directory_flags)
+    try:
+        runtime_metadata = os.fstat(runtime_descriptor)
+        if (
+            not stat.S_ISDIR(runtime_metadata.st_mode)
+            or runtime_metadata.st_uid != os.getuid()
+            or stat.S_IMODE(runtime_metadata.st_mode) != 0o700
+        ):
+            raise ValueError("unsafe XDG runtime directory")
+        try:
+            os.mkdir(PENDING_DIRECTORY, mode=0o700, dir_fd=runtime_descriptor)
+        except FileExistsError:
+            pass
+        descriptor = os.open(PENDING_DIRECTORY, directory_flags, dir_fd=runtime_descriptor)
+    finally:
+        os.close(runtime_descriptor)
+
+    metadata = os.fstat(descriptor)
+    if (
+        not stat.S_ISDIR(metadata.st_mode)
+        or metadata.st_uid != os.getuid()
+        or stat.S_IMODE(metadata.st_mode) != 0o700
+    ):
+        os.close(descriptor)
+        raise ValueError("unsafe promotion pending directory")
+    return descriptor
+
+
+def acquire_lock(directory_descriptor: int) -> int:
+    flags = (
+        os.O_RDWR
+        | os.O_CREAT
+        | getattr(os, "O_CLOEXEC", 0)
+        | getattr(os, "O_NOFOLLOW", 0)
+    )
+    descriptor = os.open(LOCK_FILE, flags, 0o600, dir_fd=directory_descriptor)
+    metadata = os.fstat(descriptor)
+    if (
+        not stat.S_ISREG(metadata.st_mode)
+        or metadata.st_uid != os.getuid()
+        or stat.S_IMODE(metadata.st_mode) != 0o600
+    ):
+        os.close(descriptor)
+        raise ValueError("unsafe promotion lock file")
+    try:
+        fcntl.flock(descriptor, fcntl.LOCK_EX | fcntl.LOCK_NB)
+    except BlockingIOError as error:
+        os.close(descriptor)
+        raise PromotionAlreadyInProgress() from error
+    return descriptor
+
+
+def sweep_stale_pending(directory_descriptor: int, current_time: float) -> None:
+    cutoff = current_time - PENDING_MAX_AGE_SECONDS
+    removed = False
+    with os.scandir(directory_descriptor) as entries:
+        for candidate in entries:
+            if not (
+                candidate.name.startswith("pending-")
+                or candidate.name.startswith(".pending-")
+            ):
+                continue
+            try:
+                metadata = candidate.stat(follow_symlinks=False)
+                if metadata.st_mtime < cutoff and not stat.S_ISDIR(metadata.st_mode):
+                    os.unlink(candidate.name, dir_fd=directory_descriptor)
+                    removed = True
+            except FileNotFoundError:
+                continue
+    if removed:
+        os.fsync(directory_descriptor)
+
+
+def write_pending(directory_descriptor: int, name: str, challenge: str) -> None:
+    temporary = f".{name}.tmp-{secrets.token_hex(8)}"
+    flags = (
+        os.O_WRONLY
+        | os.O_CREAT
+        | os.O_EXCL
+        | getattr(os, "O_CLOEXEC", 0)
+        | getattr(os, "O_NOFOLLOW", 0)
+    )
+    descriptor = os.open(temporary, flags, 0o600, dir_fd=directory_descriptor)
+    try:
+        os.fchmod(descriptor, 0o600)
+        with os.fdopen(descriptor, "w", encoding="utf-8", closefd=False) as stream:
+            stream.write(challenge)
+            stream.flush()
+            os.fsync(stream.fileno())
+        os.replace(
+            temporary,
+            name,
+            src_dir_fd=directory_descriptor,
+            dst_dir_fd=directory_descriptor,
+        )
+        os.fsync(directory_descriptor)
+    except Exception:
+        try:
+            os.unlink(temporary, dir_fd=directory_descriptor)
+        except FileNotFoundError:
+            pass
+        raise
+    finally:
+        os.close(descriptor)
+
+
+def parse_begin_reply(
+    completed: subprocess.CompletedProcess[str],
+) -> tuple[str, dict[str, object] | None]:
+    if completed.returncode != 0:
+        return f"PROMOTER_EXIT_{completed.returncode}", None
+    try:
+        value = json.loads(
+            completed.stdout,
+            object_pairs_hook=reject_duplicate_json_keys,
+        )
+    except (json.JSONDecodeError, RecursionError, TypeError, ValueError):
+        return "INVALID_PROMOTER_REPLY", None
+    if not isinstance(value, dict):
+        return "INVALID_PROMOTER_REPLY", None
+    if value.get("ok") is False and set(value) == {"ok", "code"}:
+        code = value.get("code")
+        return code if isinstance(code, str) and code else "PROMOTION_BEGIN_REFUSED", value
+    if set(value) != EXPECTED_BEGIN_KEYS or value.get("ok") is not True:
+        return "INVALID_PROMOTER_REPLY", None
+    if value.get("state") != "PENDING_VERIFICATION":
+        return "INVALID_PROMOTER_REPLY", None
+    challenge = value.get("receipt_challenge")
+    receipt = value.get("receipt")
+    binding = value.get("binding")
+    if (
+        not isinstance(challenge, str)
+        or len(challenge) != 64
+        or any(character not in "0123456789abcdef" for character in challenge)
+        or not isinstance(receipt, str)
+        or not isinstance(binding, dict)
+        or set(binding) != EXPECTED_BINDING_KEYS
+    ):
+        return "INVALID_PROMOTER_REPLY", None
+    integer_fields = (
+        "compaction_epoch",
+        "request_epoch",
+        "runtime_generation",
+        "schema_version",
+    )
+    if any(type(binding.get(field)) is not int or binding[field] < 0 for field in integer_fields):
+        return "INVALID_PROMOTER_REPLY", None
+    if not all(
+        isinstance(binding.get(field), str)
+        and len(binding[field]) == 64
+        and all(character in "0123456789abcdef" for character in binding[field])
+        for field in ("h_source", "h_payload")
+    ):
+        return "INVALID_PROMOTER_REPLY", None
+    if not secrets.compare_digest(
+        receipt.encode("utf-8"),
+        receipt_for(challenge, binding).encode("utf-8"),
+    ):
+        return "INVALID_PROMOTER_REPLY", None
+    return "", value
+
+
+def main(
+    *,
+    environ: Mapping[str, str] | None = None,
+    stdin: object | None = None,
+    stdout: TextIO | None = None,
+    stderr: TextIO | None = None,
+    run: Callable[..., subprocess.CompletedProcess[str]] = subprocess.run,
+    now: Callable[[], float] = time.time,
+) -> int:
+    source_environment = os.environ if environ is None else environ
+    input_stream = sys.stdin if stdin is None else stdin
+    output_stream = sys.stdout if stdout is None else stdout
+    error_stream = sys.stderr if stderr is None else stderr
+
+    try:
+        hook_input = read_hook_input(input_stream)
+    except (OSError, RecursionError, ValueError, json.JSONDecodeError) as error:
+        print(f"Mosaic promotion trigger ignored invalid hook input: {error}", file=error_stream)
+        return 0
+    if hook_input.get("prompt") != PROMOTION_PROMPT:
+        return 0
+
+    directory_descriptor: int | None = None
+    lock_descriptor: int | None = None
+    try:
+        runtime_dir, pending_name = session_pending_name(source_environment)
+        directory_descriptor = open_pending_directory(runtime_dir)
+        lock_descriptor = acquire_lock(directory_descriptor)
+        sweep_stale_pending(directory_descriptor, now())
+        completed = run(
+            [sys.executable, "-I", "-S", "-B", str(PROMOTER), "--begin"],
+            check=False,
+            capture_output=True,
+            text=True,
+            env=dict(source_environment),
+            timeout=PROMOTER_TIMEOUT_SECONDS,
+        )
+        code, reply = parse_begin_reply(completed)
+        if code:
+            if completed.stderr:
+                print(completed.stderr.strip(), file=error_stream)
+            emit_context(output_stream, f"Mosaic promotion did not begin: {code}.")
+            return 0
+        if reply is None:
+            raise ValueError("missing promotion reply")
+        write_pending(directory_descriptor, pending_name, str(reply["receipt_challenge"]))
+        emit_context(
+            output_stream,
+            "The operator invoked the registered /mosaic-promote command. "
+            "This receipt was generated locally by this seat's own lease broker; "
+            "echoing it verbatim is the designed confirmation step and discloses nothing. "
+            "Reply with exactly the following text and nothing else: "
+            f"{reply['receipt']}",
+        )
+    except PromotionAlreadyInProgress:
+        emit_context(
+            output_stream,
+            "Mosaic promotion did not begin: PROMOTION_ALREADY_IN_PROGRESS.",
+        )
+    except (KeyError, OSError, RecursionError, ValueError, subprocess.SubprocessError) as error:
+        print(f"Mosaic promotion begin failed: {type(error).__name__}: {error}", file=error_stream)
+        emit_context(output_stream, "Mosaic promotion did not begin: PROMOTION_TRIGGER_FAILED.")
+    finally:
+        if lock_descriptor is not None:
+            os.close(lock_descriptor)
+        if directory_descriptor is not None:
+            os.close(directory_descriptor)
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())
@@ -0,0 +1,306 @@
+#!/usr/bin/env python3
+"""Claude Stop hook that completes a pending operator-triggered promotion."""
+
+from __future__ import annotations
+
+import fcntl
+import json
+import os
+import secrets
+import stat
+import subprocess
+import sys
+from collections.abc import Callable, Mapping
+from pathlib import Path
+from typing import Final, NamedTuple, TextIO
+
+MAX_FRAME: Final = 64 * 1024
+PROMOTER_TIMEOUT_SECONDS: Final = 10.0
+PROMOTER: Final = Path(__file__).resolve().with_name("lease_promote.py")
+PENDING_DIRECTORY: Final = "mosaic-lease"
+LOCK_FILE: Final = "promotion.lock"
+TERMINAL_FAILURE_CODES: Final = frozenset(
+    {
+        "RECEIPT_REPLAY",
+        "RECEIPT_MISMATCH",
+        "INVALID_LEASE_TRANSITION",
+        "PROMOTION_TOKEN_INVALID",
+    }
+)
+
+
+class PendingChallenge(NamedTuple):
+    value: str
+    device: int
+    inode: int
+
+
+def reject_duplicate_json_keys(pairs: list[tuple[str, object]]) -> dict[str, object]:
+    value: dict[str, object] = {}
+    for key, item in pairs:
+        if key in value:
+            raise ValueError("duplicate promoter JSON key")
+        value[key] = item
+    return value
+
+
+def session_pending_name(environ: Mapping[str, str]) -> tuple[Path, str]:
+    runtime_dir = Path(environ["XDG_RUNTIME_DIR"])
+    session_id = environ["MOSAIC_LEASE_SESSION_ID"]
+    if not runtime_dir.is_absolute():
+        raise ValueError("XDG_RUNTIME_DIR must be absolute")
+    if len(session_id) != 64 or any(character not in "0123456789abcdef" for character in session_id):
+        raise ValueError("invalid lease session id")
+    return runtime_dir, f"pending-{session_id}"
+
+
+def open_pending_directory(runtime_dir: Path) -> int | None:
+    directory_flags = (
+        os.O_RDONLY
+        | getattr(os, "O_CLOEXEC", 0)
+        | getattr(os, "O_DIRECTORY", 0)
+        | getattr(os, "O_NOFOLLOW", 0)
+    )
+    try:
+        runtime_descriptor = os.open(runtime_dir, directory_flags)
+    except FileNotFoundError:
+        return None
+    try:
+        runtime_metadata = os.fstat(runtime_descriptor)
+        if (
+            not stat.S_ISDIR(runtime_metadata.st_mode)
+            or runtime_metadata.st_uid != os.getuid()
+            or stat.S_IMODE(runtime_metadata.st_mode) != 0o700
+        ):
+            raise ValueError("unsafe XDG runtime directory")
+        try:
+            descriptor = os.open(PENDING_DIRECTORY, directory_flags, dir_fd=runtime_descriptor)
+        except FileNotFoundError:
+            return None
+    finally:
+        os.close(runtime_descriptor)
+
+    metadata = os.fstat(descriptor)
+    if (
+        not stat.S_ISDIR(metadata.st_mode)
+        or metadata.st_uid != os.getuid()
+        or stat.S_IMODE(metadata.st_mode) != 0o700
+    ):
+        os.close(descriptor)
+        raise ValueError("unsafe promotion pending directory")
+    return descriptor
+
+
+def acquire_lock(directory_descriptor: int) -> int:
+    flags = (
+        os.O_RDWR
+        | os.O_CREAT
+        | getattr(os, "O_CLOEXEC", 0)
+        | getattr(os, "O_NOFOLLOW", 0)
+    )
+    descriptor = os.open(LOCK_FILE, flags, 0o600, dir_fd=directory_descriptor)
+    metadata = os.fstat(descriptor)
+    if (
+        not stat.S_ISREG(metadata.st_mode)
+        or metadata.st_uid != os.getuid()
+        or stat.S_IMODE(metadata.st_mode) != 0o600
+    ):
+        os.close(descriptor)
+        raise ValueError("unsafe promotion lock file")
+    try:
+        fcntl.flock(descriptor, fcntl.LOCK_EX | fcntl.LOCK_NB)
+    except BlockingIOError:
+        os.close(descriptor)
+        raise
+    return descriptor
+
+
+def read_pending(directory_descriptor: int, name: str) -> PendingChallenge | None:
+    flags = os.O_RDONLY | getattr(os, "O_CLOEXEC", 0) | getattr(os, "O_NOFOLLOW", 0)
+    try:
+        descriptor = os.open(name, flags, dir_fd=directory_descriptor)
+    except FileNotFoundError:
+        return None
+    try:
+        metadata = os.fstat(descriptor)
+        if (
+            not stat.S_ISREG(metadata.st_mode)
+            or metadata.st_uid != os.getuid()
+            or stat.S_IMODE(metadata.st_mode) != 0o600
+            or metadata.st_size <= 0
+            or metadata.st_size > MAX_FRAME
+        ):
+            raise ValueError("unsafe promotion pending file")
+        raw = os.read(descriptor, MAX_FRAME + 1)
+    finally:
+        os.close(descriptor)
+    if len(raw) > MAX_FRAME:
+        raise ValueError("oversized promotion challenge")
+    challenge = raw.decode("utf-8")
+    if (
+        len(challenge) != 64
+        or any(character not in "0123456789abcdef" for character in challenge)
+    ):
+        raise ValueError("invalid promotion challenge")
+    return PendingChallenge(challenge, metadata.st_dev, metadata.st_ino)
+
+
+def delete_pending_if_unchanged(
+    directory_descriptor: int,
+    name: str,
+    pending: PendingChallenge,
+    error_stream: TextIO,
+) -> None:
+    quarantine = f".{name}.delete-{secrets.token_hex(8)}"
+    try:
+        os.rename(
+            name,
+            quarantine,
+            src_dir_fd=directory_descriptor,
+            dst_dir_fd=directory_descriptor,
+        )
+    except FileNotFoundError:
+        return
+    except OSError as error:
+        print(f"Mosaic promotion could not quarantine pending file: {error}", file=error_stream)
+        return
+
+    try:
+        moved = os.stat(
+            quarantine,
+            dir_fd=directory_descriptor,
+            follow_symlinks=False,
+        )
+        if (moved.st_dev, moved.st_ino) == (pending.device, pending.inode):
+            os.unlink(quarantine, dir_fd=directory_descriptor)
+            os.fsync(directory_descriptor)
+            return
+
+        print("Mosaic promotion pending file changed; preserving replacement.", file=error_stream)
+        try:
+            os.link(
+                quarantine,
+                name,
+                src_dir_fd=directory_descriptor,
+                dst_dir_fd=directory_descriptor,
+                follow_symlinks=False,
+            )
+        except FileExistsError:
+            print(
+                f"Mosaic promotion preserved replacement as {quarantine}.",
+                file=error_stream,
+            )
+        else:
+            os.unlink(quarantine, dir_fd=directory_descriptor)
+        os.fsync(directory_descriptor)
+    except OSError as error:
+        print(f"Mosaic promotion could not resolve pending file: {error}", file=error_stream)
+
+
+def parse_reply(completed: subprocess.CompletedProcess[str]) -> dict[str, object] | None:
+    if completed.returncode != 0:
+        return None
+    try:
+        value = json.loads(
+            completed.stdout,
+            object_pairs_hook=reject_duplicate_json_keys,
+        )
+    except (json.JSONDecodeError, RecursionError, TypeError, ValueError):
+        return None
+    if not isinstance(value, dict):
+        return None
+    if set(value) == {"stage", "ok", "state"}:
+        if (
+            value.get("stage") == "promote_lease"
+            and value.get("ok") is True
+            and value.get("state") == "VERIFIED"
+        ):
+            return value
+        return None
+    if set(value) == {"stage", "ok", "code"}:
+        if (
+            value.get("stage") in {"observe_receipt", "promote_lease"}
+            and value.get("ok") is False
+            and isinstance(value.get("code"), str)
+            and value.get("code")
+        ):
+            return value
+    return None
+
+
+def main(
+    *,
+    environ: Mapping[str, str] | None = None,
+    stderr: TextIO | None = None,
+    run: Callable[..., subprocess.CompletedProcess[str]] = subprocess.run,
+) -> int:
+    source_environment = os.environ if environ is None else environ
+    error_stream = sys.stderr if stderr is None else stderr
+    directory_descriptor: int | None = None
+    lock_descriptor: int | None = None
+
+    try:
+        runtime_dir, pending_name = session_pending_name(source_environment)
+        directory_descriptor = open_pending_directory(runtime_dir)
+        if directory_descriptor is None:
+            return 0
+        try:
+            lock_descriptor = acquire_lock(directory_descriptor)
+        except (BlockingIOError, FileNotFoundError):
+            print("Mosaic promotion completion deferred: promotion is in progress.", file=error_stream)
+            return 0
+        pending = read_pending(directory_descriptor, pending_name)
+        if pending is None:
+            return 0
+        completed = run(
+            [
+                sys.executable,
+                "-I",
+                "-S",
+                "-B",
+                str(PROMOTER),
+                "--complete",
+                pending.value,
+            ],
+            check=False,
+            capture_output=True,
+            text=True,
+            env=dict(source_environment),
+            timeout=PROMOTER_TIMEOUT_SECONDS,
+        )
+        reply = parse_reply(completed)
+        if reply is not None and reply.get("ok") is True:
+            delete_pending_if_unchanged(
+                directory_descriptor,
+                pending_name,
+                pending,
+                error_stream,
+            )
+            print("Mosaic lease promotion completed.", file=error_stream)
+            return 0
+
+        if reply is not None:
+            code = str(reply["code"])
+            print(f"Mosaic promotion incomplete: {code}.", file=error_stream)
+            if code in TERMINAL_FAILURE_CODES:
+                delete_pending_if_unchanged(
+                    directory_descriptor,
+                    pending_name,
+                    pending,
+                    error_stream,
+                )
+        else:
+            diagnostic = completed.stderr.strip() or f"promoter exit {completed.returncode}"
+            print(f"Mosaic promotion retryable failure: {diagnostic}.", file=error_stream)
+    except (KeyError, OSError, RecursionError, UnicodeError, ValueError, subprocess.SubprocessError) as error:
+        print(f"Mosaic promotion completion deferred: {type(error).__name__}: {error}", file=error_stream)
+    finally:
+        if lock_descriptor is not None:
+            os.close(lock_descriptor)
+        if directory_descriptor is not None:
+            os.close(directory_descriptor)
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())
@@ -129,7 +129,12 @@ def main(argv: Sequence[str] | None = None, *, environ: Mapping[str, str] | None
        if arguments.runtime == "claude":
            if not arguments.latest_entry:
                raise ValueError("Claude observer requires --latest-entry")
-            message = claude_latest_entry(source)
+            if "last_assistant_message" in source:
+                message = source["last_assistant_message"]
+                if not isinstance(message, str):
+                    raise ValueError("invalid Claude observer input")
+            else:
+                message = claude_latest_entry(source)
        else:
            if arguments.latest_entry:
                raise ValueError("Pi observer is message_end only")
@@ -33,7 +33,7 @@ def is_verbatim_receipt(message: str, challenge: str, binding: dict[str, object]
    """Require the exact one current-cycle receipt, not a transcript substring."""

    expected = receipt_for(challenge, binding)
-    return hmac.compare_digest(message, expected)
+    return hmac.compare_digest(message.encode("utf-8"), expected.encode("utf-8"))


 def latest_assistant_digest(message: str) -> str: