Python Checkpointed Local Log

Install from this directory with pip install . or pip install -e ".[dev]". The installed package is cll, including checkpoint, ledger, log, revocation and signing; the command is cll. From the repository root, use pip install ./python. Run tests here with uv run --extra dev pytest.

CLL storage backends

cll.log implements the CLL backend contract shared with Go and TypeScript: the EntrySource, EntryStore, CheckpointStateStore, WitnessStateStore, CheckpointStore and Backend protocols, their values and error classes, and four backends.

from datetime import datetime, timezone
from cll.log import AppendInput, jsonl

jsonl.init("cll.jsonl")
store = jsonl.open("cll.jsonl")
result = store.append(AppendInput(bytes(32), datetime.now(timezone.utc)))
store.close()

The JSONL, SQLite and MySQL formats interoperate with Go and TypeScript: a log any of them writes opens, continues and verifies in the others. The MySQL backend needs the mysql extra (pip install ".[mysql]"); its target is a mysql://user:password@host:port/database URL. Importing cll or cll.log loads no database driver.

cll.log.conformance runs the shared conformance vectors against any backend, including your own; see its module docstring. cll.log.ledger puts the Python-specific LedgerStore behind EntryStore (without bare-identity append) and any LogSource behind EntrySource.

The MySQL tests read CLL_MYSQL_URL and skip when it is unset, except under CI, where they fail.

The authoritative specification and shared vectors live at the repository root. See the repository README for API and trust boundaries.