# `gate.ledger`: Session ledger

```{py:currentmodule} gate.ledger
```

Agent session ledger adapter: lifecycle parsing and session-spend correlation.
Distills Claude Code and Factory Droid JSONL session transcripts into
`SessionRecord` dataclasses, correlates them with LiteLLM gateway spend rows,
and aggregates them into a `SessionSummary` for CLI reporting.

The module is deliberately content-free: it never retains or exposes prompts,
responses, reasoning, or tool arguments from the parsed transcripts.

## Session parsing

```{eval-rst}
.. autofunction:: gate.ledger.parse_session_file
.. autofunction:: gate.ledger.discover_sessions
.. autofunction:: gate.ledger.parse_window
```

## Data models

```{eval-rst}
.. autoclass:: gate.ledger.SessionRecord
.. autoclass:: gate.ledger.SessionSummary
```

## Cost correlation

```{eval-rst}
.. autofunction:: gate.ledger.correlate_session_cost
.. autofunction:: gate.ledger.approximate_session_cost
.. autofunction:: gate.ledger.baseline_cost
```

## Aggregation

```{eval-rst}
.. autofunction:: gate.ledger.summarize_sessions
```