# Local CDSL Engine

This package rebuilds `cad.cdsl.llm.v1` models through the CDSL-only path:

`semantic validation -> capability analysis -> sketch resolution -> session runtime -> STEP`

`runtime.py` owns the executor registry, an `ExecutionSession`, and the
feature/topology lifecycle. `build123d_adapter.py` is the only layer that
creates or mutates B-rep objects. `runtime_types.py` owns runtime-neutral
feature, context, selector, and topology contracts. `llm_compiler.py` and
`llm_engine.py` remain available for legacy engine-plan compatibility but are
not used by `run_cdsl_only`.

Supported profiles are defined by `SHAPE_GENERATORS` in `sketch_solver.py`.
Supported feature atomic operations are defined by `EXECUTORS` in `runtime.py`.
Their human-readable contract is in `profile_schema.json`; the complete,
machine-enforced CDSL object contract is in `cdsl_schema.json`.
The Studio only accepts self-contained profile data and requires successful
`engine=cdsl_only` output. It never uses the legacy translator fallback or
`compiler_context`.

## Engine schema maintenance

`profile_schema.json` and `cdsl_schema.json` together are the source of truth
for the engine contract exposed to the CAD Agent and the backend validator.
Any addition, removal, rename, or parameter-contract change in
`sketch_solver.py`, `runtime.py`, or the build adapter must update both files
in the same change.
`backend/tests/test_profile_schema.py` fails when the registered profiles or
supported atomic operations diverge from the document.

## Batch baseline

Use the resumable batch entry point to produce feature-level eligibility and
rebuild reports. `--build` invokes only the session-based CDSL runtime; it
never falls back to `compiler_context` or the legacy translator.

```bash
PYTHONPATH=backend/engine python -m cdsl_engine.batch_rebuild \
  json_to_cdsl/output --out /tmp/cdsl-batch --build --build-timeout 15
```

The output directory contains `manifest.json`, one report per part under
`parts/`, `summary-by-atomic.json`, and `summary-by-blocker.json`. Re-run the
same command to resume completed work; use `--max-parts` to run a bounded CI
shard.

Use `--part-ids 046112,053393` to run an exact, comma-separated regression
subset. Unknown ids are rejected so a phase baseline cannot silently omit a
requested part.

Use `--phase p3`, `--phase p4`, or `--phase p6` to run a documented
strict-closed static pool. The
selector lives in `phase_pools.py`; its membership is regression-tested
against the committed exports rather than copied into a shell command.

The runtime foundation test suite also analyzes every committed export without
building STEP, so CI verifies that the full corpus always yields one
machine-readable capability result per input. Use the batch command above for
the slower, resumable truth-build layer.