Vendored slice — do not edit here

Synced from graphopt:docs/public_api.md @ ed89ead — the phase-1 frozen manifest (API_VERSION = "0.1.0"). This page is the eqsat slice: the substrate rows of the contract, landed at the plan-0032 phase-4 split. The manifest upstream carries all three slices; the game rows are gamekit's and the domain rows are graphopt's.

The frozen public API — the eqsat (substrate) slice

Version: from mlopt_core import API_VERSION. The 0.x series covered the monorepo contract; with the split landed, each repo versions its own slice — the rows below are the ones handl-lang/eqsat must not break.

• Frozen — a name in the table below. Renaming, retyping, or re-homing it without an API_VERSION major bump is a contract break.
• Public, unfrozen — any other name in a module's __all__.
• Internal — everything else, including underscore compat re-exports (egraph._term_match, cost._memo_dispatch, …). Reachable is not public.

Substrate contracts

Contract	Canonical location	Frozen surface
Term IR	mlopt_core.ir	IR, Op (incl. Op.make), Var, Param, Const, TensorType, op_repr, op_repr_dag, term_to_data, term_from_data
E-graph engine	mlopt_core.egraph	EGraph, ENode, EClass, UnionFind, Rewrite
EGraph protocol	mlopt_core.egraph.EGraph	add_term(term) -> eid, find(eid), rebuild(classes=None), extract_best(eid, cost_fn, **kw), certificate(src, dst, root_eid=...), run(rules, root_eid, *, max_iterations=100, max_nodes=100_000, rule_budgets=None, stop="fixed_point", patience=3, cost_fn=None, policy=None) -> stats — stats carries stop, n_enodes, n_classes, rule_fires, rule_budgets
Certificates	mlopt_core.egraph	Certificate, CertStep, ProofEdge, CertificateVerificationError, cert_to_data, cert_from_data, verify_certificate(term, cert, *, strict=False) — the standalone derivation replay
DAG pricing	mlopt_core.cost	dag_cost(term, cost_fn, memo=None) — the shared-subtree-honest price; plus the shipped models count_cost, flops_cost, param_bytes_cost, param_bytes_cost_for, backend_cost, executor_cost_for, fused_cost_for, lowering_aware_cost_for, depth_cost, depth_cost_for, roofline_cost, roofline_cost_for, launch_aware_cost, fusion_regions, fusion_member_key, CostModel, LOWERINGS
Ports	mlopt_core.ports	Sink (lower/verify/executors on top of Capabilities's supported_ops/ops), Source, Engine (the engine= contract below), Composer, Executor, ExecutorSpec, Runner, Meter, Verifier, VerifyResult, CostFn, Criterion, Policy, Strategy, TaskMetric, PerformanceModel, Profiler, OpRegistry, RuleSetLike, RuleLike, RuleSetProvider, Binding, TimingResult, signature_conforms
Law machinery	mlopt_core.laws	RuleSet, preset, DEFAULT, FULL, SYMMETRY, ALL_RULES, tags, provenance — the names are frozen; the bank contents (ALL_RULES membership, MACHINE_SHIPPED rows) are each domain repo's data, not the substrate's contract
Provenance registry	mlopt_core.laws.provenance	MACHINE_SHIPPED, MACHINE_STORED, MACHINE_LAWS, law_provenance(rule) -> "machine" | "human"
The pipeline	mlopt_orchestrator	Optimizer, search(model, x, *, source, capabilities=None, criteria=None, cost_fn=None, rules=None, engine=None, policy=None, …) -> SearchResult, lower, SearchResult, LowerResult, Backend, discover_alternatives, DEFAULT_RULES, OptimizationResourceError, strategies Monolithic/Compositional/Autotuned, runners IdentityRunner/ChainedRunner/runner_candidate, criteria family (Criterion, Criteria, Blend, criteria_cost, peak_bytes_cost, LatencyCriterion, MemoryCriterion, FlopsCriterion, DepthCriterion, CompiledCriterion, PredictedCriterion), delivered_cost_for, structural_key
engine=	search/Optimizer kwarg	An Engine-port value — instance, class, or zero-arg factory. Engines are never auto-detected; stats["engine"] records which ran ("python" reference default, "native" for mlopt_native.NativeEngine). The port covers the search only — certificates and the non-local passes are Python-engine capabilities

Boundary notes

• mlopt_native is an opt-in engine behind engine=, not a frozen import path: it is excluded from the uv workspace, so the contract binds the Engine port, not the package.
• Registry contents vs registry shape: ALL_RULES / MACHINE_SHIPPED contents are data — the names and access functions are frozen, the rows are each consuming repo's business.

The full manifest — including the domain-side rows — is docs/public_api.md upstream.