diff --git a/src/portfolio_optimiser/__init__.py b/src/portfolio_optimiser/__init__.py
index ce57d54..9d3a659 100644
--- a/src/portfolio_optimiser/__init__.py
+++ b/src/portfolio_optimiser/__init__.py
@@ -1,3 +1,7 @@
 """portfolio-optimiser — generic MAF framework for per-project cost-savings optimization."""
 
+from portfolio_optimiser.run import RunResult, run_project
+
 __version__ = "0.1.0"
+
+__all__ = ["RunResult", "run_project", "__version__"]
diff --git a/src/portfolio_optimiser/run.py b/src/portfolio_optimiser/run.py
new file mode 100644
index 0000000..3ecb6ed
--- /dev/null
+++ b/src/portfolio_optimiser/run.py
@@ -0,0 +1,187 @@
+"""Vertical-slice orchestrator + single-command entry (two-layer HITL wiring).
+
+``run_project`` composes the whole method for ONE synthetic project on real (or injected)
+chat clients:
+
+1. ``load_contracts`` — fail-fast: every config (incl. the verdict-feedback shape) is
+   validated BEFORE any chat client is built.
+2. load the project + retrieve cited chunks via the Step-7 data source -> first-class
+   ``provenance.Citation`` list.
+3. a FRESH maker-checker ``GroupChat`` debate (``fresh_workflow``), round-capped
+   (``with_max_rounds``); **Layer-1 HITL** = the optional in-run ``with_request_info`` gate.
+4. ``generate_via_llm`` -> blocking ``validate_proposal`` -> ``ValidatedProposal | Rejection``
+   (the token bound is the ``meter`` checked in the generate loop).
+5. attach a first-class ``ProvenanceStamp``.
+6. **Layer-2 (out-of-band)**: ``capture_verdict`` mints a stable id from the proposal's
+   features; the decision/rationale come from ``verdict_input`` (function arg / CLI / fixture).
+   The B11 expert notification is a STUB (``notify``) in Fase 2.
+7. persist to the ``VerdictStore`` -> the next run's ``ExpeLContextProvider`` retrieval (the
+   learning loop; this run also exercises the two-arg ``extend_instructions`` injection).
+
+The two HITL layers are deliberately distinct: **Layer-1** is the optional synchronous in-run
+review gate (no checkpoint — research 01: durable resume is fragile); **Layer-2** is the
+durable learned verdict captured out-of-band in the VerdictStore (D7-portable).
+"""
+
+from __future__ import annotations
+
+from collections.abc import Callable
+from dataclasses import dataclass
+
+from agent_framework import BaseChatClient, SessionContext
+
+from portfolio_optimiser.backends import Profile, get_backend, resolve_model
+from portfolio_optimiser.budget import Budget, TokenMeter
+from portfolio_optimiser.contracts import load_contracts
+from portfolio_optimiser.datasource import chunk_dict_to_citation, retrieve_chunks
+from portfolio_optimiser.generate import generate_via_llm
+from portfolio_optimiser.ir import SavingsProposal
+from portfolio_optimiser.provenance import ProvenanceStamp
+from portfolio_optimiser.reference_domain import Project, load_reference_projects
+from portfolio_optimiser.validator import Rejection, ValidatedProposal
+from portfolio_optimiser.verdicts import (
+    ExpeLContextProvider,
+    ProposalFeatures,
+    Verdict,
+    VerdictStore,
+    capture_verdict,
+)
+from portfolio_optimiser.workflow import fresh_workflow
+
+
+@dataclass(frozen=True)
+class RunResult:
+    """The outcome of one project run: the validated/rejected proposal, its first-class
+    provenance, the captured (Layer-2) verdict, the ExpeL hits surfaced for it, and the store."""
+
+    outcome: ValidatedProposal | Rejection
+    provenance: ProvenanceStamp
+    verdict: Verdict
+    retrieved: list[Verdict]
+    store: VerdictStore
+
+
+def _project_by_id(project_id: str) -> Project:
+    for project in load_reference_projects():
+        if project.id == project_id:
+            return project
+    raise ValueError(f"unknown project_id: {project_id!r}")
+
+
+def _features_of(proposal: SavingsProposal) -> ProposalFeatures:
+    return ProposalFeatures(
+        affected_codes=frozenset(item.code for item in proposal.affected_items),
+        measure_type=proposal.measure,
+        claimed_saving_nok=proposal.claimed_saving_nok,
+        description=proposal.measure,
+    )
+
+
+def _default_factory(profile: Profile | str) -> Callable[[str], BaseChatClient]:
+    def factory(role: str) -> BaseChatClient:
+        return get_backend(profile).create_chat_client(model=resolve_model(profile, role))
+
+    return factory
+
+
+async def run_project(
+    project_id: str,
+    profile: Profile | str = Profile.LOCAL,
+    *,
+    docs_dir: str,
+    verdict_input: dict[str, str],
+    store: VerdictStore | None = None,
+    client_factory: Callable[[str], BaseChatClient] | None = None,
+    max_rounds: int = 3,
+    max_tokens: int = 100_000,
+    top_k: int = 3,
+    enable_layer1_hitl: bool = False,
+    notify: Callable[[Verdict], None] | None = None,
+) -> RunResult:
+    """Run the vertical slice for ONE project. ``client_factory`` is the test-injection seam
+    (defaults to the real backend). ``verdict_input`` carries the expert decision/rationale
+    (Layer-2). Raises ``pydantic.ValidationError`` on a bad contract and ``BudgetExceeded``
+    when the token/round cap is crossed."""
+    # 1. Fail-fast: validate ALL contracts (incl. the verdict-feedback shape) before any client.
+    load_contracts(
+        {"docs_dir": docs_dir, "top_k": top_k},
+        {"max_rounds": max_rounds, "max_tokens": max_tokens},
+        verdict_input,
+    )
+
+    # 2-3. Project + cited chunks (first-class provenance citations).
+    project = _project_by_id(project_id)
+    chunks = retrieve_chunks("cost saving measure", docs_dir, top_k)
+    citations = [chunk_dict_to_citation(c) for c in chunks]
+    if not citations:
+        raise ValueError(f"no citable content in docs_dir: {docs_dir!r}")
+    context = "\n".join(c["snippet"] for c in chunks)
+
+    # 4. Budget + maker-checker debate (round-capped; Layer-1 HITL optional).
+    meter = TokenMeter(Budget(max_tokens=max_tokens, max_rounds=max(max_rounds * 4, 4)))
+    factory = client_factory if client_factory is not None else _default_factory(profile)
+    debate = fresh_workflow(factory, max_rounds=max_rounds, enable_layer1_hitl=enable_layer1_hitl)
+    await debate.run(f"Find a cost-saving measure for {project.id}.\nContext:\n{context}")
+
+    # 5. Structured candidate -> blocking validation; token bound = the meter in this loop.
+    outcome = await generate_via_llm(factory("proposer"), project, context, meter)
+    proposal = outcome.proposal
+
+    # 6. First-class provenance stamp (authoritative; independent of MAF Annotation).
+    model = "fake-model" if client_factory is not None else resolve_model(profile, "proposer")
+    stamp = ProvenanceStamp(
+        citations=citations,
+        model=model,
+        role="proposer",
+        validator_decision="validated" if isinstance(outcome, ValidatedProposal) else "rejected",
+        token_usage=meter.tokens,
+    )
+
+    # 7. ExpeL: surface prior verdicts for this proposal (exercises the two-arg
+    #    extend_instructions injection on a real SessionContext — the learning loop).
+    store = store if store is not None else VerdictStore(verdicts=[])
+    features = _features_of(proposal)
+    provider = ExpeLContextProvider(store, features, k=top_k)
+    sctx = SessionContext(input_messages=[], instructions=[])
+    await provider.before_run(agent=None, session=None, context=sctx, state={})
+    retrieved = store.retrieve(features, k=top_k) if store.verdicts else []
+
+    # 8. Layer-2 (out-of-band): capture the durable verdict + persist; B11 notify is a stub.
+    verdict = capture_verdict(features, verdict_input["decision"], verdict_input["rationale"])
+    store.add(verdict)
+    if notify is not None:
+        notify(verdict)
+
+    return RunResult(
+        outcome=outcome, provenance=stamp, verdict=verdict, retrieved=retrieved, store=store
+    )
+
+
+def main(argv: list[str] | None = None) -> int:
+    """Single-command console entry: run the slice for one project against a docs folder."""
+    import argparse
+    import asyncio
+
+    parser = argparse.ArgumentParser(description="portfolio-optimiser vertical slice")
+    parser.add_argument("project_id")
+    parser.add_argument("--profile", default="local")
+    parser.add_argument("--docs-dir", required=True)
+    parser.add_argument("--decision", default="approved", choices=["approved", "rejected"])
+    parser.add_argument("--rationale", default="reviewed by expert")
+    args = parser.parse_args(argv)
+
+    result = asyncio.run(
+        run_project(
+            args.project_id,
+            args.profile,
+            docs_dir=args.docs_dir,
+            verdict_input={"decision": args.decision, "rationale": args.rationale},
+        )
+    )
+    kind = type(result.outcome).__name__
+    print(f"{args.project_id}: {kind} (verdict id={result.verdict.id}, decision={args.decision})")
+    return 0
+
+
+if __name__ == "__main__":  # pragma: no cover - console entry
+    raise SystemExit(main())
diff --git a/tests/test_run_smoke.py b/tests/test_run_smoke.py
new file mode 100644
index 0000000..d95d9c5
--- /dev/null
+++ b/tests/test_run_smoke.py
@@ -0,0 +1,40 @@
+"""Step 12 smoke — run_project composes the slice end-to-end on an injected FakeChatClient.
+
+Returns a ValidatedProposal with a populated first-class ProvenanceStamp. Pattern:
+tests/test_smoke.py.
+"""
+
+from spikes._harness import FakeChatClient
+
+from portfolio_optimiser.provenance import ProvenanceStamp
+from portfolio_optimiser.run import run_project
+from portfolio_optimiser.validator import ValidatedProposal
+
+_VALID = (
+    '{"project_id":"FV42-GSV-E1","measure":"Reduce scope",'
+    '"affected_items":[{"code":"05.2","quantity":4300,"unit_cost":215},'
+    '{"code":"03.1","quantity":1800,"unit_cost":310}],"claimed_saving_nok":200000}'
+)
+
+
+async def test_run_project_smoke(tmp_path) -> None:
+    docs = tmp_path / "docs"
+    docs.mkdir()
+    (docs / "cost.txt").write_text(
+        "Asphalt Ab11 unit rate renegotiation reduced the paving cost on the school stretch.",
+        encoding="utf-8",
+    )
+
+    def factory(role: str) -> FakeChatClient:
+        return FakeChatClient(default_reply=_VALID)
+
+    result = await run_project(
+        "FV42-GSV-E1",
+        "local",
+        docs_dir=str(docs),
+        verdict_input={"decision": "approved", "rationale": "feasible within range"},
+        client_factory=factory,
+    )
+    assert isinstance(result.outcome, ValidatedProposal)
+    assert isinstance(result.provenance, ProvenanceStamp)
+    assert len(result.provenance.citations) >= 1