allocator_service.py

@@ -23,6 +23,7 @@ import json
 import os
 import uuid
 from dataclasses import dataclass, field
+from datetime import datetime, timezone
 from typing import Any, Mapping, Sequence
 
 from control_plane_db import (
@@ -738,6 +739,46 @@ def normalize_exclude_issue_numbers(
     return sorted(out)
 
 
+def _claim_expires_at(claim: Any) -> datetime | None:
+    """Parse a claim's ``expires_at``, or ``None`` when it is absent/malformed."""
+    if not isinstance(claim, Mapping):
+        return None
+    text = str(claim.get("expires_at") or "").strip()
+    if not text:
+        return None
+    if text.endswith("Z"):
+        text = text[:-1] + "+00:00"
+    try:
+        parsed = datetime.fromisoformat(text)
+    except ValueError:
+        return None
+    if parsed.tzinfo is None:
+        parsed = parsed.replace(tzinfo=timezone.utc)
+    return parsed.astimezone(timezone.utc)
+
+
+def _drop_expired_claims(
+    claims: Mapping[tuple[str, int], dict[str, Any]],
+    *,
+    now: datetime | None = None,
+) -> dict[tuple[str, int], dict[str, Any]]:
+    """Claims minus those whose lease has already expired (#643).
+
+    The read-only mirror of ``expire_stale_leases``: the sweep marks such rows
+    ``expired`` so they stop being returned as claims, and this reaches the same
+    view without writing. A claim with no parseable ``expires_at`` is **kept** —
+    an unreadable expiry is not evidence that work is free.
+    """
+    moment = now or datetime.now(timezone.utc)
+    kept: dict[tuple[str, int], dict[str, Any]] = {}
+    for key, claim in (claims or {}).items():
+        expires_at = _claim_expires_at(claim)
+        if expires_at is not None and expires_at <= moment:
+            continue
+        kept[key] = claim
+    return kept
+
+
 def candidate_set_fingerprint(
     candidates: Sequence[WorkCandidate],
     *,
@@ -826,12 +867,22 @@ def allocate_next_work(
     exclude_issue_numbers: Sequence[int] | None = None,
     expected_candidate_set_fingerprint: str | None = None,
     allocation_mode: str | None = None,
+    side_effect_free: bool = False,
 ) -> dict[str, Any]:
     """Select and optionally reserve the next work unit via control-plane DB.
 
     *apply=False* (default): dry-run selection only — no lease/assignment.
     *apply=True*: atomic ``assign_and_lease`` for the selected candidate.
 
+    *side_effect_free* (#643): a dry run that writes **nothing** to the
+    control-plane DB. A plain ``apply=False`` still registered a session row and
+    swept stale leases globally, so a caller advertising a read-only preview was
+    mutating on every call. Under this flag both writes are suppressed and stale
+    leases are instead filtered out of the claim map in memory, which yields the
+    same selection the sweep would have produced without persisting anything.
+    Incompatible with *apply* — the combination fails closed rather than
+    silently reserving.
+
     *allocation_mode* (#840): ``cross_role`` (default for controller) inspects
     the complete queue and returns one authoritative selection naming the
     required downstream role/profile/action. ``role_scoped`` keeps prior
@@ -885,40 +936,57 @@ def allocate_next_work(
             "allocation_mode": (allocation_mode or "").strip() or None,
         }
 
-    session_id = (session_id or "").strip() or f"alloc-{uuid.uuid4().hex[:12]}"
+    # A side-effect-free run may never reserve: reserving is a write, and the
-    try:
+    # flag is the caller's assertion that this call writes nothing (#643).
-        db.upsert_session(
+    if side_effect_free and apply:
-            session_id=session_id,
-            role=role_norm,
-            profile=profile_name,
-            pid=os.getpid(),
-            controller_instance_id=controller_instance_id,
-        )
-    except Exception as exc:  # noqa: BLE001 — surface structured
         return {
             "success": False,
             "outcome": OUTCOME_NO_SAFE,
+            "apply": True,
             "reasons": [
-                f"failed to register session in control-plane DB: {exc} "
+                "side_effect_free is incompatible with apply=True; an "
-                "(fail closed, #613)"
+                "assignment is a write (fail closed, #643)"
             ],
             "skipped": [],
             "assignment": None,
             "substrate": "control_plane_db",
         }
 
-    # Expire stale leases globally before selection.
+    session_id = (session_id or "").strip() or f"alloc-{uuid.uuid4().hex[:12]}"
-    try:
+    if not side_effect_free:
-        db.expire_stale_leases()
+        try:
-    except Exception as exc:  # noqa: BLE001
+            db.upsert_session(
-        return {
+                session_id=session_id,
-            "success": False,
+                role=role_norm,
-            "outcome": OUTCOME_NO_SAFE,
+                profile=profile_name,
-            "reasons": [f"lease expiry failed: {exc} (fail closed)"],
+                pid=os.getpid(),
-            "skipped": [],
+                controller_instance_id=controller_instance_id,
-            "assignment": None,
+            )
-            "substrate": "control_plane_db",
+        except Exception as exc:  # noqa: BLE001 — surface structured
-        }
+            return {
+                "success": False,
+                "outcome": OUTCOME_NO_SAFE,
+                "reasons": [
+                    f"failed to register session in control-plane DB: {exc} "
+                    "(fail closed, #613)"
+                ],
+                "skipped": [],
+                "assignment": None,
+                "substrate": "control_plane_db",
+            }
+
+        # Expire stale leases globally before selection.
+        try:
+            db.expire_stale_leases()
+        except Exception as exc:  # noqa: BLE001
+            return {
+                "success": False,
+                "outcome": OUTCOME_NO_SAFE,
+                "reasons": [f"lease expiry failed: {exc} (fail closed)"],
+                "skipped": [],
+                "assignment": None,
+                "substrate": "control_plane_db",
+            }
 
     terminal = None
     try:
@@ -953,6 +1021,12 @@ def allocate_next_work(
                 "assignment": None,
                 "substrate": "control_plane_db",
             }
+        if side_effect_free:
+            # ``list_active_claims`` filters on status alone, so without the
+            # global sweep an already-expired lease would still read as a live
+            # claim and the preview would report work as taken that is free.
+            # Drop those in memory: same view the sweep produces, no write.
+            claims = _drop_expired_claims(claims)
 
     try:
         exclude_nums = normalize_exclude_issue_numbers(exclude_issue_numbers)

docs/webui-authz-audit.md

@@ -94,6 +94,7 @@ already define, and a regression test asserts each mapping matches.
 | `record_analytics_usage` | operator | gated_write | `runtime.record_analytics_usage` | Yes | No | No | 2 |
 | `system.reload_namespace` | controller | privileged | `runtime.reload_namespace` | Yes | No | No | 2 |
 | `system.restart_namespace` | admin | destructive | `runtime.restart_namespace` | Yes | **Yes** | **Yes** | 2 |
+| `initiate_workflow` | operator | gated_write | `gitea.read` | Yes | No | No | 2 |
 
 **Dual control** means the acting principal may not be the sole authority: a
 second distinct principal must confirm. **Break-glass** means the action is
@@ -112,6 +113,12 @@ by the console — both hand off to a host supervisor, and neither exposes a raw
 process kill. See
 [`sanctioned-restart-controls.md`](sanctioned-restart-controls.md) (#642).
 
+`initiate_workflow` (#643) is operator-class because its outcome is a *claim*,
+not a Gitea verdict. Requesting reviewer or merger work reserves that work
+through the allocator; it does not grant the right to approve or merge, which
+stays with the MCP role profile and its own capability gates. See
+[`webui-requests.md`](webui-requests.md).
+
 ### Authorization decision
 
 `authorize(action_id, principal, for_execution=False)` returns a decision
@@ -126,9 +133,24 @@ record and **denies by default**. The deny reasons are closed and enumerated:
 | `phase_not_active` | Execution requested for an action whose phase is not open. |
 | `allowed_preview_only` | Authorized — preview only, execution still disabled. |
 
-There is no implicit allow branch. Even the allow result reports
+There is no implicit allow branch.
-`execution_enabled: false` while the console is in Phase 1, so no caller can
+
-read an allow as permission to mutate.
+`execution_enabled` on the decision reports whether the action has a live
+execution path at all, and is computed by `execution_wired(action)`. There are
+exactly two ways to be wired:
+
+1. the action's `phase` is at or below `ACTIVE_PHASE`; or
+2. the action declares an `execution_env_flag` **and** that variable is set.
+
+Every action that declares no flag therefore reports `execution_enabled: false`
+while the console is in Phase 1, so no caller can read an allow as permission
+to mutate. The per-action flag exists because raising `ACTIVE_PHASE` would
+enable execution for every action of that phase at once, including ones whose
+execution path is not implemented. One implemented action goes live on its own
+flag instead of dragging its unimplemented phase-mates with it.
+
+`initiate_workflow` is the only action that currently declares a flag
+(`WEBUI_REQUESTS_EXECUTION`), and it stays denied until an operator sets it.
 
 ## Secret redaction
 
@@ -235,13 +257,22 @@ second one. The integration points are already wired and observable:
   instead of adding a parallel check.
 - **`GET /api/console/security-model`** publishes the RBAC matrix, redaction
   policy, and audit policy as JSON for operators and tests.
+- **`POST /api/v1/requests/preview` and `.../apply`** (#643) are the first
+  actions to use this model for a real execution path. Preview always returns a
+  decision and an audited `previewed` record; apply requires `confirm=true`,
+  emits `succeeded` or `denied`, and reserves work only through the allocator.
+  See [`webui-requests.md`](webui-requests.md).
 
-To open Phase 2, a child issue must: raise `ACTIVE_PHASE`, implement the
+A Phase 2 action must: use `execution_wired` rather than a private enable flag,
-confirmation and dual-control flow the matrix already declares, emit a
+implement the confirmation and dual-control flow the matrix already declares,
-`succeeded` or `failed` record alongside the `gitea_audit` mutation record, and
+emit a `succeeded` or `failed` record alongside the `gitea_audit` mutation
-keep `viewer` unable to reach any of it. Turning on execution without the
+record, and keep `viewer` unable to reach any of it. Turning on execution
-confirmation flow contradicts a declared requirement and is a review failure,
+without the confirmation flow contradicts a declared requirement and is a
-not a shortcut.
+review failure, not a shortcut.
+
+Raising `ACTIVE_PHASE` remains the way to open a whole phase at once, and is
+deliberately *not* what #643 did: an action-scoped opt-in cannot enable an
+action whose execution path nobody wrote.
 
 ## Local-dev mode
 
@@ -294,6 +325,7 @@ Until Phase 2 wires it, probe protection rests on network placement alone, as
 | `WEBUI_ROLE_MAP` | unset | JSON subject → role map |
 | `WEBUI_REQUIRE_PROBE_AUTH` | unset | Require auth for non-public probes |
 | `WEBUI_CONSOLE_AUDIT_LOG` | unset | Append-only audit sink path |
+| `WEBUI_REQUESTS_EXECUTION` | unset | Opt in to `initiate_workflow` execution (#643) |
 
 All are read server-side only. None is ever rendered into a page or returned by
 an API.

docs/webui-requests.md

@@ -0,0 +1,160 @@
+# Web console requests: intent preview and workflow initiation (#643)
+
+**Phase 2. Preview is always live and always read-only. Initiation is wired but
+denied until an operator opts in.**
+
+Before this surface, starting role work meant pasting a prompt into a terminal
+and trusting the operator to have checked the allocator first. Nothing enforced
+that check, so two sessions could reach for the same issue and each believe it
+was theirs. This page replaces the paste with a *request*: a desired role, an
+issue or PR, and a stated intent, answered by an authorization decision and —
+on confirmation — an exclusive assignment from the allocator.
+
+| Concern | Module |
+|---------|--------|
+| Request model, preview, initiation | `webui/request_service.py` |
+| Form and preview rendering | `webui/request_views.py` |
+| Authorization | `webui/console_authz.py` (`initiate_workflow`) |
+| Audit | `webui/console_audit.py` |
+| Ownership substrate | `allocator_service.py` + `control_plane_db.py` |
+
+## Surfaces
+
+| Path | Method | Purpose |
+|------|--------|---------|
+| `/requests` | GET | Request form |
+| `/requests` | POST | Render an intent preview. **Never assigns.** |
+| `/api/v1/requests/preview` | POST | Intent preview as JSON |
+| `/api/v1/requests/apply` | POST | Initiate — confirmed, audited, allocator-owned |
+
+The HTML form has no initiate button on purpose. Initiating requires a
+confirmed POST to `/api/v1/requests/apply`, so a stray form submission cannot
+reserve work as a side effect.
+
+## The request
+
+```json
+{
+  "desired_role": "author",
+  "work_kind": "issue",
+  "work_number": 643,
+  "intent_summary": "implement request preview and initiation",
+  "remote": "prgs",
+  "org": "Scaled-Tech-Consulting",
+  "repo": "Gitea-Tools",
+  "expected_head_sha": null
+}
+```
+
+`desired_role` is one of `author`, `reviewer`, `merger`, `reconciler`,
+`controller`. `work_kind` is `issue` or `pr`. `remote`/`org`/`repo` default to
+the first project in the registry when omitted; when neither the request nor
+the registry resolves them, the request is rejected rather than pointed at some
+other repository. `intent_summary` is required — it is what the audit record
+states as the reason — and is truncated to 500 characters.
+
+Parsing rejects rather than corrects. An unknown role, an unknown work kind, a
+non-positive number, or a missing intent each return `400` with a `reason_code`
+and the offending `field`.
+
+## Preview
+
+Five checks, each with its own verdict, reason code, and detail:
+
+| Check | Passes when |
+|-------|-------------|
+| `authorization` | The console principal holds `operator` or above |
+| `capability` | The desired role maps to a declared profile and MCP namespace |
+| `lease_availability` | No active claim holds the work unit |
+| `next_safe_action` | The allocator would independently select this exact work unit |
+| `head_pin` | PR work resolves to a head SHA, and a supplied SHA still matches |
+
+A preview also returns the role's `allowed_actions` and `prohibited_actions`
+(from `allocator_service.ROLE_ACTIONS`), the `required_profile` and
+`required_namespace` the work must run under, and a `correlation_id` that ties
+the preview to its audit record and to any assignment that follows.
+
+Preview is read-only in the strict sense: it calls the allocator with
+`apply=false` and writes nothing but an audit line. An unauthorized principal
+never reaches the allocator or the control-plane DB at all, so a denial cannot
+be used to enumerate the queue.
+
+## Initiation
+
+`POST /api/v1/requests/apply` refuses in this order, and every refusal returns
+before any assignment is attempted:
+
+| Condition | Outcome | Status |
+|-----------|---------|--------|
+| Unparseable request | `invalid_request` | 400 |
+| Not authorized, or execution not wired | `denied` | 403 |
+| `confirm` not set | `denied` / `confirmation_required` | 409 |
+| Work unit already claimed | `blocked` / `duplicate_assignment` | 409 |
+| Allocator would select other work | `wait` / `not_next_safe_work` | 409 |
+| Allocator declines on apply | `blocked` or `wait` | 409 |
+| Evidence unavailable | `wait` / `evidence_unavailable` | 503 |
+| Assigned | `assigned_work` | 201 |
+
+A success returns the assignment plus a `handoff` block naming the profile, the
+namespace, and the actions that stay forbidden — enough for the operator to
+continue in the right MCP namespace without guessing.
+
+### Why apply runs the allocator twice
+
+The allocator is the only source of exclusive ownership (#600 / #613), and it
+selects work; it does not take orders. So `apply` runs a dry-run first and
+proceeds only when the allocator would independently pick the requested work
+unit. If it would not, the request reports `wait` and mutates nothing.
+
+A request is therefore a *confirmation* of the allocator's decision, never an
+override of it. The apply call carries the dry-run's
+`candidate_set_fingerprint` as a CAS pin (#776), so a queue that changed
+between the two calls fails closed rather than assigning against a stale view.
+The result is checked again on the way out: an assignment naming a different
+work unit is not read as success.
+
+### Fail-closed defaults
+
+- An unreadable control-plane DB denies. It is never treated as "nothing holds
+  this work unit".
+- An incomplete queue inventory denies (#758). Ranking a partial candidate set
+  can select the wrong work.
+- An allocator that raises denies.
+- PR work with no resolvable head SHA denies; a supplied SHA that no longer
+  matches denies with `head_moved`.
+
+## Enabling initiation
+
+Execution is wired off. Set `WEBUI_REQUESTS_EXECUTION=1` to enable it for the
+`initiate_workflow` action only — see
+[`webui-authz-audit.md`](webui-authz-audit.md) for why this is an
+action-scoped flag rather than a phase bump. With the variable unset, `apply`
+returns `403` with `reason_code: unauthorized` no matter who asks.
+
+Enabling execution does **not** enable approvals or merges. Those are phase 3
+console actions and remain forbidden in every path here; the console reserves
+work and hands off, and the MCP role profile enforces what that role may then
+do.
+
+## Audit
+
+Every preview and every apply emits a console audit record (schema in
+[`webui-authz-audit.md`](webui-authz-audit.md)):
+
+| Event | `result` |
+|-------|----------|
+| Preview | `previewed` |
+| Refusal at any stage | `denied` |
+| Assignment created | `succeeded` |
+
+`correlation.request_id` carries the request's `correlation_id`, and a
+successful record's `metadata` carries `assignment_id` and `lease_id`, so an
+assignment can be traced back to the intent that produced it. The operator's
+`intent_summary` travels in `metadata` and passes through the standard
+redaction pass before persistence like every other field.
+
+## Non-goals
+
+- No browser-initiated approve or merge, in this phase or any other.
+- No bypass of allocator exclusive ownership; no self-selection of work.
+- No auto-start from raw monitoring incidents (#612 stays downstream).

tests/test_allocator_service.py

@@ -7,6 +7,7 @@ import tempfile
 import threading
 import unittest
 from concurrent.futures import ThreadPoolExecutor, as_completed
+from datetime import datetime, timezone
 
 from allocator_service import (
     OUTCOME_ASSIGNED,
@@ -15,6 +16,7 @@ from allocator_service import (
     OUTCOME_PREVIEW,
     OUTCOME_WAIT,
     WorkCandidate,
+    _drop_expired_claims,
     allocate_next_work,
     candidate_from_dict,
     classify_skip,
@@ -362,5 +364,161 @@ class AllocatorServiceTest(unittest.TestCase):
         self.assertIn("unavailable", res["reasons"][0].lower())
 
 
+class SideEffectFreeAllocationTest(unittest.TestCase):
+    """``side_effect_free`` dry runs write nothing to the control plane (#643).
+
+    A plain ``apply=False`` still called ``upsert_session`` and
+    ``expire_stale_leases`` before the apply branch was consulted, so a caller
+    advertising a read-only preview mutated on every call — one unreferenced
+    session row per preview, plus a global lease sweep.
+    """
+
+    def setUp(self) -> None:
+        self._tmp = tempfile.TemporaryDirectory()
+        self.db = ControlPlaneDB(os.path.join(self._tmp.name, "cp.sqlite3"))
+
+    def tearDown(self) -> None:
+        self._tmp.cleanup()
+
+    def _alloc(self, **kwargs):
+        defaults = dict(
+            db=self.db,
+            session_id="s-preview",
+            role="author",
+            remote="prgs",
+            org="org",
+            repo="repo",
+            candidates=[
+                WorkCandidate(kind="issue", number=643, labels=("status:ready",))
+            ],
+            apply=False,
+            profile_name="prgs-author",
+            username="jcwalker3",
+        )
+        defaults.update(kwargs)
+        return allocate_next_work(**defaults)
+
+    def _session_ids(self) -> set[str]:
+        return {str(r.get("session_id")) for r in self.db.list_sessions()}
+
+    def test_side_effect_free_preview_writes_no_session_row(self):
+        before = self._session_ids()
+        result = self._alloc(side_effect_free=True)
+        self.assertEqual(result["outcome"], OUTCOME_PREVIEW)
+        self.assertEqual(self._session_ids(), before)
+        self.assertNotIn("s-preview", self._session_ids())
+
+    def test_plain_dry_run_still_registers_a_session(self):
+        # The default is unchanged for every existing caller.
+        self._alloc()
+        self.assertIn("s-preview", self._session_ids())
+
+    def test_repeated_previews_do_not_accumulate_rows(self):
+        for index in range(5):
+            self._alloc(side_effect_free=True, session_id=f"s-{index}")
+        self.assertEqual(self._session_ids(), set())
+
+    def test_side_effect_free_does_not_sweep_stale_leases(self):
+        self.db.upsert_session(session_id="owner", role="author", pid=1)
+        assigned = self.db.assign_and_lease(
+            session_id="owner",
+            role="author",
+            remote="prgs",
+            org="org",
+            repo="repo",
+            kind="issue",
+            number=999,
+            lease_ttl_seconds=-60,  # already expired
+        )
+        self.assertEqual(assigned.outcome, "assigned")
+
+        self._alloc(side_effect_free=True)
+
+        # The expired row is still 'active' in the DB: nothing swept it.
+        statuses = {
+            r["lease_id"]: r["status"]
+            for r in self.db.list_leases(
+                remote="prgs", org="org", repo="repo",
+                statuses=("active", "expired"),
+            )
+        }
+        self.assertEqual(statuses.get(assigned.lease_id), "active")
+
+    def test_expired_claims_are_filtered_in_memory_so_work_stays_selectable(self):
+        """The read-only mirror of the sweep: expired claims must not block."""
+        self.db.upsert_session(session_id="owner", role="author", pid=1)
+        self.db.assign_and_lease(
+            session_id="owner",
+            role="author",
+            remote="prgs",
+            org="org",
+            repo="repo",
+            kind="issue",
+            number=643,
+            lease_ttl_seconds=-60,  # expired: must not withhold #643
+        )
+        result = self._alloc(side_effect_free=True)
+        self.assertEqual(result["outcome"], OUTCOME_PREVIEW)
+        self.assertEqual(result["selected"]["number"], 643)
+
+    def test_a_live_claim_still_withholds_the_work(self):
+        self.db.upsert_session(session_id="owner", role="author", pid=1)
+        self.db.assign_and_lease(
+            session_id="owner",
+            role="author",
+            remote="prgs",
+            org="org",
+            repo="repo",
+            kind="issue",
+            number=643,
+            lease_ttl_seconds=3600,
+        )
+        result = self._alloc(side_effect_free=True)
+        self.assertNotEqual(result["outcome"], OUTCOME_ASSIGNED)
+        self.assertNotEqual((result.get("selected") or {}).get("number"), 643)
+
+    def test_side_effect_free_with_apply_fails_closed(self):
+        result = self._alloc(side_effect_free=True, apply=True)
+        self.assertFalse(result["success"])
+        self.assertEqual(result["outcome"], OUTCOME_NO_SAFE)
+        self.assertIsNone(result["assignment"])
+        self.assertIn("incompatible with apply", result["reasons"][0])
+        # And it reserved nothing.
+        self.assertEqual(
+            self.db.list_leases(remote="prgs", org="org", repo="repo"), []
+        )
+
+
+class DropExpiredClaimsTest(unittest.TestCase):
+    """The in-memory expiry filter behind side-effect-free previews (#643)."""
+
+    def test_unparseable_expiry_is_kept_rather_than_assumed_free(self):
+        claims = {
+            ("issue", 1): {"lease_id": "l1", "expires_at": "not-a-date"},
+            ("issue", 2): {"lease_id": "l2"},
+            ("issue", 3): {"lease_id": "l3", "expires_at": None},
+        }
+        self.assertEqual(_drop_expired_claims(claims), claims)
+
+    def test_expired_dropped_and_future_kept(self):
+        now = datetime(2026, 7, 25, 12, 0, tzinfo=timezone.utc)
+        claims = {
+            ("issue", 1): {"expires_at": "2026-07-25T11:59:59+00:00"},
+            ("issue", 2): {"expires_at": "2026-07-25T12:00:01+00:00"},
+            ("issue", 3): {"expires_at": "2026-07-25T12:00:00+00:00"},  # boundary
+        }
+        kept = _drop_expired_claims(claims, now=now)
+        self.assertEqual(set(kept), {("issue", 2)})
+
+    def test_naive_and_zulu_timestamps_are_treated_as_utc(self):
+        now = datetime(2026, 7, 25, 12, 0, tzinfo=timezone.utc)
+        claims = {
+            ("issue", 1): {"expires_at": "2026-07-25T11:00:00"},  # naive, past
+            ("issue", 2): {"expires_at": "2026-07-25T13:00:00Z"},  # zulu, future
+        }
+        kept = _drop_expired_claims(claims, now=now)
+        self.assertEqual(set(kept), {("issue", 2)})
+
+
 if __name__ == "__main__":
     unittest.main()

webui/app.py

@@ -72,6 +72,8 @@ from webui.system_health import (
     snapshot_to_dict as system_health_to_dict,
 )
 from webui.system_health_views import render_system_health_page
+from webui import request_service
+from webui.request_views import render_requests_page
 
 _READ_ONLY_METHODS = frozenset({"GET", "HEAD", "OPTIONS"})
 _AUDIT_MUTATION_PATHS = frozenset({"/audit", "/api/audit"})
@@ -739,6 +741,109 @@ async def api_v1_analytics_ingest(request: Request) -> JSONResponse:
     )
 
 
+def _default_request_scope() -> dict[str, str]:
+    """Resolve remote/org/repo from the project registry for request forms.
+
+    Returns an empty mapping when the registry cannot be read, which makes
+    ``parse_request`` reject a request that did not name its own scope rather
+    than letting it default to some other repository.
+    """
+    from webui.queue_loader import _host_from_url  # host normalisation helper
+
+    registry, error = _load_project_registry()
+    if error is not None or not registry.projects:
+        return {}
+    project = registry.projects[0]
+    host = _host_from_url(project.remote_host)
+    return {
+        "remote": _derive_remote(host),
+        "org": project.gitea_owner or "",
+        "repo": project.repo_name or "",
+    }
+
+
+async def _request_payload(request: Request) -> dict[str, object]:
+    """Read a request body as JSON or form-encoded. Never raises."""
+    content_type = (request.headers.get("content-type") or "").lower()
+    if "application/json" in content_type:
+        try:
+            body = await request.json()
+        except Exception:
+            return {}
+        return dict(body) if isinstance(body, dict) else {}
+    try:
+        form = await request.form()
+    except Exception:
+        return {}
+    return {key: form[key] for key in form}
+
+
+async def requests_page(request: Request) -> HTMLResponse:
+    """Operator request form and intent preview (#643).
+
+    POST here only ever *previews*. Initiation is a separate confirmed call to
+    ``/api/v1/requests/apply`` so that submitting this form cannot reserve
+    work as a side effect.
+    """
+    submitted: dict[str, object] = {}
+    preview = None
+    error = None
+    if request.method == "POST":
+        submitted = await _request_payload(request)
+        work_request, error = request_service.parse_request(
+            submitted, default_scope=_default_request_scope()
+        )
+        if work_request is not None:
+            preview = request_service.preview_request(
+                work_request,
+                principal=resolve_principal(headers=dict(request.headers)),
+            )
+    return HTMLResponse(
+        render_requests_page(
+            preview=preview, error=error, submitted=submitted
+        )
+    )
+
+
+async def api_v1_request_preview(request: Request) -> JSONResponse:
+    """Dry-run authorization and intent preview for a work request (#643)."""
+    payload = await _request_payload(request)
+    work_request, error = request_service.parse_request(
+        payload, default_scope=_default_request_scope()
+    )
+    if work_request is None:
+        return JSONResponse(error.to_dict(), status_code=400)
+    preview = request_service.preview_request(
+        work_request,
+        principal=resolve_principal(headers=dict(request.headers)),
+    )
+    return JSONResponse(
+        preview.to_dict(), status_code=200 if preview.authorized else 403
+    )
+
+
+async def api_v1_request_apply(request: Request) -> JSONResponse:
+    """Initiate a previewed work request through the allocator (#643).
+
+    Fail-closed at every step: unauthorized, unconfirmed, not-next-safe, and
+    already-claimed all return without attempting an assignment.
+    """
+    payload = await _request_payload(request)
+    work_request, error = request_service.parse_request(
+        payload, default_scope=_default_request_scope()
+    )
+    if work_request is None:
+        return JSONResponse(error.to_dict(), status_code=400)
+    confirm = _truthy_flag(str(payload.get("confirm") or ""))
+    result = request_service.apply_request(
+        work_request,
+        principal=resolve_principal(headers=dict(request.headers)),
+        confirm=confirm,
+    )
+    status = int(result.pop("status_code", 403))
+    return JSONResponse(result, status_code=status)
+
+
 async def method_not_allowed(request: Request, _exc: Exception) -> Response:
     path = request.url.path
     if path in _AUDIT_MUTATION_PATHS and request.method == "POST":
@@ -806,6 +911,17 @@ def create_app(*, bind_host: str | None = None) -> Starlette:
                 api_action_attempt,
                 methods=["POST"],
             ),
+            Route("/requests", requests_page, methods=["GET", "POST"]),
+            Route(
+                "/api/v1/requests/preview",
+                api_v1_request_preview,
+                methods=["POST"],
+            ),
+            Route(
+                "/api/v1/requests/apply",
+                api_v1_request_apply,
+                methods=["POST"],
+            ),
             Route("/api/leases", api_leases, methods=["GET"]),
             Route("/api/v1/inventory", api_inventory, methods=["GET"]),
             Route(

webui/console_authz.py

@@ -115,6 +115,12 @@ class ConsoleAction:
     break_glass: bool
     phase: int
     summary: str
+    # Opt-in switch for an action whose execution path is genuinely wired
+    # ahead of its phase becoming globally active (#643). Naming a variable
+    # here enables nothing on its own: the variable must also be set in the
+    # environment. An action that leaves this ``None`` can only execute once
+    # ACTIVE_PHASE reaches its phase, exactly as before.
+    execution_env_flag: str | None = None
 
     @property
     def mcp_permission(self) -> str:
@@ -277,6 +283,27 @@ _ACTION_SPECS: tuple[ConsoleAction, ...] = (
         phase=2,
         summary="Restart one MCP namespace via the host supervisor.",
     ),
+    # #643: submit a work request — desired role, issue/PR, intent — and let
+    # the allocator reserve it. This is the one Phase 2 action whose execution
+    # path is actually implemented (``webui.request_service``), so it carries
+    # the opt-in flag; it stays denied until an operator sets that variable.
+    # Authority is operator-class because the outcome is a claim, not a Gitea
+    # verdict: initiating reviewer or merger *work* does not grant the right
+    # to approve or merge, which stays with the MCP role profile.
+    ConsoleAction(
+        action_id="initiate_workflow",
+        task_key="allocate_next_work",
+        action_class=CLASS_WRITE,
+        minimum_role=OPERATOR,
+        requires_confirmation=True,
+        dual_control=False,
+        break_glass=False,
+        phase=2,
+        summary=(
+            "Preview and initiate allocator-owned workflow work for a role."
+        ),
+        execution_env_flag="WEBUI_REQUESTS_EXECUTION",
+    ),
 )
 
 ACTIONS: dict[str, ConsoleAction] = {a.action_id: a for a in _ACTION_SPECS}
@@ -430,6 +457,33 @@ ALLOW_PREVIEW = "allowed_preview_only"
 # gated on this model landing; nothing here enables it.
 ACTIVE_PHASE = 1
 
+_TRUTHY = frozenset({"1", "true", "yes", "on"})
+
+
+def execution_wired(
+    action: ConsoleAction | None, env: dict[str, str] | None = None
+) -> bool:
+    """Whether *action* has a live execution path right now.
+
+    Two ways to be wired, and only two. The action's phase is active, or the
+    action declares an opt-in environment variable *and* that variable is set.
+    Everything else — including every action that never declares a flag — is
+    unwired, so the default across the registry stays deny.
+
+    Bumping ``ACTIVE_PHASE`` would enable execution for every action of that
+    phase at once. The per-action flag exists so a single implemented action
+    can go live without dragging its unimplemented phase-mates with it.
+    """
+    if action is None:
+        return False
+    if action.phase <= ACTIVE_PHASE:
+        return True
+    flag = (action.execution_env_flag or "").strip()
+    if not flag:
+        return False
+    source = env if env is not None else os.environ
+    return (source.get(flag) or "").strip().lower() in _TRUTHY
+
 
 @dataclass(frozen=True)
 class AuthorizationDecision:
@@ -469,16 +523,19 @@ def authorize(
     principal: Principal | None = None,
     *,
     for_execution: bool = False,
+    env: dict[str, str] | None = None,
 ) -> AuthorizationDecision:
     """Decide whether *principal* may invoke *action_id*. Deny by default.
 
     ``for_execution`` distinguishes a read-only preview from a real invocation.
-    Even an allowed decision reports ``execution_enabled=False`` while the
+    ``execution_enabled`` reports whether the action has a live execution path
-    console is in Phase 1, so no caller can read an allow as permission to
+    at all (:func:`execution_wired`) — for every action without an explicit
-    mutate.
+    opt-in flag that stays ``False`` while the console is in Phase 1, so no
+    caller can read an allow as permission to mutate.
     """
     who = principal if principal is not None else ANONYMOUS
     action = get_action(action_id)
+    wired = execution_wired(action, env)
 
     if action is None:
         return AuthorizationDecision(
@@ -497,7 +554,7 @@ def authorize(
         "requires_confirmation": action.requires_confirmation,
         "dual_control": action.dual_control,
         "break_glass": action.break_glass,
-        "execution_enabled": False,
+        "execution_enabled": wired,
     }
 
     if not who.authenticated:
@@ -530,13 +587,19 @@ def authorize(
             **base,
         )
 
-    if for_execution and action.phase > ACTIVE_PHASE:
+    if for_execution and not wired:
         return AuthorizationDecision(
             allowed=False,
             reason_code=DENY_PHASE_NOT_ACTIVE,
             detail=(
                 f"Action {action_id!r} belongs to phase {action.phase}; the "
-                f"console is in phase {ACTIVE_PHASE}. Execution is not wired."
+                f"console is in phase {ACTIVE_PHASE}"
+                + (
+                    f" and {action.execution_env_flag} is not set"
+                    if action.execution_env_flag
+                    else ""
+                )
+                + ". Execution is not wired."
             ),
             **base,
         )
@@ -545,8 +608,8 @@ def authorize(
         allowed=True,
         reason_code=ALLOW_PREVIEW,
         detail=(
-            "Principal holds the required role. Preview only — execution "
+            "Principal holds the required role. Execution proceeds only for an "
-            "remains disabled until the Phase 2 action framework ships."
+            "action with a wired execution path; everything else is preview."
         ),
         **base,
     )

webui/nav.py

@@ -45,6 +45,7 @@ NAV_GROUPS: tuple[NavGroup, ...] = (
         NavItem("/queue", "Queue"),
         NavItem("/leases", "Leases"),
         NavItem("/actions", "Actions"),
+        NavItem("/requests", "Requests"),
     )),
     NavGroup("Runtime/Sessions", (
         NavItem("/runtime", "Runtime health"),

webui/request_views.py

@@ -0,0 +1,164 @@
+"""HTML views for the operator request surface (#643).
+
+The form is deliberately a *preview* form. It has no initiate button, because
+initiating requires a confirmed POST to ``/api/v1/requests/apply`` and a stray
+form submission must not be able to produce one by accident.
+
+Nothing rendered here is trusted input: every interpolated value is escaped,
+and the page renders only values the service already produced rather than
+echoing a raw request body back.
+"""
+
+from __future__ import annotations
+
+import html
+import json
+from typing import Any
+
+from webui.layout import render_page
+from webui.request_service import (
+    REQUESTABLE_ROLES,
+    WORK_KINDS,
+    RequestError,
+    RequestPreview,
+)
+
+REQUESTS_PATH = "/requests"
+PREVIEW_API_PATH = "/api/v1/requests/preview"
+APPLY_API_PATH = "/api/v1/requests/apply"
+
+
+def _escape(text: Any) -> str:
+    return html.escape(str(text if text is not None else ""), quote=True)
+
+
+REQUEST_PAGE_STYLES = """
+<style>
+  .request-form { display: grid; gap: 0.75rem; max-width: 44rem; }
+  .request-form label { display: grid; gap: 0.25rem; font-size: 0.9rem; }
+  .request-check { margin: 0.35rem 0; }
+  .request-check .verdict-ok { color: var(--accent); }
+  .request-check .verdict-fail { color: #d14; }
+  .request-prohibited code { margin-right: 0.4rem; }
+</style>
+"""
+
+
+def _options(values: tuple[str, ...], selected: Any) -> str:
+    return "".join(
+        f"<option value='{_escape(value)}'"
+        + (" selected" if selected == value else "")
+        + f">{_escape(value)}</option>"
+        for value in values
+    )
+
+
+def _form(values: dict[str, Any] | None = None) -> str:
+    current = dict(values or {})
+    number = current.get("work_number")
+    return (
+        f"<form class='request-form' method='post' action='{REQUESTS_PATH}'>"
+        "<label>Desired role<select name='desired_role'>"
+        f"{_options(REQUESTABLE_ROLES, current.get('desired_role'))}"
+        "</select></label>"
+        "<label>Work kind<select name='work_kind'>"
+        f"{_options(WORK_KINDS, current.get('work_kind'))}"
+        "</select></label>"
+        "<label>Issue or PR number"
+        "<input type='number' name='work_number' min='1' required "
+        f"value='{_escape(number) if number else ''}'></label>"
+        "<label>Intent summary"
+        "<input type='text' name='intent_summary' maxlength='500' required "
+        f"value='{_escape(current.get('intent_summary'))}'></label>"
+        "<label>Expected head SHA <span class='muted'>(PR work only)</span>"
+        "<input type='text' name='expected_head_sha' "
+        f"value='{_escape(current.get('expected_head_sha'))}'></label>"
+        "<button type='submit' class='copy-btn'>Preview request</button>"
+        "<p class='muted meta'>Preview is read-only and creates no assignment. "
+        f"Initiating requires a confirmed POST to <code>{APPLY_API_PATH}</code>."
+        "</p>"
+        "</form>"
+    )
+
+
+def _checks_block(preview: RequestPreview) -> str:
+    rows = []
+    for check in preview.checks:
+        verdict = "PASS" if check.ok else "FAIL"
+        css = "verdict-ok" if check.ok else "verdict-fail"
+        rows.append(
+            "<li class='request-check'>"
+            f"<span class='{css}'><strong>{verdict}</strong></span> "
+            f"<code>{_escape(check.name)}</code> — {_escape(check.detail)} "
+            f"<span class='muted meta'>({_escape(check.reason_code)})</span>"
+            "</li>"
+        )
+    return "<ul>" + "".join(rows) + "</ul>"
+
+
+def _preview_block(preview: RequestPreview) -> str:
+    verdict = "AUTHORIZED" if preview.authorized else "DENIED"
+    prohibited = "".join(
+        f"<code>{_escape(action)}</code>" for action in preview.prohibited_actions
+    )
+    request = preview.request
+    evidence = json.dumps(preview.allocator_evidence, indent=2, default=str)
+    return (
+        "<h3>Intent preview</h3>"
+        f"<p><strong>{verdict}</strong> — {_escape(preview.detail)}</p>"
+        "<p class='meta'>"
+        f"Role <code>{_escape(request.desired_role)}</code> · "
+        f"{_escape(request.work_kind)} <code>{_escape(request.display_ref)}</code>"
+        f" · profile <code>{_escape(preview.required_profile)}</code> · "
+        f"namespace <code>{_escape(preview.required_namespace)}</code> · "
+        f"permission <code>{_escape(preview.required_permission)}</code>"
+        "</p>"
+        f"<p>Intent: {_escape(request.intent_summary)}</p>"
+        f"{_checks_block(preview)}"
+        f"<p><strong>Next safe action:</strong> "
+        f"{_escape(preview.next_safe_action)}</p>"
+        "<p class='request-prohibited'><strong>Prohibited for this role:</strong> "
+        + (prohibited or "<span class='muted'>none declared</span>")
+        + "</p>"
+        "<p class='muted meta'>Correlation id "
+        f"<code>{_escape(preview.correlation_id)}</code></p>"
+        "<details><summary>Allocator evidence</summary>"
+        f"<pre class='prompt-text'>{_escape(evidence)}</pre>"
+        "</details>"
+    )
+
+
+def _error_block(error: RequestError) -> str:
+    field = (
+        f"<p class='meta'>Field: <code>{_escape(error.field_name)}</code></p>"
+        if error.field_name
+        else ""
+    )
+    return (
+        "<h3>Request rejected</h3>"
+        f"<p><strong>{_escape(error.reason_code)}</strong> — "
+        f"{_escape(error.detail)}</p>{field}"
+    )
+
+
+def render_requests_page(
+    *,
+    preview: RequestPreview | None = None,
+    error: RequestError | None = None,
+    submitted: dict[str, Any] | None = None,
+) -> str:
+    """Render the request form, plus a preview or rejection when one exists."""
+    body = (
+        "<h2>Requests</h2>"
+        "<p>Submit a work request — desired role, issue or PR, and intent — "
+        "and see whether it would be authorized before anything is reserved. "
+        "Initiation goes through the allocator (#600/#613); this console never "
+        "self-selects work, never approves, and never merges.</p>"
+        + _form(submitted)
+        + (_error_block(error) if error is not None else "")
+        + (_preview_block(preview) if preview is not None else "")
+        + f"<p class='meta'><a href='{PREVIEW_API_PATH}'>Preview API</a> · "
+        "<a href='/api/console/security-model'>RBAC model</a></p>"
+        + REQUEST_PAGE_STYLES
+    )
+    return render_page(title="Requests", body_html=body)

webui/traffic_loader.py

@@ -201,6 +201,16 @@ def _candidates_from_queue_snapshot(q_snap: QueueSnapshot) -> list[WorkCandidate
     return candidates
 
 
+def candidates_from_queue_snapshot(q_snap: QueueSnapshot) -> list[WorkCandidate]:
+    """Public alias for :func:`_candidates_from_queue_snapshot` (#643).
+
+    The request-initiation service ranks the same candidate set this view
+    renders, so both must agree on how a queue row becomes a candidate. One
+    construction, two callers — not two that can drift apart.
+    """
+    return _candidates_from_queue_snapshot(q_snap)
+
+
 def _claim_lease_records(inventory: dict[str, Any] | None) -> list[dict[str, Any]]:
     """Normalize ``build_claim_inventory`` entries into lease records.