diff --git a/backend/app/api/endpoints/session_suggested_fixes.py b/backend/app/api/endpoints/session_suggested_fixes.py
index d18b8f18..60f59674 100644
--- a/backend/app/api/endpoints/session_suggested_fixes.py
+++ b/backend/app/api/endpoints/session_suggested_fixes.py
@@ -30,6 +30,7 @@ from app.schemas.session_suggested_fix import (
     ResolutionPostResponse,
     SessionSuggestedFixDecisionRequest,
     SessionSuggestedFixDecisionResponse,
+    SessionSuggestedFixOutcomeRequest,
     SessionSuggestedFixResponse,
 )
 from app.models.draft_template import DraftTemplate
@@ -216,6 +217,70 @@ async def record_decision(
     )
 
 
+# ── Suggested fix: outcome ────────────────────────────────────────────────
+
+@router.patch(
+    "/suggested-fixes/{fix_id}/outcome",
+    response_model=SessionSuggestedFixResponse,
+)
+async def patch_suggested_fix_outcome(
+    session_id: UUID,
+    fix_id: UUID,
+    body: SessionSuggestedFixOutcomeRequest,
+    current_user: Annotated[User, Depends(get_current_active_user)],
+    db: Annotated[AsyncSession, Depends(get_db)],
+    _: None = Depends(require_engineer_or_admin),
+) -> SessionSuggestedFixResponse:
+    """Record the engineer's outcome for an applied fix.
+
+    See `SessionSuggestedFixOutcomeRequest` for transition rules.
+    """
+    await _load_session_or_404(db, session_id)
+    now = datetime.now(timezone.utc)
+
+    result = await db.execute(
+        select(SessionSuggestedFix).where(
+            SessionSuggestedFix.id == fix_id,
+            SessionSuggestedFix.session_id == session_id,
+        )
+    )
+    fix = result.scalar_one_or_none()
+    if fix is None:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND, detail="Suggested fix not found"
+        )
+
+    if body.outcome == "applied_partial" and not (body.notes and body.notes.strip()):
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="notes are required when outcome is applied_partial",
+        )
+
+    TERMINAL = {"applied_success", "applied_failed", "dismissed"}
+    if fix.status in TERMINAL:
+        raise HTTPException(
+            status_code=status.HTTP_409_CONFLICT,
+            detail=f"Fix is already in terminal status {fix.status!r}",
+        )
+
+    fix.status = body.outcome
+    if body.outcome == "applied_partial":
+        fix.partial_notes = (body.notes or "").strip() or None
+    elif body.outcome == "applied_failed":
+        fix.failure_reason = (body.notes or "").strip() or None
+        fix.verified_at = now
+    elif body.outcome == "applied_success":
+        fix.verified_at = now
+    # dismissed: no timestamp/notes stamping
+
+    if fix.applied_at is None and body.outcome != "dismissed":
+        fix.applied_at = now
+
+    await db.commit()
+    await db.refresh(fix)
+    return SessionSuggestedFixResponse.model_validate(fix)
+
+
 async def _summarize_session_for_extraction(
     db: AsyncSession, session_id: UUID,
 ) -> str:
diff --git a/backend/app/models/network_diagram.py b/backend/app/models/network_diagram.py
index 347216da..2a8f3e45 100644
--- a/backend/app/models/network_diagram.py
+++ b/backend/app/models/network_diagram.py
@@ -3,7 +3,7 @@ import uuid
 from datetime import datetime, timezone
 from typing import Any, TYPE_CHECKING
 
-from sqlalchemy import String, Text, Boolean, DateTime, ForeignKey
+from sqlalchemy import String, Text, Boolean, DateTime, ForeignKey, text
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 from sqlalchemy.dialects.postgresql import UUID, JSONB
 
@@ -30,8 +30,8 @@ class NetworkDiagram(Base):
     client_name: Mapped[str | None] = mapped_column(String(255), nullable=True)
     asset_name: Mapped[str | None] = mapped_column(String(255), nullable=True)
     description: Mapped[str | None] = mapped_column(Text, nullable=True)
-    nodes: Mapped[list[dict[str, Any]]] = mapped_column(JSONB, nullable=False, server_default="'[]'")
-    edges: Mapped[list[dict[str, Any]]] = mapped_column(JSONB, nullable=False, server_default="'[]'")
+    nodes: Mapped[list[dict[str, Any]]] = mapped_column(JSONB, nullable=False, server_default=text("'[]'::jsonb"))
+    edges: Mapped[list[dict[str, Any]]] = mapped_column(JSONB, nullable=False, server_default=text("'[]'::jsonb"))
     thumbnail_url: Mapped[str | None] = mapped_column(Text, nullable=True)
     is_archived: Mapped[bool] = mapped_column(
         Boolean, nullable=False, default=False,
diff --git a/backend/app/schemas/session_suggested_fix.py b/backend/app/schemas/session_suggested_fix.py
index 816874b0..38f380b5 100644
--- a/backend/app/schemas/session_suggested_fix.py
+++ b/backend/app/schemas/session_suggested_fix.py
@@ -103,9 +103,11 @@ class SessionSuggestedFixOutcomeRequest(BaseModel):
     engineer took); outcome captures whether the fix actually worked.
 
     Allowed transitions:
-    - from `proposed`: any of applied_success | applied_failed | applied_partial | dismissed
-    - from `applied_partial`: applied_success | applied_failed  (partial is not terminal)
-    - from any terminal outcome: no change (server returns 409)
+    - from `proposed` or `applied_partial`: any outcome is valid
+      (partial is parked, not terminal — the engineer may update notes,
+      abandon via dismiss, or advance to success/failed)
+    - from any terminal outcome (`applied_success`, `applied_failed`,
+      `dismissed`): server returns 409
     """
     outcome: FixOutcome
     # Required for applied_partial, optional for applied_failed, ignored otherwise.
diff --git a/backend/tests/test_fix_outcome_endpoint.py b/backend/tests/test_fix_outcome_endpoint.py
new file mode 100644
index 00000000..7b5dd702
--- /dev/null
+++ b/backend/tests/test_fix_outcome_endpoint.py
@@ -0,0 +1,199 @@
+"""Integration tests for PATCH /ai-sessions/{sid}/suggested-fixes/{fid}/outcome.
+
+Fixture style follows test_session_suggested_fixes_api.py:
+  client, test_user, auth_headers, test_db
+"""
+from __future__ import annotations
+
+import pytest
+from httpx import AsyncClient
+
+from app.models.ai_session import AISession
+from app.models.session_suggested_fix import SessionSuggestedFix
+
+
+# ── shared helper ────────────────────────────────────────────────────────────
+
+async def _make_session_with_fix(test_db, user) -> tuple[str, str]:
+    """Create an AISession + active proposed SessionSuggestedFix.
+
+    Returns (session_id_str, fix_id_str).
+    """
+    session = AISession(
+        user_id=user["user_data"]["id"],
+        account_id=user["user_data"]["account_id"],
+        session_type="chat",
+        intake_type="free_text",
+        intake_content={"text": "outcome test"},
+        status="active",
+        confidence_tier="discovery",
+        conversation_messages=[],
+    )
+    test_db.add(session)
+    await test_db.flush()
+
+    fix = SessionSuggestedFix(
+        session_id=session.id,
+        account_id=session.account_id,
+        title="Reset credential cache",
+        description="Clear stale credentials from the domain cache.",
+        confidence_pct=82,
+    )
+    test_db.add(fix)
+    await test_db.commit()
+    await test_db.refresh(fix)
+
+    return str(session.id), str(fix.id)
+
+
+# ── tests ────────────────────────────────────────────────────────────────────
+
+@pytest.mark.asyncio
+async def test_patch_outcome_marks_success(
+    client: AsyncClient, test_user, auth_headers, test_db
+):
+    session_id, fix_id = await _make_session_with_fix(test_db, test_user)
+
+    r = await client.patch(
+        f"/api/v1/ai-sessions/{session_id}/suggested-fixes/{fix_id}/outcome",
+        headers=auth_headers,
+        json={"outcome": "applied_success"},
+    )
+    assert r.status_code == 200, r.text
+    body = r.json()
+    assert body["status"] == "applied_success"
+    assert body["verified_at"] is not None
+
+
+@pytest.mark.asyncio
+async def test_patch_outcome_partial_requires_notes(
+    client: AsyncClient, test_user, auth_headers, test_db
+):
+    session_id, fix_id = await _make_session_with_fix(test_db, test_user)
+
+    r = await client.patch(
+        f"/api/v1/ai-sessions/{session_id}/suggested-fixes/{fix_id}/outcome",
+        headers=auth_headers,
+        json={"outcome": "applied_partial"},
+    )
+    assert r.status_code == 400
+    assert "notes" in r.text.lower()
+
+
+@pytest.mark.asyncio
+async def test_partial_to_success_allowed(
+    client: AsyncClient, test_user, auth_headers, test_db
+):
+    session_id, fix_id = await _make_session_with_fix(test_db, test_user)
+
+    r1 = await client.patch(
+        f"/api/v1/ai-sessions/{session_id}/suggested-fixes/{fix_id}/outcome",
+        headers=auth_headers,
+        json={"outcome": "applied_partial", "notes": "ran cred clear only"},
+    )
+    assert r1.status_code == 200, r1.text
+
+    r2 = await client.patch(
+        f"/api/v1/ai-sessions/{session_id}/suggested-fixes/{fix_id}/outcome",
+        headers=auth_headers,
+        json={"outcome": "applied_success"},
+    )
+    assert r2.status_code == 200
+    assert r2.json()["status"] == "applied_success"
+
+
+@pytest.mark.asyncio
+async def test_terminal_outcome_is_locked(
+    client: AsyncClient, test_user, auth_headers, test_db
+):
+    session_id, fix_id = await _make_session_with_fix(test_db, test_user)
+
+    r1 = await client.patch(
+        f"/api/v1/ai-sessions/{session_id}/suggested-fixes/{fix_id}/outcome",
+        headers=auth_headers,
+        json={"outcome": "applied_failed", "notes": "no change"},
+    )
+    assert r1.status_code == 200
+
+    r2 = await client.patch(
+        f"/api/v1/ai-sessions/{session_id}/suggested-fixes/{fix_id}/outcome",
+        headers=auth_headers,
+        json={"outcome": "applied_success"},
+    )
+    assert r2.status_code == 409
+
+
+@pytest.mark.asyncio
+async def test_partial_notes_can_be_updated(
+    client: AsyncClient, test_user, auth_headers, test_db
+):
+    """partial→partial with new notes updates the stored notes."""
+    session_id, fix_id = await _make_session_with_fix(test_db, test_user)
+
+    r1 = await client.patch(
+        f"/api/v1/ai-sessions/{session_id}/suggested-fixes/{fix_id}/outcome",
+        json={"outcome": "applied_partial", "notes": "ran cred clear only"},
+        headers=auth_headers,
+    )
+    assert r1.status_code == 200
+    assert r1.json()["partial_notes"] == "ran cred clear only"
+
+    r2 = await client.patch(
+        f"/api/v1/ai-sessions/{session_id}/suggested-fixes/{fix_id}/outcome",
+        json={"outcome": "applied_partial", "notes": "also finished the rebuild; not verified yet"},
+        headers=auth_headers,
+    )
+    assert r2.status_code == 200
+    assert r2.json()["partial_notes"] == "also finished the rebuild; not verified yet"
+
+
+@pytest.mark.asyncio
+async def test_dismissed_sets_no_timestamps(
+    client: AsyncClient, test_user, auth_headers, test_db
+):
+    """dismissed outcome does not stamp applied_at or verified_at."""
+    session_id, fix_id = await _make_session_with_fix(test_db, test_user)
+    r = await client.patch(
+        f"/api/v1/ai-sessions/{session_id}/suggested-fixes/{fix_id}/outcome",
+        json={"outcome": "dismissed"},
+        headers=auth_headers,
+    )
+    assert r.status_code == 200
+    body = r.json()
+    assert body["status"] == "dismissed"
+    assert body["applied_at"] is None
+    assert body["verified_at"] is None
+
+
+@pytest.mark.asyncio
+async def test_applied_at_auto_stamped_on_first_outcome(
+    client: AsyncClient, test_user, auth_headers, test_db
+):
+    """If applied_at is null when the engineer sets outcome, server stamps it."""
+    session_id, fix_id = await _make_session_with_fix(test_db, test_user)
+    r = await client.patch(
+        f"/api/v1/ai-sessions/{session_id}/suggested-fixes/{fix_id}/outcome",
+        json={"outcome": "applied_success"},
+        headers=auth_headers,
+    )
+    assert r.status_code == 200
+    body = r.json()
+    assert body["applied_at"] is not None
+    assert body["verified_at"] is not None
+
+
+@pytest.mark.asyncio
+async def test_failed_outcome_stores_notes_as_failure_reason(
+    client: AsyncClient, test_user, auth_headers, test_db
+):
+    """applied_failed stores notes under failure_reason (not partial_notes)."""
+    session_id, fix_id = await _make_session_with_fix(test_db, test_user)
+    r = await client.patch(
+        f"/api/v1/ai-sessions/{session_id}/suggested-fixes/{fix_id}/outcome",
+        json={"outcome": "applied_failed", "notes": "user reports no change"},
+        headers=auth_headers,
+    )
+    assert r.status_code == 200
+    body = r.json()
+    assert body["failure_reason"] == "user reports no change"
+    assert body["partial_notes"] is None
diff --git a/docs/FlowAssist_Migration/phase-8-fix-outcome-banner.md b/docs/FlowAssist_Migration/phase-8-fix-outcome-banner.md
index d6451cf0..3f33de3c 100644
--- a/docs/FlowAssist_Migration/phase-8-fix-outcome-banner.md
+++ b/docs/FlowAssist_Migration/phase-8-fix-outcome-banner.md
@@ -238,9 +238,11 @@ class SessionSuggestedFixOutcomeRequest(BaseModel):
     engineer took); outcome captures whether the fix actually worked.
 
     Allowed transitions:
-    - from `proposed`: any of applied_success | applied_failed | applied_partial | dismissed
-    - from `applied_partial`: applied_success | applied_failed  (partial is not terminal)
-    - from any terminal outcome: no change (server returns 409)
+    - from `proposed` or `applied_partial`: any outcome is valid
+      (partial is parked, not terminal — the engineer may update notes,
+      abandon via dismiss, or advance to success/failed)
+    - from any terminal outcome (`applied_success`, `applied_failed`,
+      `dismissed`): server returns 409
     """
     outcome: Literal[
         "applied_success", "applied_failed", "applied_partial", "dismissed"
@@ -769,9 +771,9 @@ Add a new method on `sessionSuggestedFixesApi` (after `recordDecision`):
 ```ts
   /**
    * Record the outcome of applying a suggested fix. Transitions:
-   * - from 'proposed': any non-proposed outcome
-   * - from 'applied_partial': applied_success | applied_failed
-   * - terminal statuses are locked (server returns 409)
+   * - from 'proposed' or 'applied_partial': any outcome is valid
+   *   (partial→partial updates notes, partial→dismissed abandons)
+   * - terminal statuses (applied_success, applied_failed, dismissed) are locked (server returns 409)
    */
   async patchOutcome(
     sessionId: string,