diff --git a/api/core/workflow_copilot/handlers_fix.py b/api/core/workflow_copilot/handlers_fix.py
index 42563c30c04..1e844cbfb81 100644
--- a/api/core/workflow_copilot/handlers_fix.py
+++ b/api/core/workflow_copilot/handlers_fix.py
@@ -41,7 +41,7 @@ from core.workflow_copilot.models import (
     ChangeSet,
     ChecklistError,
     ConversationItem,
-    FixContext,
+    CopilotContext,
     NodeOutput,
     Run,
     Session,
@@ -76,7 +76,7 @@ __all__ = [
 # ---- helpers ---------------------------------------------------------------
 
 
-def append_item(fc: FixContext, kind: str, payload: dict[str, Any]) -> list[ConversationItem]:
+def append_item(fc: CopilotContext, kind: str, payload: dict[str, Any]) -> list[ConversationItem]:
     """Append a conversation item stamped with the next sequence number.
 
     ``fc.next_seq`` is the seq authority (port of ``handlers_fix.go:9-13``):
@@ -90,7 +90,7 @@ def append_item(fc: FixContext, kind: str, payload: dict[str, Any]) -> list[Conv
     return [item]
 
 
-def append_card(fc: FixContext, card) -> list[ConversationItem]:
+def append_card(fc: CopilotContext, card) -> list[ConversationItem]:
     """Stamp a typed card into the conversation at the next seq (mirrors
     append_item's seq authority; at_version preserved as the prior code's 0).
     """
@@ -123,7 +123,7 @@ def _mode_or_default(mode: str) -> str:
 # ---- handlers ---------------------------------------------------------------
 
 
-def handle_diagnose(env: Env, turn: Turn, s: Session, fc: FixContext) -> StepResult:
+def handle_diagnose(env: Env, turn: Turn, s: Session, fc: CopilotContext) -> StepResult:
     """(working) Read the failed run's node outputs, diagnose, capture the
     pre-repair checkpoint. Port of ``handlers_fix.go:38``."""
     failed = env.repo.get_run(fc.failed_run_id)
@@ -153,7 +153,7 @@ def handle_diagnose(env: Env, turn: Turn, s: Session, fc: FixContext) -> StepRes
     )
 
 
-def handle_propose(env: Env, turn: Turn, s: Session, fc: FixContext) -> StepResult:
+def handle_propose(env: Env, turn: Turn, s: Session, fc: CopilotContext) -> StepResult:
     """(working) Ask the agent for repair intents + risk, stage them, branch
     on risk. Port of ``handlers_fix.go:97``. Also serves as
     ``checklist.propose`` (Task 7 reuses this handler, as Go does)."""
@@ -179,7 +179,7 @@ def handle_propose(env: Env, turn: Turn, s: Session, fc: FixContext) -> StepResu
     return StepResult(next=next_state, context=fc, items=items)
 
 
-def handle_await_approval(env: Env, turn: Turn, s: Session, fc: FixContext) -> StepResult:
+def handle_await_approval(env: Env, turn: Turn, s: Session, fc: CopilotContext) -> StepResult:
     """(waiting) High-risk gate. Only an explicit ``approve_repair`` advances
     to ``fix.apply``; any other/absent action kind is a no-op that stays at
     the gate. Port of ``handlers_fix.go:123``."""
@@ -193,7 +193,7 @@ def handle_await_approval(env: Env, turn: Turn, s: Session, fc: FixContext) -> S
     return StepResult(next=PcState.FIX_AWAIT_APPROVAL, context=fc)
 
 
-def handle_apply(env: Env, turn: Turn, s: Session, fc: FixContext) -> StepResult:
+def handle_apply(env: Env, turn: Turn, s: Session, fc: CopilotContext) -> StepResult:
     """(working) Apply the staged repair to the real draft. The next state
     branches on ``fc.source``: the run-fix path always lands at
     ``fix.await_verify``; the checklist-fix path lands at
@@ -222,7 +222,7 @@ def handle_apply(env: Env, turn: Turn, s: Session, fc: FixContext) -> StepResult
     return StepResult(next=next_state, context=fc, items=items)
 
 
-def handle_await_verify(env: Env, turn: Turn, s: Session, fc: FixContext) -> StepResult:
+def handle_await_verify(env: Env, turn: Turn, s: Session, fc: CopilotContext) -> StepResult:
     """(waiting) The user runs verification or undoes. Port of
     ``handlers_fix.go:163``."""
     if turn.action is not None and turn.action.kind == "undo":
@@ -234,7 +234,7 @@ def handle_await_verify(env: Env, turn: Turn, s: Session, fc: FixContext) -> Ste
     return StepResult(next=PcState.FIX_VERIFY, context=fc)
 
 
-def handle_await_testdata(env: Env, turn: Turn, s: Session, fc: FixContext) -> StepResult:
+def handle_await_testdata(env: Env, turn: Turn, s: Session, fc: CopilotContext) -> StepResult:
     """(waiting) Prepare inputs for the verify run. Port of
     ``handlers_fix.go:176``."""
     mode, _ = action_string(turn, "mode")
@@ -254,7 +254,7 @@ def handle_await_testdata(env: Env, turn: Turn, s: Session, fc: FixContext) -> S
     return StepResult(next=PcState.FIX_VERIFY, context=fc)
 
 
-def handle_verify(env: Env, turn: Turn, s: Session, fc: FixContext) -> StepResult:
+def handle_verify(env: Env, turn: Turn, s: Session, fc: CopilotContext) -> StepResult:
     """(working) Run the repaired draft, mint a NEW immutable Run. Advances
     to ``fix.await_decision`` on both pass and fail; never touches the
     original failed run. Port of ``handlers_fix.go:206``."""
@@ -304,7 +304,7 @@ def handle_verify(env: Env, turn: Turn, s: Session, fc: FixContext) -> StepResul
     )
 
 
-def handle_await_decision(env: Env, turn: Turn, s: Session, fc: FixContext) -> StepResult:
+def handle_await_decision(env: Env, turn: Turn, s: Session, fc: CopilotContext) -> StepResult:
     """(waiting) Terminal choice. Port of ``handlers_fix.go:239``."""
     kind = turn.action.kind if turn.action is not None else ""
     if kind == "publish":
@@ -329,7 +329,7 @@ def handle_await_decision(env: Env, turn: Turn, s: Session, fc: FixContext) -> S
     return StepResult(next=PcState.SUCCESS, context=fc, items=items)
 
 
-def handle_publish(env: Env, turn: Turn, s: Session, fc: FixContext) -> StepResult:
+def handle_publish(env: Env, turn: Turn, s: Session, fc: CopilotContext) -> StepResult:
     """(working) Publish the repaired workflow. Port of
     ``handlers_fix.go:316``."""
     env.dify.publish(s.app_id, turn.actor)
@@ -340,7 +340,7 @@ def handle_publish(env: Env, turn: Turn, s: Session, fc: FixContext) -> StepResu
 # ---- checklist handlers -----------------------------------------------------
 
 
-def handle_checklist_diagnose(env: Env, turn: Turn, s: Session, fc: FixContext) -> StepResult:
+def handle_checklist_diagnose(env: Env, turn: Turn, s: Session, fc: CopilotContext) -> StepResult:
     """(working) Mirrors ``handle_diagnose`` but diagnoses from the
     pre-publish checklist's config errors instead of a failed run's node
     outputs — there is no ``fc.failed_run_id`` on this path, so no run
@@ -370,7 +370,7 @@ def handle_checklist_diagnose(env: Env, turn: Turn, s: Session, fc: FixContext)
     )
 
 
-def handle_await_recheck(env: Env, turn: Turn, s: Session, fc: FixContext) -> StepResult:
+def handle_await_recheck(env: Env, turn: Turn, s: Session, fc: CopilotContext) -> StepResult:
     """(waiting) The checklist-fix counterpart of ``handle_await_verify``:
     instead of running the workflow, the caller re-runs the pre-publish
     checklist and reports the result via a ``"recheck"`` action. On ``undo``
diff --git a/api/core/workflow_copilot/models.py b/api/core/workflow_copilot/models.py
index 81ada062cb1..b3f1cf10d58 100644
--- a/api/core/workflow_copilot/models.py
+++ b/api/core/workflow_copilot/models.py
@@ -14,13 +14,13 @@ Deltas from the Go source (per the P1 port plan's Global Constraints / ADR):
   Go test suite constructs these structs: almost every struct literal in
   ``*_test.go`` sets only a handful of fields and relies on Go's implicit
   zero-initialization for the rest (e.g. ``&Session{AppID: "app", ...}``,
-  ``&FixContext{}``, ``&FixContext{FailedRunID: "TR-1"}``). The excepted
+  ``&CopilotContext{}``, ``&CopilotContext{FailedRunID: "TR-1"}``). The excepted
   fields have no meaningful "empty" value (an empty string is not a valid
   ``PcState``/``EntryMode`` member) and are always set explicitly in the Go
   suite, so they stay required here.
 - ``Diagnosis`` / ``Risk`` / ``MutationIntent`` / ``ChangeSet`` / ``NodeEvent``
   / ``ApplyResult`` (Go: ``ports.go``) live here rather than in ``ports.py``.
-  ``FixContext`` embeds ``Diagnosis``/``Risk``/``ChangeSet``/
+  ``CopilotContext`` embeds ``Diagnosis``/``Risk``/``ChangeSet``/
   ``MutationIntent`` directly, and defining them in ``ports.py`` (which
   imports the rest of these models) would create a models<->ports import
   cycle; ``ports.py`` imports them back out of this module instead.
@@ -205,9 +205,16 @@ class ApplyResult:
 
 
 @dataclass(kw_only=True)
-class FixContext:
-    """Per-session working state persisted as the commit context."""
+class CopilotContext:
+    """Per-session working state persisted as the commit context.
 
+    One context type for all entry modes (Fix, checklist, Build, Edit).
+    Fix-specific and Build-specific fields coexist; each scenario touches
+    only its own, all default-valued (serialized as a JSON blob -- no
+    migration on rename or on adding fields).
+    """
+
+    # -- Fix / checklist fields --
     failed_run_id: str = ""
     diagnosis: Diagnosis | None = None
     staged_repair: list[MutationIntent] = field(default_factory=list)
@@ -222,6 +229,14 @@ class FixContext:
     source: str = ""
     checklist_errors: list[ChecklistError] = field(default_factory=list)
 
+    # -- Build fields (Slice 2, additive) --
+    goal_text: str = ""
+    requirements: dict[str, Any] = field(default_factory=dict)
+    plan_items: list[str] = field(default_factory=list)
+    plan_version_tag: str = ""
+    resource_selection: dict[str, Any] = field(default_factory=dict)
+    built_node_ids: list[str] = field(default_factory=list)
+
 
 @dataclass(kw_only=True)
 class Action:
diff --git a/api/core/workflow_copilot/ports.py b/api/core/workflow_copilot/ports.py
index daec254be88..f864ce1451b 100644
--- a/api/core/workflow_copilot/ports.py
+++ b/api/core/workflow_copilot/ports.py
@@ -11,7 +11,7 @@ Deltas from the Go source (per the P1 port plan's Global Constraints / ADR):
 - The value types Go defines in this file (``Diagnosis``, ``Risk``,
   ``MutationIntent``, ``ChangeSet``, ``NodeEvent``, ``ApplyResult``) live in
   ``models.py`` instead, alongside the rest of the domain dataclasses —
-  ``FixContext`` embeds several of them directly, and defining them here
+  ``CopilotContext`` embeds several of them directly, and defining them here
   (where the models are imported) would create a models<->ports import
   cycle. They are re-exported from here for convenience.
 - ``interface`` becomes ``typing.Protocol``, marked ``@runtime_checkable`` so
@@ -29,8 +29,8 @@ from core.workflow_copilot.models import (
     ChecklistError,
     Checkpoint,
     ConversationItem,
+    CopilotContext,
     Diagnosis,
-    FixContext,
     Graph,
     Inputs,
     MutationIntent,
@@ -109,16 +109,16 @@ class Repository(Protocol):
     ``base_version``, else raises ``ConflictError``.
     """
 
-    def create_session(self, session: Session, initial_fc: FixContext, items: list[ConversationItem]) -> None: ...
+    def create_session(self, session: Session, initial_fc: CopilotContext, items: list[ConversationItem]) -> None: ...
 
-    def get_session(self, id: str) -> tuple[Session, FixContext]: ...
+    def get_session(self, id: str) -> tuple[Session, CopilotContext]: ...
 
     def compare_and_advance(
         self,
         session_id: str,
         base_version: int,
         next: PcState,
-        fc: FixContext,
+        fc: CopilotContext,
         items: list[ConversationItem],
     ) -> int: ...
 
diff --git a/api/core/workflow_copilot/runner.py b/api/core/workflow_copilot/runner.py
index d6d45bf4414..3b1bc12d2e0 100644
--- a/api/core/workflow_copilot/runner.py
+++ b/api/core/workflow_copilot/runner.py
@@ -27,7 +27,7 @@ from core.workflow_copilot.errors import ConflictError
 from core.workflow_copilot.models import (
     Checkpoint,
     ConversationItem,
-    FixContext,
+    CopilotContext,
     NodeEvent,
     Run,
     Session,
@@ -61,14 +61,14 @@ class Env:
 @dataclass
 class StepResult:
     next: PcState
-    context: FixContext | None = None
+    context: CopilotContext | None = None
     items: list[ConversationItem] = field(default_factory=list)
     checkpoint: Snapshot | None = None  # if set, persist a checkpoint from this snapshot before advancing
     run: Run | None = None  # if set, persist this run before advancing
     run_id_sink: list[str] | None = None  # internal: runner writes the saved run id to run_id_sink[0]
 
 
-Handler = Callable[[Env, Turn, Session, FixContext], StepResult]
+Handler = Callable[[Env, Turn, Session, CopilotContext], StepResult]
 
 
 class Runner:
diff --git a/api/models/workflow_copilot.py b/api/models/workflow_copilot.py
index 81fc45ffe72..b2a4604edc3 100644
--- a/api/models/workflow_copilot.py
+++ b/api/models/workflow_copilot.py
@@ -46,7 +46,7 @@ class CopilotSessionCommit(Base):
     Copilot Session Commit Model
 
     One immutable row per session version, carrying the serialized
-    `FixContext` (`context`) as of that version. The latest commit by
+    `CopilotContext` (`context`) as of that version. The latest commit by
     `version` for a given `session_id` is the session's current context.
     """
 
diff --git a/api/services/workflow_copilot/repository.py b/api/services/workflow_copilot/repository.py
index af29271a302..3419e42f280 100644
--- a/api/services/workflow_copilot/repository.py
+++ b/api/services/workflow_copilot/repository.py
@@ -30,8 +30,8 @@ from core.workflow_copilot.errors import ConflictError, NotFoundError
 from core.workflow_copilot.models import (
     Checkpoint,
     ConversationItem,
+    CopilotContext,
     EntryMode,
-    FixContext,
     NodeOutput,
     Run,
     Snapshot,
@@ -50,7 +50,7 @@ from models.workflow_copilot import (
     CopilotSnapshot,
     CopilotTestInput,
 )
-from services.workflow_copilot.serde import fix_context_from_dict, fix_context_to_dict
+from services.workflow_copilot.serde import context_from_dict, context_to_dict
 
 __all__ = ["SqlCopilotRepository"]
 
@@ -63,7 +63,7 @@ class SqlCopilotRepository:
 
     # -- sessions --
 
-    def create_session(self, session: DomainSession, initial_fc: FixContext, items: list[ConversationItem]) -> None:
+    def create_session(self, session: DomainSession, initial_fc: CopilotContext, items: list[ConversationItem]) -> None:
         with self._session_factory() as db_session, db_session.begin():
             row = CopilotSession(
                 app_id=session.app_id,
@@ -93,12 +93,12 @@ class SqlCopilotRepository:
                     session_id=row.id,
                     version=1,
                     state=str(session.current_state),
-                    context=fix_context_to_dict(initial_fc),
+                    context=context_to_dict(initial_fc),
                     actor="",
                 )
             )
 
-    def get_session(self, id: str) -> tuple[DomainSession, FixContext]:
+    def get_session(self, id: str) -> tuple[DomainSession, CopilotContext]:
         with self._session_factory() as db_session, db_session.begin():
             row = db_session.get(CopilotSession, id)
             if row is None:
@@ -114,7 +114,7 @@ class SqlCopilotRepository:
             if commit is None:
                 raise NotFoundError(f"no commits found for session {id}")
 
-            fc = fix_context_from_dict(commit.context)
+            fc = context_from_dict(commit.context)
             return self._to_domain_session(row), fc
 
     def compare_and_advance(
@@ -122,7 +122,7 @@ class SqlCopilotRepository:
         session_id: str,
         base_version: int,
         next: PcState,
-        fc: FixContext,
+        fc: CopilotContext,
         items: list[ConversationItem],
     ) -> int:
         new_version = base_version + 1
@@ -145,7 +145,7 @@ class SqlCopilotRepository:
                     session_id=session_id,
                     version=new_version,
                     state=str(next),
-                    context=fix_context_to_dict(fc),
+                    context=context_to_dict(fc),
                     actor="",
                 )
             )
diff --git a/api/services/workflow_copilot/run_mapping.py b/api/services/workflow_copilot/run_mapping.py
index d530d964af3..e4a905f6db2 100644
--- a/api/services/workflow_copilot/run_mapping.py
+++ b/api/services/workflow_copilot/run_mapping.py
@@ -47,7 +47,7 @@ def map_run_result(data: Mapping[str, Any], node_execs: Sequence[Any]) -> Run:
     """Map a blocking ``AppGenerateService.generate`` result into a ``Run``.
 
     ``Run.id`` is deliberately left ``""`` — the caller (``handle_verify``)
-    assigns the id and sets ``FixContext.verify_run_id``, not this function.
+    assigns the id and sets ``CopilotContext.verify_run_id``, not this function.
     """
     if _is_paused_shape(data):
         status = "failed"
diff --git a/api/services/workflow_copilot/serde.py b/api/services/workflow_copilot/serde.py
index 121cb7d5aa0..9e8d1090417 100644
--- a/api/services/workflow_copilot/serde.py
+++ b/api/services/workflow_copilot/serde.py
@@ -1,11 +1,13 @@
-"""Pure JSON (de)serialization for the domain ``FixContext``.
+"""Pure JSON (de)serialization for the domain ``CopilotContext``.
 
-``FixContext`` (see ``core.workflow_copilot.models``) is the per-session
+``CopilotContext`` (see ``core.workflow_copilot.models``) is the per-session
 working state persisted, one row per version, as the ``context`` JSONB
-column on ``workflow_copilot_session_commits`` (P3a Task 4). This module
-has no I/O and no SQLAlchemy dependency -- it only converts between the
-dataclass and a JSON-safe ``dict``, so the SQL repository can hand the dict
-straight to an ``AdjustedJSON`` column and get it back unchanged.
+column on ``workflow_copilot_session_commits``. This module has no I/O and
+no SQLAlchemy dependency -- it only converts between the dataclass and a
+JSON-safe ``dict``, so the SQL repository can hand the dict straight to an
+``AdjustedJSON`` column and get it back unchanged. The on-disk key names are
+unchanged from the pre-rename dataclass form so existing rows deserialize
+as-is.
 """
 
 from dataclasses import asdict
@@ -14,34 +16,31 @@ from typing import Any
 from core.workflow_copilot.models import (
     ChangeSet,
     ChecklistError,
+    CopilotContext,
     Diagnosis,
-    FixContext,
     MutationIntent,
     Risk,
 )
 
 
-def fix_context_to_dict(fc: FixContext) -> dict[str, Any]:
-    """Serialize a ``FixContext`` to a JSON-safe dict.
+def context_to_dict(fc: CopilotContext) -> dict[str, Any]:
+    """Serialize a ``CopilotContext`` to a JSON-safe dict.
 
     ``dataclasses.asdict`` recurses into the nested dataclasses
     (``Diagnosis``, ``MutationIntent``, ``Risk``, ``ChangeSet``,
-    ``ChecklistError``), turning each into a plain dict, and every field on
-    ``FixContext`` and its nested dataclasses is already a
+    ``ChecklistError``), turning each into a plain dict; every field is a
     str/int/bool/list/dict/None -- so the result is JSON-safe as-is.
     """
     return asdict(fc)
 
 
-def fix_context_from_dict(d: dict[str, Any]) -> FixContext:
-    """Rebuild a ``FixContext`` from a dict produced by ``fix_context_to_dict``.
+def context_from_dict(d: dict[str, Any]) -> CopilotContext:
+    """Rebuild a ``CopilotContext`` from a dict produced by ``context_to_dict``.
 
-    Reconstructs the nested dataclasses explicitly rather than splatting
-    ``d`` into ``FixContext(**d)`` -- the nested values are plain dicts (and
-    lists of dicts) after a JSON round-trip and must become the right
-    dataclass instances. Every lookup is defensive (``.get`` with a default
-    matching the ``FixContext``/nested-dataclass field default) so an
-    older or partial dict still yields a valid ``FixContext``.
+    Reconstructs the nested dataclasses explicitly (they are plain dicts
+    after a JSON round-trip). Every lookup is defensive (``.get`` with a
+    default matching the field default) so an older or partial dict still
+    yields a valid ``CopilotContext``.
     """
     diagnosis = Diagnosis(**d["diagnosis"]) if d.get("diagnosis") else None
     staged_repair = [MutationIntent(**m) for m in d.get("staged_repair", [])]
@@ -49,7 +48,7 @@ def fix_context_from_dict(d: dict[str, Any]) -> FixContext:
     change_set = ChangeSet(**d["change_set"]) if d.get("change_set") else None
     checklist_errors = [ChecklistError(**e) for e in d.get("checklist_errors", [])]
 
-    return FixContext(
+    return CopilotContext(
         failed_run_id=d.get("failed_run_id", ""),
         diagnosis=diagnosis,
         staged_repair=staged_repair,
@@ -62,4 +61,10 @@ def fix_context_from_dict(d: dict[str, Any]) -> FixContext:
         next_seq=d.get("next_seq", 0),
         source=d.get("source", ""),
         checklist_errors=checklist_errors,
+        goal_text=d.get("goal_text", ""),
+        requirements=dict(d.get("requirements") or {}),
+        plan_items=list(d.get("plan_items") or []),
+        plan_version_tag=d.get("plan_version_tag", ""),
+        resource_selection=dict(d.get("resource_selection") or {}),
+        built_node_ids=list(d.get("built_node_ids") or []),
     )
diff --git a/api/services/workflow_copilot/service.py b/api/services/workflow_copilot/service.py
index 75051862d50..d9d7c60561b 100644
--- a/api/services/workflow_copilot/service.py
+++ b/api/services/workflow_copilot/service.py
@@ -21,8 +21,8 @@ from core.workflow_copilot.models import (
     Actor,
     ChecklistError,
     ConversationItem,
+    CopilotContext,
     EntryMode,
-    FixContext,
     Run,
     Session,
 )
@@ -223,7 +223,7 @@ class WorkflowCopilotService:
         failed_run: Run | None = None
         if checklist_errors:
             entry_mode, state = EntryMode.FIX_CHECKLIST, PcState.CHECKLIST_DIAGNOSE
-            fc = FixContext(source="checklist", checklist_errors=checklist_errors)
+            fc = CopilotContext(source="checklist", checklist_errors=checklist_errors)
         else:
             entry_mode, state = EntryMode.FIX, PcState.FIX_DIAGNOSE
             failed_run = Run(
@@ -233,7 +233,7 @@ class WorkflowCopilotService:
                 status="failed",
                 immutable=True,
             )
-            fc = FixContext(failed_run_id=failed_run.id, source="run")
+            fc = CopilotContext(failed_run_id=failed_run.id, source="run")
 
         s = Session(
             app_id=app_id,
diff --git a/api/tests/unit_tests/core/workflow_copilot/fakes.py b/api/tests/unit_tests/core/workflow_copilot/fakes.py
index 49b65c012b4..70d8d669cdc 100644
--- a/api/tests/unit_tests/core/workflow_copilot/fakes.py
+++ b/api/tests/unit_tests/core/workflow_copilot/fakes.py
@@ -42,8 +42,8 @@ from core.workflow_copilot.models import (
     ChecklistError,
     Checkpoint,
     ConversationItem,
+    CopilotContext,
     Diagnosis,
-    FixContext,
     Graph,
     Inputs,
     MutationIntent,
@@ -75,7 +75,7 @@ class InMemoryRepository:
     def __init__(self) -> None:
         self._lock = threading.Lock()
         self._sessions: dict[str, Session] = {}
-        self._contexts: dict[str, FixContext] = {}
+        self._contexts: dict[str, CopilotContext] = {}
         self._commits: dict[str, list[int]] = {}
         self._checkpoints: dict[str, Checkpoint] = {}
         self._snapshots: dict[str, Snapshot] = {}
@@ -86,7 +86,7 @@ class InMemoryRepository:
 
     # -- sessions --
 
-    def create_session(self, session: Session, initial_fc: FixContext, items: list[ConversationItem]) -> None:
+    def create_session(self, session: Session, initial_fc: CopilotContext, items: list[ConversationItem]) -> None:
         with self._lock:
             if not session.id:
                 session.id = str(uuid.uuid4())
@@ -109,7 +109,7 @@ class InMemoryRepository:
             self._items[session.id] = copy.deepcopy(items)
             self._used_seqs[session.id] = seqs
 
-    def get_session(self, id: str) -> tuple[Session, FixContext]:
+    def get_session(self, id: str) -> tuple[Session, CopilotContext]:
         with self._lock:
             session = self._sessions.get(id)
             if session is None:
@@ -121,7 +121,7 @@ class InMemoryRepository:
         session_id: str,
         base_version: int,
         next: PcState,
-        fc: FixContext,
+        fc: CopilotContext,
         items: list[ConversationItem],
     ) -> int:
         with self._lock:
diff --git a/api/tests/unit_tests/core/workflow_copilot/test_fakes.py b/api/tests/unit_tests/core/workflow_copilot/test_fakes.py
index cf98664c273..e6053100470 100644
--- a/api/tests/unit_tests/core/workflow_copilot/test_fakes.py
+++ b/api/tests/unit_tests/core/workflow_copilot/test_fakes.py
@@ -16,9 +16,9 @@ from core.workflow_copilot.models import (
     Actor,
     Checkpoint,
     ConversationItem,
+    CopilotContext,
     Diagnosis,
     EntryMode,
-    FixContext,
     MutationIntent,
     Run,
     Session,
@@ -62,7 +62,7 @@ def test_create_session_assigns_id_and_starts_at_version_1():
     repo = InMemoryRepository()
     s = _session()
 
-    repo.create_session(s, FixContext(), [])
+    repo.create_session(s, CopilotContext(), [])
 
     assert s.id != ""
     assert s.version == 1
@@ -75,7 +75,7 @@ def test_create_session_assigns_id_and_starts_at_version_1():
 def test_create_session_sets_next_seq_to_seed_item_count():
     repo = InMemoryRepository()
     s = _session()
-    fc = FixContext()
+    fc = CopilotContext()
     items = [
         ConversationItem(seq=0, kind="run-context", at_version=1),
         ConversationItem(seq=1, kind="user", at_version=1),
@@ -93,7 +93,7 @@ def test_create_session_sets_next_seq_to_seed_item_count():
 def test_create_session_does_not_downgrade_an_already_larger_next_seq():
     repo = InMemoryRepository()
     s = _session()
-    fc = FixContext(next_seq=5)
+    fc = CopilotContext(next_seq=5)
 
     repo.create_session(s, fc, [])
 
@@ -109,7 +109,7 @@ def test_create_session_rejects_duplicate_seq_within_seed_items():
     ]
 
     with pytest.raises(ConflictError):
-        repo.create_session(s, FixContext(), items)
+        repo.create_session(s, CopilotContext(), items)
 
 
 # ---- compare_and_advance: version CAS -------------------------------------
@@ -118,10 +118,10 @@ def test_create_session_rejects_duplicate_seq_within_seed_items():
 def test_compare_and_advance_rejects_stale_base_version():
     repo = InMemoryRepository()
     s = _session()
-    repo.create_session(s, FixContext(), [])
+    repo.create_session(s, CopilotContext(), [])
 
     with pytest.raises(ConflictError):
-        repo.compare_and_advance(s.id, 0, PcState.FIX_PROPOSE, FixContext(), [])
+        repo.compare_and_advance(s.id, 0, PcState.FIX_PROPOSE, CopilotContext(), [])
 
     # Nothing applied.
     stored, _ = repo.get_session(s.id)
@@ -132,13 +132,13 @@ def test_compare_and_advance_rejects_stale_base_version():
 def test_compare_and_advance_accepts_current_version_and_bumps_it():
     repo = InMemoryRepository()
     s = _session()
-    repo.create_session(s, FixContext(), [])
+    repo.create_session(s, CopilotContext(), [])
 
     new_version = repo.compare_and_advance(
         s.id,
         1,
         PcState.FIX_PROPOSE,
-        FixContext(diagnosis=Diagnosis(culprit_node_id="n1")),
+        CopilotContext(diagnosis=Diagnosis(culprit_node_id="n1")),
         [],
     )
 
@@ -154,15 +154,15 @@ def test_compare_and_advance_on_unknown_session_raises_not_found():
     repo = InMemoryRepository()
 
     with pytest.raises(NotFoundError):
-        repo.compare_and_advance("nope", 1, PcState.FIX_PROPOSE, FixContext(), [])
+        repo.compare_and_advance("nope", 1, PcState.FIX_PROPOSE, CopilotContext(), [])
 
 
 def test_compare_and_advance_deep_copies_the_stored_context():
     repo = InMemoryRepository()
     s = _session()
-    repo.create_session(s, FixContext(), [])
+    repo.create_session(s, CopilotContext(), [])
 
-    fc = FixContext(staged_repair=[MutationIntent(op="set_node_config")])
+    fc = CopilotContext(staged_repair=[MutationIntent(op="set_node_config")])
     repo.compare_and_advance(s.id, 1, PcState.FIX_APPLY, fc, [])
 
     # Mutating the caller's fc after the commit must not affect stored state.
@@ -179,7 +179,7 @@ def test_compare_and_advance_deep_copies_the_stored_context():
 def test_compare_and_advance_rejects_duplicate_seq_within_one_batch():
     repo = InMemoryRepository()
     s = _session()
-    repo.create_session(s, FixContext(), [])
+    repo.create_session(s, CopilotContext(), [])
 
     dup_items = [
         ConversationItem(seq=0, kind="a", at_version=2),
@@ -187,7 +187,7 @@ def test_compare_and_advance_rejects_duplicate_seq_within_one_batch():
     ]
 
     with pytest.raises(ConflictError):
-        repo.compare_and_advance(s.id, 1, PcState.FIX_PROPOSE, FixContext(), dup_items)
+        repo.compare_and_advance(s.id, 1, PcState.FIX_PROPOSE, CopilotContext(), dup_items)
 
     # Nothing applied: neither version nor conversation items advanced.
     stored, _ = repo.get_session(s.id)
@@ -198,14 +198,14 @@ def test_compare_and_advance_rejects_duplicate_seq_within_one_batch():
 def test_compare_and_advance_rejects_seq_reused_from_a_previous_commit():
     repo = InMemoryRepository()
     s = _session()
-    repo.create_session(s, FixContext(), [ConversationItem(seq=0, kind="run-context", at_version=1)])
+    repo.create_session(s, CopilotContext(), [ConversationItem(seq=0, kind="run-context", at_version=1)])
 
     with pytest.raises(ConflictError):
         repo.compare_and_advance(
             s.id,
             1,
             PcState.FIX_PROPOSE,
-            FixContext(),
+            CopilotContext(),
             [ConversationItem(seq=0, kind="user", at_version=2)],
         )
 
@@ -217,13 +217,13 @@ def test_compare_and_advance_rejects_seq_reused_from_a_previous_commit():
 def test_compare_and_advance_accepts_the_next_seq_in_order():
     repo = InMemoryRepository()
     s = _session()
-    repo.create_session(s, FixContext(), [ConversationItem(seq=0, kind="run-context", at_version=1)])
+    repo.create_session(s, CopilotContext(), [ConversationItem(seq=0, kind="run-context", at_version=1)])
 
     repo.compare_and_advance(
         s.id,
         1,
         PcState.FIX_PROPOSE,
-        FixContext(),
+        CopilotContext(),
         [ConversationItem(seq=1, kind="user", at_version=2)],
     )
 
diff --git a/api/tests/unit_tests/core/workflow_copilot/test_fix_flow.py b/api/tests/unit_tests/core/workflow_copilot/test_fix_flow.py
index dbf2b8425ae..bec1d3fada3 100644
--- a/api/tests/unit_tests/core/workflow_copilot/test_fix_flow.py
+++ b/api/tests/unit_tests/core/workflow_copilot/test_fix_flow.py
@@ -24,8 +24,8 @@ from core.workflow_copilot.models import (
     Actor,
     ChecklistError,
     ConversationItem,
+    CopilotContext,
     EntryMode,
-    FixContext,
     Run,
     Session,
     Turn,
@@ -66,12 +66,12 @@ def _fix_session(**overrides) -> Session:
 
 def _seed_fix_session(repo: InMemoryRepository) -> Session:
     """Seed a session at fix.diagnose with a run-context item and a
-    FixContext pointing at a pre-existing failed run. The Fix flow diagnoses
+    CopilotContext pointing at a pre-existing failed run. The Fix flow diagnoses
     from this already-ingested "red" run; it never re-runs it."""
     s = _fix_session()
     repo.create_session(
         s,
-        FixContext(failed_run_id="TR-1"),
+        CopilotContext(failed_run_id="TR-1"),
         [ConversationItem(kind="run-context", seq=0, payload={"failed_run_id": "TR-1"})],
     )
     repo.save_run(s.id, Run(id="TR-1", kind="original-failed", status="failed", immutable=True))
@@ -219,7 +219,7 @@ def _seed_checklist_session(repo: InMemoryRepository, errors: list[ChecklistErro
     s = _fix_session(entry_mode=EntryMode.FIX_CHECKLIST, current_state=PcState.CHECKLIST_DIAGNOSE)
     repo.create_session(
         s,
-        FixContext(source="checklist", checklist_errors=errors),
+        CopilotContext(source="checklist", checklist_errors=errors),
         [ConversationItem(kind="run-context", seq=0)],
     )
     return s
diff --git a/api/tests/unit_tests/core/workflow_copilot/test_handlers_fix.py b/api/tests/unit_tests/core/workflow_copilot/test_handlers_fix.py
index 5fd924ca9f5..7c568d3d4ae 100644
--- a/api/tests/unit_tests/core/workflow_copilot/test_handlers_fix.py
+++ b/api/tests/unit_tests/core/workflow_copilot/test_handlers_fix.py
@@ -24,8 +24,8 @@ from core.workflow_copilot.models import (
     Actor,
     ChecklistError,
     ConversationItem,
+    CopilotContext,
     EntryMode,
-    FixContext,
     Run,
     Session,
     Turn,
@@ -81,7 +81,7 @@ def _run_fix_registry() -> dict[PcState, object]:
 
 def _seed_diagnose_session(repo: InMemoryRepository) -> Session:
     s = _session()
-    repo.create_session(s, FixContext(failed_run_id="TR-1"), [ConversationItem(kind="run-context", seq=0)])
+    repo.create_session(s, CopilotContext(failed_run_id="TR-1"), [ConversationItem(kind="run-context", seq=0)])
     repo.save_run(s.id, Run(id="TR-1", kind="original-failed", status="failed", immutable=True))
     return s
 
@@ -374,7 +374,7 @@ def _seed_checklist_session(repo: InMemoryRepository, errors: list[ChecklistErro
     s = _session(entry_mode=EntryMode.FIX_CHECKLIST, current_state=PcState.CHECKLIST_DIAGNOSE)
     repo.create_session(
         s,
-        FixContext(source="checklist", checklist_errors=errors),
+        CopilotContext(source="checklist", checklist_errors=errors),
         [ConversationItem(kind="run-context", seq=0)],
     )
     return s
diff --git a/api/tests/unit_tests/core/workflow_copilot/test_models.py b/api/tests/unit_tests/core/workflow_copilot/test_models.py
index 05698a1da03..17965c08e06 100644
--- a/api/tests/unit_tests/core/workflow_copilot/test_models.py
+++ b/api/tests/unit_tests/core/workflow_copilot/test_models.py
@@ -6,7 +6,7 @@ these structs (see e.g. handlers_fix_test.go, runner_test.go): almost every
 struct literal in that suite sets only a handful of fields and relies on
 Go's implicit zero-initialization for the rest (``&Session{AppID: "app",
 TenantID: "t", OwnerAccountID: "u", EntryMode: EntryModeFix, CurrentState:
-FixDiagnose}``, ``&FixContext{}``, ``&FixContext{FailedRunID: "TR-1"}``).
+FixDiagnose}``, ``&CopilotContext{}``, ``&CopilotContext{FailedRunID: "TR-1"}``).
 These tests port that same terse-construction ergonomics and assert the
 Python defaults match the Go zero values field-for-field.
 """
@@ -19,8 +19,8 @@ from core.workflow_copilot.models import (
     ChecklistError,
     Checkpoint,
     ConversationItem,
+    CopilotContext,
     EntryMode,
-    FixContext,
     NodeOutput,
     Run,
     Session,
@@ -162,8 +162,8 @@ def test_conversation_item_defaults():
 
 
 def test_fix_context_round_trip_defaults_empty():
-    # Mirrors runner_test.go: repo.CreateSession(..., &FixContext{}, nil)
-    fc = FixContext()
+    # Mirrors runner_test.go: repo.CreateSession(..., &CopilotContext{}, nil)
+    fc = CopilotContext()
     assert fc.failed_run_id == ""
     assert fc.diagnosis is None
     assert fc.staged_repair == []
@@ -179,14 +179,14 @@ def test_fix_context_round_trip_defaults_empty():
 
 
 def test_fix_context_partial_construction():
-    # Mirrors handlers_fix_test.go: &FixContext{FailedRunID: "TR-1"}
-    fc = FixContext(failed_run_id="TR-1")
+    # Mirrors handlers_fix_test.go: &CopilotContext{FailedRunID: "TR-1"}
+    fc = CopilotContext(failed_run_id="TR-1")
     assert fc.failed_run_id == "TR-1"
     assert fc.source == ""
 
-    # Mirrors handlers_fix_test.go: &FixContext{Source: "checklist", ChecklistErrors: errs}
+    # Mirrors handlers_fix_test.go: &CopilotContext{Source: "checklist", ChecklistErrors: errs}
     errs = [ChecklistError(node_id="n1", unconnected=True)]
-    fc2 = FixContext(source="checklist", checklist_errors=errs)
+    fc2 = CopilotContext(source="checklist", checklist_errors=errs)
     assert fc2.source == "checklist"
     assert fc2.checklist_errors == errs
     assert fc2.failed_run_id == ""
diff --git a/api/tests/unit_tests/core/workflow_copilot/test_ports.py b/api/tests/unit_tests/core/workflow_copilot/test_ports.py
index f27856d356d..8b252e7b4a5 100644
--- a/api/tests/unit_tests/core/workflow_copilot/test_ports.py
+++ b/api/tests/unit_tests/core/workflow_copilot/test_ports.py
@@ -14,8 +14,8 @@ from core.workflow_copilot.models import (
     Actor,
     ApplyResult,
     ChangeSet,
+    CopilotContext,
     Diagnosis,
-    FixContext,
     MutationIntent,
     NodeEvent,
     Risk,
@@ -86,7 +86,7 @@ def test_apply_result_defaults_and_changed_nodes_not_shared():
 
 
 def test_fix_context_embeds_the_tightened_value_types():
-    fc = FixContext(
+    fc = CopilotContext(
         diagnosis=Diagnosis(culprit_node_id="n1"),
         staged_repair=[MutationIntent(op="set_node_config")],
         risk=Risk(level="low"),
diff --git a/api/tests/unit_tests/core/workflow_copilot/test_runner.py b/api/tests/unit_tests/core/workflow_copilot/test_runner.py
index e80ac03e56a..b04f1058f64 100644
--- a/api/tests/unit_tests/core/workflow_copilot/test_runner.py
+++ b/api/tests/unit_tests/core/workflow_copilot/test_runner.py
@@ -10,7 +10,7 @@ from datetime import datetime
 import pytest
 
 from core.workflow_copilot.errors import ConflictError
-from core.workflow_copilot.models import Action, Actor, EntryMode, FixContext, Session, Turn
+from core.workflow_copilot.models import Action, Actor, CopilotContext, EntryMode, Session, Turn
 from core.workflow_copilot.runner import Env, Runner, StepResult
 from core.workflow_copilot.state import PcState
 from tests.unit_tests.core.workflow_copilot.fakes import FakeDifyPort, InMemoryRepository, StubAgent
@@ -36,7 +36,7 @@ def _toy_registry() -> dict[PcState, object]:
     """A working -> waiting toy machine: FIX_DIAGNOSE auto-advances to
     FIX_AWAIT_APPROVAL (a waiting state), where the loop stops."""
 
-    def diagnose(_env: Env, _turn: Turn, _s: Session, fc: FixContext) -> StepResult:
+    def diagnose(_env: Env, _turn: Turn, _s: Session, fc: CopilotContext) -> StepResult:
         return StepResult(next=PcState.FIX_AWAIT_APPROVAL, context=fc)
 
     return {PcState.FIX_DIAGNOSE: diagnose}
@@ -56,7 +56,7 @@ def _new_env() -> tuple[Env, InMemoryRepository]:
 def test_advance_commits_each_transition_and_stops_at_waiting():
     env, repo = _new_env()
     s = _session()
-    repo.create_session(s, FixContext(), [])
+    repo.create_session(s, CopilotContext(), [])
 
     runner = Runner(env, _toy_registry())
     turn = Turn(action=Action(kind="request_fix", base_version=1), actor=_actor())
@@ -73,7 +73,7 @@ def test_advance_commits_each_transition_and_stops_at_waiting():
 def test_advance_stale_base_version_raises_conflict_with_nothing_applied():
     env, repo = _new_env()
     s = _session()
-    repo.create_session(s, FixContext(), [])
+    repo.create_session(s, CopilotContext(), [])
 
     runner = Runner(env, _toy_registry())
     turn = Turn(action=Action(kind="request_fix", base_version=99), actor=_actor())
@@ -90,7 +90,7 @@ def test_advance_stale_base_version_raises_conflict_with_nothing_applied():
 def test_advance_missing_handler_raises():
     env, repo = _new_env()
     s = _session()
-    repo.create_session(s, FixContext(), [])
+    repo.create_session(s, CopilotContext(), [])
 
     runner = Runner(env, {})  # empty registry: no handler for FIX_DIAGNOSE
     turn = Turn(action=Action(kind="request_fix", base_version=1), actor=_actor())
@@ -102,7 +102,7 @@ def test_advance_missing_handler_raises():
 def test_advance_missing_handler_error_message_names_the_state():
     env, repo = _new_env()
     s = _session()
-    repo.create_session(s, FixContext(), [])
+    repo.create_session(s, CopilotContext(), [])
 
     runner = Runner(env, {})
     turn = Turn(action=Action(kind="request_fix", base_version=1), actor=_actor())
@@ -114,7 +114,7 @@ def test_advance_missing_handler_error_message_names_the_state():
 def test_advance_waiting_state_first_turn_no_action_returns_session_unchanged():
     env, repo = _new_env()
     s = _session(current_state=PcState.FIX_AWAIT_APPROVAL)
-    repo.create_session(s, FixContext(), [])
+    repo.create_session(s, CopilotContext(), [])
 
     runner = Runner(env, {})  # never consulted: loop returns before handler lookup
     turn = Turn(actor=_actor())  # no action
@@ -127,7 +127,7 @@ def test_advance_waiting_state_first_turn_no_action_returns_session_unchanged():
 def test_advance_terminal_state_returns_session_unchanged():
     env, repo = _new_env()
     s = _session(current_state=PcState.SUCCESS)
-    repo.create_session(s, FixContext(), [])
+    repo.create_session(s, CopilotContext(), [])
 
     runner = Runner(env, {})  # never consulted: terminal short-circuits first
     turn = Turn(actor=_actor())
@@ -143,15 +143,15 @@ def test_advance_passes_full_turn_to_first_step_and_actor_only_turn_to_subsequen
     handler must see a Turn with Action consumed (None) but the same Actor."""
     env, repo = _new_env()
     s = _session()
-    repo.create_session(s, FixContext(), [])
+    repo.create_session(s, CopilotContext(), [])
 
     seen_turns: list[Turn] = []
 
-    def diagnose(_env: Env, turn: Turn, _s: Session, fc: FixContext) -> StepResult:
+    def diagnose(_env: Env, turn: Turn, _s: Session, fc: CopilotContext) -> StepResult:
         seen_turns.append(turn)
         return StepResult(next=PcState.FIX_PROPOSE, context=fc)
 
-    def propose(_env: Env, turn: Turn, _s: Session, fc: FixContext) -> StepResult:
+    def propose(_env: Env, turn: Turn, _s: Session, fc: CopilotContext) -> StepResult:
         seen_turns.append(turn)
         return StepResult(next=PcState.FIX_AWAIT_APPROVAL, context=fc)
 
diff --git a/api/tests/unit_tests/services/workflow_copilot/test_advance_task.py b/api/tests/unit_tests/services/workflow_copilot/test_advance_task.py
index 87429eaf8bd..287ee1858a1 100644
--- a/api/tests/unit_tests/services/workflow_copilot/test_advance_task.py
+++ b/api/tests/unit_tests/services/workflow_copilot/test_advance_task.py
@@ -21,7 +21,7 @@ from sqlalchemy.engine import Engine
 from sqlalchemy.orm import sessionmaker
 
 import tasks.workflow_copilot_advance_task as mod
-from core.workflow_copilot.models import ConversationItem, EntryMode, FixContext, Run, Session
+from core.workflow_copilot.models import ConversationItem, CopilotContext, EntryMode, Run, Session
 from core.workflow_copilot.state import PcState
 from models.base import Base
 from services.workflow_copilot.repository import SqlCopilotRepository
@@ -55,7 +55,7 @@ def _seed_fix_session(repo: SqlCopilotRepository) -> Session:
     )
     repo.create_session(
         s,
-        FixContext(failed_run_id="TR-1"),
+        CopilotContext(failed_run_id="TR-1"),
         [ConversationItem(kind="run-context", seq=0)],
     )
     repo.save_run(s.id, Run(id="TR-1", kind="original-failed", status="failed", immutable=True))
diff --git a/api/tests/unit_tests/services/workflow_copilot/test_async_flow.py b/api/tests/unit_tests/services/workflow_copilot/test_async_flow.py
index a7fa58eeb4e..787112cca88 100644
--- a/api/tests/unit_tests/services/workflow_copilot/test_async_flow.py
+++ b/api/tests/unit_tests/services/workflow_copilot/test_async_flow.py
@@ -29,7 +29,7 @@ from sqlalchemy.orm import sessionmaker
 
 import tasks.workflow_copilot_advance_task as task_mod
 from core.workflow_copilot.errors import BusyError
-from core.workflow_copilot.models import Action, Actor, ConversationItem, EntryMode, FixContext, Run, Session
+from core.workflow_copilot.models import Action, Actor, ConversationItem, CopilotContext, EntryMode, Run, Session
 from core.workflow_copilot.state import PcState
 from models.base import Base
 from services.workflow_copilot import session_lock
@@ -170,7 +170,7 @@ def test_submit_action_while_lock_held_raises_busy_eager_async(
         entry_mode=EntryMode.FIX,
         current_state=PcState.FIX_DIAGNOSE,
     )
-    repo.create_session(s, FixContext(failed_run_id="TR-1"), [ConversationItem(kind="run-context", seq=0)])
+    repo.create_session(s, CopilotContext(failed_run_id="TR-1"), [ConversationItem(kind="run-context", seq=0)])
 
     # Manually hold the lock, simulating an in-flight advance on another
     # worker.
diff --git a/api/tests/unit_tests/services/workflow_copilot/test_engine_on_sql_repo.py b/api/tests/unit_tests/services/workflow_copilot/test_engine_on_sql_repo.py
index 1e68bc81b25..64b2252fdf2 100644
--- a/api/tests/unit_tests/services/workflow_copilot/test_engine_on_sql_repo.py
+++ b/api/tests/unit_tests/services/workflow_copilot/test_engine_on_sql_repo.py
@@ -28,8 +28,8 @@ from core.workflow_copilot.models import (
     Actor,
     ChecklistError,
     ConversationItem,
+    CopilotContext,
     EntryMode,
-    FixContext,
     Run,
     Session,
     Turn,
@@ -87,13 +87,13 @@ def _fix_session(**overrides) -> Session:
 
 def _seed_fix_session(repo: SqlCopilotRepository) -> Session:
     """Seed a session at fix.diagnose with a run-context item and a
-    FixContext pointing at a pre-existing failed run -- mirrors the P1
+    CopilotContext pointing at a pre-existing failed run -- mirrors the P1
     full-flow acceptance's seed, persisted through the SQL repo instead of
     the in-memory fake."""
     s = _fix_session()
     repo.create_session(
         s,
-        FixContext(failed_run_id="TR-1"),
+        CopilotContext(failed_run_id="TR-1"),
         [ConversationItem(kind="run-context", seq=0, payload={"failed_run_id": "TR-1"})],
     )
     repo.save_run(s.id, Run(id="TR-1", kind="original-failed", status="failed", immutable=True))
@@ -244,7 +244,7 @@ def _seed_checklist_session(repo: SqlCopilotRepository, errors: list[ChecklistEr
     s = _fix_session(entry_mode=EntryMode.FIX_CHECKLIST, current_state=PcState.CHECKLIST_DIAGNOSE)
     repo.create_session(
         s,
-        FixContext(source="checklist", checklist_errors=errors),
+        CopilotContext(source="checklist", checklist_errors=errors),
         [ConversationItem(kind="run-context", seq=0)],
     )
     return s
diff --git a/api/tests/unit_tests/services/workflow_copilot/test_reconcile.py b/api/tests/unit_tests/services/workflow_copilot/test_reconcile.py
index e2ea51a9cae..d5a0f493108 100644
--- a/api/tests/unit_tests/services/workflow_copilot/test_reconcile.py
+++ b/api/tests/unit_tests/services/workflow_copilot/test_reconcile.py
@@ -24,7 +24,7 @@ from sqlalchemy.orm import sessionmaker
 
 import schedule.workflow_copilot_reconcile_task as mod
 from configs import dify_config
-from core.workflow_copilot.models import ConversationItem, EntryMode, FixContext, Session
+from core.workflow_copilot.models import ConversationItem, CopilotContext, EntryMode, Session
 from core.workflow_copilot.state import PcState
 from libs.datetime_utils import naive_utc_now
 from models.base import Base
@@ -63,7 +63,7 @@ def _seed(repo: SqlCopilotRepository, state: PcState) -> Session:
         entry_mode=EntryMode.FIX,
         current_state=state,
     )
-    repo.create_session(s, FixContext(), [ConversationItem(kind="run-context", seq=0)])
+    repo.create_session(s, CopilotContext(), [ConversationItem(kind="run-context", seq=0)])
     return s
 
 
diff --git a/api/tests/unit_tests/services/workflow_copilot/test_repository.py b/api/tests/unit_tests/services/workflow_copilot/test_repository.py
index cf8b01112c9..367470db2b4 100644
--- a/api/tests/unit_tests/services/workflow_copilot/test_repository.py
+++ b/api/tests/unit_tests/services/workflow_copilot/test_repository.py
@@ -19,8 +19,8 @@ from core.workflow_copilot.errors import ConflictError, NotFoundError
 from core.workflow_copilot.models import (
     Checkpoint,
     ConversationItem,
+    CopilotContext,
     EntryMode,
-    FixContext,
     MutationIntent,
     NodeOutput,
     Run,
@@ -67,7 +67,7 @@ def _make_domain_session(**overrides) -> DomainSession:
 
 def test_create_session_then_get_session_round_trips(repo: SqlCopilotRepository) -> None:
     domain_session = _make_domain_session()
-    fc = FixContext(failed_run_id="TR-1")
+    fc = CopilotContext(failed_run_id="TR-1")
     items = [
         ConversationItem(seq=0, kind="run-context", payload={"a": 1}, at_version=1),
         ConversationItem(seq=1, kind="assistant-turn", payload={"b": 2}, at_version=1),
@@ -90,7 +90,7 @@ def test_create_session_then_get_session_round_trips(repo: SqlCopilotRepository)
     assert loaded_session.entry_mode == EntryMode.FIX
     assert loaded_session.current_state == PcState.FIX_DIAGNOSE
     assert loaded_session.version == 1
-    assert loaded_fc == FixContext(failed_run_id="TR-1", next_seq=2)
+    assert loaded_fc == CopilotContext(failed_run_id="TR-1", next_seq=2)
 
 
 def test_get_session_missing_id_raises_not_found(repo: SqlCopilotRepository) -> None:
@@ -100,10 +100,10 @@ def test_get_session_missing_id_raises_not_found(repo: SqlCopilotRepository) ->
 
 def test_compare_and_advance_bumps_version_and_appends_commit_and_items(repo: SqlCopilotRepository) -> None:
     domain_session = _make_domain_session()
-    fc = FixContext(failed_run_id="TR-1")
+    fc = CopilotContext(failed_run_id="TR-1")
     repo.create_session(domain_session, fc, [])
 
-    next_fc = FixContext(failed_run_id="TR-1", staged_repair=[MutationIntent(op="set_node_config")])
+    next_fc = CopilotContext(failed_run_id="TR-1", staged_repair=[MutationIntent(op="set_node_config")])
     new_items = [ConversationItem(seq=0, kind="diagnosis", payload={"x": 1}, at_version=2)]
 
     new_version = repo.compare_and_advance(
@@ -122,7 +122,7 @@ def test_compare_and_advance_stale_version_raises_conflict_and_leaves_row_unchan
     repo: SqlCopilotRepository,
 ) -> None:
     domain_session = _make_domain_session()
-    fc = FixContext(failed_run_id="TR-1")
+    fc = CopilotContext(failed_run_id="TR-1")
     repo.create_session(domain_session, fc, [])
 
     with pytest.raises(ConflictError):
@@ -130,7 +130,7 @@ def test_compare_and_advance_stale_version_raises_conflict_and_leaves_row_unchan
             domain_session.id,
             base_version=999,
             next=PcState.FIX_PROPOSE,
-            fc=FixContext(),
+            fc=CopilotContext(),
             items=[],
         )
 
@@ -146,14 +146,14 @@ def test_compare_and_advance_missing_session_raises_not_found(repo: SqlCopilotRe
             "does-not-exist",
             base_version=1,
             next=PcState.FIX_PROPOSE,
-            fc=FixContext(),
+            fc=CopilotContext(),
             items=[],
         )
 
 
 def test_compare_and_advance_duplicate_seq_raises_conflict(repo: SqlCopilotRepository) -> None:
     domain_session = _make_domain_session()
-    fc = FixContext(failed_run_id="TR-1")
+    fc = CopilotContext(failed_run_id="TR-1")
     seed_items = [ConversationItem(seq=0, kind="run-context", payload={}, at_version=1)]
     repo.create_session(domain_session, fc, seed_items)
 
@@ -162,7 +162,7 @@ def test_compare_and_advance_duplicate_seq_raises_conflict(repo: SqlCopilotRepos
             domain_session.id,
             base_version=1,
             next=PcState.FIX_PROPOSE,
-            fc=FixContext(),
+            fc=CopilotContext(),
             items=[ConversationItem(seq=0, kind="diagnosis", payload={}, at_version=2)],
         )
 
@@ -177,7 +177,7 @@ def test_compare_and_advance_duplicate_seq_raises_conflict(repo: SqlCopilotRepos
 
 def test_create_checkpoint_then_get_checkpoint_round_trips(repo: SqlCopilotRepository) -> None:
     domain_session = _make_domain_session()
-    fc = FixContext(failed_run_id="TR-1")
+    fc = CopilotContext(failed_run_id="TR-1")
     repo.create_session(domain_session, fc, [])
 
     snap = Snapshot(session_id=domain_session.id, hash="h1", graph={"nodes": [1, 2, 3]})
@@ -290,7 +290,7 @@ def test_get_test_input_missing_id_raises_not_found(repo: SqlCopilotRepository)
 
 def test_list_conversation_returns_items_ordered_by_seq(repo: SqlCopilotRepository) -> None:
     domain_session = _make_domain_session()
-    fc = FixContext(failed_run_id="TR-1")
+    fc = CopilotContext(failed_run_id="TR-1")
     items = [
         ConversationItem(seq=0, kind="run-context", payload={"a": 1}, at_version=1),
         ConversationItem(seq=1, kind="assistant-turn", payload={"b": 2}, at_version=1),
@@ -299,7 +299,7 @@ def test_list_conversation_returns_items_ordered_by_seq(repo: SqlCopilotReposito
 
     more_items = [ConversationItem(seq=2, kind="diagnosis", payload={"c": 3}, at_version=2)]
     repo.compare_and_advance(
-        domain_session.id, base_version=1, next=PcState.FIX_PROPOSE, fc=FixContext(), items=more_items
+        domain_session.id, base_version=1, next=PcState.FIX_PROPOSE, fc=CopilotContext(), items=more_items
     )
 
     conv = repo.list_conversation(domain_session.id)
diff --git a/api/tests/unit_tests/services/workflow_copilot/test_serde.py b/api/tests/unit_tests/services/workflow_copilot/test_serde.py
index 052207e2bab..1263e4450e8 100644
--- a/api/tests/unit_tests/services/workflow_copilot/test_serde.py
+++ b/api/tests/unit_tests/services/workflow_copilot/test_serde.py
@@ -1,6 +1,6 @@
-"""Round-trip tests for the ``FixContext`` JSON (de)serializer.
+"""Round-trip tests for the ``CopilotContext`` JSON (de)serializer.
 
-``FixContext`` is the per-session working state persisted as the
+``CopilotContext`` is the per-session working state persisted as the
 ``context`` JSONB column on ``workflow_copilot_session_commits`` (P3a Task 4).
 This module verifies the pure (de)serializer is lossless and produces a
 JSON-safe dict, independent of any database concern.
@@ -11,16 +11,16 @@ import json
 from core.workflow_copilot.models import (
     ChangeSet,
     ChecklistError,
+    CopilotContext,
     Diagnosis,
-    FixContext,
     MutationIntent,
     Risk,
 )
-from services.workflow_copilot.serde import fix_context_from_dict, fix_context_to_dict
+from services.workflow_copilot.serde import context_from_dict, context_to_dict
 
 
-def _full_fix_context() -> FixContext:
-    return FixContext(
+def _full_fix_context() -> CopilotContext:
+    return CopilotContext(
         failed_run_id="TR-1",
         diagnosis=Diagnosis(
             culprit_node_id="n1",
@@ -57,15 +57,15 @@ def _full_fix_context() -> FixContext:
 def test_fully_populated_fix_context_round_trips():
     fc = _full_fix_context()
 
-    result = fix_context_from_dict(fix_context_to_dict(fc))
+    result = context_from_dict(context_to_dict(fc))
 
     assert result == fc
 
 
 def test_empty_fix_context_round_trips():
-    fc = FixContext()
+    fc = CopilotContext()
 
-    result = fix_context_from_dict(fix_context_to_dict(fc))
+    result = context_from_dict(context_to_dict(fc))
 
     assert result == fc
 
@@ -73,7 +73,7 @@ def test_empty_fix_context_round_trips():
 def test_to_dict_output_is_json_serializable():
     fc = _full_fix_context()
 
-    d = fix_context_to_dict(fc)
+    d = context_to_dict(fc)
 
     # Must not raise -- this is what actually lands in the JSONB column.
     json.dumps(d)
@@ -83,6 +83,33 @@ def test_from_dict_tolerates_missing_optional_keys():
     # An older/partial persisted dict -- only a subset of keys present.
     d = {"failed_run_id": "TR-9"}
 
-    fc = fix_context_from_dict(d)
+    fc = context_from_dict(d)
 
-    assert fc == FixContext(failed_run_id="TR-9")
+    assert fc == CopilotContext(failed_run_id="TR-9")
+
+
+def test_context_round_trips_build_fields():
+    from core.workflow_copilot.models import CopilotContext
+    from services.workflow_copilot.serde import context_from_dict, context_to_dict
+
+    fc = CopilotContext(
+        goal_text="Build a quarterly report workflow",
+        requirements={"currency": "USD", "prefer_audited": True},
+        plan_items=["Retrieve", "Summarize", "Emit"],
+        plan_version_tag="v2",
+        resource_selection={"resource_ids": ["kb-company"], "conflict_policy": "audited"},
+        built_node_ids=["start", "llm", "end"],
+    )
+    out = context_from_dict(context_to_dict(fc))
+    assert out == fc
+
+
+def test_context_from_dict_defaults_build_fields_when_absent():
+    from core.workflow_copilot.models import CopilotContext
+    from services.workflow_copilot.serde import context_from_dict
+
+    fc = context_from_dict({"failed_run_id": "TR-9"})
+    assert fc == CopilotContext(failed_run_id="TR-9")
+    assert fc.goal_text == ""
+    assert fc.requirements == {}
+    assert fc.plan_items == []
diff --git a/api/tests/unit_tests/services/workflow_copilot/test_service.py b/api/tests/unit_tests/services/workflow_copilot/test_service.py
index a0be009eb94..429e973b79c 100644
--- a/api/tests/unit_tests/services/workflow_copilot/test_service.py
+++ b/api/tests/unit_tests/services/workflow_copilot/test_service.py
@@ -21,8 +21,8 @@ from core.workflow_copilot.models import (
     Actor,
     ChecklistError,
     ConversationItem,
+    CopilotContext,
     EntryMode,
-    FixContext,
     Session,
 )
 from core.workflow_copilot.state import PcState
@@ -251,7 +251,7 @@ def _seed_free_session(repo: SqlCopilotRepository) -> Session:
         entry_mode=EntryMode.FIX,
         current_state=PcState.FIX_DIAGNOSE,
     )
-    repo.create_session(s, FixContext(failed_run_id="TR-1"), [ConversationItem(kind="run-context", seq=0)])
+    repo.create_session(s, CopilotContext(failed_run_id="TR-1"), [ConversationItem(kind="run-context", seq=0)])
     return s
 
 
@@ -266,7 +266,7 @@ def _seed_session_at(repo: SqlCopilotRepository, state: PcState) -> Session:
         entry_mode=EntryMode.FIX,
         current_state=state,
     )
-    repo.create_session(s, FixContext(failed_run_id="TR-1"), [ConversationItem(kind="run-context", seq=0)])
+    repo.create_session(s, CopilotContext(failed_run_id="TR-1"), [ConversationItem(kind="run-context", seq=0)])
     return s