From aa2eb572a373400b5549ac544c4f9a5febb5717e Mon Sep 17 00:00:00 2001
From: Michael Chou <michael.chou@scale.com>
Date: Wed, 10 Jun 2026 16:01:13 -0700
Subject: [PATCH 1/4] update task params in db; send temporal signal to
 workflow

---
 agentex/openapi.yaml                          | 78 +++++++++++++++++++
 agentex/src/api/routes/tasks.py               | 27 +++++++
 agentex/src/api/schemas/tasks.py              | 32 ++++++++
 .../domain/repositories/task_repository.py    | 42 +++++++++-
 agentex/src/domain/services/task_service.py   | 10 +++
 .../src/domain/use_cases/tasks_use_case.py    | 46 +++++++++++
 6 files changed, 234 insertions(+), 1 deletion(-)

diff --git a/agentex/openapi.yaml b/agentex/openapi.yaml
index b122020e..0ad7f0fb 100644
--- a/agentex/openapi.yaml
+++ b/agentex/openapi.yaml
@@ -824,6 +824,42 @@ paths:
             application/json:
               schema:
                 $ref: '#/components/schemas/HTTPValidationError'
+  /tasks/{task_id}/signal:
+    post:
+      tags:
+      - Tasks
+      summary: Signal Task
+      description: Dispatch a Temporal signal to the task's workflow. The workflow
+        must have a `@workflow.signal(name=...)` handler registered for the supplied
+        `signal_name`; the optional `payload` is forwarded as the signal's single
+        argument. Returns 4xx if the task isn't currently RUNNING.
+      operationId: signal_task_tasks__task_id__signal_post
+      parameters:
+      - name: task_id
+        in: path
+        required: true
+        schema:
+          type: string
+          title: Task Id
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/SignalTaskRequest'
+      responses:
+        '200':
+          description: Successful Response
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Task'
+        '422':
+          description: Validation Error
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/HTTPValidationError'
   /tasks/{task_id}/stream:
     get:
       tags:
@@ -5638,6 +5674,48 @@ components:
       required:
       - content
       title: SendMessageRequest
+    SignalTaskRequest:
+      properties:
+        signal_name:
+          type: string
+          title: Name of the Temporal signal to dispatch
+        payload:
+          anyOf:
+          - additionalProperties: true
+            type: object
+          - type: 'null'
+          title: Optional JSON payload forwarded to the workflow's signal handler
+        merge_params:
+          anyOf:
+          - additionalProperties: true
+            type: object
+          - type: 'null'
+          title: Optional shallow-merge patch applied to the task's params column
+            after the signal succeeds. Top-level keys overwrite; pass full nested
+            objects to change subfields.
+      type: object
+      required:
+      - signal_name
+      title: SignalTaskRequest
+      description: 'Dispatch a Temporal signal to a running task''s workflow.
+
+
+        The workflow must register a matching `@workflow.signal(name=...)`
+
+        handler for the supplied ``signal_name``. ``payload`` is forwarded as
+
+        the signal''s single argument; the workflow is responsible for any
+
+        shape validation.
+
+
+        ``merge_params`` is an optional shallow-merge into the task''s stored
+
+        ``params`` JSONB column. Used by live-config flows that want the
+
+        persisted task row to reflect the new config alongside the workflow
+
+        signal (e.g. ConfigModal Save).'
     Span:
       properties:
         id:
diff --git a/agentex/src/api/routes/tasks.py b/agentex/src/api/routes/tasks.py
index dc557ed3..af196dec 100644
--- a/agentex/src/api/routes/tasks.py
+++ b/agentex/src/api/routes/tasks.py
@@ -12,6 +12,7 @@
 )
 from src.api.schemas.delete_response import DeleteResponse
 from src.api.schemas.tasks import (
+    SignalTaskRequest,
     Task,
     TaskRelationships,
     TaskResponse,
@@ -302,6 +303,32 @@ async def timeout_task(
     return Task.model_validate(updated)
 
 
+@router.post(
+    "/{task_id}/signal",
+    response_model=Task,
+    summary="Signal Task",
+    description=(
+        "Dispatch a Temporal signal to the task's workflow. The workflow "
+        "must have a `@workflow.signal(name=...)` handler registered for "
+        "the supplied `signal_name`; the optional `payload` is forwarded "
+        "as the signal's single argument. Returns 4xx if the task isn't "
+        "currently RUNNING."
+    ),
+)
+async def signal_task(
+    task_id: DAuthorizedId(AgentexResourceType.task, AuthorizedOperationType.update),
+    request: SignalTaskRequest,
+    task_use_case: DTaskUseCase,
+) -> Task:
+    updated = await task_use_case.signal_task(
+        id=task_id,
+        signal_name=request.signal_name,
+        payload=request.payload,
+        merge_params=request.merge_params,
+    )
+    return Task.model_validate(updated)
+
+
 @router.get(
     "/{task_id}/stream",
     summary="Stream Task Events by ID",
diff --git a/agentex/src/api/schemas/tasks.py b/agentex/src/api/schemas/tasks.py
index 9a8a53dd..bf6e52f6 100644
--- a/agentex/src/api/schemas/tasks.py
+++ b/agentex/src/api/schemas/tasks.py
@@ -84,3 +84,35 @@ class TaskStatusReasonRequest(BaseModel):
         None,
         title="Optional reason for the status change",
     )
+
+
+class SignalTaskRequest(BaseModel):
+    """Dispatch a Temporal signal to a running task's workflow.
+
+    The workflow must register a matching `@workflow.signal(name=...)`
+    handler for the supplied ``signal_name``. ``payload`` is forwarded as
+    the signal's single argument; the workflow is responsible for any
+    shape validation.
+
+    ``merge_params`` is an optional shallow-merge into the task's stored
+    ``params`` JSONB column. Used by live-config flows that want the
+    persisted task row to reflect the new config alongside the workflow
+    signal (e.g. ConfigModal Save).
+    """
+
+    signal_name: str = Field(
+        ...,
+        title="Name of the Temporal signal to dispatch",
+    )
+    payload: dict[str, Any] | None = Field(
+        None,
+        title="Optional JSON payload forwarded to the workflow's signal handler",
+    )
+    merge_params: dict[str, Any] | None = Field(
+        None,
+        title=(
+            "Optional shallow-merge patch applied to the task's params column "
+            "after the signal succeeds. Top-level keys overwrite; pass full "
+            "nested objects to change subfields."
+        ),
+    )
diff --git a/agentex/src/domain/repositories/task_repository.py b/agentex/src/domain/repositories/task_repository.py
index 231c0e9c..96949bc3 100644
--- a/agentex/src/domain/repositories/task_repository.py
+++ b/agentex/src/domain/repositories/task_repository.py
@@ -3,7 +3,8 @@
 from typing import Annotated, Literal
 
 from fastapi import Depends
-from sqlalchemy import distinct, func, select, update
+from sqlalchemy import cast, distinct, func, select, update
+from sqlalchemy.dialects.postgresql import JSONB
 from sqlalchemy.orm import selectinload
 from src.adapters.crud_store.adapter_postgres import (
     ColumnPrimitiveValue,
@@ -213,6 +214,45 @@ async def update(self, task: TaskEntity) -> TaskEntity:
             # Return with agents populated
             return TaskEntity.model_validate(modified_orm)
 
+    async def merge_params(self, task_id: str, patch: dict) -> TaskEntity | None:
+        """Atomically shallow-merge ``patch`` into the task's ``params``
+        JSONB column. Returns the updated entity, or ``None`` if no task
+        with that id exists.
+
+        Uses Postgres' ``||`` operator on JSONB so the read-modify-write
+        is collapsed to a single statement (no race with concurrent
+        writers). ``patch`` keys overwrite existing keys at the top
+        level; nested objects are NOT deep-merged — pass the full nested
+        replacement if you need to change a subfield.
+
+        Intended for surfaces that need ``tasks.params`` to reflect the
+        latest agent config after a live edit (see
+        ``TasksUseCase.signal_task``); not a general-purpose updater.
+        """
+
+        async with (
+            self.start_async_db_session(True) as session,
+            async_sql_exception_handler(),
+        ):
+            # ``COALESCE(params, '{}'::jsonb)`` so a NULL existing value
+            # doesn't poison the concat to NULL. Both operands cast to
+            # JSONB explicitly so Postgres picks the JSONB ``||`` operator
+            # (not the text concat overload).
+            existing = func.coalesce(TaskORM.params, cast({}, JSONB))
+            merged = existing.op("||", return_type=JSONB)(cast(patch, JSONB))
+            stmt = (
+                update(TaskORM)
+                .where(TaskORM.id == task_id)
+                .values(params=merged)
+                .returning(TaskORM)
+            )
+            result = await session.execute(stmt)
+            row = result.scalar_one_or_none()
+            await session.commit()
+            if row is None:
+                return None
+            return TaskEntity.model_validate(row)
+
     async def transition_status(
         self,
         task_id: str,
diff --git a/agentex/src/domain/services/task_service.py b/agentex/src/domain/services/task_service.py
index 809dd954..9cdee218 100644
--- a/agentex/src/domain/services/task_service.py
+++ b/agentex/src/domain/services/task_service.py
@@ -242,6 +242,16 @@ async def update_task(self, task: TaskEntity) -> TaskEntity:
 
         return updated_task
 
+    async def merge_task_params(self, task_id: str, patch: dict) -> TaskEntity | None:
+        """Atomically merge ``patch`` into ``tasks.params``. Returns the
+        updated entity, or ``None`` if no task with ``task_id`` exists.
+
+        Used by live-config flows (e.g. ConfigModal Save → signal +
+        DB persistence) so the persisted task row reflects the new
+        agent config without waiting for the next task to be created.
+        """
+        return await self.task_repository.merge_params(task_id, patch)
+
     async def delete_task(self, id: str | None = None, name: str | None = None) -> None:
         """
         Delete a task from the repository.
diff --git a/agentex/src/domain/use_cases/tasks_use_case.py b/agentex/src/domain/use_cases/tasks_use_case.py
index 4ad1a61a..f3e30816 100644
--- a/agentex/src/domain/use_cases/tasks_use_case.py
+++ b/agentex/src/domain/use_cases/tasks_use_case.py
@@ -3,6 +3,7 @@
 from fastapi import Depends
 
 from src.adapters.crud_store.exceptions import ItemDoesNotExist
+from src.adapters.temporal.adapter_temporal import DTemporalAdapter
 from src.domain.entities.tasks import TaskEntity, TaskRelationships, TaskStatus
 from src.domain.exceptions import ClientError
 from src.domain.services.task_service import DAgentTaskService
@@ -19,8 +20,10 @@ class TasksUseCase:
     def __init__(
         self,
         task_service: DAgentTaskService,
+        temporal_adapter: DTemporalAdapter,
     ):
         self.task_service = task_service
+        self.temporal_adapter = temporal_adapter
 
     async def get_task(
         self,
@@ -192,5 +195,48 @@ async def timeout_task(
             TaskStatus.TIMED_OUT, id=id, name=name, reason=reason
         )
 
+    async def signal_task(
+        self,
+        id: str,
+        signal_name: str,
+        payload: dict[str, Any] | None = None,
+        merge_params: dict[str, Any] | None = None,
+    ) -> TaskEntity:
+        """Dispatch a Temporal signal to a running task's workflow.
+
+        Validates that the task is currently RUNNING before signaling —
+        Temporal will raise its own ``WorkflowNotFoundError`` for closed
+        workflows, but returning a 4xx-mapped ``ClientError`` upfront is
+        friendlier than the bare-exception round-trip. The signal name +
+        payload are forwarded as-is; the workflow's registered
+        ``@workflow.signal`` handler owns shape validation.
+
+        ``workflow_id`` matches the task id in this codebase (see
+        TasksService.create_task — Temporal workflows are started with
+        ``workflow_id=task.id``).
+
+        Optional ``merge_params``: if supplied, shallow-merges into the
+        task's ``params`` JSONB column after the signal dispatch
+        succeeds. Used by live-config flows so the persisted task row
+        reflects the new agent config without waiting for the next task
+        to be created. Returns the task entity post-merge (or pre-merge
+        if no patch was given).
+        """
+        task = await self.task_service.get_task(id=id)
+        if task.status != TaskStatus.RUNNING:
+            raise ClientError(
+                f"Task {id} is not running (status={task.status}); cannot signal."
+            )
+        await self.temporal_adapter.signal_workflow(
+            workflow_id=id,
+            signal=signal_name,
+            arg=payload,
+        )
+        if merge_params:
+            merged = await self.task_service.merge_task_params(id, merge_params)
+            if merged is not None:
+                return merged
+        return task
+
 
 DTaskUseCase = Annotated[TasksUseCase, Depends(TasksUseCase)]

From 2ee665ffdb7aa2d5a9fb3d84ae6872f33253ee00 Mon Sep 17 00:00:00 2001
From: Michael Chou <michael.chou@scale.com>
Date: Thu, 18 Jun 2026 15:32:45 -0700
Subject: [PATCH 2/4] update task

---
 agentex/openapi.yaml                          |  9 ++++++++
 agentex/src/api/routes/tasks.py               |  4 +++-
 agentex/src/api/schemas/tasks.py              |  9 ++++++++
 .../src/domain/use_cases/tasks_use_case.py    | 22 +++++++++++++++----
 4 files changed, 39 insertions(+), 5 deletions(-)

diff --git a/agentex/openapi.yaml b/agentex/openapi.yaml
index 0ad7f0fb..c8d37299 100644
--- a/agentex/openapi.yaml
+++ b/agentex/openapi.yaml
@@ -6732,6 +6732,15 @@ components:
             type: object
           - type: 'null'
           title: If provided, replaces task_metadata with this value
+        merge_params:
+          anyOf:
+          - additionalProperties: true
+            type: object
+          - type: 'null'
+          title: Optional shallow-merge patch applied to the task's params column.
+            Top-level keys overwrite; pass full nested objects to change subfields.
+            The worker is expected to re-read task.params at turn boundaries to pick
+            up the new values.
       type: object
       title: UpdateTaskRequest
     ValidationError:
diff --git a/agentex/src/api/routes/tasks.py b/agentex/src/api/routes/tasks.py
index af196dec..87f5fbae 100644
--- a/agentex/src/api/routes/tasks.py
+++ b/agentex/src/api/routes/tasks.py
@@ -194,7 +194,9 @@ async def update_task(
     task_use_case: DTaskUseCase,
 ) -> Task:
     updated_task_entity = await task_use_case.update_mutable_fields_on_task(
-        id=task_id, task_metadata=request.task_metadata
+        id=task_id,
+        task_metadata=request.task_metadata,
+        merge_params=request.merge_params,
     )
     return Task.model_validate(updated_task_entity)
 
diff --git a/agentex/src/api/schemas/tasks.py b/agentex/src/api/schemas/tasks.py
index bf6e52f6..f66f2569 100644
--- a/agentex/src/api/schemas/tasks.py
+++ b/agentex/src/api/schemas/tasks.py
@@ -77,6 +77,15 @@ class UpdateTaskRequest(BaseModel):
         None,
         title="If provided, replaces task_metadata with this value",
     )
+    merge_params: dict[str, Any] | None = Field(
+        None,
+        title=(
+            "Optional shallow-merge patch applied to the task's params column. "
+            "Top-level keys overwrite; pass full nested objects to change "
+            "subfields. The worker is expected to re-read task.params at turn "
+            "boundaries to pick up the new values."
+        ),
+    )
 
 
 class TaskStatusReasonRequest(BaseModel):
diff --git a/agentex/src/domain/use_cases/tasks_use_case.py b/agentex/src/domain/use_cases/tasks_use_case.py
index f3e30816..0eb13f53 100644
--- a/agentex/src/domain/use_cases/tasks_use_case.py
+++ b/agentex/src/domain/use_cases/tasks_use_case.py
@@ -97,6 +97,7 @@ async def update_mutable_fields_on_task(
         id: str | None = None,
         name: str | None = None,
         task_metadata: dict[str, Any] | None = None,
+        merge_params: dict[str, Any] | None = None,
     ) -> TaskEntity:
         """Update mutable fields on a task entity. This is used by our API since not all fields should be mutable."""
 
@@ -111,15 +112,28 @@ async def update_mutable_fields_on_task(
             else:
                 raise ItemDoesNotExist(f"Task {name} not found")
 
-        # if no mutations are provided, don't do anything
-        if task_metadata is None:
+        # No-op if neither field was supplied.
+        if task_metadata is None and merge_params is None:
             return task_entity
 
         if task_metadata is not None:
             task_entity.task_metadata = task_metadata
 
-        updated_task_entity = await self.task_service.update_task(task=task_entity)
-        return updated_task_entity
+        # `merge_params` is a separate atomic JSONB shallow-merge so concurrent
+        # callers don't overwrite each other's fields (vs reading→mutating→writing
+        # the whole params dict on task_entity). Falls through to a normal save
+        # only when task_metadata also changed.
+        if merge_params:
+            merged = await self.task_service.merge_task_params(
+                task_entity.id, merge_params
+            )
+            if merged is not None:
+                task_entity = merged
+
+        if task_metadata is not None:
+            task_entity = await self.task_service.update_task(task=task_entity)
+
+        return task_entity
 
     async def _transition_to_terminal(
         self,

From 5dc4a24463f1ded20e03c934ee65804c752465b2 Mon Sep 17 00:00:00 2001
From: Michael Chou <michael.chou@scale.com>
Date: Thu, 18 Jun 2026 15:53:35 -0700
Subject: [PATCH 3/4] remove signal

---
 agentex/openapi.yaml                          | 78 -------------------
 agentex/src/api/routes/tasks.py               | 27 -------
 agentex/src/api/schemas/tasks.py              | 32 --------
 .../domain/repositories/task_repository.py    |  3 +-
 .../src/domain/use_cases/tasks_use_case.py    | 46 -----------
 5 files changed, 2 insertions(+), 184 deletions(-)

diff --git a/agentex/openapi.yaml b/agentex/openapi.yaml
index 449211ff..0716710e 100644
--- a/agentex/openapi.yaml
+++ b/agentex/openapi.yaml
@@ -824,42 +824,6 @@ paths:
             application/json:
               schema:
                 $ref: '#/components/schemas/HTTPValidationError'
-  /tasks/{task_id}/signal:
-    post:
-      tags:
-      - Tasks
-      summary: Signal Task
-      description: Dispatch a Temporal signal to the task's workflow. The workflow
-        must have a `@workflow.signal(name=...)` handler registered for the supplied
-        `signal_name`; the optional `payload` is forwarded as the signal's single
-        argument. Returns 4xx if the task isn't currently RUNNING.
-      operationId: signal_task_tasks__task_id__signal_post
-      parameters:
-      - name: task_id
-        in: path
-        required: true
-        schema:
-          type: string
-          title: Task Id
-      requestBody:
-        required: true
-        content:
-          application/json:
-            schema:
-              $ref: '#/components/schemas/SignalTaskRequest'
-      responses:
-        '200':
-          description: Successful Response
-          content:
-            application/json:
-              schema:
-                $ref: '#/components/schemas/Task'
-        '422':
-          description: Validation Error
-          content:
-            application/json:
-              schema:
-                $ref: '#/components/schemas/HTTPValidationError'
   /tasks/{task_id}/stream:
     get:
       tags:
@@ -5680,48 +5644,6 @@ components:
       required:
       - content
       title: SendMessageRequest
-    SignalTaskRequest:
-      properties:
-        signal_name:
-          type: string
-          title: Name of the Temporal signal to dispatch
-        payload:
-          anyOf:
-          - additionalProperties: true
-            type: object
-          - type: 'null'
-          title: Optional JSON payload forwarded to the workflow's signal handler
-        merge_params:
-          anyOf:
-          - additionalProperties: true
-            type: object
-          - type: 'null'
-          title: Optional shallow-merge patch applied to the task's params column
-            after the signal succeeds. Top-level keys overwrite; pass full nested
-            objects to change subfields.
-      type: object
-      required:
-      - signal_name
-      title: SignalTaskRequest
-      description: 'Dispatch a Temporal signal to a running task''s workflow.
-
-
-        The workflow must register a matching `@workflow.signal(name=...)`
-
-        handler for the supplied ``signal_name``. ``payload`` is forwarded as
-
-        the signal''s single argument; the workflow is responsible for any
-
-        shape validation.
-
-
-        ``merge_params`` is an optional shallow-merge into the task''s stored
-
-        ``params`` JSONB column. Used by live-config flows that want the
-
-        persisted task row to reflect the new config alongside the workflow
-
-        signal (e.g. ConfigModal Save).'
     Span:
       properties:
         id:
diff --git a/agentex/src/api/routes/tasks.py b/agentex/src/api/routes/tasks.py
index 3a3aa9f8..a8ae9642 100644
--- a/agentex/src/api/routes/tasks.py
+++ b/agentex/src/api/routes/tasks.py
@@ -12,7 +12,6 @@
 )
 from src.api.schemas.delete_response import DeleteResponse
 from src.api.schemas.tasks import (
-    SignalTaskRequest,
     Task,
     TaskRelationships,
     TaskResponse,
@@ -308,32 +307,6 @@ async def timeout_task(
     return Task.model_validate(updated)
 
 
-@router.post(
-    "/{task_id}/signal",
-    response_model=Task,
-    summary="Signal Task",
-    description=(
-        "Dispatch a Temporal signal to the task's workflow. The workflow "
-        "must have a `@workflow.signal(name=...)` handler registered for "
-        "the supplied `signal_name`; the optional `payload` is forwarded "
-        "as the signal's single argument. Returns 4xx if the task isn't "
-        "currently RUNNING."
-    ),
-)
-async def signal_task(
-    task_id: DAuthorizedId(AgentexResourceType.task, AuthorizedOperationType.update),
-    request: SignalTaskRequest,
-    task_use_case: DTaskUseCase,
-) -> Task:
-    updated = await task_use_case.signal_task(
-        id=task_id,
-        signal_name=request.signal_name,
-        payload=request.payload,
-        merge_params=request.merge_params,
-    )
-    return Task.model_validate(updated)
-
-
 @router.get(
     "/{task_id}/stream",
     summary="Stream Task Events by ID",
diff --git a/agentex/src/api/schemas/tasks.py b/agentex/src/api/schemas/tasks.py
index f66f2569..84ee031a 100644
--- a/agentex/src/api/schemas/tasks.py
+++ b/agentex/src/api/schemas/tasks.py
@@ -93,35 +93,3 @@ class TaskStatusReasonRequest(BaseModel):
         None,
         title="Optional reason for the status change",
     )
-
-
-class SignalTaskRequest(BaseModel):
-    """Dispatch a Temporal signal to a running task's workflow.
-
-    The workflow must register a matching `@workflow.signal(name=...)`
-    handler for the supplied ``signal_name``. ``payload`` is forwarded as
-    the signal's single argument; the workflow is responsible for any
-    shape validation.
-
-    ``merge_params`` is an optional shallow-merge into the task's stored
-    ``params`` JSONB column. Used by live-config flows that want the
-    persisted task row to reflect the new config alongside the workflow
-    signal (e.g. ConfigModal Save).
-    """
-
-    signal_name: str = Field(
-        ...,
-        title="Name of the Temporal signal to dispatch",
-    )
-    payload: dict[str, Any] | None = Field(
-        None,
-        title="Optional JSON payload forwarded to the workflow's signal handler",
-    )
-    merge_params: dict[str, Any] | None = Field(
-        None,
-        title=(
-            "Optional shallow-merge patch applied to the task's params column "
-            "after the signal succeeds. Top-level keys overwrite; pass full "
-            "nested objects to change subfields."
-        ),
-    )
diff --git a/agentex/src/domain/repositories/task_repository.py b/agentex/src/domain/repositories/task_repository.py
index 96949bc3..45662015 100644
--- a/agentex/src/domain/repositories/task_repository.py
+++ b/agentex/src/domain/repositories/task_repository.py
@@ -227,7 +227,8 @@ async def merge_params(self, task_id: str, patch: dict) -> TaskEntity | None:
 
         Intended for surfaces that need ``tasks.params`` to reflect the
         latest agent config after a live edit (see
-        ``TasksUseCase.signal_task``); not a general-purpose updater.
+        ``TasksUseCase.update_mutable_fields_on_task``); not a
+        general-purpose updater.
         """
 
         async with (
diff --git a/agentex/src/domain/use_cases/tasks_use_case.py b/agentex/src/domain/use_cases/tasks_use_case.py
index 0eb13f53..dffc6ec3 100644
--- a/agentex/src/domain/use_cases/tasks_use_case.py
+++ b/agentex/src/domain/use_cases/tasks_use_case.py
@@ -3,7 +3,6 @@
 from fastapi import Depends
 
 from src.adapters.crud_store.exceptions import ItemDoesNotExist
-from src.adapters.temporal.adapter_temporal import DTemporalAdapter
 from src.domain.entities.tasks import TaskEntity, TaskRelationships, TaskStatus
 from src.domain.exceptions import ClientError
 from src.domain.services.task_service import DAgentTaskService
@@ -20,10 +19,8 @@ class TasksUseCase:
     def __init__(
         self,
         task_service: DAgentTaskService,
-        temporal_adapter: DTemporalAdapter,
     ):
         self.task_service = task_service
-        self.temporal_adapter = temporal_adapter
 
     async def get_task(
         self,
@@ -209,48 +206,5 @@ async def timeout_task(
             TaskStatus.TIMED_OUT, id=id, name=name, reason=reason
         )
 
-    async def signal_task(
-        self,
-        id: str,
-        signal_name: str,
-        payload: dict[str, Any] | None = None,
-        merge_params: dict[str, Any] | None = None,
-    ) -> TaskEntity:
-        """Dispatch a Temporal signal to a running task's workflow.
-
-        Validates that the task is currently RUNNING before signaling —
-        Temporal will raise its own ``WorkflowNotFoundError`` for closed
-        workflows, but returning a 4xx-mapped ``ClientError`` upfront is
-        friendlier than the bare-exception round-trip. The signal name +
-        payload are forwarded as-is; the workflow's registered
-        ``@workflow.signal`` handler owns shape validation.
-
-        ``workflow_id`` matches the task id in this codebase (see
-        TasksService.create_task — Temporal workflows are started with
-        ``workflow_id=task.id``).
-
-        Optional ``merge_params``: if supplied, shallow-merges into the
-        task's ``params`` JSONB column after the signal dispatch
-        succeeds. Used by live-config flows so the persisted task row
-        reflects the new agent config without waiting for the next task
-        to be created. Returns the task entity post-merge (or pre-merge
-        if no patch was given).
-        """
-        task = await self.task_service.get_task(id=id)
-        if task.status != TaskStatus.RUNNING:
-            raise ClientError(
-                f"Task {id} is not running (status={task.status}); cannot signal."
-            )
-        await self.temporal_adapter.signal_workflow(
-            workflow_id=id,
-            signal=signal_name,
-            arg=payload,
-        )
-        if merge_params:
-            merged = await self.task_service.merge_task_params(id, merge_params)
-            if merged is not None:
-                return merged
-        return task
-
 
 DTaskUseCase = Annotated[TasksUseCase, Depends(TasksUseCase)]

From 4369c55ac1f53428561f71011cebd98a7e6b8264 Mon Sep 17 00:00:00 2001
From: Michael Chou <michael.chou@scale.com>
Date: Thu, 18 Jun 2026 16:23:39 -0700
Subject: [PATCH 4/4] comments

---
 agentex/openapi.yaml                        | 2 --
 agentex/src/api/schemas/tasks.py            | 3 +--
 agentex/src/domain/services/task_service.py | 9 ++++-----
 3 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/agentex/openapi.yaml b/agentex/openapi.yaml
index 0716710e..caa12c7f 100644
--- a/agentex/openapi.yaml
+++ b/agentex/openapi.yaml
@@ -6667,8 +6667,6 @@ components:
           - type: 'null'
           title: Optional shallow-merge patch applied to the task's params column.
             Top-level keys overwrite; pass full nested objects to change subfields.
-            The worker is expected to re-read task.params at turn boundaries to pick
-            up the new values.
       type: object
       title: UpdateTaskRequest
     ValidationError:
diff --git a/agentex/src/api/schemas/tasks.py b/agentex/src/api/schemas/tasks.py
index 84ee031a..74c8d83d 100644
--- a/agentex/src/api/schemas/tasks.py
+++ b/agentex/src/api/schemas/tasks.py
@@ -82,8 +82,7 @@ class UpdateTaskRequest(BaseModel):
         title=(
             "Optional shallow-merge patch applied to the task's params column. "
             "Top-level keys overwrite; pass full nested objects to change "
-            "subfields. The worker is expected to re-read task.params at turn "
-            "boundaries to pick up the new values."
+            "subfields."
         ),
     )
 
diff --git a/agentex/src/domain/services/task_service.py b/agentex/src/domain/services/task_service.py
index 9cdee218..299494b8 100644
--- a/agentex/src/domain/services/task_service.py
+++ b/agentex/src/domain/services/task_service.py
@@ -243,12 +243,11 @@ async def update_task(self, task: TaskEntity) -> TaskEntity:
         return updated_task
 
     async def merge_task_params(self, task_id: str, patch: dict) -> TaskEntity | None:
-        """Atomically merge ``patch`` into ``tasks.params``. Returns the
-        updated entity, or ``None`` if no task with ``task_id`` exists.
+        """Atomically shallow-merge ``patch`` into ``tasks.params``. Returns
+        the updated entity, or ``None`` if no task with ``task_id`` exists.
 
-        Used by live-config flows (e.g. ConfigModal Save → signal +
-        DB persistence) so the persisted task row reflects the new
-        agent config without waiting for the next task to be created.
+        Lets callers update agent config on the task row in place; the agent
+        picks up the new values when it next reads ``task.params``.
         """
         return await self.task_repository.merge_params(task_id, patch)