diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index d1eff5521..8032c17e8 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "0.11.4"
+  ".": "0.12.0"
 }
diff --git a/.stats.yml b/.stats.yml
index 1de9197e7..5e5e990c0 100644
--- a/.stats.yml
+++ b/.stats.yml
@@ -1,4 +1,4 @@
 configured_endpoints: 63
-openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/sgp/agentex-sdk-77ce1b851a8b44f0e67ce2c3ebc20cd92d5af16ab9d3a9224344cd4c83ffb564.yml
-openapi_spec_hash: d31d828c46635cbc20165177c7187a70
+openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/sgp/agentex-sdk-4d4bf80af19e6a2ef6b890d5d978316b86e9939d8d5116e94b90117525c61325.yml
+openapi_spec_hash: 133afeacb42000ed4f9e076abf4b50fd
 config_hash: ba5183ca635940fd202d05a2a9fcb630
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 35cf6735e..e5efcbe04 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,23 @@
 # Changelog
 
+## 0.12.0 (2026-05-27)
+
+Full Changelog: [v0.11.4...v0.12.0](https://github.com/scaleapi/scale-agentex-python/compare/v0.11.4...v0.12.0)
+
+### Features
+
+* **api:** add cleaned_at field to task response types ([38ed338](https://github.com/scaleapi/scale-agentex-python/commit/38ed3384094f7f07f6b2482489f457fd1dc4f76d))
+
+
+### Chores
+
+* **deps:** drop unused runtime deps and exclude tests from wheel ([#367](https://github.com/scaleapi/scale-agentex-python/issues/367)) ([f4303d1](https://github.com/scaleapi/scale-agentex-python/commit/f4303d1e7211783d19beca6554e44eb73bb29c42))
+
+
+### Refactors
+
+* **types:** promote protocol types to agentex.protocol.* ([#371](https://github.com/scaleapi/scale-agentex-python/issues/371)) ([6f1c14f](https://github.com/scaleapi/scale-agentex-python/commit/6f1c14fd61077da52038361642a9fbc4a0a56c8b))
+
 ## 0.11.4 (2026-05-26)
 
 Full Changelog: [v0.11.3...v0.11.4](https://github.com/scaleapi/scale-agentex-python/compare/v0.11.3...v0.11.4)
diff --git a/CLAUDE.md b/CLAUDE.md
index 7e0df1779..7f62a42fd 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -55,11 +55,27 @@ The package provides the `agentex` CLI with these main commands:
 
 ### Code Structure
 - `/src/agentex/` - Core SDK and generated API client code
+- `/src/agentex/protocol/` - **Canonical** location for wire-protocol shapes
+  (JSON-RPC envelopes, ACP method-param types). Depends only on `pydantic`
+  and the Stainless-generated `agentex.types.*` surface, so it is safe to
+  import from a future slim REST-only install.
+  - `acp.py` - `RPCMethod`, `CreateTaskParams`, `SendMessageParams`,
+    `SendEventParams`, `CancelTaskParams`, `RPC_SYNC_METHODS`,
+    `PARAMS_MODEL_BY_METHOD`
+  - `json_rpc.py` - `JSONRPCRequest`, `JSONRPCResponse`, `JSONRPCError`
 - `/src/agentex/lib/` - Custom library code (not modified by code generator)
   - `/cli/` - Command-line interface implementation
   - `/core/` - Core services, adapters, and temporal workflows
   - `/sdk/` - SDK utilities and FastACP implementation
   - `/types/` - Custom type definitions
+    - `acp.py`, `json_rpc.py` - **back-compat shims** re-exporting from
+      `agentex.protocol.*`. Existing `from agentex.lib.types.{acp,json_rpc}
+      import ...` keeps working; new code should import from the canonical
+      `agentex.protocol.*` paths.
+    - Other modules (`tracing`, `agent_card`, `credentials`, `fastacp`,
+      `llm_messages`, `converters`, etc.) stay here — they have heavier
+      transitive deps (temporal, openai-agents, model_utils/yaml) and
+      aren't slim-safe.
   - `/utils/` - Utility functions
 - `/examples/` - Example implementations and tutorials
 - `/tests/` - Test suites
diff --git a/pyproject.toml b/pyproject.toml
index bc210cace..dc6705ac4 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "agentex-sdk"
-version = "0.11.4"
+version = "0.12.0"
 description = "The official Python library for the agentex API"
 dynamic = ["readme"]
 license = "Apache-2.0"
@@ -20,7 +20,6 @@ dependencies = [
     "rich>=13.9.2,<14",
     "fastapi>=0.115.0",
     "starlette>=0.49.1",
-    "tornado>=6.5.5",
     "uvicorn>=0.31.1",
     "watchfiles>=0.24.0,<1.0",
     "python-on-whales>=0.73.0,<0.74",
@@ -33,24 +32,17 @@ dependencies = [
     "litellm>=1.83.7,<2",
     "kubernetes>=25.0.0,<36.0.0",
     "jinja2>=3.1.3,<4",
-    "mcp[cli]>=1.4.1",
+    "mcp>=1.4.1",
     "scale-gp>=0.1.0a59",
     "openai-agents==0.14.1",
     "pydantic-ai-slim>=1.0,<2",
-    "tzlocal>=5.3.1",
-    "tzdata>=2025.2",
-    "pytest>=8.4.0",
     "json_log_formatter>=1.1.1",
-    "pytest-asyncio>=1.0.0",
     "scale-gp-beta>=0.2.0",
-    "ipykernel>=6.29.5",
     "openai>=2.2,<3", # Required by openai-agents; litellm now supports openai 2.x (issue #13711 resolved: https://github.com/BerriAI/litellm/issues/13711)
     "cloudpickle>=3.1.1",
-    "datadog>=0.52.1",
     "ddtrace>=3.13.0",
     "yaspin>=3.1.0",
     "claude-agent-sdk>=0.1.0",
-    "anthropic>=0.40.0",
     "langgraph-checkpoint>=2.0.0",
     "opentelemetry-sdk>=1.20.0",
     "opentelemetry-api>=1.20.0",
@@ -152,6 +144,14 @@ include = [
 
 [tool.hatch.build.targets.wheel]
 packages = ["src/agentex"]
+# Don't ship internal test files in the wheel. `lib/cli/templates/**/test_agent.py.j2`
+# is intentionally kept — those render into user projects.
+exclude = [
+  "src/agentex/lib/**/tests/**",
+  "src/agentex/lib/**/test_*.py",
+  "src/agentex/lib/**/conftest.py",
+  "src/agentex/lib/**/pytest.ini",
+]
 
 [tool.hatch.build.targets.sdist]
 # Basically everything except hidden files/directories (such as .github, .devcontainers, .python-version, etc)
diff --git a/src/agentex/_version.py b/src/agentex/_version.py
index 4efc70f7f..80a336119 100644
--- a/src/agentex/_version.py
+++ b/src/agentex/_version.py
@@ -1,4 +1,4 @@
 # File generated from our OpenAPI spec by Stainless. See CONTRIBUTING.md for details.
 
 __title__ = "agentex"
-__version__ = "0.11.4"  # x-release-please-version
+__version__ = "0.12.0"  # x-release-please-version
diff --git a/src/agentex/lib/cli/templates/default-langgraph/project/acp.py.j2 b/src/agentex/lib/cli/templates/default-langgraph/project/acp.py.j2
index 6099f5c3e..3309dc07e 100644
--- a/src/agentex/lib/cli/templates/default-langgraph/project/acp.py.j2
+++ b/src/agentex/lib/cli/templates/default-langgraph/project/acp.py.j2
@@ -18,7 +18,7 @@ import agentex.lib.adk as adk
 from agentex.lib.adk import create_langgraph_tracing_handler, stream_langgraph_events
 from agentex.lib.core.tracing.tracing_processor_manager import add_tracing_processor_config
 from agentex.lib.sdk.fastacp.fastacp import FastACP
-from agentex.lib.types.acp import SendEventParams, CancelTaskParams, CreateTaskParams
+from agentex.protocol.acp import SendEventParams, CancelTaskParams, CreateTaskParams
 from agentex.lib.types.fastacp import AsyncACPConfig
 from agentex.lib.types.tracing import SGPTracingProcessorConfig
 from agentex.lib.utils.logging import make_logger
diff --git a/src/agentex/lib/cli/templates/default-pydantic-ai/project/acp.py.j2 b/src/agentex/lib/cli/templates/default-pydantic-ai/project/acp.py.j2
index b63683da1..5692396b2 100644
--- a/src/agentex/lib/cli/templates/default-pydantic-ai/project/acp.py.j2
+++ b/src/agentex/lib/cli/templates/default-pydantic-ai/project/acp.py.j2
@@ -28,7 +28,7 @@ from agentex.lib.adk import (
     stream_pydantic_ai_events,
     create_pydantic_ai_tracing_handler,
 )
-from agentex.lib.types.acp import SendEventParams, CancelTaskParams, CreateTaskParams
+from agentex.protocol.acp import SendEventParams, CancelTaskParams, CreateTaskParams
 from agentex.lib.types.fastacp import AsyncACPConfig
 from agentex.lib.types.tracing import SGPTracingProcessorConfig
 from agentex.lib.utils.logging import make_logger
diff --git a/src/agentex/lib/cli/templates/default/project/acp.py.j2 b/src/agentex/lib/cli/templates/default/project/acp.py.j2
index 5478b51b5..b0da14a5c 100644
--- a/src/agentex/lib/cli/templates/default/project/acp.py.j2
+++ b/src/agentex/lib/cli/templates/default/project/acp.py.j2
@@ -1,6 +1,6 @@
 from agentex.lib.sdk.fastacp.fastacp import FastACP
 from agentex.lib.types.fastacp import AsyncACPConfig
-from agentex.lib.types.acp import SendEventParams, CancelTaskParams, CreateTaskParams
+from agentex.protocol.acp import SendEventParams, CancelTaskParams, CreateTaskParams
 from agentex.lib.utils.logging import make_logger
 from agentex.types.text_content import TextContent
 from agentex.lib import adk
diff --git a/src/agentex/lib/cli/templates/sync-langgraph/project/acp.py.j2 b/src/agentex/lib/cli/templates/sync-langgraph/project/acp.py.j2
index 2edd20fcb..54538d0c9 100644
--- a/src/agentex/lib/cli/templates/sync-langgraph/project/acp.py.j2
+++ b/src/agentex/lib/cli/templates/sync-langgraph/project/acp.py.j2
@@ -11,7 +11,7 @@ import agentex.lib.adk as adk
 from agentex.lib.adk import create_langgraph_tracing_handler, convert_langgraph_to_agentex_events
 from agentex.lib.core.tracing.tracing_processor_manager import add_tracing_processor_config
 from agentex.lib.sdk.fastacp.fastacp import FastACP
-from agentex.lib.types.acp import SendMessageParams
+from agentex.protocol.acp import SendMessageParams
 from agentex.lib.types.tracing import SGPTracingProcessorConfig
 from agentex.lib.utils.logging import make_logger
 from agentex.types.task_message_content import TaskMessageContent
diff --git a/src/agentex/lib/cli/templates/sync-openai-agents/project/acp.py.j2 b/src/agentex/lib/cli/templates/sync-openai-agents/project/acp.py.j2
index 0b3b482fe..4e2517838 100644
--- a/src/agentex/lib/cli/templates/sync-openai-agents/project/acp.py.j2
+++ b/src/agentex/lib/cli/templates/sync-openai-agents/project/acp.py.j2
@@ -4,7 +4,7 @@ from typing import AsyncGenerator, List
 from agentex.lib import adk
 from agentex.lib.adk.providers._modules.sync_provider import SyncStreamingProvider, convert_openai_to_agentex_events
 from agentex.lib.sdk.fastacp.fastacp import FastACP
-from agentex.lib.types.acp import SendMessageParams
+from agentex.protocol.acp import SendMessageParams
 from agentex.lib.core.tracing.tracing_processor_manager import add_tracing_processor_config
 from agentex.lib.types.tracing import SGPTracingProcessorConfig
 from agentex.lib.utils.model_utils import BaseModel
diff --git a/src/agentex/lib/cli/templates/sync-pydantic-ai/project/acp.py.j2 b/src/agentex/lib/cli/templates/sync-pydantic-ai/project/acp.py.j2
index e07f57a1a..4925e847f 100644
--- a/src/agentex/lib/cli/templates/sync-pydantic-ai/project/acp.py.j2
+++ b/src/agentex/lib/cli/templates/sync-pydantic-ai/project/acp.py.j2
@@ -22,7 +22,7 @@ from agentex.lib.adk import (
     create_pydantic_ai_tracing_handler,
     convert_pydantic_ai_to_agentex_events,
 )
-from agentex.lib.types.acp import SendMessageParams
+from agentex.protocol.acp import SendMessageParams
 from agentex.lib.types.tracing import SGPTracingProcessorConfig
 from agentex.lib.utils.logging import make_logger
 from agentex.lib.sdk.fastacp.fastacp import FastACP
diff --git a/src/agentex/lib/cli/templates/sync/project/acp.py.j2 b/src/agentex/lib/cli/templates/sync/project/acp.py.j2
index 7184d26aa..ce5069a4c 100644
--- a/src/agentex/lib/cli/templates/sync/project/acp.py.j2
+++ b/src/agentex/lib/cli/templates/sync/project/acp.py.j2
@@ -1,6 +1,6 @@
 from typing import AsyncGenerator, Union
 from agentex.lib.sdk.fastacp.fastacp import FastACP
-from agentex.lib.types.acp import SendMessageParams
+from agentex.protocol.acp import SendMessageParams
 
 from agentex.types.task_message_update import TaskMessageUpdate
 from agentex.types.task_message_content import TaskMessageContent
diff --git a/src/agentex/lib/cli/templates/temporal-openai-agents/project/workflow.py.j2 b/src/agentex/lib/cli/templates/temporal-openai-agents/project/workflow.py.j2
index 5b95d4479..2b81bb335 100644
--- a/src/agentex/lib/cli/templates/temporal-openai-agents/project/workflow.py.j2
+++ b/src/agentex/lib/cli/templates/temporal-openai-agents/project/workflow.py.j2
@@ -4,7 +4,7 @@ import os
 from temporalio import workflow
 
 from agentex.lib import adk
-from agentex.lib.types.acp import CreateTaskParams, SendEventParams
+from agentex.protocol.acp import CreateTaskParams, SendEventParams
 from agentex.lib.core.temporal.workflows.workflow import BaseWorkflow
 from agentex.lib.core.temporal.types.workflow import SignalName
 from agentex.lib.utils.logging import make_logger
diff --git a/src/agentex/lib/cli/templates/temporal-pydantic-ai/project/workflow.py.j2 b/src/agentex/lib/cli/templates/temporal-pydantic-ai/project/workflow.py.j2
index 23e5156f1..66a91d7a8 100644
--- a/src/agentex/lib/cli/templates/temporal-pydantic-ai/project/workflow.py.j2
+++ b/src/agentex/lib/cli/templates/temporal-pydantic-ai/project/workflow.py.j2
@@ -23,7 +23,7 @@ from temporalio import workflow
 from project.agent import TaskDeps, temporal_agent
 
 from agentex.lib import adk
-from agentex.lib.types.acp import SendEventParams, CreateTaskParams
+from agentex.protocol.acp import SendEventParams, CreateTaskParams
 from agentex.lib.types.tracing import SGPTracingProcessorConfig
 from agentex.lib.utils.logging import make_logger
 from agentex.types.text_content import TextContent
diff --git a/src/agentex/lib/cli/templates/temporal/project/workflow.py.j2 b/src/agentex/lib/cli/templates/temporal/project/workflow.py.j2
index ad756eb15..56db5abf3 100644
--- a/src/agentex/lib/cli/templates/temporal/project/workflow.py.j2
+++ b/src/agentex/lib/cli/templates/temporal/project/workflow.py.j2
@@ -3,7 +3,7 @@ import json
 from temporalio import workflow
 
 from agentex.lib import adk
-from agentex.lib.types.acp import CreateTaskParams, SendEventParams
+from agentex.protocol.acp import CreateTaskParams, SendEventParams
 from agentex.lib.core.temporal.workflows.workflow import BaseWorkflow
 from agentex.lib.core.temporal.types.workflow import SignalName
 from agentex.lib.utils.logging import make_logger
diff --git a/src/agentex/lib/core/temporal/services/temporal_task_service.py b/src/agentex/lib/core/temporal/services/temporal_task_service.py
index 81eb22389..9d66c0c1f 100644
--- a/src/agentex/lib/core/temporal/services/temporal_task_service.py
+++ b/src/agentex/lib/core/temporal/services/temporal_task_service.py
@@ -6,7 +6,7 @@
 from agentex.types.task import Task
 from agentex.types.agent import Agent
 from agentex.types.event import Event
-from agentex.lib.types.acp import SendEventParams, CreateTaskParams
+from agentex.protocol.acp import SendEventParams, CreateTaskParams
 from agentex.lib.environment_variables import EnvironmentVariables
 from agentex.lib.core.clients.temporal.types import WorkflowState
 from agentex.lib.core.temporal.types.workflow import SignalName
diff --git a/src/agentex/lib/core/temporal/workflows/workflow.py b/src/agentex/lib/core/temporal/workflows/workflow.py
index 727f3ac85..3e4498162 100644
--- a/src/agentex/lib/core/temporal/workflows/workflow.py
+++ b/src/agentex/lib/core/temporal/workflows/workflow.py
@@ -2,7 +2,7 @@
 
 from temporalio import workflow
 
-from agentex.lib.types.acp import SendEventParams, CreateTaskParams
+from agentex.protocol.acp import SendEventParams, CreateTaskParams
 from agentex.lib.utils.logging import make_logger
 from agentex.lib.core.temporal.types.workflow import SignalName
 
diff --git a/src/agentex/lib/sdk/fastacp/base/base_acp_server.py b/src/agentex/lib/sdk/fastacp/base/base_acp_server.py
index c48816020..b0b1c3685 100644
--- a/src/agentex/lib/sdk/fastacp/base/base_acp_server.py
+++ b/src/agentex/lib/sdk/fastacp/base/base_acp_server.py
@@ -14,7 +14,7 @@
 from starlette.types import Send, Scope, ASGIApp, Receive
 from fastapi.responses import StreamingResponse
 
-from agentex.lib.types.acp import (
+from agentex.protocol.acp import (
     RPC_SYNC_METHODS,
     PARAMS_MODEL_BY_METHOD,
     RPCMethod,
@@ -24,7 +24,7 @@
     SendMessageParams,
 )
 from agentex.lib.utils.logging import make_logger, ctx_var_request_id
-from agentex.lib.types.json_rpc import JSONRPCError, JSONRPCRequest, JSONRPCResponse
+from agentex.protocol.json_rpc import JSONRPCError, JSONRPCRequest, JSONRPCResponse
 from agentex.lib.utils.model_utils import BaseModel
 from agentex.lib.utils.registration import register_agent
 
diff --git a/src/agentex/lib/sdk/fastacp/impl/async_base_acp.py b/src/agentex/lib/sdk/fastacp/impl/async_base_acp.py
index d2b8bac92..e9d20f150 100644
--- a/src/agentex/lib/sdk/fastacp/impl/async_base_acp.py
+++ b/src/agentex/lib/sdk/fastacp/impl/async_base_acp.py
@@ -1,7 +1,7 @@
 from typing import Any
 from typing_extensions import override
 
-from agentex.lib.types.acp import (
+from agentex.protocol.acp import (
     SendEventParams,
     CancelTaskParams,
     CreateTaskParams,
diff --git a/src/agentex/lib/sdk/fastacp/impl/sync_acp.py b/src/agentex/lib/sdk/fastacp/impl/sync_acp.py
index 4898a9637..5ecad073e 100644
--- a/src/agentex/lib/sdk/fastacp/impl/sync_acp.py
+++ b/src/agentex/lib/sdk/fastacp/impl/sync_acp.py
@@ -3,7 +3,7 @@
 from typing import Any, override
 from collections.abc import AsyncGenerator
 
-from agentex.lib.types.acp import SendMessageParams
+from agentex.protocol.acp import SendMessageParams
 from agentex.lib.utils.logging import make_logger
 from agentex.types.task_message_delta import TextDelta
 from agentex.types.task_message_update import (
diff --git a/src/agentex/lib/sdk/fastacp/impl/temporal_acp.py b/src/agentex/lib/sdk/fastacp/impl/temporal_acp.py
index f64e16d72..54fe72e6c 100644
--- a/src/agentex/lib/sdk/fastacp/impl/temporal_acp.py
+++ b/src/agentex/lib/sdk/fastacp/impl/temporal_acp.py
@@ -6,7 +6,7 @@
 from fastapi import FastAPI
 from temporalio.converter import PayloadCodec
 
-from agentex.lib.types.acp import (
+from agentex.protocol.acp import (
     SendEventParams,
     CancelTaskParams,
     CreateTaskParams,
diff --git a/src/agentex/lib/sdk/fastacp/tests/conftest.py b/src/agentex/lib/sdk/fastacp/tests/conftest.py
index 8941f16eb..59ecbfee3 100644
--- a/src/agentex/lib/sdk/fastacp/tests/conftest.py
+++ b/src/agentex/lib/sdk/fastacp/tests/conftest.py
@@ -13,12 +13,12 @@
 
 from agentex.types.task import Task
 from agentex.types.agent import Agent
-from agentex.lib.types.acp import (
+from agentex.protocol.acp import (
     CancelTaskParams,
     CreateTaskParams,
     SendMessageParams,
 )
-from agentex.lib.types.json_rpc import JSONRPCRequest
+from agentex.protocol.json_rpc import JSONRPCRequest
 from agentex.types.task_message import TaskMessageContent
 from agentex.types.task_message_content import TextContent
 from agentex.lib.sdk.fastacp.impl.sync_acp import SyncACP
diff --git a/src/agentex/lib/sdk/fastacp/tests/test_base_acp_server.py b/src/agentex/lib/sdk/fastacp/tests/test_base_acp_server.py
index 0816ac436..8a218187e 100644
--- a/src/agentex/lib/sdk/fastacp/tests/test_base_acp_server.py
+++ b/src/agentex/lib/sdk/fastacp/tests/test_base_acp_server.py
@@ -5,7 +5,7 @@
 import pytest
 from fastapi.testclient import TestClient
 
-from agentex.lib.types.acp import (
+from agentex.protocol.acp import (
     RPCMethod,
     SendEventParams,
     CancelTaskParams,
diff --git a/src/agentex/lib/sdk/fastacp/tests/test_integration.py b/src/agentex/lib/sdk/fastacp/tests/test_integration.py
index c6f310af1..c72d336e3 100644
--- a/src/agentex/lib/sdk/fastacp/tests/test_integration.py
+++ b/src/agentex/lib/sdk/fastacp/tests/test_integration.py
@@ -5,7 +5,7 @@
 import httpx
 import pytest
 
-from agentex.lib.types.acp import (
+from agentex.protocol.acp import (
     RPCMethod,
     SendEventParams,
     CancelTaskParams,
diff --git a/src/agentex/lib/types/acp.py b/src/agentex/lib/types/acp.py
index d719b4fd5..74295ef88 100644
--- a/src/agentex/lib/types/acp.py
+++ b/src/agentex/lib/types/acp.py
@@ -1,116 +1,15 @@
-from __future__ import annotations
-
-from enum import Enum
-from typing import Any
-
-from pydantic import Field, BaseModel
-
-from agentex.types.task import Task
-from agentex.types.agent import Agent
-from agentex.types.event import Event
-from agentex.types.task_message_content import TaskMessageContent
-
-
-class RPCMethod(str, Enum):
-    """Available JSON-RPC methods for agent communication."""
-
-    EVENT_SEND = "event/send"
-    MESSAGE_SEND = "message/send"
-    TASK_CANCEL = "task/cancel"
-    TASK_CREATE = "task/create"
-
-
-class CreateTaskParams(BaseModel):
-    """Parameters for task/create method.
-
-    Attributes:
-        agent: The agent that the task was sent to.
-        task: The task to be created.
-        params: The parameters for the task as inputted by the user.
-        request: Additional request context including headers forwarded to this agent.
-    """
-
-    agent: Agent = Field(..., description="The agent that the task was sent to")
-    task: Task = Field(..., description="The task to be created")
-    params: dict[str, Any] | None = Field(
-        None,
-        description="The parameters for the task as inputted by the user",
-    )
-    request: dict[str, Any] | None = Field(
-        default=None,
-        description="Additional request context including headers forwarded to this agent",
-    )
-
-
-class SendMessageParams(BaseModel):
-    """Parameters for message/send method.
-
-    Attributes:
-        agent: The agent that the message was sent to.
-        task: The task that the message was sent to.
-        content: The message that was sent to the agent.
-        stream: Whether to stream the message back to the agentex server from the agent.
-        request: Additional request context including headers forwarded to this agent.
-    """
-
-    agent: Agent = Field(..., description="The agent that the message was sent to")
-    task: Task = Field(..., description="The task that the message was sent to")
-    content: TaskMessageContent = Field(
-        ..., description="The message that was sent to the agent"
-    )
-    stream: bool = Field(
-        False,
-        description="Whether to stream the message back to the agentex server from the agent",
-    )
-    request: dict[str, Any] | None = Field(
-        default=None,
-        description="Additional request context including headers forwarded to this agent",
-    )
-
-
-class SendEventParams(BaseModel):
-    """Parameters for event/send method.
-
-    Attributes:
-        agent: The agent that the event was sent to.
-        task: The task that the message was sent to.
-        event: The event that was sent to the agent.
-        request: Additional request context including headers forwarded to this agent.
-    """
-
-    agent: Agent = Field(..., description="The agent that the event was sent to")
-    task: Task = Field(..., description="The task that the message was sent to")
-    event: Event = Field(..., description="The event that was sent to the agent")
-    request: dict[str, Any] | None = Field(
-        default=None,
-        description="Additional request context including headers forwarded to this agent",
-    )
-
-
-class CancelTaskParams(BaseModel):
-    """Parameters for task/cancel method.
-
-    Attributes:
-        agent: The agent that the task was sent to.
-        task: The task that was cancelled.
-        request: Additional request context including headers forwarded to this agent.
-    """
-
-    agent: Agent = Field(..., description="The agent that the task was sent to")
-    task: Task = Field(..., description="The task that was cancelled")
-    request: dict[str, Any] | None = Field(
-        default=None,
-        description="Additional request context including headers forwarded to this agent",
-    )
-
-
-RPC_SYNC_METHODS = [
-    RPCMethod.MESSAGE_SEND,
-]
-
-PARAMS_MODEL_BY_METHOD: dict[RPCMethod, type[BaseModel]] = {
-    RPCMethod.EVENT_SEND: SendEventParams,
-    RPCMethod.TASK_CANCEL: CancelTaskParams,
-    RPCMethod.MESSAGE_SEND: SendMessageParams,
-    RPCMethod.TASK_CREATE: CreateTaskParams,
-}
+"""Back-compat shim. The canonical location is :mod:`agentex.protocol.acp`.
+
+Kept here so existing ``from agentex.lib.types.acp import ...`` imports
+continue to work. New code should import from the canonical path.
+"""
+
+from agentex.protocol.acp import (  # noqa: F401
+    RPC_SYNC_METHODS,
+    PARAMS_MODEL_BY_METHOD,
+    RPCMethod,
+    SendEventParams,
+    CancelTaskParams,
+    CreateTaskParams,
+    SendMessageParams,
+)
diff --git a/src/agentex/lib/types/json_rpc.py b/src/agentex/lib/types/json_rpc.py
index b89e9d6b2..b010f93f7 100644
--- a/src/agentex/lib/types/json_rpc.py
+++ b/src/agentex/lib/types/json_rpc.py
@@ -1,51 +1,11 @@
-from __future__ import annotations
+"""Back-compat shim. The canonical location is :mod:`agentex.protocol.json_rpc`.
 
-from typing import Any, Literal
+Kept here so existing ``from agentex.lib.types.json_rpc import ...`` imports
+continue to work. New code should import from the canonical path.
+"""
 
-from agentex.lib.utils.model_utils import BaseModel
-
-
-class JSONRPCError(BaseModel):
-    """JSON-RPC 2.0 Error
-
-    Attributes:
-        code: The error code
-        message: The error message
-        data: The error data
-    """
-
-    code: int
-    message: str
-    data: Any | None = None
-
-
-class JSONRPCRequest(BaseModel):
-    """JSON-RPC 2.0 Request
-
-    Attributes:
-        jsonrpc: The JSON-RPC version
-        method: The method to call
-        params: The parameters for the request
-        id: The ID of the request
-    """
-
-    jsonrpc: Literal["2.0"] = "2.0"
-    method: str
-    params: dict[str, Any]
-    id: int | str | None = None
-
-
-class JSONRPCResponse(BaseModel):
-    """JSON-RPC 2.0 Response
-
-    Attributes:
-        jsonrpc: The JSON-RPC version
-        result: The result of the request
-        error: The error of the request
-        id: The ID of the request
-    """
-
-    jsonrpc: Literal["2.0"] = "2.0"
-    result: dict[str, Any] | None = None
-    error: JSONRPCError | None = None
-    id: int | str | None = None
+from agentex.protocol.json_rpc import (  # noqa: F401
+    JSONRPCError,
+    JSONRPCRequest,
+    JSONRPCResponse,
+)
diff --git a/src/agentex/protocol/__init__.py b/src/agentex/protocol/__init__.py
new file mode 100644
index 000000000..be9db981a
--- /dev/null
+++ b/src/agentex/protocol/__init__.py
@@ -0,0 +1,16 @@
+"""Wire-protocol shapes for Agentex.
+
+The modules under `agentex.protocol.*` are the typed shapes for talking to
+an Agentex agent over JSON-RPC (the ACP / Agent Communication Protocol)
+without pulling in the heavy ADK runtime. They depend only on pydantic and
+the Stainless-generated `agentex.types.*` surface, so they are safe to
+import from a slim REST-only install.
+
+Hand-rolled JSON-RPC clients (e.g. the one in `egp-api-backend`) can switch
+from constructing `{"jsonrpc": "2.0", "method": "...", "params": {...}}`
+dicts by hand to constructing `JSONRPCRequest(method=RPCMethod.TASK_CREATE,
+params=CreateTaskParams(...).model_dump())`.
+
+For back-compat, the same classes are re-exported from
+`agentex.lib.types.{acp,json_rpc}` (the historical locations).
+"""
diff --git a/src/agentex/protocol/acp.py b/src/agentex/protocol/acp.py
new file mode 100644
index 000000000..d719b4fd5
--- /dev/null
+++ b/src/agentex/protocol/acp.py
@@ -0,0 +1,116 @@
+from __future__ import annotations
+
+from enum import Enum
+from typing import Any
+
+from pydantic import Field, BaseModel
+
+from agentex.types.task import Task
+from agentex.types.agent import Agent
+from agentex.types.event import Event
+from agentex.types.task_message_content import TaskMessageContent
+
+
+class RPCMethod(str, Enum):
+    """Available JSON-RPC methods for agent communication."""
+
+    EVENT_SEND = "event/send"
+    MESSAGE_SEND = "message/send"
+    TASK_CANCEL = "task/cancel"
+    TASK_CREATE = "task/create"
+
+
+class CreateTaskParams(BaseModel):
+    """Parameters for task/create method.
+
+    Attributes:
+        agent: The agent that the task was sent to.
+        task: The task to be created.
+        params: The parameters for the task as inputted by the user.
+        request: Additional request context including headers forwarded to this agent.
+    """
+
+    agent: Agent = Field(..., description="The agent that the task was sent to")
+    task: Task = Field(..., description="The task to be created")
+    params: dict[str, Any] | None = Field(
+        None,
+        description="The parameters for the task as inputted by the user",
+    )
+    request: dict[str, Any] | None = Field(
+        default=None,
+        description="Additional request context including headers forwarded to this agent",
+    )
+
+
+class SendMessageParams(BaseModel):
+    """Parameters for message/send method.
+
+    Attributes:
+        agent: The agent that the message was sent to.
+        task: The task that the message was sent to.
+        content: The message that was sent to the agent.
+        stream: Whether to stream the message back to the agentex server from the agent.
+        request: Additional request context including headers forwarded to this agent.
+    """
+
+    agent: Agent = Field(..., description="The agent that the message was sent to")
+    task: Task = Field(..., description="The task that the message was sent to")
+    content: TaskMessageContent = Field(
+        ..., description="The message that was sent to the agent"
+    )
+    stream: bool = Field(
+        False,
+        description="Whether to stream the message back to the agentex server from the agent",
+    )
+    request: dict[str, Any] | None = Field(
+        default=None,
+        description="Additional request context including headers forwarded to this agent",
+    )
+
+
+class SendEventParams(BaseModel):
+    """Parameters for event/send method.
+
+    Attributes:
+        agent: The agent that the event was sent to.
+        task: The task that the message was sent to.
+        event: The event that was sent to the agent.
+        request: Additional request context including headers forwarded to this agent.
+    """
+
+    agent: Agent = Field(..., description="The agent that the event was sent to")
+    task: Task = Field(..., description="The task that the message was sent to")
+    event: Event = Field(..., description="The event that was sent to the agent")
+    request: dict[str, Any] | None = Field(
+        default=None,
+        description="Additional request context including headers forwarded to this agent",
+    )
+
+
+class CancelTaskParams(BaseModel):
+    """Parameters for task/cancel method.
+
+    Attributes:
+        agent: The agent that the task was sent to.
+        task: The task that was cancelled.
+        request: Additional request context including headers forwarded to this agent.
+    """
+
+    agent: Agent = Field(..., description="The agent that the task was sent to")
+    task: Task = Field(..., description="The task that was cancelled")
+    request: dict[str, Any] | None = Field(
+        default=None,
+        description="Additional request context including headers forwarded to this agent",
+    )
+
+
+RPC_SYNC_METHODS = [
+    RPCMethod.MESSAGE_SEND,
+]
+
+PARAMS_MODEL_BY_METHOD: dict[RPCMethod, type[BaseModel]] = {
+    RPCMethod.EVENT_SEND: SendEventParams,
+    RPCMethod.TASK_CANCEL: CancelTaskParams,
+    RPCMethod.MESSAGE_SEND: SendMessageParams,
+    RPCMethod.TASK_CREATE: CreateTaskParams,
+}
diff --git a/src/agentex/protocol/json_rpc.py b/src/agentex/protocol/json_rpc.py
new file mode 100644
index 000000000..be03a4936
--- /dev/null
+++ b/src/agentex/protocol/json_rpc.py
@@ -0,0 +1,63 @@
+from __future__ import annotations
+
+from typing import Any, Literal
+
+from pydantic import BaseModel, ConfigDict
+
+# Preserve the config the previous `agentex.lib.utils.model_utils.BaseModel`
+# applied — `from_attributes=True` lets callers `model_validate` from
+# attribute-bearing objects (not just dicts); `populate_by_name=True` is a
+# harmless default future-proofing for any field aliases.
+_PROTOCOL_MODEL_CONFIG = ConfigDict(from_attributes=True, populate_by_name=True)
+
+
+class JSONRPCError(BaseModel):
+    """JSON-RPC 2.0 Error
+
+    Attributes:
+        code: The error code
+        message: The error message
+        data: The error data
+    """
+
+    model_config = _PROTOCOL_MODEL_CONFIG
+
+    code: int
+    message: str
+    data: Any | None = None
+
+
+class JSONRPCRequest(BaseModel):
+    """JSON-RPC 2.0 Request
+
+    Attributes:
+        jsonrpc: The JSON-RPC version
+        method: The method to call
+        params: The parameters for the request
+        id: The ID of the request
+    """
+
+    model_config = _PROTOCOL_MODEL_CONFIG
+
+    jsonrpc: Literal["2.0"] = "2.0"
+    method: str
+    params: dict[str, Any]
+    id: int | str | None = None
+
+
+class JSONRPCResponse(BaseModel):
+    """JSON-RPC 2.0 Response
+
+    Attributes:
+        jsonrpc: The JSON-RPC version
+        result: The result of the request
+        error: The error of the request
+        id: The ID of the request
+    """
+
+    model_config = _PROTOCOL_MODEL_CONFIG
+
+    jsonrpc: Literal["2.0"] = "2.0"
+    result: dict[str, Any] | None = None
+    error: JSONRPCError | None = None
+    id: int | str | None = None
diff --git a/src/agentex/types/task.py b/src/agentex/types/task.py
index 8b9cde47f..3769d5128 100644
--- a/src/agentex/types/task.py
+++ b/src/agentex/types/task.py
@@ -12,6 +12,8 @@
 class Task(BaseModel):
     id: str
 
+    cleaned_at: Optional[datetime] = None
+
     created_at: Optional[datetime] = None
 
     name: Optional[str] = None
diff --git a/src/agentex/types/task_list_response.py b/src/agentex/types/task_list_response.py
index 85f87c0e5..b8d0ab73d 100644
--- a/src/agentex/types/task_list_response.py
+++ b/src/agentex/types/task_list_response.py
@@ -17,6 +17,8 @@ class TaskListResponseItem(BaseModel):
 
     agents: Optional[List[Agent]] = None
 
+    cleaned_at: Optional[datetime] = None
+
     created_at: Optional[datetime] = None
 
     name: Optional[str] = None
diff --git a/src/agentex/types/task_retrieve_by_name_response.py b/src/agentex/types/task_retrieve_by_name_response.py
index 1ffc6819a..557764d04 100644
--- a/src/agentex/types/task_retrieve_by_name_response.py
+++ b/src/agentex/types/task_retrieve_by_name_response.py
@@ -17,6 +17,8 @@ class TaskRetrieveByNameResponse(BaseModel):
 
     agents: Optional[List[Agent]] = None
 
+    cleaned_at: Optional[datetime] = None
+
     created_at: Optional[datetime] = None
 
     name: Optional[str] = None
diff --git a/src/agentex/types/task_retrieve_response.py b/src/agentex/types/task_retrieve_response.py
index 5f2629468..bb1398d67 100644
--- a/src/agentex/types/task_retrieve_response.py
+++ b/src/agentex/types/task_retrieve_response.py
@@ -17,6 +17,8 @@ class TaskRetrieveResponse(BaseModel):
 
     agents: Optional[List[Agent]] = None
 
+    cleaned_at: Optional[datetime] = None
+
     created_at: Optional[datetime] = None
 
     name: Optional[str] = None
diff --git a/tests/test_header_forwarding.py b/tests/test_header_forwarding.py
index 51c3a685f..596c6729c 100644
--- a/tests/test_header_forwarding.py
+++ b/tests/test_header_forwarding.py
@@ -46,7 +46,7 @@ class _StubTracer(_StubAsyncTracer):
 
 from agentex.lib.core.services.adk.acp.acp import ACPService
 from agentex.lib.sdk.fastacp.base.base_acp_server import BaseACPServer
-from agentex.lib.types.acp import RPCMethod, SendMessageParams, SendEventParams
+from agentex.protocol.acp import RPCMethod, SendMessageParams, SendEventParams
 from agentex.types.task_message_content import TextContent
 from agentex.lib.sdk.fastacp.impl.temporal_acp import TemporalACP
 from agentex.lib.core.temporal.services.temporal_task_service import TemporalTaskService
diff --git a/tests/test_protocol_shims.py b/tests/test_protocol_shims.py
new file mode 100644
index 000000000..e5e651b68
--- /dev/null
+++ b/tests/test_protocol_shims.py
@@ -0,0 +1,98 @@
+"""Tests that pin the back-compat contract for protocol-type shims.
+
+The canonical location for wire-protocol shapes is :mod:`agentex.protocol`
+(see PR scaleapi/scale-agentex-python#371). The historical locations
+:mod:`agentex.lib.types.acp` and :mod:`agentex.lib.types.json_rpc` are
+preserved as re-export shims so external consumers' existing imports
+continue to work.
+
+These tests enforce two invariants:
+
+1. **Symbol parity** — every public name the original modules exported
+   is still importable from the old path. Greptile flagged
+   ``RPC_SYNC_METHODS`` and ``PARAMS_MODEL_BY_METHOD`` as missing in an
+   earlier pass; this test prevents that regression.
+2. **Identity** — the class objects at the shim path are the *same*
+   objects as the canonical path. Without this, type-narrowing via
+   ``isinstance`` or pattern matching would silently misbehave for code
+   that mixes import styles.
+
+Also asserts the :class:`pydantic.ConfigDict` settings on the JSON-RPC
+classes survived the move from :mod:`agentex.lib.utils.model_utils` to
+plain :mod:`pydantic` — Greptile flagged the silent loss of
+``from_attributes=True`` / ``populate_by_name=True``.
+"""
+
+from __future__ import annotations
+
+
+def test_acp_shim_re_exports_all_original_symbols() -> None:
+    """Every name historically exported from agentex.lib.types.acp must
+    still be importable from that path via the back-compat shim."""
+    # Importing each symbol; ImportError here means the shim regressed.
+    from agentex.lib.types.acp import (  # noqa: F401
+        RPC_SYNC_METHODS,
+        PARAMS_MODEL_BY_METHOD,
+        RPCMethod,
+        SendEventParams,
+        CancelTaskParams,
+        CreateTaskParams,
+        SendMessageParams,
+    )
+
+
+def test_json_rpc_shim_re_exports_all_original_symbols() -> None:
+    """Every name historically exported from agentex.lib.types.json_rpc
+    must still be importable from that path via the back-compat shim."""
+    from agentex.lib.types.json_rpc import (  # noqa: F401
+        JSONRPCError,
+        JSONRPCRequest,
+        JSONRPCResponse,
+    )
+
+
+def test_acp_shim_classes_are_identical_to_canonical() -> None:
+    """Shim re-exports must be the *same* class objects as the canonical
+    path. Different objects would break ``isinstance`` for code that
+    mixes import styles."""
+    from agentex.protocol import acp as canon
+    from agentex.lib.types import acp as shim
+
+    assert shim.RPCMethod is canon.RPCMethod
+    assert shim.CreateTaskParams is canon.CreateTaskParams
+    assert shim.SendMessageParams is canon.SendMessageParams
+    assert shim.SendEventParams is canon.SendEventParams
+    assert shim.CancelTaskParams is canon.CancelTaskParams
+    assert shim.RPC_SYNC_METHODS is canon.RPC_SYNC_METHODS
+    assert shim.PARAMS_MODEL_BY_METHOD is canon.PARAMS_MODEL_BY_METHOD
+
+
+def test_json_rpc_shim_classes_are_identical_to_canonical() -> None:
+    """Same identity check for the JSON-RPC envelope types."""
+    from agentex.protocol import json_rpc as canon
+    from agentex.lib.types import json_rpc as shim
+
+    assert shim.JSONRPCError is canon.JSONRPCError
+    assert shim.JSONRPCRequest is canon.JSONRPCRequest
+    assert shim.JSONRPCResponse is canon.JSONRPCResponse
+
+
+def test_json_rpc_classes_preserve_legacy_model_config() -> None:
+    """Pre-refactor, JSON-RPC classes inherited
+    ``from_attributes=True`` / ``populate_by_name=True`` from
+    ``agentex.lib.utils.model_utils.BaseModel``. The refactor swapped
+    to plain ``pydantic.BaseModel`` and set ``model_config`` explicitly
+    to preserve both flags. Catch any future drop."""
+    from agentex.protocol.json_rpc import (
+        JSONRPCError,
+        JSONRPCRequest,
+        JSONRPCResponse,
+    )
+
+    for cls in (JSONRPCError, JSONRPCRequest, JSONRPCResponse):
+        assert cls.model_config.get("from_attributes") is True, (
+            f"{cls.__name__}.model_config dropped from_attributes=True"
+        )
+        assert cls.model_config.get("populate_by_name") is True, (
+            f"{cls.__name__}.model_config dropped populate_by_name=True"
+        )