feat: update to unstable schema and metadata

examples/agent.py

@@ -28,7 +28,7 @@
     Implementation,
     ResourceContentBlock,
     SseMcpServer,
-    StdioMcpServer,
+    McpServerStdio,
     TextContentBlock,
 )
 
@@ -66,7 +66,7 @@ async def authenticate(self, method_id: str, **kwargs: Any) -> AuthenticateRespo
         return AuthenticateResponse()
 
     async def new_session(
-        self, cwd: str, mcp_servers: list[HttpMcpServer | SseMcpServer | StdioMcpServer], **kwargs: Any
+        self, cwd: str, mcp_servers: list[HttpMcpServer | SseMcpServer | McpServerStdio], **kwargs: Any
     ) -> NewSessionResponse:
         logging.info("Received new session request")
         session_id = str(self._next_session_id)
@@ -75,7 +75,7 @@ async def new_session(
         return NewSessionResponse(session_id=session_id, modes=None)
 
     async def load_session(
-        self, cwd: str, mcp_servers: list[HttpMcpServer | SseMcpServer | StdioMcpServer], session_id: str, **kwargs: Any
+        self, cwd: str, mcp_servers: list[HttpMcpServer | SseMcpServer | McpServerStdio], session_id: str, **kwargs: Any
     ) -> LoadSessionResponse | None:
         logging.info("Received load session request %s", session_id)
         self._sessions.add(session_id)

examples/echo_agent.py

@@ -22,7 +22,7 @@
     Implementation,
     ResourceContentBlock,
     SseMcpServer,
-    StdioMcpServer,
+    McpServerStdio,
     TextContentBlock,
 )
 
@@ -43,7 +43,7 @@ async def initialize(
         return InitializeResponse(protocol_version=protocol_version)
 
     async def new_session(
-        self, cwd: str, mcp_servers: list[HttpMcpServer | SseMcpServer | StdioMcpServer], **kwargs: Any
+        self, cwd: str, mcp_servers: list[HttpMcpServer | SseMcpServer | McpServerStdio], **kwargs: Any
     ) -> NewSessionResponse:
         return NewSessionResponse(session_id=uuid4().hex)
 

schema/VERSION

@@ -1 +1 @@
-refs/tags/v0.6.3
+refs/tags/v0.7.0

schema/meta.json

@@ -3,6 +3,7 @@
     "authenticate": "authenticate",
     "initialize": "initialize",
     "session_cancel": "session/cancel",
+    "session_list": "session/list",
     "session_load": "session/load",
     "session_new": "session/new",
     "session_prompt": "session/prompt",

scripts/gen_all.py

@@ -109,8 +109,8 @@ def resolve_ref(version: str | None) -> str:
 
 def download_schema(repo: str, ref: str) -> None:
     SCHEMA_DIR.mkdir(parents=True, exist_ok=True)
-    schema_url = f"https://raw.githubusercontent.com/{repo}/{ref}/schema/schema.json"
-    meta_url = f"https://raw.githubusercontent.com/{repo}/{ref}/schema/meta.json"
+    schema_url = f"https://raw.githubusercontent.com/{repo}/{ref}/schema/schema.unstable.json"
+    meta_url = f"https://raw.githubusercontent.com/{repo}/{ref}/schema/meta.unstable.json"
     try:
         schema_data = fetch_json(schema_url)
         meta_data = fetch_json(meta_url)

scripts/gen_schema.py

@@ -28,7 +28,7 @@
 
 STDIO_TYPE_LITERAL = 'Literal["2#-datamodel-code-generator-#-object-#-special-#"]'
 STDIO_TYPE_PATTERN = re.compile(
-    r"^    type:\s*Literal\[['\"]2#-datamodel-code-generator-#-object-#-special-#['\"]\]"
+    r"^    type:\s*Literal\[['\"]McpServerStdio['\"]\]"
     r"(?:\s*=\s*['\"][^'\"]+['\"])?\s*$",
     re.MULTILINE,
 )
@@ -40,7 +40,6 @@
     "AgentOutgoingMessage2": "AgentResponseMessage",
     "AgentOutgoingMessage3": "AgentErrorMessage",
     "AgentOutgoingMessage4": "AgentNotificationMessage",
-    "AvailableCommandInput1": "CommandInputHint",
     "ClientOutgoingMessage1": "ClientRequestMessage",
     "ClientOutgoingMessage2": "ClientResponseMessage",
     "ClientOutgoingMessage3": "ClientErrorMessage",
@@ -52,7 +51,6 @@
     "ContentBlock5": "EmbeddedResourceContentBlock",
     "McpServer1": "HttpMcpServer",
     "McpServer2": "SseMcpServer",
-    "McpServer3": "StdioMcpServer",
     "RequestPermissionOutcome1": "DeniedOutcome",
     "RequestPermissionOutcome2": "AllowedOutcome",
     "SessionUpdate1": "UserMessageChunk",
@@ -68,6 +66,10 @@
     "ToolCallContent3": "TerminalToolCallContent",
 }
 
+ALIASES_MAP = {
+    "StdioMcpServer": "McpServerStdio",
+}
+
 ENUM_LITERAL_MAP: dict[str, tuple[str, ...]] = {
     "PermissionOptionKind": (
         "allow_once",
@@ -87,16 +89,15 @@
     ("PlanEntry", "priority", "PlanEntryPriority", False),
     ("PlanEntry", "status", "PlanEntryStatus", False),
     ("PromptResponse", "stop_reason", "StopReason", False),
-    ("ToolCallProgress", "kind", "ToolKind", True),
-    ("ToolCallProgress", "status", "ToolCallStatus", True),
-    ("ToolCallStart", "kind", "ToolKind", True),
-    ("ToolCallStart", "status", "ToolCallStatus", True),
     ("ToolCall", "kind", "ToolKind", True),
     ("ToolCall", "status", "ToolCallStatus", True),
+    ("ToolCallUpdate", "kind", "ToolKind", True),
+    ("ToolCallUpdate", "status", "ToolCallStatus", True),
 )
 
 DEFAULT_VALUE_OVERRIDES: tuple[tuple[str, str, str], ...] = (
     ("AgentCapabilities", "mcp_capabilities", "McpCapabilities()"),
+    ("AgentCapabilities", "session_capabilities", "SessionCapabilities()"),
     (
         "AgentCapabilities",
         "prompt_capabilities",
@@ -222,6 +223,7 @@ def _build_header_block() -> str:
 
 def _build_alias_block() -> str:
     alias_lines = [f"{old} = {new}" for old, new in sorted(RENAME_MAP.items())]
+    alias_lines += [f"{old} = {new}" for old, new in sorted(ALIASES_MAP.items())]
     return BACKCOMPAT_MARKER + "\n" + "\n".join(alias_lines) + "\n"
 
 
@@ -421,6 +423,7 @@ def _normalize_stdio_model(content: str) -> str:
     replacement_line = '    type: Literal["stdio"] = "stdio"'
     new_content, count = STDIO_TYPE_PATTERN.subn(replacement_line, content)
     if count == 0:
+        print("Warning: stdio type placeholder not found; no replacements made.", file=sys.stderr)
         return content
     if count > 1:
         print(

src/acp/agent/connection.py

@@ -28,9 +28,9 @@
     SessionNotification,
     TerminalOutputRequest,
     TerminalOutputResponse,
-    ToolCall,
     ToolCallProgress,
     ToolCallStart,
+    ToolCallUpdate,
     UserMessageChunk,
     WaitForTerminalExitRequest,
     WaitForTerminalExitResponse,
@@ -56,12 +56,14 @@ def __init__(
         input_stream: Any,
         output_stream: Any,
         listening: bool = True,
+        *,
+        use_unstable_protocol: bool = False,
         **connection_kwargs: Any,
     ) -> None:
         agent = to_agent(cast(Client, self)) if callable(to_agent) else to_agent
         if not isinstance(input_stream, asyncio.StreamWriter) or not isinstance(output_stream, asyncio.StreamReader):
             raise TypeError(_AGENT_CONNECTION_ERROR)
-        handler = build_agent_router(cast(Agent, agent))
+        handler = build_agent_router(cast(Agent, agent), use_unstable_protocol=use_unstable_protocol)
         self._conn = Connection(handler, input_stream, output_stream, listening=listening, **connection_kwargs)
         if on_connect := getattr(agent, "on_connect", None):
             on_connect(self)
@@ -92,7 +94,7 @@ async def session_update(
 
     @param_model(RequestPermissionRequest)
     async def request_permission(
-        self, options: list[PermissionOption], session_id: str, tool_call: ToolCall, **kwargs: Any
+        self, options: list[PermissionOption], session_id: str, tool_call: ToolCallUpdate, **kwargs: Any
     ) -> RequestPermissionResponse:
         return await request_model(
             self._conn,

src/acp/agent/router.py

@@ -10,6 +10,7 @@
     AuthenticateRequest,
     CancelNotification,
     InitializeRequest,
+    ListSessionsRequest,
     LoadSessionRequest,
     NewSessionRequest,
     PromptRequest,
@@ -21,8 +22,8 @@
 __all__ = ["build_agent_router"]
 
 
-def build_agent_router(agent: Agent) -> MessageRouter:
-    router = MessageRouter()
+def build_agent_router(agent: Agent, use_unstable_protocol: bool = False) -> MessageRouter:
+    router = MessageRouter(use_unstable_protocol=use_unstable_protocol)
 
     router.route_request(AGENT_METHODS["initialize"], InitializeRequest, agent, "initialize")
     router.route_request(AGENT_METHODS["session_new"], NewSessionRequest, agent, "new_session")
@@ -33,6 +34,7 @@ def build_agent_router(agent: Agent) -> MessageRouter:
         "load_session",
         adapt_result=normalize_result,
     )
+    router.route_request(AGENT_METHODS["session_list"], ListSessionsRequest, agent, "list_sessions", unstable=True)
     router.route_request(
         AGENT_METHODS["session_set_mode"],
         SetSessionModeRequest,
@@ -47,6 +49,7 @@ def build_agent_router(agent: Agent) -> MessageRouter:
         agent,
         "set_session_model",
         adapt_result=normalize_result,
+        unstable=True,
     )
     router.route_request(
         AGENT_METHODS["authenticate"],

src/acp/client/connection.py

@@ -19,8 +19,11 @@
     Implementation,
     InitializeRequest,
     InitializeResponse,
+    ListSessionsRequest,
+    ListSessionsResponse,
     LoadSessionRequest,
     LoadSessionResponse,
+    McpServerStdio,
     NewSessionRequest,
     NewSessionResponse,
     PromptRequest,
@@ -31,7 +34,6 @@
     SetSessionModeRequest,
     SetSessionModeResponse,
     SseMcpServer,
-    StdioMcpServer,
     TextContentBlock,
 )
 from ..utils import compatible_class, notify_model, param_model, request_model, request_model_from_dict
@@ -51,12 +53,14 @@ def __init__(
         to_client: Callable[[Agent], Client] | Client,
         input_stream: Any,
         output_stream: Any,
+        *,
+        use_unstable_protocol: bool = False,
         **connection_kwargs: Any,
     ) -> None:
         if not isinstance(input_stream, asyncio.StreamWriter) or not isinstance(output_stream, asyncio.StreamReader):
             raise TypeError(_CLIENT_CONNECTION_ERROR)
         client = to_client(cast(Agent, self)) if callable(to_client) else to_client
-        handler = build_client_router(cast(Client, client))
+        handler = build_client_router(cast(Client, client), use_unstable_protocol=use_unstable_protocol)
         self._conn = Connection(handler, input_stream, output_stream, **connection_kwargs)
         if on_connect := getattr(client, "on_connect", None):
             on_connect(self)
@@ -83,7 +87,7 @@ async def initialize(
 
     @param_model(NewSessionRequest)
     async def new_session(
-        self, cwd: str, mcp_servers: list[HttpMcpServer | SseMcpServer | StdioMcpServer], **kwargs: Any
+        self, cwd: str, mcp_servers: list[HttpMcpServer | SseMcpServer | McpServerStdio], **kwargs: Any
     ) -> NewSessionResponse:
         return await request_model(
             self._conn,
@@ -94,7 +98,7 @@ async def new_session(
 
     @param_model(LoadSessionRequest)
     async def load_session(
-        self, cwd: str, mcp_servers: list[HttpMcpServer | SseMcpServer | StdioMcpServer], session_id: str, **kwargs: Any
+        self, cwd: str, mcp_servers: list[HttpMcpServer | SseMcpServer | McpServerStdio], session_id: str, **kwargs: Any
     ) -> LoadSessionResponse:
         return await request_model_from_dict(
             self._conn,
@@ -103,6 +107,17 @@ async def load_session(
             LoadSessionResponse,
         )
 
+    @param_model(ListSessionsRequest)
+    async def list_sessions(
+        self, cursor: str | None = None, cwd: str | None = None, **kwargs: Any
+    ) -> ListSessionsResponse:
+        return await request_model_from_dict(
+            self._conn,
+            AGENT_METHODS["session_list"],
+            ListSessionsRequest(cursor=cursor, cwd=cwd, field_meta=kwargs or None),
+            ListSessionsResponse,
+        )
+
     @param_model(SetSessionModeRequest)
     async def set_session_mode(self, mode_id: str, session_id: str, **kwargs: Any) -> SetSessionModeResponse:
         return await request_model_from_dict(

src/acp/client/router.py

@@ -22,8 +22,8 @@
 __all__ = ["build_client_router"]
 
 
-def build_client_router(client: Client) -> MessageRouter:
-    router = MessageRouter()
+def build_client_router(client: Client, use_unstable_protocol: bool = False) -> MessageRouter:
+    router = MessageRouter(use_unstable_protocol=use_unstable_protocol)
 
     router.route_request(CLIENT_METHODS["fs_write_text_file"], WriteTextFileRequest, client, "write_text_file")
     router.route_request(CLIENT_METHODS["fs_read_text_file"], ReadTextFileRequest, client, "read_text_file")

src/acp/contrib/permissions.py

@@ -4,7 +4,7 @@
 from typing import Any
 
 from ..helpers import text_block, tool_content
-from ..schema import PermissionOption, RequestPermissionRequest, RequestPermissionResponse, ToolCall
+from ..schema import PermissionOption, RequestPermissionRequest, RequestPermissionResponse, ToolCallUpdate
 from .tool_calls import ToolCallTracker, _copy_model_list
 
 
@@ -60,7 +60,7 @@ async def request_for(
         description: str | None = None,
         options: Sequence[PermissionOption] | None = None,
         content: Sequence[Any] | None = None,
-        tool_call: ToolCall | None = None,
+        tool_call: ToolCallUpdate | None = None,
     ) -> RequestPermissionResponse:
         """Request user approval for a tool call."""
         if tool_call is None:

src/acp/contrib/tool_calls.py

@@ -7,7 +7,14 @@
 from pydantic import BaseModel, ConfigDict
 
 from ..helpers import text_block, tool_content
-from ..schema import ToolCall, ToolCallLocation, ToolCallProgress, ToolCallStart, ToolCallStatus, ToolKind
+from ..schema import (
+    ToolCallLocation,
+    ToolCallProgress,
+    ToolCallStart,
+    ToolCallStatus,
+    ToolCallUpdate,
+    ToolKind,
+)
 
 
 class _MissingToolCallTitleError(ValueError):
@@ -91,8 +98,8 @@ def to_view(self) -> TrackedToolCallView:
             raw_output=self.raw_output,
         )
 
-    def to_tool_call_model(self) -> ToolCall:
-        return ToolCall(
+    def to_tool_call_model(self) -> ToolCallUpdate:
+        return ToolCallUpdate(
             tool_call_id=self.tool_call_id,
             title=self.title,
             kind=self.kind,
@@ -249,7 +256,7 @@ def view(self, external_id: str) -> TrackedToolCallView:
         state = self._require_call(external_id)
         return state.to_view()
 
-    def tool_call_model(self, external_id: str) -> ToolCall:
+    def tool_call_model(self, external_id: str) -> ToolCallUpdate:
         """Return a deep copy of the tool call suitable for permission requests."""
         state = self._require_call(external_id)
         return state.to_tool_call_model()