refactor(client): move the status contract to the harness plane

docs/modules/client/src.mdx

@@ -13,7 +13,7 @@ Public barrel for the MoltZap client package.
 
 ## Public surface
 
-### [`acquireHarnessClient`](https://github.com/chughtapan/moltzap/blob/main/packages/client/src/harness-client.ts#L201)
+### [`acquireHarnessClient`](https://github.com/chughtapan/moltzap/blob/main/packages/client/src/harness-client.ts#L196)
 
 _Function_
 
@@ -76,7 +76,7 @@ export interface ConversationMeta {
 
 Describes conversation meta.
 
-### [`ConversationWithParticipants`](https://github.com/chughtapan/moltzap/blob/main/packages/client/src/harness/runtime.ts#L95)
+### [`ConversationWithParticipants`](https://github.com/chughtapan/moltzap/blob/main/packages/client/src/harness/runtime.ts#L105)
 
 _TypeAlias_
 
@@ -147,7 +147,7 @@ export interface HarnessTurn extends EnrichedInboundMessage {
 
 Existing adapter presentation with reply authority bound to its live turn.
 
-### [`makeHarnessClientLayer`](https://github.com/chughtapan/moltzap/blob/main/packages/client/src/harness-client.ts#L232)
+### [`makeHarnessClientLayer`](https://github.com/chughtapan/moltzap/blob/main/packages/client/src/harness-client.ts#L227)
 
 _Function_
 

packages/client/src/MODULE.md

@@ -8,7 +8,7 @@ Public barrel for the MoltZap client package.
 
 ## Public surface
 
-### [`acquireHarnessClient`](./harness-client.ts#L201)
+### [`acquireHarnessClient`](./harness-client.ts#L196)
 
 _Function_
 
@@ -71,7 +71,7 @@ export interface ConversationMeta {
 
 Describes conversation meta.
 
-### [`ConversationWithParticipants`](./harness/runtime.ts#L95)
+### [`ConversationWithParticipants`](./harness/runtime.ts#L105)
 
 _TypeAlias_
 
@@ -142,7 +142,7 @@ export interface HarnessTurn extends EnrichedInboundMessage {
 
 Existing adapter presentation with reply authority bound to its live turn.
 
-### [`makeHarnessClientLayer`](./harness-client.ts#L232)
+### [`makeHarnessClientLayer`](./harness-client.ts#L227)
 
 _Function_
 

packages/client/src/harness-client.test.ts

@@ -72,12 +72,13 @@ import {
   type HarnessStartConversationInput,
   type HarnessStartConversationResult,
   type HarnessTurnEvent,
+  harnessStatusInputJsonSchema,
+  harnessStatusResultJsonSchema,
 } from "./harness/index.js";
 import {
   makeHarnessMcpSubscriptionHandler,
   type HarnessMcpSubscriptionHandler,
 } from "./harness-mcp-subscription.js";
-import { statusCommandRpc } from "./local-daemon-rpc.js";
 
 const SERVER_IMPLEMENTATION = {
   name: "harness-client-test",
@@ -208,6 +209,11 @@ const startConversationResultSchema =
     /* Safe because Effect and MCP expose the same JSON Schema wire shape with different array mutability declarations. */ harnessStartConversationResultJsonSchema as JsonSchemaType,
   );
 
+const jsonSchemaToMcpSchema = <A>(schema: unknown) =>
+  fromJsonSchema<A>(
+    /* Safe because Effect and MCP expose the same JSON Schema wire shape with different array mutability declarations. */ schema as JsonSchemaType,
+  );
+
 const effectSchemaToMcpSchema = <A>(schema: Schema.Schema.AnyNoContext) =>
   fromJsonSchema<A>(
     /* Safe because Effect and MCP expose the same JSON Schema wire shape with different array mutability declarations. */ JSONSchema.make(
@@ -257,8 +263,8 @@ const registerStatusTool = (server: McpServer): void => {
   server.registerTool(
     HARNESS_STATUS_TOOL,
     {
-      inputSchema: effectSchemaToMcpSchema(statusCommandRpc.payloadSchema),
-      outputSchema: effectSchemaToMcpSchema(statusCommandRpc.successSchema),
+      inputSchema: jsonSchemaToMcpSchema(harnessStatusInputJsonSchema),
+      outputSchema: jsonSchemaToMcpSchema(harnessStatusResultJsonSchema),
     },
     () =>
       Effect.runPromise(

packages/client/src/harness-client.ts

@@ -26,11 +26,11 @@ import {
   HARNESS_STATUS_TOOL,
   decodeHarnessSearchConversationsResult,
   decodeHarnessStartConversationResult,
+  decodeHarnessStatusResult,
   type ConversationWithParticipants,
   type HarnessClientInternalService,
   type HarnessTurnInternal,
 } from "./harness/index.js";
-import { statusCommandRpc } from "./local-daemon-rpc.js";
 
 /** MCP-local conversation projection including participant identities. */
 export type { ConversationWithParticipants } from "./harness/index.js";
@@ -103,12 +103,7 @@ const readActiveAgentId = (
   session: HarnessClientInternalService,
 ): Effect.Effect<AgentId, Error> =>
   session.callTool(HARNESS_STATUS_TOOL, {}).pipe(
-    Effect.flatMap((result) =>
-      Schema.decodeUnknown(statusCommandRpc.successSchema)(
-        result,
-        strictDecodeOptions,
-      ),
-    ),
+    Effect.flatMap((result) => decodeHarnessStatusResult(result)),
     Effect.mapError(asError),
     Effect.flatMap((status) => {
       if (status.agentId === undefined) {

packages/client/src/harness-mcp-server.test.ts

@@ -32,11 +32,10 @@ import {
 } from "effect";
 import { afterEach, describe, expect, it, vi } from "vitest";
 import { conversationCheckpoint } from "@moltzap/protocol/message";
+import type { AgentId } from "@moltzap/protocol/identity";
 import { agentId, agentName, conversationId } from "@moltzap/protocol/testing";
 import { makeHarnessMcpHttpHandlers } from "./harness-mcp-wire.js";
 import { HARNESS_EVENTS_EXTENSION } from "./harness/index.js";
-import { localDaemonCommands } from "./local-daemon-rpc.js";
-import { makeLocalDaemonHandlers } from "./service-local-daemon.js";
 import { acquireHarnessMcpHttpServer } from "./harness-mcp-server.js";
 import { makeHarnessMcpSubscriptionHandler } from "./harness-mcp-subscription.js";
 
@@ -374,25 +373,17 @@ const closesActiveSubscriptionWhenScopeReleases = async () => {
   expect(running.server.listening).toBe(false);
 };
 
+const makeStatusHandler = (ownAgentId: AgentId, conversations: number) => () =>
+  Effect.succeed({ agentId: ownAgentId, connected: true, conversations });
+
 const makeSubscriptionHarnessHandlers = () => {
   const ownAgentId = agentId("550e8400-e29b-41d4-a716-446655440041");
-  const localHandlers = makeLocalDaemonHandlers({
-    ownAgentId,
-    connected: () => true,
-    conversationCount: () => 0,
-    call: () => {
-      throw new Error("subscription must not call an agent RPC");
-    },
-    handleHistoryRequest: () => {
-      throw new Error("subscription must not read local history");
-    },
-  });
   return makeHarnessMcpHttpHandlers({
     implementation: SERVER_IMPLEMENTATION,
     ...makeReadPlaneHandlers(),
     reply: () => Effect.void,
     startConversation: makeStartConversationHandler(),
-    status: localHandlers[localDaemonCommands.status],
+    status: makeStatusHandler(ownAgentId, 0),
   });
 };
 
@@ -682,25 +673,14 @@ const expectStartConversationTool = async (
 
 const exposesActiveTools = async () => {
   const ownAgentId = agentId("550e8400-e29b-41d4-a716-446655440040");
-  const localHandlers = makeLocalDaemonHandlers({
-    ownAgentId,
-    connected: () => true,
-    conversationCount: () => 3,
-    call: () => {
-      throw new Error("status must not call an agent RPC");
-    },
-    handleHistoryRequest: () => {
-      throw new Error("status must not read local history");
-    },
-  });
   const readPlane = makeReadPlaneHandlers();
   const startConversation = makeStartConversationHandler();
   const handlers = makeHarnessMcpHttpHandlers({
     implementation: SERVER_IMPLEMENTATION,
     ...readPlane,
     reply: () => Effect.void,
     startConversation,
-    status: localHandlers[localDaemonCommands.status],
+    status: makeStatusHandler(ownAgentId, 3),
   });
   const baseUrl = await makeServerWithHandlers(
     handlers.registration,

packages/client/src/harness-mcp-wire.ts

@@ -6,8 +6,6 @@ import {
   type JsonSchemaType,
   type McpHttpHandler,
 } from "@modelcontextprotocol/server";
-import { Headers } from "@effect/platform";
-import { Rpc } from "@effect/rpc";
 import { Effect, JSONSchema, type Schema } from "effect";
 import {
   conversationSearch,
@@ -34,26 +32,25 @@ import {
   harnessReplyResultJsonSchema,
   harnessStartConversationInputJsonSchema,
   harnessStartConversationResultJsonSchema,
+  harnessStatusInputJsonSchema,
+  harnessStatusResultJsonSchema,
   type HarnessReplyInput,
   type HarnessReplyResult,
   type HarnessSearchConversationsResult,
   type HarnessStartConversationInput,
   type HarnessStartConversationResult,
+  type HarnessStatusInput,
+  type HarnessStatusResult,
   type HarnessTurnEvent,
 } from "./harness/index.js";
 import {
   makeHarnessMcpSubscriptionHandler,
   type HarnessMcpSubscriptionHandler,
 } from "./harness-mcp-subscription.js";
-import {
-  statusCommandRpc,
-  type localDaemonCommands,
-  type LocalDaemonHandlers,
-} from "./local-daemon-rpc.js";
 
-type StatusPayload = Schema.Schema.Type<typeof statusCommandRpc.payloadSchema>;
-type StatusResult = Schema.Schema.Type<typeof statusCommandRpc.successSchema>;
-type StatusHandler = LocalDaemonHandlers[typeof localDaemonCommands.status];
+type StatusPayload = HarnessStatusInput;
+type StatusResult = HarnessStatusResult;
+type StatusHandler = (payload: StatusPayload) => Effect.Effect<StatusResult>;
 type ReplyHandler = (
   conversationId: ConversationId,
   payload: string,
@@ -87,16 +84,10 @@ const effectSchemaToMcpSchema = <A>(schema: Schema.Schema.AnyNoContext) =>
   );
 
 const statusInputSchema = fromJsonSchema<StatusPayload>(
-  /* Safe because Effect and MCP expose the same JSON Schema wire shape with different array mutability declarations. */ JSONSchema.make(
-    statusCommandRpc.payloadSchema,
-    { target: "jsonSchema2020-12" },
-  ) as JsonSchemaType,
+  /* Safe because Effect and MCP expose the same JSON Schema wire shape with different array mutability declarations. */ harnessStatusInputJsonSchema as JsonSchemaType,
 );
 const statusOutputSchema = fromJsonSchema<StatusResult>(
-  /* Safe because Effect and MCP expose the same JSON Schema wire shape with different array mutability declarations. */ JSONSchema.make(
-    statusCommandRpc.successSchema,
-    { target: "jsonSchema2020-12" },
-  ) as JsonSchemaType,
+  /* Safe because Effect and MCP expose the same JSON Schema wire shape with different array mutability declarations. */ harnessStatusResultJsonSchema as JsonSchemaType,
 );
 
 const replyInputSchema = fromJsonSchema<HarnessReplyInput>(
@@ -214,24 +205,13 @@ const registerStatusTool = (server: McpServer, status: StatusHandler): void => {
       inputSchema: statusInputSchema,
       outputSchema: statusOutputSchema,
     },
-    (payload) => {
-      const response = status(payload, {
-        clientId: 0,
-        headers: Headers.empty,
-      });
-      const effect = Rpc.isWrapper(response) ? response.value : response;
-      const runnableEffect =
-        /* Safe because the local daemon handler closes over all services while HandlersFrom widens that known-empty environment to `any`. */ effect as Effect.Effect<
-          StatusResult,
-          unknown
-        >;
-      return Effect.runPromise(
-        Effect.map(runnableEffect, (result) => ({
+    (payload) =>
+      Effect.runPromise(
+        Effect.map(status(payload), (result) => ({
           content: [{ type: "text", text: JSON.stringify(result) }],
           structuredContent: result,
         })),
-      );
-    },
+      ),
   );
 };
 

packages/client/src/harness/index.ts

@@ -9,6 +9,7 @@ export {
   decodeHarnessReplyRoute,
   decodeHarnessSearchConversationsResult,
   decodeHarnessStartConversationResult,
+  decodeHarnessStatusResult,
   HARNESS_EVENTS_EXTENSION,
   HARNESS_READ_CONVERSATION_TOOL,
   HARNESS_REPLY_TOOL,
@@ -30,5 +31,9 @@ export {
   harnessStartConversationResultJsonSchema,
   type HarnessStartConversationInput,
   type HarnessStartConversationResult,
+  harnessStatusInputJsonSchema,
+  harnessStatusResultJsonSchema,
+  type HarnessStatusInput,
+  type HarnessStatusResult,
   type HarnessTurnEvent,
 } from "./runtime.js";

packages/client/src/harness/runtime.ts

@@ -86,6 +86,16 @@ const harnessReplyRouteSchema = Schema.Struct({
   conversationId,
 });
 
+/** Status takes no arguments; the daemon reports on the slot it already owns. */
+const harnessStatusInputSchema = Schema.Struct({});
+
+/** Active daemon identity and connection state. */
+const harnessStatusResultSchema = Schema.Struct({
+  agentId: Schema.optional(agentId),
+  connected: Schema.Boolean,
+  conversations: Schema.Number.pipe(Schema.int(), Schema.nonNegative()),
+});
+
 /** Decoded harness turn event. */
 export type HarnessTurnEvent = Schema.Schema.Type<
   typeof harnessTurnEventSchema
@@ -126,6 +136,16 @@ export type HarnessReplyRoute = Schema.Schema.Type<
   typeof harnessReplyRouteSchema
 >;
 
+/** Decoded status input. */
+export type HarnessStatusInput = Schema.Schema.Type<
+  typeof harnessStatusInputSchema
+>;
+
+/** Decoded status result. */
+export type HarnessStatusResult = Schema.Schema.Type<
+  typeof harnessStatusResultSchema
+>;
+
 const strictDecodeOptions = { onExcessProperty: "error" } as const;
 const decodeTurnEvent = Schema.decodeUnknown(harnessTurnEventSchema);
 const decodeSearchConversationsResult = Schema.decodeUnknown(
@@ -135,6 +155,7 @@ const decodeStartConversationResult = Schema.decodeUnknown(
   harnessStartConversationResultSchema,
 );
 const decodeReplyRoute = Schema.decodeUnknown(harnessReplyRouteSchema);
+const decodeStatusResult = Schema.decodeUnknown(harnessStatusResultSchema);
 
 /** JSON Schema advertised for start-conversation arguments. */
 export const harnessStartConversationInputJsonSchema = JSONSchema.make(
@@ -166,6 +187,18 @@ export const harnessReplyResultJsonSchema = JSONSchema.make(
   { target: "jsonSchema2020-12" },
 );
 
+/** JSON Schema advertised for the empty status arguments. */
+export const harnessStatusInputJsonSchema = JSONSchema.make(
+  harnessStatusInputSchema,
+  { target: "jsonSchema2020-12" },
+);
+
+/** JSON Schema advertised for the status result. */
+export const harnessStatusResultJsonSchema = JSONSchema.make(
+  harnessStatusResultSchema,
+  { target: "jsonSchema2020-12" },
+);
+
 /**
  * Strictly decode a turn event received from the MCP boundary.
  * @param value Untrusted notification parameters.
@@ -190,6 +223,14 @@ export const decodeHarnessSearchConversationsResult = (value: unknown) =>
 export const decodeHarnessStartConversationResult = (value: unknown) =>
   decodeStartConversationResult(value, strictDecodeOptions);
 
+/**
+ * Strictly decode the daemon status reported over the MCP boundary.
+ * @param value Untrusted structured tool content.
+ * @returns The decoded identity and connection state.
+ */
+export const decodeHarnessStatusResult = (value: unknown) =>
+  decodeStatusResult(value, strictDecodeOptions);
+
 /**
  * Build the private request metadata consumed by the production harness client.
  * @param originatingConversationId Conversation associated with the live turn.

packages/client/src/local-daemon-rpc.ts

@@ -18,6 +18,11 @@ const UUID_V4_RE =
 const CONVERSATION_TARGET_PREFIX = "conv:";
 const PARTICIPANT_PREFIX = "agent:";
 
+// The harness plane owns the status contract. This socket surface states the
+// same shape independently so the surviving plane never imports the dying one;
+// a schema constructor cannot be shared across them. Drift is a compile error
+// either way, because service-local-daemon.ts and moltzapd.ts each implement a
+// handler against its own side.
 const emptyPayload = Schema.Struct({});
 const localDaemonStatusResultSchema = Schema.Struct({
   agentId: Schema.optional(agentId),
@@ -236,8 +241,7 @@ export const toLocalDaemonError = (error: unknown): LocalDaemonError =>
     ? error
     : new LocalDaemonInputError({ message: errorMessage(error) });
 
-/** Provides the status command rpc runtime value. */
-export const statusCommandRpc = Rpc.make(localDaemonCommands.status, {
+const statusCommandRpc = Rpc.make(localDaemonCommands.status, {
   payload: emptyPayload,
   success: localDaemonStatusResultSchema,
   error: localDaemonErrorSchema,