Fix : Scope implicit TypeAgent conversation bindings to Copilot sessions

ts/packages/copilot-plugin/README.md

@@ -300,19 +300,28 @@ pending prompts/unsupported interaction rather than pretending completion.
 
 ### Explicit binding, reconnect, and trust
 
-NL and structured calls use the same conversation selection in every routing
-mode. With no explicit ID, the first caller resolves the server default and
-saves its **concrete conversation ID** under the plugin data directory's
-`conversation-bindings` folder, keyed by server URL. Later hooks, MCP processes,
-and reconnects reuse that ID even if the server default changes. Concurrent
-first callers atomically adopt the same saved ID. Routing mode does not change
-which conversation data is visible.
-
-This is shared plugin/server context, not one conversation per Copilot chat:
-stdio does not provide an intrinsic Copilot session identity. Sessions using the
-same plugin data directory and server share the saved default, as NL callers
-already shared the server default. Separate plugin data directories or explicit
-IDs select separate context.
+NL, direct/dev hooks, extension history, and structured calls share automatic
+conversation selection **within a Copilot session**. The first caller resolves
+the server default and saves its concrete ID, keyed by server URL and host
+session ID. Later calls, reconnects, and resumed sessions retain that selection
+even if the server default changes. Concurrent first callers atomically adopt
+the same saved ID. A fresh Copilot session resolves the current server default,
+not another session's saved selection. This does not create a private TypeAgent
+conversation per chat: sessions resolving the same default still share its data.
+
+Copilot CLI supplies `COPILOT_AGENT_SESSION_ID` to MCP children. Hooks use their
+input `sessionId` instead of a potentially inherited environment value; extension
+history uses the joined SDK session ID. Hosts without an MCP session ID share
+automatic NL/structured selection only inside that MCP process. Cross-process
+alignment on those hosts requires an explicit existing conversation ID.
+
+Session bindings live in `conversation-bindings/sessions` under
+`TYPEAGENT_PLUGIN_DATA`, or `~/.typeagent-copilot` by default. Unlike configuration
+lookup, binding storage does not use `CLAUDE_PLUGIN_DATA`: Copilot injects that
+variable into hooks but not MCP processes. Explicit `TYPEAGENT_PLUGIN_DATA`
+isolates both configuration and bindings and must be consistent across callers.
+Legacy server-only `conversation-bindings/*.json` defaults are ignored and left
+untouched; they are not explicit user pins and must not bind unrelated new chats.
 
 The two routes keep separate connections. Structured calls explicitly join the
 selected ID with `structuredActions: {}` to obtain an independent owner; the
@@ -331,12 +340,14 @@ before changing selection, then start fresh sessions; pending work is not
 automatically moved or replayed. Two fresh processes using the same public ID
 still get isolated structured owners.
 
-A missing/deleted conversation or an unreadable/corrupt saved binding is an
-error, not a reason to silently choose a new default. To select another existing
-conversation, configure its ID. To intentionally resolve the default again,
-close sessions, remove only the matching server's saved binding file, and start
-fresh sessions with no explicit ID. Configuration fields such as selected
-skills are not rewritten when the default ID is saved.
+A missing/deleted conversation or an unreadable/corrupt binding in the current
+session is an error, not a reason to silently choose a new default. To select
+another existing conversation, configure its ID and start a fresh session.
+Without an explicit pin, starting a **new** Copilot session resolves the current
+default; resuming the old session intentionally retains its selection and may
+still fail. No request is automatically retried, and pending approvals, scopes,
+and resume capabilities never move to another conversation. Configuration fields
+such as selected skills are not rewritten when a default ID is saved.
 
 The server's structured resume token is retained only in private volatile
 connector memory. It is never logged, printed, persisted, put in config, or sent
@@ -829,14 +840,14 @@ The plugin stores config at `%USERPROFILE%\.typeagent-copilot\config.json` (Wind
 
 **Environment variable overrides** (take precedence over config file):
 
-| Variable                    | Default                            | Description                                                                                      |
-| --------------------------- | ---------------------------------- | ------------------------------------------------------------------------------------------------ |
-| `TYPEAGENT_MODE`            | `direct`                           | `direct`, `mcp`, `dev`, or `bypass`                                                              |
-| `TYPEAGENT_HOST`            | `localhost`                        | TypeAgent server host                                                                            |
-| `TYPEAGENT_PORT`            | `8999`                             | TypeAgent server port                                                                            |
-| `TYPEAGENT_CONVERSATION_ID` | Dedicated per-process conversation | Optional existing public conversation ID for structured tools; overrides config `conversationId` |
-| `TYPEAGENT_PLUGIN_DATA`     | `~/.typeagent-copilot`             | Config directory                                                                                 |
-| `TYPEAGENT_WORKSPACE_ROOTS` | Copilot process working directory  | Approved roots for workspace MCP tools, separated by the platform path delimiter                 |
+| Variable                    | Default                           | Description                                                                                                        |
+| --------------------------- | --------------------------------- | ------------------------------------------------------------------------------------------------------------------ |
+| `TYPEAGENT_MODE`            | `direct`                          | `direct`, `mcp`, `dev`, or `bypass`                                                                                |
+| `TYPEAGENT_HOST`            | `localhost`                       | TypeAgent server host                                                                                              |
+| `TYPEAGENT_PORT`            | `8999`                            | TypeAgent server port                                                                                              |
+| `TYPEAGENT_CONVERSATION_ID` | Session-selected server default   | Optional existing public conversation ID for all routes; overrides config `conversationId` and automatic selection |
+| `TYPEAGENT_PLUGIN_DATA`     | `~/.typeagent-copilot`            | Config directory                                                                                                   |
+| `TYPEAGENT_WORKSPACE_ROOTS` | Copilot process working directory | Approved roots for workspace MCP tools, separated by the platform path delimiter                                   |
 
 ---
 

ts/packages/copilot-plugin/src/extension/session-capture.ts

@@ -53,17 +53,21 @@ function resultText(result: unknown): string {
 }
 
 async function withDispatcher(
+    sessionId: string,
     operation: (dispatcher: Dispatcher) => Promise<void>,
 ): Promise<void> {
-    const dispatcher = await connectToTypeAgent(createClientIO({}));
+    const dispatcher = await connectToTypeAgent(createClientIO({}), sessionId);
     try {
         await operation(dispatcher);
     } finally {
         await dispatcher.close();
     }
 }
 
-async function insertToolHistory(event: ExtensionSessionEvent): Promise<void> {
+async function insertToolHistory(
+    event: ExtensionSessionEvent,
+    sessionId: string,
+): Promise<void> {
     if (event.data.success !== true) return;
     const toolName =
         typeof event.data.toolName === "string"
@@ -89,7 +93,7 @@ async function insertToolHistory(event: ExtensionSessionEvent): Promise<void> {
             source: "copilot-cli",
         },
     };
-    await withDispatcher(async (dispatcher) => {
+    await withDispatcher(sessionId, async (dispatcher) => {
         await awaitCommand(
             dispatcher,
             `@history insert ${JSON.stringify(message)}`,
@@ -99,6 +103,7 @@ async function insertToolHistory(event: ExtensionSessionEvent): Promise<void> {
 
 async function insertTurnHistory(
     trace: RecordedInteractionTrace,
+    sessionId: string,
 ): Promise<void> {
     if (
         trace.toolCalls.some((tool) =>
@@ -116,7 +121,7 @@ async function insertTurnHistory(
             source: "copilot-cli",
         },
     };
-    await withDispatcher(async (dispatcher) => {
+    await withDispatcher(sessionId, async (dispatcher) => {
         await awaitCommand(
             dispatcher,
             `@history insert ${JSON.stringify(message)}`,
@@ -200,10 +205,13 @@ export class SessionCapture {
             const metadata = this.toolMetadata.get(key);
             this.toolMetadata.delete(key);
             if (metadata) {
-                await this.dependencies.insertToolHistory({
-                    ...event,
-                    data: { ...event.data, ...metadata },
-                });
+                await this.dependencies.insertToolHistory(
+                    {
+                        ...event,
+                        data: { ...event.data, ...metadata },
+                    },
+                    this.sessionId,
+                );
             }
         }
         if (event.type === "session.idle") {
@@ -249,7 +257,10 @@ export class SessionCapture {
                 }
             }
             if (trace && !aborted) {
-                await this.dependencies.insertTurnHistory(trace);
+                await this.dependencies.insertTurnHistory(
+                    trace,
+                    this.sessionId,
+                );
                 writeDemoState({
                     event: "turnComplete",
                     turnId: makeTurnId(this.sessionId),

ts/packages/copilot-plugin/src/hooks/hook-dev-actions.ts

@@ -159,7 +159,10 @@ export async function handleDevActions(
 
     try {
         abortSignal?.throwIfAborted();
-        dispatcher = await dependencies.connectToTypeAgent(clientIO);
+        dispatcher = await dependencies.connectToTypeAgent(
+            clientIO,
+            input.sessionId,
+        );
         abortSignal?.throwIfAborted();
         submissionStarted = true;
         const submitResult = await dispatcher.submitCommand(

ts/packages/copilot-plugin/src/hooks/hook-direct.ts

@@ -142,7 +142,10 @@ export async function handleDirect(
         dependencies.emitProgress("Connecting to TypeAgent...", {
             temporary: true,
         });
-        dispatcher = await dependencies.connectToTypeAgent(clientIO);
+        dispatcher = await dependencies.connectToTypeAgent(
+            clientIO,
+            input.sessionId,
+        );
         dependencies.emitProgress("Processing command...", {
             temporary: true,
         });

ts/packages/copilot-plugin/src/mcp/server.ts

@@ -18,7 +18,7 @@ const server =
             : new TypeAgentMcpServer();
 
 if (server instanceof TypeAgentMcpServer) {
-    // Stdio has no intrinsic Copilot session identity. This process retains one
+    // The host session selects public context; this process alone retains the
     // private structured owner until shutdown, without cancelling pending work.
     process.once("SIGINT", () => void server.close());
     process.once("SIGTERM", () => void server.close());

ts/packages/copilot-plugin/src/shared/conversation-selection.ts

@@ -4,16 +4,36 @@
 import { createHash, randomUUID } from "node:crypto";
 import { link, mkdir, readFile, unlink, writeFile } from "node:fs/promises";
 import { dirname, join } from "node:path";
+import { homedir } from "node:os";
 import type {
     AgentServerConnection,
     ClientIO,
 } from "@typeagent/agent-server-client";
-import { getConfigDir, getConversationId } from "./plugin-config.js";
+import { getConversationId } from "./plugin-config.js";
 
-function bindingPath(url: string): string {
+const processBindings = new Map<string, string>();
+
+function bindingKey(url: string, sessionId: string | undefined): string {
     const server = new URL(url).href;
-    const key = createHash("sha256").update(server).digest("hex");
-    return join(getConfigDir(), "conversation-bindings", `${key}.json`);
+    return createHash("sha256")
+        .update(JSON.stringify([server, sessionId]))
+        .digest("hex");
+}
+
+function bindingLocation(url: string, sessionId: string | undefined) {
+    // Copilot supplies CLAUDE_PLUGIN_DATA to hooks but not to MCP children.
+    const directory =
+        process.env.TYPEAGENT_PLUGIN_DATA ??
+        join(homedir(), ".typeagent-copilot");
+    if (sessionId !== undefined && !sessionId.trim()) {
+        throw new Error("TypeAgent conversation session ID must not be empty.");
+    }
+    return join(
+        directory,
+        "conversation-bindings",
+        "sessions",
+        `${bindingKey(url, sessionId)}.json`,
+    );
 }
 
 function hasCode(error: unknown, code: string): boolean {
@@ -51,22 +71,26 @@ async function readBinding(path: string): Promise<string | undefined> {
     return requireId(value.conversationId);
 }
 
-/** Public context only, shared by hook/MCP processes using this config and server. */
+/** Public context only; automatic selections belong to a host session, not a server. */
 export async function readSelectedConversationId(
     url: string,
+    sessionId: string | undefined = process.env.COPILOT_AGENT_SESSION_ID,
 ): Promise<string | undefined> {
     const configured = getConversationId();
-    return configured === undefined
-        ? readBinding(bindingPath(url))
-        : requireId(configured);
+    if (configured !== undefined) return requireId(configured);
+    const path = bindingLocation(url, sessionId);
+    return sessionId === undefined
+        ? processBindings.get(path)
+        : readBinding(path);
 }
 
 export async function selectConversationId(
     connection: AgentServerConnection,
     clientIO: ClientIO,
     url: string,
+    sessionId: string | undefined = process.env.COPILOT_AGENT_SESSION_ID,
 ): Promise<string> {
-    const selected = await readSelectedConversationId(url);
+    const selected = await readSelectedConversationId(url, sessionId);
     if (selected !== undefined) return selected;
 
     const joined = await connection.joinConversation(clientIO, {
@@ -75,7 +99,13 @@ export async function selectConversationId(
     });
     await connection.leaveConversation(joined.conversationId);
     const conversationId = requireId(joined.conversationId);
-    const path = bindingPath(url);
+    const path = bindingLocation(url, sessionId);
+    if (sessionId === undefined) {
+        // Unknown hosts share NL/structured context only inside this process.
+        const winner = processBindings.get(path) ?? conversationId;
+        processBindings.set(path, winner);
+        return winner;
+    }
     await mkdir(dirname(path), { recursive: true });
     const temporary = `${path}.${randomUUID()}.tmp`;
     await writeFile(temporary, JSON.stringify({ conversationId }), {
@@ -92,7 +122,7 @@ export async function selectConversationId(
     } finally {
         await unlink(temporary);
     }
-    const winner = await readSelectedConversationId(url);
+    const winner = await readSelectedConversationId(url, sessionId);
     if (winner === undefined) {
         throw new Error(
             "TypeAgent conversation binding disappeared during selection.",

ts/packages/copilot-plugin/src/shared/structured-action-client.ts

@@ -18,17 +18,23 @@ export function createStructuredActionClient(
     connect?: StructuredActionClientOptions["connect"],
 ): StructuredActionClient {
     const conversationId = getConversationId();
+    const sessionId = process.env.COPILOT_AGENT_SESSION_ID;
     const clientIO = createClientIO({});
     return new StructuredActionClient({
         url: TYPEAGENT_URL,
         clientIO,
         ...(connect === undefined ? {} : { connect }),
         ...(conversationId === undefined ? {} : { conversationId }),
         resolveConversationId: (connection) =>
-            selectConversationId(connection, clientIO, TYPEAGENT_URL),
+            selectConversationId(
+                connection,
+                clientIO,
+                TYPEAGENT_URL,
+                sessionId,
+            ),
         validateConversationId: async (conversationId) => {
             if (
-                (await readSelectedConversationId(TYPEAGENT_URL)) !==
+                (await readSelectedConversationId(TYPEAGENT_URL, sessionId)) !==
                 conversationId
             ) {
                 throw new StructuredActionClientError(

ts/packages/copilot-plugin/src/shared/typeagent-client.ts

@@ -123,15 +123,20 @@ export function createClientIO(callbacks: DisplayCallbacks): ClientIO {
  */
 export async function connectToTypeAgent(
     clientIO: ClientIO,
+    sessionId: string | undefined = process.env.COPILOT_AGENT_SESSION_ID,
 ): Promise<Dispatcher> {
-    let conversationId = await readSelectedConversationId(TYPEAGENT_URL);
+    let conversationId = await readSelectedConversationId(
+        TYPEAGENT_URL,
+        sessionId,
+    );
     if (conversationId === undefined) {
         const connection = await connectToAgentServer();
         try {
             conversationId = await selectConversationId(
                 connection,
                 clientIO,
                 TYPEAGENT_URL,
+                sessionId,
             );
         } finally {
             await connection.close();