single chat sot

packages/coding-agent/src/core/gateway/index.ts

@@ -12,6 +12,7 @@ export type {
   GatewayMessageResult,
   GatewayRuntimeOptions,
   GatewaySessionFactory,
+  GatewaySessionState,
   GatewaySessionSnapshot,
   HistoryMessage,
   HistoryPart,

packages/coding-agent/src/core/gateway/internal-types.ts

@@ -1,9 +1,11 @@
+import type { AgentMessage } from "@mariozechner/pi-agent-core";
 import type { AgentSession } from "../agent-session.js";
 import type {
   GatewayMessageRequest,
   GatewayMessageResult,
   GatewaySessionSnapshot,
 } from "./types.js";
+import type { GatewayTransientToolResult } from "./session-state.js";
 
 export interface GatewayQueuedMessage {
   request: GatewayMessageRequest;
@@ -60,6 +62,8 @@ export interface ManagedGatewaySession {
   session: AgentSession;
   queue: GatewayQueuedMessage[];
   processing: boolean;
+  activeAssistantMessage: AgentMessage | null;
+  pendingToolResults: GatewayTransientToolResult[];
   createdAt: number;
   lastActiveAt: number;
   listeners: Set<(event: GatewayEvent) => void>;

packages/coding-agent/src/core/gateway/runtime.ts

@@ -7,7 +7,6 @@ import {
 import { rm } from "node:fs/promises";
 import { join } from "node:path";
 import { URL } from "node:url";
-import type { AgentMessage } from "@mariozechner/pi-agent-core";
 import type { AgentSession, AgentSessionEvent } from "../agent-session.js";
 import { extractMessageText, getLastAssistantText } from "./helpers.js";
 import {
@@ -24,6 +23,7 @@ import type {
   GatewayMessageResult,
   GatewayRuntimeOptions,
   GatewaySessionFactory,
+  GatewaySessionState,
   GatewaySessionSnapshot,
   HistoryMessage,
   HistoryPart,
@@ -36,6 +36,10 @@ import {
   extractUserText,
   finishVercelStream,
 } from "./vercel-ai-stream.js";
+import {
+  buildGatewaySessionStateMessages,
+  messageContentToHistoryParts,
+} from "./session-state.js";
 export {
   createGatewaySessionManager,
   sanitizeSessionKey,
@@ -47,6 +51,7 @@ export type {
   GatewayMessageResult,
   GatewayRuntimeOptions,
   GatewaySessionFactory,
+  GatewaySessionState,
   GatewaySessionSnapshot,
   HistoryMessage,
   HistoryPart,
@@ -246,6 +251,8 @@ export class GatewayRuntime {
       this.rejectQueuedMessages(managedSession, "Session reset");
       await managedSession.session.newSession();
       managedSession.processing = false;
+      managedSession.activeAssistantMessage = null;
+      managedSession.pendingToolResults = [];
       managedSession.lastActiveAt = Date.now();
       this.emitState(managedSession);
       return;
@@ -284,6 +291,8 @@ export class GatewayRuntime {
       session,
       queue: [],
       processing: false,
+      activeAssistantMessage: null,
+      pendingToolResults: [],
       createdAt: Date.now(),
       lastActiveAt: Date.now(),
       listeners: new Set(),
@@ -359,6 +368,8 @@ export class GatewayRuntime {
     } finally {
       queued.onFinish?.();
       managedSession.processing = false;
+      managedSession.activeAssistantMessage = null;
+      managedSession.pendingToolResults = [];
       managedSession.lastActiveAt = Date.now();
       this.emitState(managedSession);
       if (managedSession.queue.length > 0) {
@@ -396,18 +407,24 @@ export class GatewayRuntime {
   ): void {
     switch (event.type) {
       case "turn_start":
+        managedSession.lastActiveAt = Date.now();
         this.emit(managedSession, {
           type: "turn_start",
           sessionKey: managedSession.sessionKey,
         });
         return;
       case "turn_end":
+        managedSession.lastActiveAt = Date.now();
         this.emit(managedSession, {
           type: "turn_end",
           sessionKey: managedSession.sessionKey,
         });
         return;
       case "message_start":
+        managedSession.lastActiveAt = Date.now();
+        if (event.message.role === "assistant") {
+          managedSession.activeAssistantMessage = event.message;
+        }
         this.emit(managedSession, {
           type: "message_start",
           sessionKey: managedSession.sessionKey,
@@ -415,6 +432,10 @@ export class GatewayRuntime {
         });
         return;
       case "message_update":
+        managedSession.lastActiveAt = Date.now();
+        if (event.message.role === "assistant") {
+          managedSession.activeAssistantMessage = event.message;
+        }
         switch (event.assistantMessageEvent.type) {
           case "text_delta":
             this.emit(managedSession, {
@@ -435,15 +456,32 @@ export class GatewayRuntime {
         }
         return;
       case "message_end":
+        managedSession.lastActiveAt = Date.now();
         if (event.message.role === "assistant") {
+          managedSession.activeAssistantMessage = null;
           this.emit(managedSession, {
             type: "message_complete",
             sessionKey: managedSession.sessionKey,
             text: extractMessageText(event.message),
           });
+          return;
+        }
+        if (event.message.role === "toolResult") {
+          const toolCallId =
+            typeof (event.message as { toolCallId?: unknown }).toolCallId ===
+            "string"
+              ? ((event.message as { toolCallId: string }).toolCallId ?? "")
+              : "";
+          if (toolCallId) {
+            managedSession.pendingToolResults =
+              managedSession.pendingToolResults.filter(
+                (entry) => entry.toolCallId !== toolCallId,
+              );
+          }
         }
         return;
       case "tool_execution_start":
+        managedSession.lastActiveAt = Date.now();
         this.emit(managedSession, {
           type: "tool_start",
           sessionKey: managedSession.sessionKey,
@@ -453,6 +491,7 @@ export class GatewayRuntime {
         });
         return;
       case "tool_execution_update":
+        managedSession.lastActiveAt = Date.now();
         this.emit(managedSession, {
           type: "tool_update",
           sessionKey: managedSession.sessionKey,
@@ -462,6 +501,19 @@ export class GatewayRuntime {
         });
         return;
       case "tool_execution_end":
+        managedSession.lastActiveAt = Date.now();
+        managedSession.pendingToolResults = [
+          ...managedSession.pendingToolResults.filter(
+            (entry) => entry.toolCallId !== event.toolCallId,
+          ),
+          {
+            toolCallId: event.toolCallId,
+            toolName: event.toolName,
+            result: event.result,
+            isError: event.isError,
+            timestamp: Date.now(),
+          },
+        ];
         this.emit(managedSession, {
           type: "tool_complete",
           sessionKey: managedSession.sessionKey,
@@ -491,6 +543,20 @@ export class GatewayRuntime {
     });
   }
 
+  private createSessionState(
+    managedSession: ManagedGatewaySession,
+  ): GatewaySessionState {
+    return {
+      session: this.createSnapshot(managedSession),
+      messages: buildGatewaySessionStateMessages({
+        sessionKey: managedSession.sessionKey,
+        rawMessages: managedSession.session.messages,
+        activeAssistantMessage: managedSession.activeAssistantMessage,
+        pendingToolResults: managedSession.pendingToolResults,
+      }),
+    };
+  }
+
   private createSnapshot(
     managedSession: ManagedGatewaySession,
   ): GatewaySessionSnapshot {
@@ -731,7 +797,7 @@ export class GatewayRuntime {
     }
 
     const sessionMatch = path.match(
-      /^\/sessions\/([^/]+)(?:\/(events|messages|abort|reset|chat|history|model|reload))?$/,
+      /^\/sessions\/([^/]+)(?:\/(events|messages|abort|reset|chat|history|model|reload|state))?$/,
     );
     if (!sessionMatch) {
       this.writeJson(response, 404, { error: "Not found" });
@@ -809,6 +875,12 @@ export class GatewayRuntime {
       return;
     }
 
+    if (action === "state" && method === "GET") {
+      const session = await this.ensureSession(sessionKey);
+      this.writeJson(response, 200, this.createSessionState(session));
+      return;
+    }
+
     if (action === "model" && method === "POST") {
       const body = await this.readJsonBody(request);
       const provider = typeof body.provider === "string" ? body.provider : "";
@@ -1080,7 +1152,7 @@ export class GatewayRuntime {
       messages.push({
         id: `${msg.timestamp}-${msg.role}-${index}`,
         role: msg.role,
-        parts: this.messageContentToParts(msg),
+        parts: messageContentToHistoryParts(msg),
         timestamp: msg.timestamp,
       });
     }
@@ -1173,87 +1245,6 @@ export class GatewayRuntime {
     managed.session.settingsManager.reload();
   }
 
-  private messageContentToParts(msg: AgentMessage): HistoryPart[] {
-    if (msg.role === "user") {
-      const content = msg.content;
-      if (typeof content === "string") {
-        return [{ type: "text", text: content }];
-      }
-      if (Array.isArray(content)) {
-        return content
-          .filter(
-            (c): c is { type: "text"; text: string } =>
-              typeof c === "object" && c !== null && c.type === "text",
-          )
-          .map((c) => ({ type: "text" as const, text: c.text }));
-      }
-      return [];
-    }
-
-    if (msg.role === "assistant") {
-      const content = msg.content;
-      if (!Array.isArray(content)) return [];
-      const parts: HistoryPart[] = [];
-      for (const c of content) {
-        if (typeof c !== "object" || c === null) continue;
-        if (c.type === "text") {
-          parts.push({
-            type: "text",
-            text: (c as { type: "text"; text: string }).text,
-          });
-        } else if (c.type === "thinking") {
-          parts.push({
-            type: "reasoning",
-            text: (c as { type: "thinking"; thinking: string }).thinking,
-          });
-        } else if (c.type === "toolCall") {
-          const tc = c as {
-            type: "toolCall";
-            id: string;
-            name: string;
-            arguments: unknown;
-          };
-          parts.push({
-            type: "tool-invocation",
-            toolCallId: tc.id,
-            toolName: tc.name,
-            args: tc.arguments,
-            state: "call",
-          });
-        }
-      }
-      return parts;
-    }
-
-    if (msg.role === "toolResult") {
-      const tr = msg as {
-        role: "toolResult";
-        toolCallId: string;
-        toolName: string;
-        content: unknown;
-        isError: boolean;
-      };
-      const textParts = Array.isArray(tr.content)
-        ? (tr.content as { type: string; text?: string }[])
-            .filter((c) => c.type === "text" && typeof c.text === "string")
-            .map((c) => c.text as string)
-            .join("")
-        : "";
-      return [
-        {
-          type: "tool-invocation",
-          toolCallId: tr.toolCallId,
-          toolName: tr.toolName,
-          args: undefined,
-          state: tr.isError ? "error" : "result",
-          result: textParts,
-        },
-      ];
-    }
-
-    return [];
-  }
-
   getGatewaySessionDir(sessionKey: string): string {
     return join(this.sessionDirRoot, sanitizeSessionKey(sessionKey));
   }

packages/coding-agent/src/core/gateway/session-state.ts

@@ -0,0 +1,195 @@
+import type { AgentMessage } from "@mariozechner/pi-agent-core";
+import type { HistoryMessage, HistoryPart } from "./types.js";
+
+export interface GatewayTransientToolResult {
+  toolCallId: string;
+  toolName: string;
+  result: unknown;
+  isError: boolean;
+  timestamp: number;
+}
+
+function isSupportedHistoryRole(
+  role: AgentMessage["role"],
+): role is "user" | "assistant" | "toolResult" {
+  return role === "user" || role === "assistant" || role === "toolResult";
+}
+
+function historyMessageId(message: AgentMessage, index: number): string {
+  return `${message.timestamp}-${message.role}-${index}`;
+}
+
+function transientAssistantId(
+  sessionKey: string,
+  message: AgentMessage | null,
+): string {
+  return `draft:${sessionKey}:${message?.timestamp ?? 0}`;
+}
+
+function transientToolResultId(sessionKey: string, toolCallId: string): string {
+  return `draft-tool:${sessionKey}:${toolCallId}`;
+}
+
+export function messageContentToHistoryParts(msg: AgentMessage): HistoryPart[] {
+  if (msg.role === "user") {
+    const content = msg.content;
+    if (typeof content === "string") {
+      return [{ type: "text", text: content }];
+    }
+    if (Array.isArray(content)) {
+      return content
+        .filter(
+          (contentPart): contentPart is { type: "text"; text: string } =>
+            typeof contentPart === "object" &&
+            contentPart !== null &&
+            contentPart.type === "text",
+        )
+        .map((contentPart) => ({
+          type: "text" as const,
+          text: contentPart.text,
+        }));
+    }
+    return [];
+  }
+
+  if (msg.role === "assistant") {
+    const content = msg.content;
+    if (!Array.isArray(content)) return [];
+    const parts: HistoryPart[] = [];
+    for (const contentPart of content) {
+      if (typeof contentPart !== "object" || contentPart === null) {
+        continue;
+      }
+      if (contentPart.type === "text") {
+        parts.push({
+          type: "text",
+          text: (contentPart as { type: "text"; text: string }).text,
+        });
+      } else if (contentPart.type === "thinking") {
+        parts.push({
+          type: "reasoning",
+          text: (contentPart as { type: "thinking"; thinking: string })
+            .thinking,
+        });
+      } else if (contentPart.type === "toolCall") {
+        const toolCall = contentPart as {
+          type: "toolCall";
+          id: string;
+          name: string;
+          arguments: unknown;
+        };
+        parts.push({
+          type: "tool-invocation",
+          toolCallId: toolCall.id,
+          toolName: toolCall.name,
+          args: toolCall.arguments,
+          state: "call",
+        });
+      }
+    }
+    return parts;
+  }
+
+  if (msg.role === "toolResult") {
+    const toolResult = msg as {
+      role: "toolResult";
+      toolCallId: string;
+      toolName: string;
+      content: unknown;
+      isError: boolean;
+    };
+    const textParts = Array.isArray(toolResult.content)
+      ? (toolResult.content as { type: string; text?: string }[])
+          .filter((contentPart) => {
+            return (
+              contentPart.type === "text" &&
+              typeof contentPart.text === "string"
+            );
+          })
+          .map((contentPart) => contentPart.text as string)
+          .join("")
+      : "";
+
+    return [
+      {
+        type: "tool-invocation",
+        toolCallId: toolResult.toolCallId,
+        toolName: toolResult.toolName,
+        args: undefined,
+        state: toolResult.isError ? "error" : "result",
+        result: textParts,
+      },
+    ];
+  }
+
+  return [];
+}
+
+export function buildGatewaySessionStateMessages(params: {
+  sessionKey: string;
+  rawMessages: AgentMessage[];
+  activeAssistantMessage: AgentMessage | null;
+  pendingToolResults: GatewayTransientToolResult[];
+}): HistoryMessage[] {
+  const {
+    sessionKey,
+    rawMessages,
+    activeAssistantMessage,
+    pendingToolResults,
+  } = params;
+  const messages: HistoryMessage[] = [];
+  const persistedToolCallIds = new Set<string>();
+
+  for (const [index, message] of rawMessages.entries()) {
+    if (!isSupportedHistoryRole(message.role)) {
+      continue;
+    }
+
+    if (
+      message.role === "toolResult" &&
+      typeof (message as { toolCallId?: unknown }).toolCallId === "string"
+    ) {
+      persistedToolCallIds.add((message as { toolCallId: string }).toolCallId);
+    }
+
+    messages.push({
+      id: historyMessageId(message, index),
+      role: message.role,
+      parts: messageContentToHistoryParts(message),
+      timestamp: message.timestamp,
+    });
+  }
+
+  if (activeAssistantMessage?.role === "assistant") {
+    messages.push({
+      id: transientAssistantId(sessionKey, activeAssistantMessage),
+      role: "assistant",
+      parts: messageContentToHistoryParts(activeAssistantMessage),
+      timestamp: activeAssistantMessage.timestamp ?? Date.now(),
+    });
+  }
+
+  for (const pendingToolResult of pendingToolResults) {
+    if (persistedToolCallIds.has(pendingToolResult.toolCallId)) {
+      continue;
+    }
+
+    messages.push({
+      id: transientToolResultId(sessionKey, pendingToolResult.toolCallId),
+      role: "toolResult",
+      parts: [
+        {
+          type: "tool-invocation",
+          toolCallId: pendingToolResult.toolCallId,
+          toolName: pendingToolResult.toolName,
+          args: undefined,
+          state: pendingToolResult.isError ? "error" : "result",
+          result: pendingToolResult.result,
+        },
+      ],
+      timestamp: pendingToolResult.timestamp,
+    });
+  }
+
+  return messages;
+}

packages/coding-agent/src/core/gateway/types.ts

@@ -48,6 +48,11 @@ export interface GatewaySessionSnapshot {
   updatedAt: number;
 }
 
+export interface GatewaySessionState {
+  session: GatewaySessionSnapshot;
+  messages: HistoryMessage[];
+}
+
 export interface ModelInfo {
   provider: string;
   modelId: string;

packages/coding-agent/test/gateway-session-state.test.mjs

@@ -0,0 +1,163 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import {
+  buildGatewaySessionStateMessages,
+  messageContentToHistoryParts,
+} from "../src/core/gateway/session-state.ts";
+
+test("messageContentToHistoryParts converts assistant text, reasoning, and tool calls", () => {
+  const parts = messageContentToHistoryParts({
+    role: "assistant",
+    timestamp: 123,
+    content: [
+      { type: "text", text: "hello" },
+      { type: "thinking", thinking: "working" },
+      {
+        type: "toolCall",
+        id: "tool-1",
+        name: "bash",
+        arguments: { cmd: "pwd" },
+      },
+    ],
+  });
+
+  assert.deepEqual(parts, [
+    { type: "text", text: "hello" },
+    { type: "reasoning", text: "working" },
+    {
+      type: "tool-invocation",
+      toolCallId: "tool-1",
+      toolName: "bash",
+      args: { cmd: "pwd" },
+      state: "call",
+    },
+  ]);
+});
+
+test("buildGatewaySessionStateMessages includes the active assistant draft while a run is still processing", () => {
+  const messages = buildGatewaySessionStateMessages({
+    sessionKey: "agent:test:chat",
+    rawMessages: [
+      {
+        role: "user",
+        timestamp: 100,
+        content: "build a todo app",
+      },
+    ],
+    activeAssistantMessage: {
+      role: "assistant",
+      timestamp: 200,
+      content: [
+        { type: "text", text: "Working on it" },
+        {
+          type: "toolCall",
+          id: "tool-1",
+          name: "write",
+          arguments: { filePath: "app.tsx" },
+        },
+      ],
+    },
+    pendingToolResults: [],
+  });
+
+  assert.deepEqual(messages, [
+    {
+      id: "100-user-0",
+      role: "user",
+      parts: [{ type: "text", text: "build a todo app" }],
+      timestamp: 100,
+    },
+    {
+      id: "draft:agent:test:chat:200",
+      role: "assistant",
+      parts: [
+        { type: "text", text: "Working on it" },
+        {
+          type: "tool-invocation",
+          toolCallId: "tool-1",
+          toolName: "write",
+          args: { filePath: "app.tsx" },
+          state: "call",
+        },
+      ],
+      timestamp: 200,
+    },
+  ]);
+});
+
+test("buildGatewaySessionStateMessages keeps transient tool results until persisted history catches up", () => {
+  const messages = buildGatewaySessionStateMessages({
+    sessionKey: "agent:test:chat",
+    rawMessages: [
+      {
+        role: "user",
+        timestamp: 100,
+        content: "ship it",
+      },
+      {
+        role: "toolResult",
+        timestamp: 210,
+        toolCallId: "tool-1",
+        toolName: "bash",
+        content: [{ type: "text", text: "done" }],
+        isError: false,
+      },
+    ],
+    activeAssistantMessage: null,
+    pendingToolResults: [
+      {
+        toolCallId: "tool-1",
+        toolName: "bash",
+        result: { stdout: "done" },
+        isError: false,
+        timestamp: 220,
+      },
+      {
+        toolCallId: "tool-2",
+        toolName: "write",
+        result: { path: "README.md" },
+        isError: false,
+        timestamp: 240,
+      },
+    ],
+  });
+
+  assert.deepEqual(messages, [
+    {
+      id: "100-user-0",
+      role: "user",
+      parts: [{ type: "text", text: "ship it" }],
+      timestamp: 100,
+    },
+    {
+      id: "210-toolResult-1",
+      role: "toolResult",
+      parts: [
+        {
+          type: "tool-invocation",
+          toolCallId: "tool-1",
+          toolName: "bash",
+          args: undefined,
+          state: "result",
+          result: "done",
+        },
+      ],
+      timestamp: 210,
+    },
+    {
+      id: "draft-tool:agent:test:chat:tool-2",
+      role: "toolResult",
+      parts: [
+        {
+          type: "tool-invocation",
+          toolCallId: "tool-2",
+          toolName: "write",
+          args: undefined,
+          state: "result",
+          result: { path: "README.md" },
+        },
+      ],
+      timestamp: 240,
+    },
+  ]);
+});