fix(run-events): emit canonical past-tense run event types and tool result content

docs/architecture/28-model-driven-tool-discovery.md

@@ -97,7 +97,7 @@ mechanism.
 ## Durability and resume
 
 Exposure state is persisted as a private durable checkpoint event,
-`AGENT_RUN_TOOL_EXPOSURE_CHECKPOINT`, carrying a versioned
+`AGENT_RUN_TOOL_EXPOSURE_CHECKPOINTED`, carrying a versioned
 `ToolExposureCheckpoint`. `restoreToolExposureState` rehydrates it, so a resumed
 run keeps the schemas it had already loaded instead of starting from an empty
 set. Restoration returns exposure, not authorization: execution still re-checks

src/agent/ag-ui/chunk-encoder.test.ts

@@ -121,7 +121,7 @@ describe("agent/ag-ui-chunk-encoder", () => {
         payload: {
           toolCallId: "tool-1",
           input: { query: "ag-ui" },
-          result: { ok: true },
+          content: { ok: true },
         },
       }],
     );

src/agent/ag-ui/encoder.test.ts

@@ -112,7 +112,7 @@ describe("agent/ag-ui-encoder", () => {
       }),
       [{
         event: "ToolCallResult",
-        payload: { toolCallId: "tool-1", result: { ok: true } },
+        payload: { toolCallId: "tool-1", content: { ok: true } },
       }],
     );
     assertEquals(
@@ -313,7 +313,7 @@ describe("agent/ag-ui-encoder", () => {
         },
         {
           event: "ToolCallResult",
-          payload: { toolCallId: "tool-2", result: { error: "invalid url" }, isError: true },
+          payload: { toolCallId: "tool-2", content: { error: "invalid url" }, isError: true },
         },
       ],
     );
@@ -324,7 +324,7 @@ describe("agent/ag-ui-encoder", () => {
       }),
       [{
         event: "ToolCallResult",
-        payload: { toolCallId: "tool-3", result: { error: "Tool output denied" }, isError: true },
+        payload: { toolCallId: "tool-3", content: { error: "Tool output denied" }, isError: true },
       }],
     );
   });
@@ -499,7 +499,7 @@ describe("agent/ag-ui-encoder", () => {
         event: "ToolCallResult",
         payload: {
           toolCallId: "tool-provider",
-          result: { type: "web_search_result", answer: "resident" },
+          content: { type: "web_search_result", answer: "resident" },
         },
       }],
     );

src/agent/ag-ui/encoder.ts

@@ -603,16 +603,20 @@
   return events;
 }
 
+/**
+ * Tool results carry the canonical `content` field. The value is passed through
+ * unchanged, which is exactly what the API stores for a legacy `result` field.
+ */
 function createToolResultEvent(
   toolCallId: unknown,
-  result: Record<string, unknown> | unknown,
+  content: Record<string, unknown> | unknown,
   isError = false,
 ): AgUiEncodedEvent {
   return {
     event: "ToolCallResult",
     payload: {
       toolCallId,
-      result,
+      content,
       ...(isError ? { isError: true } : {}),
     },
   };
@@ -958,7 +962,7 @@
         event: "ToolCallResult",
         payload: {
           toolCallId: event.toolCallId,
-          result: {
+          content: {
             error: typeof event.errorText === "string" ? event.errorText : "Tool input failed",
           },
           isError: true,

src/agent/ag-ui/lifecycle-adapter.test.ts

@@ -231,7 +231,7 @@ describe("lifecycle AG-UI adapter", () => {
       events.at(-1)?.payload,
       {
         toolCallId: "provider-1",
-        result: { content: "final" },
+        content: { content: "final" },
       },
       "the final provider result must reach the client even when it carries preliminary: false",
     );

src/agent/ag-ui/lifecycle-adapter.ts

@@ -268,7 +268,7 @@ export function createLifecycleAgUiAdapter(input: {
             event: "ToolCallResult",
             payload: {
               toolCallId: event.toolCallId,
-              result: { error: "Tool input was rejected before handoff" },
+              content: { error: "Tool input was rejected before handoff" },
               isError: true,
             },
           },
@@ -282,7 +282,7 @@ export function createLifecycleAgUiAdapter(input: {
           event: "ToolCallResult",
           payload: {
             toolCallId: event.toolCallId,
-            result: safeJson(event.output),
+            content: safeJson(event.output),
             ...(event.isError ? { isError: true } : {}),
           },
         }];
@@ -292,7 +292,7 @@ export function createLifecycleAgUiAdapter(input: {
           event: "ToolCallResult",
           payload: {
             toolCallId: event.toolCallId,
-            result: { error: "Tool output denied" },
+            content: { error: "Tool output denied" },
             isError: true,
           },
         }];
@@ -302,7 +302,7 @@ export function createLifecycleAgUiAdapter(input: {
           event: "ToolCallResult",
           payload: {
             toolCallId: event.toolCallId,
-            result: { error: "Provider tool execution was cancelled" },
+            content: { error: "Provider tool execution was cancelled" },
             isError: true,
           },
         }];

src/agent/ag-ui/runtime-event-encoder.test.ts

@@ -57,7 +57,7 @@ describe("agent/ag-ui-runtime-event-encoder", () => {
         payload: {
           toolCallId: "tool-1",
           input: { query: "ag-ui" },
-          result: { ok: true },
+          content: { ok: true },
         },
       }],
     );

src/agent/ag-ui/sse-parser.test.ts

@@ -70,6 +70,30 @@ describe("agent/ag-ui-sse-parser", () => {
     );
   });
 
+  it("serializes a raw ToolCallResult content value the same way it serialized result", async () => {
+    const response = createSseResponse([
+      'event: ToolCallResult\ndata: {"toolCallId":"tool-1","content":{"ok":true}}\n\n',
+      'event: ToolCallResult\ndata: {"toolCallId":"tool-2","result":{"ok":false}}\n\n',
+    ]);
+
+    const run = await parseAgUiSseResponse(response);
+
+    assertEquals(run.events[0]?.content, '{"ok":true}');
+    assertEquals(run.events[1]?.content, '{"ok":false}');
+  });
+
+  it("keeps a null ToolCallResult content value as the serialized canonical field", async () => {
+    const response = createSseResponse([
+      'event: ToolCallResult\ndata: {"toolCallId":"tool-1","content":null}\n\n',
+      'event: ToolCallResult\ndata: {"toolCallId":"tool-2","content":null,"result":{"ok":true}}\n\n',
+    ]);
+
+    const run = await parseAgUiSseResponse(response);
+
+    assertEquals(run.events[0]?.content, "null");
+    assertEquals(run.events[1]?.content, "null");
+  });
+
   it("keeps parsing legacy raw AG-UI payloads", async () => {
     const response = createSseResponse([
       'id: 1\nevent: RunStarted\ndata: {"type":"RUN_STARTED"}\n\n',

src/agent/ag-ui/sse-parser.ts

@@ -180,12 +180,16 @@ function coerceWireEvent(
       return { type: agUiSseEventTypes.toolCallArgs, ...payload };
     case "ToolCallEnd":
       return { type: agUiSseEventTypes.toolCallEnd, ...payload };
-    case "ToolCallResult":
+    case "ToolCallResult": {
+      // The canonical `content` field wins whenever it is present, even when it
+      // is null; only a frame without it falls back to the legacy `result`.
+      const toolResult = Object.hasOwn(payload, "content") ? payload.content : payload.result;
       return {
         type: agUiSseEventTypes.toolCallResult,
         ...payload,
-        ...(payload.result !== undefined ? { content: serializeToolResult(payload.result) } : {}),
+        ...(toolResult !== undefined ? { content: serializeToolResult(toolResult) } : {}),
       };
+    }
     case "Custom":
       return { type: agUiSseEventTypes.custom, ...payload };
     case "RunError":

src/agent/conversation/durable.test.ts

@@ -40,7 +40,7 @@ const BRANCH_ID = "44444444-4444-4444-8444-444444444444";
 
 function modelCallContextEvent(content: string) {
   return {
-    type: "AGENT_RUN_MODEL_CALL_CONTEXT",
+    type: "AGENT_RUN_MODEL_CALL_CONTEXT_RECORDED",
     messages: [{ role: "system", content }],
   };
 }
@@ -663,7 +663,7 @@ describe("agent/durable", () => {
     let accessorReads = 0;
     let fetchCalls = 0;
     const event = {
-      type: "AGENT_RUN_MODEL_CALL_CONTEXT",
+      type: "AGENT_RUN_MODEL_CALL_CONTEXT_RECORDED",
       messages: [],
       extra: "invalid",
     };
@@ -702,7 +702,7 @@ describe("agent/durable", () => {
     let accessorReads = 0;
     let fetchCalls = 0;
     const event = {
-      type: "AGENT_RUN_MODEL_CALL_CONTEXT",
+      type: "AGENT_RUN_MODEL_CALL_CONTEXT_RECORDED",
       messages: [],
     };
     Object.defineProperty(event, "tools", {

src/agent/conversation/legacy-run-read-adapter.test.ts

@@ -141,7 +141,7 @@ describe("conversation run lifecycle read adapter", () => {
         event: "ToolCallResult",
         payload: {
           toolCallId: "legacy-fetch",
-          result: { error: "Stored tool call ended without a result" },
+          content: { error: "Stored tool call ended without a result" },
           isError: true,
         },
       }],
@@ -1151,7 +1151,7 @@ describe("conversation run lifecycle read adapter", () => {
       aguiEvents.filter((event) => event.event === "ToolCallResult"),
       [{
         event: "ToolCallResult",
-        payload: { toolCallId: "provider-1", result: { forecast: "sunny" } },
+        payload: { toolCallId: "provider-1", content: { forecast: "sunny" } },
       }],
     );
   });
@@ -1363,7 +1363,7 @@ describe("conversation run lifecycle read adapter", () => {
         event: "ToolCallResult",
         payload: {
           toolCallId: "provider-err",
-          result: diagnostic,
+          content: diagnostic,
           isError: true,
         },
       }],