From 6a16c41e8f5726c8bd5fab068c104fb6cb4402a3 Mon Sep 17 00:00:00 2001
From: Dax Raad <d@ironbay.co>
Date: Fri, 26 Jun 2026 22:02:30 -0400
Subject: [PATCH] fix(core): continue after tool defects

---
 packages/core/src/session/runner/llm.ts   |  3 ++-
 packages/core/test/session-runner.test.ts | 16 +++++++++++++---
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/packages/core/src/session/runner/llm.ts b/packages/core/src/session/runner/llm.ts
index 9e29ae71ee..6a123cf6d7 100644
--- a/packages/core/src/session/runner/llm.ts
+++ b/packages/core/src/session/runner/llm.ts
@@ -333,7 +333,8 @@ export const layer = Layer.effect(
           if (stream._tag === "Success" && !publisher.hasProviderError())
             yield* withPublication(publisher.failUnsettledTools("Provider did not return a tool result", true))
           if (stream._tag === "Failure") return yield* Effect.failCause(stream.cause)
-          if (settled._tag === "Failure") return yield* Effect.failCause(settled.cause)
+          if (settled._tag === "Failure" && Cause.hasInterrupts(settled.cause))
+            return yield* Effect.failCause(settled.cause)
           return { needsContinuation: !publisher.hasProviderError() && needsContinuation, step: currentStep }
         }),
       )
diff --git a/packages/core/test/session-runner.test.ts b/packages/core/test/session-runner.test.ts
index c9594e8244..2001e22757 100644
--- a/packages/core/test/session-runner.test.ts
+++ b/packages/core/test/session-runner.test.ts
@@ -2565,7 +2565,7 @@ describe("SessionRunnerLLM", () => {
     }),
   )
 
-  it.effect("propagates unexpected local tool defects operationally", () =>
+  it.effect("returns unexpected local tool defects to the model and continues", () =>
     Effect.gen(function* () {
       yield* setup
       const session = yield* SessionV2.Service
@@ -2579,11 +2579,20 @@ describe("SessionRunnerLLM", () => {
           LLMEvent.stepFinish({ index: 0, reason: "tool-calls" }),
           LLMEvent.finish({ reason: "tool-calls" }),
         ],
+        [
+          LLMEvent.stepStart({ index: 0 }),
+          LLMEvent.textStart({ id: "text-after-defect" }),
+          LLMEvent.textDelta({ id: "text-after-defect", text: "Recovered" }),
+          LLMEvent.textEnd({ id: "text-after-defect" }),
+          LLMEvent.stepFinish({ index: 0, reason: "stop" }),
+          LLMEvent.finish({ reason: "stop" }),
+        ],
       ]
 
-      expect(yield* session.resume(sessionID).pipe(Effect.catchDefect(Effect.succeed))).toBe("unexpected tool defect")
+      yield* session.resume(sessionID)
 
-      expect(requests).toHaveLength(1)
+      expect(requests).toHaveLength(2)
+      expect(requests[1]?.messages.map((message) => message.role)).toEqual(["user", "assistant", "tool"])
       expect(yield* session.context(sessionID)).toMatchObject([
         { type: "user", text: "Call defect" },
         {
@@ -2599,6 +2608,7 @@ describe("SessionRunnerLLM", () => {
             },
           ],
         },
+        { type: "assistant", finish: "stop", content: [{ type: "text", text: "Recovered" }] },
       ])
     }),
   )