fix: preserve interrupted bash output in tool results (#21598)

packages/opencode/src/session/llm.ts

@@ -234,7 +234,11 @@ export namespace LLM {
     // from the workflow service are executed via opencode's tool system
     // and results sent back over the WebSocket.
     if (language instanceof GitLabWorkflowLanguageModel) {
-      const workflowModel = language
+      const workflowModel = language as GitLabWorkflowLanguageModel & {
+        sessionID?: string
+        sessionPreapprovedTools?: string[]
+        approvalHandler?: (approvalTools: { name: string; args: string }[]) => Promise<{ approved: boolean }>
+      }
       workflowModel.sessionID = input.sessionID
       workflowModel.systemPrompt = system.join("\n")
       workflowModel.toolExecutor = async (toolName, argsJson, _requestID) => {
@@ -301,7 +305,7 @@ export namespace LLM {
             ruleset: [],
           })
           for (const name of uniqueNames) approvedToolsForSession.add(name)
-          workflowModel.sessionPreapprovedTools = [...workflowModel.sessionPreapprovedTools, ...uniqueNames]
+          workflowModel.sessionPreapprovedTools = [...(workflowModel.sessionPreapprovedTools ?? []), ...uniqueNames]
           return { approved: true }
         } catch {
           return { approved: false }

packages/opencode/src/session/message-v2.ts

@@ -751,16 +751,32 @@ export namespace MessageV2 {
                 ...(differentModel ? {} : { callProviderMetadata: providerMeta(part.metadata) }),
               })
             }
-            if (part.state.status === "error")
-              assistantMessage.parts.push({
-                type: ("tool-" + part.tool) as `tool-${string}`,
-                state: "output-error",
-                toolCallId: part.callID,
-                input: part.state.input,
-                errorText: part.state.error,
-                ...(part.metadata?.providerExecuted ? { providerExecuted: true } : {}),
-                ...(differentModel ? {} : { callProviderMetadata: providerMeta(part.metadata) }),
-              })
+            if (part.state.status === "error") {
+              const output = part.state.metadata?.interrupted === true ? part.state.metadata.output : undefined
+              if (typeof output === "string") {
+                assistantMessage.parts.push({
+                  type: ("tool-" + part.tool) as `tool-${string}`,
+                  state: "output-available",
+                  toolCallId: part.callID,
+                  input: part.state.input,
+                  output,
+                  ...(part.metadata?.providerExecuted ? { providerExecuted: true } : {}),
+                  ...(differentModel ? {} : { callProviderMetadata: providerMeta(part.metadata) }),
+                })
+              } else {
+                assistantMessage.parts.push({
+                  type: ("tool-" + part.tool) as `tool-${string}`,
+                  state: "output-error",
+                  toolCallId: part.callID,
+                  input: part.state.input,
+                  errorText: part.state.error,
+                  ...(part.metadata?.providerExecuted ? { providerExecuted: true } : {}),
+                  ...(differentModel ? {} : { callProviderMetadata: providerMeta(part.metadata) }),
+                })
+              }
+            }
+            // Handle pending/running tool calls to prevent dangling tool_use blocks
+            // Anthropic/Claude APIs require every tool_use to have a corresponding tool_result
             if (part.state.status === "pending" || part.state.status === "running")
               assistantMessage.parts.push({
                 type: ("tool-" + part.tool) as `tool-${string}`,

packages/opencode/src/session/processor.ts

@@ -18,6 +18,7 @@ import { SessionStatus } from "./status"
 import { SessionSummary } from "./summary"
 import type { Provider } from "@/provider/provider"
 import { Question } from "@/question"
+import { isRecord } from "@/util/record"
 
 export namespace SessionProcessor {
   const DOOM_LOOP_THRESHOLD = 3
@@ -398,19 +399,21 @@ export namespace SessionProcessor {
           }
           ctx.reasoningMap = {}
 
-          const parts = MessageV2.parts(ctx.assistantMessage.id)
-          for (const part of parts) {
-            if (part.type !== "tool" || part.state.status === "completed" || part.state.status === "error") continue
+          for (const part of Object.values(ctx.toolcalls)) {
+            const end = Date.now()
+            const metadata = "metadata" in part.state && isRecord(part.state.metadata) ? part.state.metadata : {}
             yield* session.updatePart({
               ...part,
               state: {
                 ...part.state,
                 status: "error",
                 error: "Tool execution aborted",
-                time: { start: Date.now(), end: Date.now() },
+                metadata: { ...metadata, interrupted: true },
+                time: { start: "time" in part.state ? part.state.time.start : end, end },
               },
             })
           }
+          ctx.toolcalls = {}
           ctx.assistantMessage.time.completed = Date.now()
           yield* session.updateMessage(ctx.assistantMessage)
         })

packages/opencode/src/session/prompt.ts

@@ -1507,7 +1507,7 @@ NOTE: At any point in time through this workflow you should feel free to ask the
                 Effect.promise(() => SystemPrompt.skills(agent)),
                 Effect.promise(() => SystemPrompt.environment(model)),
                 instruction.system().pipe(Effect.orDie),
-                Effect.promise(() => MessageV2.toModelMessages(msgs, model)),
+                MessageV2.toModelMessagesEffect(msgs, model),
               ])
               const system = [...env, ...(skills ? [skills] : []), ...instructions]
               const format = lastUser.format ?? { type: "text" as const }

packages/opencode/test/session/message-v2.test.ts

@@ -570,6 +570,81 @@ describe("session.message-v2.toModelMessage", () => {
     ])
   })
 
+  test("forwards partial bash output for aborted tool calls", async () => {
+    const userID = "m-user"
+    const assistantID = "m-assistant"
+    const output = [
+      "31403",
+      "12179",
+      "4575",
+      "",
+      "<bash_metadata>",
+      "User aborted the command",
+      "</bash_metadata>",
+    ].join("\n")
+
+    const input: MessageV2.WithParts[] = [
+      {
+        info: userInfo(userID),
+        parts: [
+          {
+            ...basePart(userID, "u1"),
+            type: "text",
+            text: "run tool",
+          },
+        ] as MessageV2.Part[],
+      },
+      {
+        info: assistantInfo(assistantID, userID),
+        parts: [
+          {
+            ...basePart(assistantID, "a1"),
+            type: "tool",
+            callID: "call-1",
+            tool: "bash",
+            state: {
+              status: "error",
+              input: { command: "for i in {1..20}; do print -- $RANDOM; sleep 1; done" },
+              error: "Tool execution aborted",
+              metadata: { interrupted: true, output },
+              time: { start: 0, end: 1 },
+            },
+          },
+        ] as MessageV2.Part[],
+      },
+    ]
+
+    expect(await MessageV2.toModelMessages(input, model)).toStrictEqual([
+      {
+        role: "user",
+        content: [{ type: "text", text: "run tool" }],
+      },
+      {
+        role: "assistant",
+        content: [
+          {
+            type: "tool-call",
+            toolCallId: "call-1",
+            toolName: "bash",
+            input: { command: "for i in {1..20}; do print -- $RANDOM; sleep 1; done" },
+            providerExecuted: undefined,
+          },
+        ],
+      },
+      {
+        role: "tool",
+        content: [
+          {
+            type: "tool-result",
+            toolCallId: "call-1",
+            toolName: "bash",
+            output: { type: "text", value: output },
+          },
+        ],
+      },
+    ])
+  })
+
   test("filters assistant messages with non-abort errors", async () => {
     const assistantID = "m-assistant"
 

packages/opencode/test/session/processor-effect.test.ts

@@ -604,6 +604,7 @@ it.live("session.processor effect tests mark pending tools as aborted on cleanup
         expect(call?.state.status).toBe("error")
         if (call?.state.status === "error") {
           expect(call.state.error).toBe("Tool execution aborted")
+          expect(call.state.metadata?.interrupted).toBe(true)
           expect(call.state.time.end).toBeDefined()
         }
       }),