feat: /continue

packages/opencode/src/cli/cmd/tui/component/prompt/index.tsx

@@ -677,6 +677,16 @@ export function Prompt(props: PromptProps) {
         command: inputText,
       })
       setStore("mode", "normal")
+    } else if (
+      inputText.startsWith("/") &&
+      iife(() => {
+        const name = inputText.split("\n")[0].split(" ")[0].slice(1)
+        const match = command.slashes().find((s) => s.display === "/" + name || s.aliases?.includes("/" + name))
+        if (match) match.onSelect()
+        return !!match
+      })
+    ) {
+      // slash command dispatched inside the iife above
     } else if (
       inputText.startsWith("/") &&
       iife(() => {

packages/opencode/src/cli/cmd/tui/routes/session/index.tsx

@@ -557,6 +557,40 @@ export function Session() {
         })
       },
     },
+    {
+      title: "Continue interrupted session",
+      value: "session.continue",
+      category: "Session",
+      slash: {
+        name: "continue",
+      },
+      onSelect: (dialog) => {
+        const status = sync.data.session_status?.[route.sessionID]
+        if (status?.type !== "idle" && status?.type !== undefined) {
+          toast.show({ message: "Session is busy", variant: "warning", duration: 3000 })
+          dialog.clear()
+          return
+        }
+        // Uses raw fetch because the SDK has not been regenerated yet
+        sdk
+          .fetch(`${sdk.url}/session/${route.sessionID}/continue`, {
+            method: "POST",
+          })
+          .then(async (r) => {
+            if (!r.ok) {
+              const body = await r.json().catch(() => null)
+              throw new Error(body?.data?.message ?? `Continue failed: ${r.status}`)
+            }
+          })
+          .catch((e) =>
+            toast.show({
+              message: e instanceof Error ? e.message : "Failed to continue session",
+              variant: "error",
+            }),
+          )
+        dialog.clear()
+      },
+    },
     {
       title: sidebarVisible() ? "Hide sidebar" : "Show sidebar",
       value: "session.sidebar.toggle",

packages/opencode/src/server/middleware.ts

@@ -21,7 +21,7 @@ export function errorHandler(log: Log.Logger): ErrorHandler {
       else status = 500
       return c.json(err.toObject(), { status })
     }
-    if (err instanceof Session.BusyError) {
+    if (err instanceof Session.BusyError || err instanceof Session.NothingToContinueError) {
       return c.json(new NamedError.Unknown({ message: err.message }).toObject(), { status: 400 })
     }
     if (err instanceof HTTPException) return err.getResponse()

packages/opencode/src/server/routes/session.ts

@@ -385,6 +385,34 @@ export const SessionRoutes = lazy(() =>
         return c.json(true)
       },
     )
+    .post(
+      "/:sessionID/continue",
+      describeRoute({
+        summary: "Continue session",
+        description: "Continue an interrupted session from where it left off without creating a new user message.",
+        operationId: "session.continue",
+        responses: {
+          200: {
+            description: "Continued session",
+            content: {
+              "application/json": {
+                schema: resolver(
+                  z.object({
+                    info: MessageV2.Assistant,
+                    parts: MessageV2.Part.array(),
+                  }),
+                ),
+              },
+            },
+          },
+          ...errors(400, 404),
+        },
+      }),
+      validator("param", z.object({ sessionID: SessionID.zod })),
+      async (c) => {
+        return c.json(await SessionPrompt.continue_(c.req.valid("param").sessionID))
+      },
+    )
     .post(
       "/:sessionID/share",
       describeRoute({

packages/opencode/src/session/index.ts

@@ -312,6 +312,12 @@ export namespace Session {
     }
   }
 
+  export class NothingToContinueError extends Error {
+    constructor(public readonly sessionID: string) {
+      super(`Nothing to continue in session ${sessionID}`)
+    }
+  }
+
   export interface Interface {
     readonly create: (input?: {
       parentID?: SessionID

packages/opencode/src/session/prompt.ts

@@ -74,6 +74,7 @@ export namespace SessionPrompt {
     readonly loop: (input: z.infer<typeof LoopInput>) => Effect.Effect<MessageV2.WithParts>
     readonly shell: (input: ShellInput) => Effect.Effect<MessageV2.WithParts>
     readonly command: (input: CommandInput) => Effect.Effect<MessageV2.WithParts>
+    readonly continue: (sessionID: SessionID) => Effect.Effect<MessageV2.WithParts>
     readonly resolvePromptParts: (template: string) => Effect.Effect<PromptInput["parts"]>
   }
 
@@ -1323,6 +1324,38 @@ NOTE: At any point in time through this workflow you should feel free to ask the
         },
       )
 
+      const continue_ = Effect.fn("SessionPrompt.continue")(function* (sessionID: SessionID) {
+        const s = yield* InstanceState.get(state)
+        if (s.runners.get(sessionID)?.busy) throw new Session.BusyError(sessionID)
+
+        const last = (yield* MessageV2.filterCompactedEffect(sessionID)).findLast(
+          (m): m is MessageV2.WithParts & { info: MessageV2.Assistant } => m.info.role === "assistant",
+        )
+        if (!last) throw new Session.NothingToContinueError(sessionID)
+
+        if (
+          last.info.finish &&
+          last.info.finish !== "tool-calls" &&
+          !last.parts.some(
+            (p) => p.type === "tool" && (p.state.status === "pending" || p.state.status === "running"),
+          ) &&
+          !last.info.error
+        ) {
+          return yield* prompt({
+            sessionID,
+            parts: [{ type: "text", text: "continue" }],
+          })
+        }
+
+        last.info.error = undefined
+        last.info.finish = "tool-calls"
+        last.info.time.completed ??= Date.now()
+        yield* sessions.updateMessage(last.info)
+
+        yield* sessions.touch(sessionID)
+        return yield* getRunner(s.runners, sessionID).ensureRunning(runLoop(sessionID))
+      })
+
       const lastAssistant = (sessionID: SessionID) =>
         Effect.promise(async () => {
           let latest: MessageV2.WithParts | undefined
@@ -1704,6 +1737,7 @@ NOTE: At any point in time through this workflow you should feel free to ask the
         loop,
         shell,
         command,
+        continue: continue_,
         resolvePromptParts,
       })
     }),
@@ -1818,6 +1852,10 @@ NOTE: At any point in time through this workflow you should feel free to ask the
     return runPromise((svc) => svc.cancel(SessionID.zod.parse(sessionID)))
   }
 
+  export async function continue_(sessionID: SessionID) {
+    return runPromise((svc) => svc.continue(SessionID.zod.parse(sessionID)))
+  }
+
   export const LoopInput = z.object({
     sessionID: SessionID.zod,
   })