feat(core): sync routes, refactor proxy, session restore, and more syncing (#22518)

11 files changed, 1132 insertions, 63 deletions

diff --git a/packages/opencode/src/control-plane/workspace.ts b/packages/opencode/src/control-plane/workspace.ts
index f330e07b7..78f3d770e 100644
--- a/packages/opencode/src/control-plane/workspace.ts
+++ b/packages/opencode/src/control-plane/workspace.ts
@@ -1,11 +1,13 @@
 import z from "zod"
 import { setTimeout as sleep } from "node:timers/promises"
 import { fn } from "@/util/fn"
-import { Database, eq } from "@/storage/db"
+import { Database, asc, eq } from "@/storage/db"
 import { Project } from "@/project/project"
 import { BusEvent } from "@/bus/bus-event"
 import { GlobalBus } from "@/bus/global"
 import { SyncEvent } from "@/sync"
+import { EventTable } from "@/sync/event.sql"
+import { Flag } from "@/flag/flag"
 import { Log } from "@/util/log"
 import { Filesystem } from "@/util/filesystem"
 import { ProjectID } from "@/project/schema"
@@ -15,6 +17,11 @@ import { getAdaptor } from "./adaptors"
 import { WorkspaceInfo } from "./types"
 import { WorkspaceID } from "./schema"
 import { parseSSE } from "./sse"
+import { Session } from "@/session"
+import { SessionTable } from "@/session/session.sql"
+import { SessionID } from "@/session/schema"
+import { errorData } from "@/util/error"
+import { AppRuntime } from "@/effect/app-runtime"
 
 export namespace Workspace {
   export const Info = WorkspaceInfo.meta({
@@ -29,6 +36,13 @@ export namespace Workspace {
   })
   export type ConnectionStatus = z.infer<typeof ConnectionStatus>
 
+  const Restore = z.object({
+    workspaceID: WorkspaceID.zod,
+    sessionID: SessionID.zod,
+    total: z.number().int().min(0),
+    step: z.number().int().min(0),
+  })
+
   export const Event = {
     Ready: BusEvent.define(
       "workspace.ready",
@@ -42,6 +56,7 @@ export namespace Workspace {
         message: z.string(),
       }),
     ),
+    Restore: BusEvent.define("workspace.restore", Restore),
     Status: BusEvent.define("workspace.status", ConnectionStatus),
   }
 
@@ -102,11 +117,170 @@ export namespace Workspace {
     return info
   })
 
+  const SessionRestoreInput = z.object({
+    workspaceID: WorkspaceID.zod,
+    sessionID: SessionID.zod,
+  })
+
+  export const sessionRestore = fn(SessionRestoreInput, async (input) => {
+    log.info("session restore requested", {
+      workspaceID: input.workspaceID,
+      sessionID: input.sessionID,
+    })
+    try {
+      const space = await get(input.workspaceID)
+      if (!space) throw new Error(`Workspace not found: ${input.workspaceID}`)
+
+      const adaptor = await getAdaptor(space.projectID, space.type)
+      const target = await adaptor.target(space)
+
+      // Need to switch the workspace of the session
+      SyncEvent.run(Session.Event.Updated, {
+        sessionID: input.sessionID,
+        info: {
+          workspaceID: input.workspaceID,
+        },
+      })
+
+      const rows = Database.use((db) =>
+        db
+          .select({
+            id: EventTable.id,
+            aggregateID: EventTable.aggregate_id,
+            seq: EventTable.seq,
+            type: EventTable.type,
+            data: EventTable.data,
+          })
+          .from(EventTable)
+          .where(eq(EventTable.aggregate_id, input.sessionID))
+          .orderBy(asc(EventTable.seq))
+          .all(),
+      )
+      if (rows.length === 0) throw new Error(`No events found for session: ${input.sessionID}`)
+
+      const all = rows
+
+      const size = 10
+      const sets = Array.from({ length: Math.ceil(all.length / size) }, (_, i) => all.slice(i * size, (i + 1) * size))
+      const total = sets.length
+      log.info("session restore prepared", {
+        workspaceID: input.workspaceID,
+        sessionID: input.sessionID,
+        workspaceType: space.type,
+        directory: space.directory,
+        target: target.type === "remote" ? String(route(target.url, "/sync/replay")) : target.directory,
+        events: all.length,
+        batches: total,
+        first: all[0]?.seq,
+        last: all.at(-1)?.seq,
+      })
+      GlobalBus.emit("event", {
+        directory: "global",
+        workspace: input.workspaceID,
+        payload: {
+          type: Event.Restore.type,
+          properties: {
+            workspaceID: input.workspaceID,
+            sessionID: input.sessionID,
+            total,
+            step: 0,
+          },
+        },
+      })
+      for (const [i, events] of sets.entries()) {
+        log.info("session restore batch starting", {
+          workspaceID: input.workspaceID,
+          sessionID: input.sessionID,
+          step: i + 1,
+          total,
+          events: events.length,
+          first: events[0]?.seq,
+          last: events.at(-1)?.seq,
+          target: target.type === "remote" ? String(route(target.url, "/sync/replay")) : target.directory,
+        })
+        if (target.type === "local") {
+          SyncEvent.replayAll(events)
+          log.info("session restore batch replayed locally", {
+            workspaceID: input.workspaceID,
+            sessionID: input.sessionID,
+            step: i + 1,
+            total,
+            events: events.length,
+          })
+        } else {
+          const url = route(target.url, "/sync/replay")
+          const headers = new Headers(target.headers)
+          headers.set("content-type", "application/json")
+          const res = await fetch(url, {
+            method: "POST",
+            headers,
+            body: JSON.stringify({
+              directory: space.directory ?? "",
+              events,
+            }),
+          })
+          if (!res.ok) {
+            const body = await res.text()
+            log.error("session restore batch failed", {
+              workspaceID: input.workspaceID,
+              sessionID: input.sessionID,
+              step: i + 1,
+              total,
+              status: res.status,
+              body,
+            })
+            throw new Error(
+              `Failed to replay session ${input.sessionID} into workspace ${input.workspaceID}: HTTP ${res.status} ${body}`,
+            )
+          }
+          log.info("session restore batch posted", {
+            workspaceID: input.workspaceID,
+            sessionID: input.sessionID,
+            step: i + 1,
+            total,
+            status: res.status,
+          })
+        }
+        GlobalBus.emit("event", {
+          directory: "global",
+          workspace: input.workspaceID,
+          payload: {
+            type: Event.Restore.type,
+            properties: {
+              workspaceID: input.workspaceID,
+              sessionID: input.sessionID,
+              total,
+              step: i + 1,
+            },
+          },
+        })
+      }
+
+      log.info("session restore complete", {
+        workspaceID: input.workspaceID,
+        sessionID: input.sessionID,
+        batches: total,
+      })
+
+      return {
+        total,
+      }
+    } catch (err) {
+      log.error("session restore failed", {
+        workspaceID: input.workspaceID,
+        sessionID: input.sessionID,
+        error: errorData(err),
+      })
+      throw err
+    }
+  })
+
   export function list(project: Project.Info) {
     const rows = Database.use((db) =>
       db.select().from(WorkspaceTable).where(eq(WorkspaceTable.project_id, project.id)).all(),
     )
     const spaces = rows.map(fromRow).sort((a, b) => a.id.localeCompare(b.id))
+
     for (const space of spaces) startSync(space)
     return spaces
   }
@@ -120,13 +294,25 @@ export namespace Workspace {
   })
 
   export const remove = fn(WorkspaceID.zod, async (id) => {
+    const sessions = Database.use((db) =>
+      db.select({ id: SessionTable.id }).from(SessionTable).where(eq(SessionTable.workspace_id, id)).all(),
+    )
+    for (const session of sessions) {
+      await AppRuntime.runPromise(Session.Service.use((svc) => svc.remove(session.id)))
+    }
+
     const row = Database.use((db) => db.select().from(WorkspaceTable).where(eq(WorkspaceTable.id, id)).get())
+
     if (row) {
       stopSync(id)
 
       const info = fromRow(row)
-      const adaptor = await getAdaptor(info.projectID, row.type)
-      adaptor.remove(info)
+      try {
+        const adaptor = await getAdaptor(info.projectID, row.type)
+        await adaptor.remove(info)
+      } catch (err) {
+        log.error("adaptor not available when removing workspace", { type: row.type })
+      }
       Database.use((db) => db.delete(WorkspaceTable).where(eq(WorkspaceTable.id, id)).run())
       return info
     }
@@ -156,51 +342,81 @@ export namespace Workspace {
 
   const log = Log.create({ service: "workspace-sync" })
 
-  async function workspaceEventLoop(space: Info, signal: AbortSignal) {
-    log.info("starting sync: " + space.id)
+  function route(url: string | URL, path: string) {
+    const next = new URL(url)
+    next.pathname = `${next.pathname.replace(/\/$/, "")}${path}`
+    next.search = ""
+    next.hash = ""
+    return next
+  }
 
+  async function syncWorkspace(space: Info, signal: AbortSignal) {
     while (!signal.aborted) {
-      log.info("connecting to sync: " + space.id)
+      log.info("connecting to global sync", { workspace: space.name })
 
-      setStatus(space.id, "connecting")
       const adaptor = await getAdaptor(space.projectID, space.type)
       const target = await adaptor.target(space)
 
       if (target.type === "local") return
 
-      const res = await fetch(target.url + "/sync/event", { method: "GET", signal }).catch((err: unknown) => {
-        setStatus(space.id, "error", String(err))
+      const res = await fetch(route(target.url, "/global/event"), {
+        method: "GET",
+        headers: target.headers,
+        signal,
+      }).catch((err: unknown) => {
+        setStatus(space.id, "error")
+
+        log.info("failed to connect to global sync", {
+          workspace: space.name,
+          error: err,
+        })
         return undefined
       })
-      if (!res || !res.ok || !res.body) {
-        log.info("failed to connect to sync: " + res?.status)
 
-        setStatus(space.id, "error", res ? `HTTP ${res.status}` : "no response")
+      if (!res || !res.ok || !res.body) {
+        log.info("failed to connect to global sync", { workspace: space.name })
+        setStatus(space.id, "error")
         await sleep(1000)
         continue
       }
+
+      log.info("global sync connected", { workspace: space.name })
       setStatus(space.id, "connected")
-      await parseSSE(res.body, signal, (evt) => {
-        const event = evt as SyncEvent.SerializedEvent
 
+      await parseSSE(res.body, signal, (evt: any) => {
         try {
-          if (!event.type.startsWith("server.")) {
-            SyncEvent.replay(event)
+          if (!("payload" in evt)) return
+
+          if (evt.payload.type === "sync") {
+            // This name -> type is temporary
+            SyncEvent.replay({ ...evt.payload, type: evt.payload.name } as SyncEvent.SerializedEvent)
           }
+
+          GlobalBus.emit("event", {
+            directory: evt.directory,
+            project: evt.project,
+            workspace: space.id,
+            payload: evt.payload,
+          })
         } catch (err) {
-          log.warn("failed to replay sync event", {
+          log.info("failed to replay global event", {
             workspaceID: space.id,
             error: err,
           })
         }
       })
+
+      log.info("disconnected from global sync: " + space.id)
       setStatus(space.id, "disconnected")
-      log.info("disconnected to sync: " + space.id)
-      await sleep(250)
+
+      // TODO: Implement exponential backoff
+      await sleep(1000)
     }
   }
 
   function startSync(space: Info) {
+    if (!Flag.OPENCODE_EXPERIMENTAL_WORKSPACES) return
+
     if (space.type === "worktree") {
       void Filesystem.exists(space.directory!).then((exists) => {
         setStatus(space.id, exists ? "connected" : "error", exists ? undefined : "directory does not exist")
@@ -213,9 +429,9 @@ export namespace Workspace {
     aborts.set(space.id, abort)
     setStatus(space.id, "disconnected")
 
-    void workspaceEventLoop(space, abort.signal).catch((error) => {
+    void syncWorkspace(space, abort.signal).catch((error) => {
       setStatus(space.id, "error", String(error))
-      log.warn("workspace sync listener failed", {
+      log.warn("workspace listener failed", {
         workspaceID: space.id,
         error,
       })
diff --git a/packages/opencode/src/server/instance/index.ts b/packages/opencode/src/server/instance/index.ts
index 86a18dc67..4a03b7b29 100644
--- a/packages/opencode/src/server/instance/index.ts
+++ b/packages/opencode/src/server/instance/index.ts
@@ -23,6 +23,7 @@ import { ConfigRoutes } from "./config"
 import { ExperimentalRoutes } from "./experimental"
 import { ProviderRoutes } from "./provider"
 import { EventRoutes } from "./event"
+import { SyncRoutes } from "./sync"
 import { WorkspaceRouterMiddleware } from "./middleware"
 import { AppRuntime } from "@/effect/app-runtime"
 
@@ -37,6 +38,7 @@ export const InstanceRoutes = (upgrade: UpgradeWebSocket): Hono =>
     .route("/permission", PermissionRoutes())
     .route("/question", QuestionRoutes())
     .route("/provider", ProviderRoutes())
+    .route("/sync", SyncRoutes())
     .route("/", FileRoutes())
     .route("/", EventRoutes())
     .route("/mcp", McpRoutes())
diff --git a/packages/opencode/src/server/instance/middleware.ts b/packages/opencode/src/server/instance/middleware.ts
index 9155ad451..824c265ef 100644
--- a/packages/opencode/src/server/instance/middleware.ts
+++ b/packages/opencode/src/server/instance/middleware.ts
@@ -11,9 +11,12 @@ import { Session } from "@/session"
 import { SessionID } from "@/session/schema"
 import { WorkspaceContext } from "@/control-plane/workspace-context"
 import { AppRuntime } from "@/effect/app-runtime"
+import { Log } from "@/util/log"
 
 type Rule = { method?: string; path: string; exact?: boolean; action: "local" | "forward" }
 
+const OPENCODE_WORKSPACE = process.env.OPENCODE_WORKSPACE
+
 const RULES: Array<Rule> = [
   { path: "/session/status", action: "forward" },
   { method: "GET", path: "/session", action: "local" },
@@ -46,6 +49,8 @@ async function getSessionWorkspace(url: URL) {
 }
 
 export function WorkspaceRouterMiddleware(upgrade: UpgradeWebSocket): MiddlewareHandler {
+  const log = Log.create({ service: "workspace-router" })
+
   return async (c, next) => {
     const raw = c.req.query("directory") || c.req.header("x-opencode-directory") || process.cwd()
     const directory = Filesystem.resolve(
@@ -63,8 +68,22 @@ export function WorkspaceRouterMiddleware(upgrade: UpgradeWebSocket): Middleware
     const sessionWorkspaceID = await getSessionWorkspace(url)
     const workspaceID = sessionWorkspaceID || url.searchParams.get("workspace")
 
-    // If no workspace is provided we use the project
-    if (!workspaceID) {
+    if (!workspaceID || url.pathname.startsWith("/console") || OPENCODE_WORKSPACE) {
+      if (OPENCODE_WORKSPACE) {
+        return WorkspaceContext.provide({
+          workspaceID: WorkspaceID.make(OPENCODE_WORKSPACE),
+          async fn() {
+            return Instance.provide({
+              directory,
+              init: () => AppRuntime.runPromise(InstanceBootstrap),
+              async fn() {
+                return next()
+              },
+            })
+          },
+        })
+      }
+
       return Instance.provide({
         directory,
         init: () => AppRuntime.runPromise(InstanceBootstrap),
@@ -77,16 +96,6 @@ export function WorkspaceRouterMiddleware(upgrade: UpgradeWebSocket): Middleware
     const workspace = await Workspace.get(WorkspaceID.make(workspaceID))
 
     if (!workspace) {
-      // Special-case deleting a session in case user's data in a
-      // weird state. Allow them to forcefully delete a synced session
-      // even if the remote workspace is not in their data.
-      //
-      // The lets the `DELETE /session/:id` endpoint through and we've
-      // made sure that it will run without an instance
-      if (url.pathname.match(/\/session\/[^/]+$/) && c.req.method === "DELETE") {
-        return next()
-      }
-
       return new Response(`Workspace not found: ${workspaceID}`, {
         status: 500,
         headers: {
@@ -95,6 +104,12 @@ export function WorkspaceRouterMiddleware(upgrade: UpgradeWebSocket): Middleware
       })
     }
 
+    if (local(c.req.method, url.pathname)) {
+      // No instance provided because we are serving cached data; there
+      // is no instance to work with
+      return next()
+    }
+
     const adaptor = await getAdaptor(workspace.projectID, workspace.type)
     const target = await adaptor.target(workspace)
 
@@ -112,24 +127,27 @@ export function WorkspaceRouterMiddleware(upgrade: UpgradeWebSocket): Middleware
       })
     }
 
-    if (local(c.req.method, url.pathname)) {
-      // No instance provided because we are serving cached data; there
-      // is no instance to work with
-      return next()
-    }
+    const proxyURL = new URL(target.url)
+    proxyURL.pathname = `${proxyURL.pathname.replace(/\/$/, "")}${url.pathname}`
+    proxyURL.search = url.search
+    proxyURL.hash = url.hash
+    proxyURL.searchParams.delete("workspace")
+
+    log.info("workspace proxy forwarding", {
+      workspaceID,
+      request: url.toString(),
+      target: String(target.url),
+      proxy: proxyURL.toString(),
+    })
 
     if (c.req.header("upgrade")?.toLowerCase() === "websocket") {
-      return ServerProxy.websocket(upgrade, target, c.req.raw, c.env)
+      return ServerProxy.websocket(upgrade, proxyURL, target.headers, c.req.raw, c.env)
     }
 
     const headers = new Headers(c.req.raw.headers)
     headers.delete("x-opencode-workspace")
 
-    return ServerProxy.http(
-      target,
-      new Request(c.req.raw, {
-        headers,
-      }),
-    )
+    const req = new Request(c.req.raw, { headers })
+    return ServerProxy.http(proxyURL, target.headers, req)
   }
 }
diff --git a/packages/opencode/src/server/instance/sync.ts b/packages/opencode/src/server/instance/sync.ts
new file mode 100644
index 000000000..c22969130
--- /dev/null
+++ b/packages/opencode/src/server/instance/sync.ts
@@ -0,0 +1,118 @@
+import z from "zod"
+import { Hono } from "hono"
+import { describeRoute, validator, resolver } from "hono-openapi"
+import { SyncEvent } from "@/sync"
+import { Database, asc, and, not, or, lte, eq } from "@/storage/db"
+import { EventTable } from "@/sync/event.sql"
+import { lazy } from "@/util/lazy"
+import { Log } from "@/util/log"
+import { errors } from "../error"
+
+const ReplayEvent = z.object({
+  id: z.string(),
+  aggregateID: z.string(),
+  seq: z.number().int().min(0),
+  type: z.string(),
+  data: z.record(z.string(), z.unknown()),
+})
+
+const log = Log.create({ service: "server.sync" })
+
+export const SyncRoutes = lazy(() =>
+  new Hono()
+    .post(
+      "/replay",
+      describeRoute({
+        summary: "Replay sync events",
+        description: "Validate and replay a complete sync event history.",
+        operationId: "sync.replay",
+        responses: {
+          200: {
+            description: "Replayed sync events",
+            content: {
+              "application/json": {
+                schema: resolver(
+                  z.object({
+                    sessionID: z.string(),
+                  }),
+                ),
+              },
+            },
+          },
+          ...errors(400),
+        },
+      }),
+      validator(
+        "json",
+        z.object({
+          directory: z.string(),
+          events: z.array(ReplayEvent).min(1),
+        }),
+      ),
+      async (c) => {
+        const body = c.req.valid("json")
+        const events = body.events
+        const source = events[0].aggregateID
+        log.info("sync replay requested", {
+          sessionID: source,
+          events: events.length,
+          first: events[0]?.seq,
+          last: events.at(-1)?.seq,
+          directory: body.directory,
+        })
+        SyncEvent.replayAll(events)
+
+        log.info("sync replay complete", {
+          sessionID: source,
+          events: events.length,
+          first: events[0]?.seq,
+          last: events.at(-1)?.seq,
+        })
+
+        return c.json({
+          sessionID: source,
+        })
+      },
+    )
+    .get(
+      "/history",
+      describeRoute({
+        summary: "List sync events",
+        description:
+          "List sync events for all aggregates. Keys are aggregate IDs the client already knows about, values are the last known sequence ID. Events with seq > value are returned for those aggregates. Aggregates not listed in the input get their full history.",
+        operationId: "sync.history.list",
+        responses: {
+          200: {
+            description: "Sync events",
+            content: {
+              "application/json": {
+                schema: resolver(
+                  z.array(
+                    z.object({
+                      id: z.string(),
+                      aggregate_id: z.string(),
+                      seq: z.number(),
+                      type: z.string(),
+                      data: z.record(z.string(), z.unknown()),
+                    }),
+                  ),
+                ),
+              },
+            },
+          },
+          ...errors(400),
+        },
+      }),
+      validator("json", z.record(z.string(), z.number().int().min(0))),
+      async (c) => {
+        const body = c.req.valid("json")
+        const exclude = Object.entries(body)
+        const where =
+          exclude.length > 0
+            ? not(or(...exclude.map(([id, seq]) => and(eq(EventTable.aggregate_id, id), lte(EventTable.seq, seq))))!)
+            : undefined
+        const rows = Database.use((db) => db.select().from(EventTable).where(where).orderBy(asc(EventTable.seq)).all())
+        return c.json(rows)
+      },
+    ),
+)
diff --git a/packages/opencode/src/server/instance/workspace.ts b/packages/opencode/src/server/instance/workspace.ts
index 7cee03197..a4ff4eda8 100644
--- a/packages/opencode/src/server/instance/workspace.ts
+++ b/packages/opencode/src/server/instance/workspace.ts
@@ -6,12 +6,10 @@ import { Workspace } from "../../control-plane/workspace"
 import { Instance } from "../../project/instance"
 import { errors } from "../error"
 import { lazy } from "../../util/lazy"
+import { Log } from "@/util/log"
+import { errorData } from "@/util/error"
 
-const WorkspaceAdaptor = z.object({
-  type: z.string(),
-  name: z.string(),
-  description: z.string(),
-})
+const log = Log.create({ service: "server.workspace" })
 
 export const WorkspaceRoutes = lazy(() =>
   new Hono()
@@ -26,7 +24,15 @@ export const WorkspaceRoutes = lazy(() =>
             description: "Workspace adaptors",
             content: {
               "application/json": {
-                schema: resolver(z.array(WorkspaceAdaptor)),
+                schema: resolver(
+                  z.array(
+                    z.object({
+                      type: z.string(),
+                      name: z.string(),
+                      description: z.string(),
+                    }),
+                  ),
+                ),
               },
             },
           },
@@ -140,5 +146,58 @@ export const WorkspaceRoutes = lazy(() =>
         const { id } = c.req.valid("param")
         return c.json(await Workspace.remove(id))
       },
+    )
+    .post(
+      "/:id/session-restore",
+      describeRoute({
+        summary: "Restore session into workspace",
+        description: "Replay a session's sync events into the target workspace in batches.",
+        operationId: "experimental.workspace.sessionRestore",
+        responses: {
+          200: {
+            description: "Session replay started",
+            content: {
+              "application/json": {
+                schema: resolver(
+                  z.object({
+                    total: z.number().int().min(0),
+                  }),
+                ),
+              },
+            },
+          },
+          ...errors(400),
+        },
+      }),
+      validator("param", z.object({ id: Workspace.Info.shape.id })),
+      validator("json", Workspace.sessionRestore.schema.omit({ workspaceID: true })),
+      async (c) => {
+        const { id } = c.req.valid("param")
+        const body = c.req.valid("json")
+        log.info("session restore route requested", {
+          workspaceID: id,
+          sessionID: body.sessionID,
+          directory: Instance.directory,
+        })
+        try {
+          const result = await Workspace.sessionRestore({
+            workspaceID: id,
+            ...body,
+          })
+          log.info("session restore route complete", {
+            workspaceID: id,
+            sessionID: body.sessionID,
+            total: result.total,
+          })
+          return c.json(result)
+        } catch (err) {
+          log.error("session restore route failed", {
+            workspaceID: id,
+            sessionID: body.sessionID,
+            error: errorData(err),
+          })
+          throw err
+        }
+      },
     ),
 )
diff --git a/packages/opencode/src/server/middleware.ts b/packages/opencode/src/server/middleware.ts
index a51ba602b..d0539eb24 100644
--- a/packages/opencode/src/server/middleware.ts
+++ b/packages/opencode/src/server/middleware.ts
@@ -86,7 +86,7 @@ const zipped = compress()
 export const CompressionMiddleware: MiddlewareHandler = (c, next) => {
   const path = c.req.path
   const method = c.req.method
-  if (path === "/event" || path === "/global/event" || path === "/global/sync-event") return next()
+  if (path === "/event" || path === "/global/event") return next()
   if (method === "POST" && /\/session\/[^/]+\/(message|prompt_async)$/.test(path)) return next()
   return zipped(c, next)
 }
diff --git a/packages/opencode/src/server/proxy.ts b/packages/opencode/src/server/proxy.ts
index c90a657dc..0c0deba20 100644
--- a/packages/opencode/src/server/proxy.ts
+++ b/packages/opencode/src/server/proxy.ts
@@ -1,6 +1,6 @@
-import type { Target } from "@/control-plane/types"
 import { Hono } from "hono"
 import type { UpgradeWebSocket } from "hono/ws"
+import { Log } from "@/util/log"
 
 const hop = new Set([
   "connection",
@@ -20,6 +20,7 @@ type Msg = string | ArrayBuffer | Uint8Array
 function headers(req: Request, extra?: HeadersInit) {
   const out = new Headers(req.headers)
   for (const key of hop) out.delete(key)
+  out.delete("accept-encoding")
   out.delete("x-opencode-directory")
   out.delete("x-opencode-workspace")
   if (!extra) return out
@@ -98,31 +99,63 @@ const app = (upgrade: UpgradeWebSocket) =>
   )
 
 export namespace ServerProxy {
-  export function http(target: Extract<Target, { type: "remote" }>, req: Request) {
+  const log = Log.Default.clone().tag("service", "server-proxy")
+
+  export function http(url: string | URL, extra: HeadersInit | undefined, req: Request) {
+    console.log("proxy http request", {
+      method: req.method,
+      request: req.url,
+      url: String(url),
+    })
     return fetch(
-      new Request(target.url, {
+      new Request(url, {
         method: req.method,
-        headers: headers(req, target.headers),
+        headers: headers(req, extra),
         body: req.method === "GET" || req.method === "HEAD" ? undefined : req.body,
         redirect: "manual",
         signal: req.signal,
       }),
-    )
+    ).then((res) => {
+      const next = new Headers(res.headers)
+      next.delete("content-encoding")
+      next.delete("content-length")
+
+      console.log("proxy http response", {
+        method: req.method,
+        request: req.url,
+        url: String(url),
+        status: res.status,
+        statusText: res.statusText,
+      })
+      return new Response(res.body, {
+        status: res.status,
+        statusText: res.statusText,
+        headers: next,
+      })
+    })
   }
 
   export function websocket(
     upgrade: UpgradeWebSocket,
-    target: Extract<Target, { type: "remote" }>,
+    target: string | URL,
+    extra: HeadersInit | undefined,
     req: Request,
     env: unknown,
   ) {
-    const url = new URL(req.url)
-    url.pathname = "/__workspace_ws"
-    url.search = ""
+    const proxy = new URL(req.url)
+    proxy.pathname = "/__workspace_ws"
+    proxy.search = ""
     const next = new Headers(req.headers)
-    next.set("x-opencode-proxy-url", socket(target.url))
+    next.set("x-opencode-proxy-url", socket(target))
+    for (const [key, value] of new Headers(extra).entries()) {
+      next.set(key, value)
+    }
+    log.info("proxy websocket", {
+      request: req.url,
+      target: String(target),
+    })
     return app(upgrade).fetch(
-      new Request(url, {
+      new Request(proxy, {
         method: req.method,
         headers: next,
         signal: req.signal,
diff --git a/packages/opencode/src/sync/index.ts b/packages/opencode/src/sync/index.ts
index d7cb7f774..ce598dae6 100644
--- a/packages/opencode/src/sync/index.ts
+++ b/packages/opencode/src/sync/index.ts
@@ -199,6 +199,25 @@ export namespace SyncEvent {
     process(def, event, { publish: !!options?.publish })
   }
 
+  export function replayAll(events: SerializedEvent[], options?: { publish: boolean }) {
+    const source = events[0]?.aggregateID
+    if (!source) return
+    if (events.some((item) => item.aggregateID !== source)) {
+      throw new Error("Replay events must belong to the same session")
+    }
+    const start = events[0].seq
+    for (const [i, item] of events.entries()) {
+      const seq = start + i
+      if (item.seq !== seq) {
+        throw new Error(`Replay sequence mismatch at index ${i}: expected ${seq}, got ${item.seq}`)
+      }
+    }
+    for (const item of events) {
+      replay(item, options)
+    }
+    return source
+  }
+
   export function run<Def extends Definition>(def: Def, data: Event<Def>["data"], options?: { publish?: boolean }) {
     const agg = (data as Record<string, string>)[def.aggregate]
     // This should never happen: we've enforced it via typescript in
diff --git a/packages/sdk/js/src/v2/gen/sdk.gen.ts b/packages/sdk/js/src/v2/gen/sdk.gen.ts
index b5fc976bb..d7bf43f50 100644
--- a/packages/sdk/js/src/v2/gen/sdk.gen.ts
+++ b/packages/sdk/js/src/v2/gen/sdk.gen.ts
@@ -35,6 +35,8 @@ import type {
   ExperimentalWorkspaceListResponses,
   ExperimentalWorkspaceRemoveErrors,
   ExperimentalWorkspaceRemoveResponses,
+  ExperimentalWorkspaceSessionRestoreErrors,
+  ExperimentalWorkspaceSessionRestoreResponses,
   ExperimentalWorkspaceStatusResponses,
   FileListResponses,
   FilePartInput,
@@ -157,6 +159,10 @@ import type {
   SessionUpdateErrors,
   SessionUpdateResponses,
   SubtaskPartInput,
+  SyncHistoryListErrors,
+  SyncHistoryListResponses,
+  SyncReplayErrors,
+  SyncReplayResponses,
   TextPartInput,
   ToolIdsErrors,
   ToolIdsResponses,
@@ -1243,6 +1249,49 @@ export class Workspace extends HeyApiClient {
     })
   }
 
+  /**
+   * Restore session into workspace
+   *
+   * Replay a session's sync events into the target workspace in batches.
+   */
+  public sessionRestore<ThrowOnError extends boolean = false>(
+    parameters: {
+      id: string
+      directory?: string
+      workspace?: string
+      sessionID?: string
+    },
+    options?: Options<never, ThrowOnError>,
+  ) {
+    const params = buildClientParams(
+      [parameters],
+      [
+        {
+          args: [
+            { in: "path", key: "id" },
+            { in: "query", key: "directory" },
+            { in: "query", key: "workspace" },
+            { in: "body", key: "sessionID" },
+          ],
+        },
+      ],
+    )
+    return (options?.client ?? this.client).post<
+      ExperimentalWorkspaceSessionRestoreResponses,
+      ExperimentalWorkspaceSessionRestoreErrors,
+      ThrowOnError
+    >({
+      url: "/experimental/workspace/{id}/session-restore",
+      ...options,
+      ...params,
+      headers: {
+        "Content-Type": "application/json",
+        ...options?.headers,
+        ...params.headers,
+      },
+    })
+  }
+
   private _adaptor?: Adaptor
   get adaptor(): Adaptor {
     return (this._adaptor ??= new Adaptor({ client: this.client }))
@@ -2961,6 +3010,109 @@ export class Provider extends HeyApiClient {
   }
 }
 
+export class History extends HeyApiClient {
+  /**
+   * List sync events
+   *
+   * List sync events for all aggregates. Keys are aggregate IDs the client already knows about, values are the last known sequence ID. Events with seq > value are returned for those aggregates. Aggregates not listed in the input get their full history.
+   */
+  public list<ThrowOnError extends boolean = false>(
+    parameters?: {
+      directory?: string
+      workspace?: string
+      body?: {
+        [key: string]: number
+      }
+    },
+    options?: Options<never, ThrowOnError>,
+  ) {
+    const params = buildClientParams(
+      [parameters],
+      [
+        {
+          args: [
+            { in: "query", key: "directory" },
+            { in: "query", key: "workspace" },
+            { key: "body", map: "body" },
+          ],
+        },
+      ],
+    )
+    return (options?.client ?? this.client).get<SyncHistoryListResponses, SyncHistoryListErrors, ThrowOnError>({
+      url: "/sync/history",
+      ...options,
+      ...params,
+      headers: {
+        "Content-Type": "application/json",
+        ...options?.headers,
+        ...params.headers,
+      },
+    })
+  }
+}
+
+export class Sync extends HeyApiClient {
+  /**
+   * Replay sync events
+   *
+   * Validate and replay a complete sync event history.
+   */
+  public replay<ThrowOnError extends boolean = false>(
+    parameters?: {
+      query_directory?: string
+      workspace?: string
+      body_directory?: string
+      events?: Array<{
+        id: string
+        aggregateID: string
+        seq: number
+        type: string
+        data: {
+          [key: string]: unknown
+        }
+      }>
+    },
+    options?: Options<never, ThrowOnError>,
+  ) {
+    const params = buildClientParams(
+      [parameters],
+      [
+        {
+          args: [
+            {
+              in: "query",
+              key: "query_directory",
+              map: "directory",
+            },
+            { in: "query", key: "workspace" },
+            {
+              in: "body",
+              key: "body_directory",
+              map: "directory",
+            },
+            { in: "body", key: "events" },
+          ],
+        },
+      ],
+    )
+    return (options?.client ?? this.client).post<SyncReplayResponses, SyncReplayErrors, ThrowOnError>({
+      url: "/sync/replay",
+      ...options,
+      ...params,
+      headers: {
+        "Content-Type": "application/json",
+        ...options?.headers,
+        ...params.headers,
+      },
+    })
+  }
+
+  private _history?: History
+  get history(): History {
+    return (this._history ??= new History({ client: this.client }))
+  }
+}
+
 export class Find extends HeyApiClient {
   /**
    * Find text
@@ -4217,6 +4369,11 @@ export class OpencodeClient extends HeyApiClient {
     return (this._provider ??= new Provider({ client: this.client }))
   }
 
+  private _sync?: Sync
+  get sync(): Sync {
+    return (this._sync ??= new Sync({ client: this.client }))
+  }
+
   private _find?: Find
   get find(): Find {
     return (this._find ??= new Find({ client: this.client }))
diff --git a/packages/sdk/js/src/v2/gen/types.gen.ts b/packages/sdk/js/src/v2/gen/types.gen.ts
index 8f4c16c5b..24c1d53bf 100644
--- a/packages/sdk/js/src/v2/gen/types.gen.ts
+++ b/packages/sdk/js/src/v2/gen/types.gen.ts
@@ -520,6 +520,16 @@ export type EventWorkspaceFailed = {
   }
 }
 
+export type EventWorkspaceRestore = {
+  type: "workspace.restore"
+  properties: {
+    workspaceID: string
+    sessionID: string
+    total: number
+    step: number
+  }
+}
+
 export type EventWorkspaceStatus = {
   type: "workspace.status"
   properties: {
@@ -1137,6 +1147,7 @@ export type GlobalEvent = {
     | EventPtyDeleted
     | EventWorkspaceReady
     | EventWorkspaceFailed
+    | EventWorkspaceRestore
     | EventWorkspaceStatus
     | EventMessageUpdated
     | EventMessageRemoved
@@ -2049,6 +2060,7 @@ export type Event =
   | EventPtyDeleted
   | EventWorkspaceReady
   | EventWorkspaceFailed
+  | EventWorkspaceRestore
   | EventWorkspaceStatus
   | EventMessageUpdated
   | EventMessageRemoved
@@ -3006,6 +3018,42 @@ export type ExperimentalWorkspaceRemoveResponses = {
 export type ExperimentalWorkspaceRemoveResponse =
   ExperimentalWorkspaceRemoveResponses[keyof ExperimentalWorkspaceRemoveResponses]
 
+export type ExperimentalWorkspaceSessionRestoreData = {
+  body?: {
+    sessionID: string
+  }
+  path: {
+    id: string
+  }
+  query?: {
+    directory?: string
+    workspace?: string
+  }
+  url: "/experimental/workspace/{id}/session-restore"
+}
+
+export type ExperimentalWorkspaceSessionRestoreErrors = {
+  /**
+   * Bad request
+   */
+  400: BadRequestError
+}
+
+export type ExperimentalWorkspaceSessionRestoreError =
+  ExperimentalWorkspaceSessionRestoreErrors[keyof ExperimentalWorkspaceSessionRestoreErrors]
+
+export type ExperimentalWorkspaceSessionRestoreResponses = {
+  /**
+   * Session replay started
+   */
+  200: {
+    total: number
+  }
+}
+
+export type ExperimentalWorkspaceSessionRestoreResponse =
+  ExperimentalWorkspaceSessionRestoreResponses[keyof ExperimentalWorkspaceSessionRestoreResponses]
+
 export type WorktreeRemoveData = {
   body?: WorktreeRemoveInput
   path?: never
@@ -4456,6 +4504,85 @@ export type ProviderOauthCallbackResponses = {
 
 export type ProviderOauthCallbackResponse = ProviderOauthCallbackResponses[keyof ProviderOauthCallbackResponses]
 
+export type SyncReplayData = {
+  body?: {
+    directory: string
+    events: Array<{
+      id: string
+      aggregateID: string
+      seq: number
+      type: string
+      data: {
+        [key: string]: unknown
+      }
+    }>
+  }
+  path?: never
+  query?: {
+    directory?: string
+    workspace?: string
+  }
+  url: "/sync/replay"
+}
+
+export type SyncReplayErrors = {
+  /**
+   * Bad request
+   */
+  400: BadRequestError
+}
+
+export type SyncReplayError = SyncReplayErrors[keyof SyncReplayErrors]
+
+export type SyncReplayResponses = {
+  /**
+   * Replayed sync events
+   */
+  200: {
+    sessionID: string
+  }
+}
+
+export type SyncReplayResponse = SyncReplayResponses[keyof SyncReplayResponses]
+
+export type SyncHistoryListData = {
+  body?: {
+    [key: string]: number
+  }
+  path?: never
+  query?: {
+    directory?: string
+    workspace?: string
+  }
+  url: "/sync/history"
+}
+
+export type SyncHistoryListErrors = {
+  /**
+   * Bad request
+   */
+  400: BadRequestError
+}
+
+export type SyncHistoryListError = SyncHistoryListErrors[keyof SyncHistoryListErrors]
+
+export type SyncHistoryListResponses = {
+  /**
+   * Sync events
+   */
+  200: Array<{
+    id: string
+    aggregate_id: string
+    seq: number
+    type: string
+    data: {
+      [key: string]: unknown
+    }
+  }>
+}
+
+export type SyncHistoryListResponse = SyncHistoryListResponses[keyof SyncHistoryListResponses]
+
 export type FindTextData = {
   body?: never
   path?: never
diff --git a/packages/sdk/openapi.json b/packages/sdk/openapi.json
index 6000e6604..ee3538d55 100644
--- a/packages/sdk/openapi.json
+++ b/packages/sdk/openapi.json
@@ -1805,6 +1805,90 @@
         ]
       }
     },
+    "/experimental/workspace/{id}/session-restore": {
+      "post": {
+        "operationId": "experimental.workspace.sessionRestore",
+        "parameters": [
+          {
+            "in": "query",
+            "name": "directory",
+            "schema": {
+              "type": "string"
+            }
+          },
+          {
+            "in": "query",
+            "name": "workspace",
+            "schema": {
+              "type": "string"
+            }
+          },
+          {
+            "in": "path",
+            "name": "id",
+            "schema": {
+              "type": "string",
+              "pattern": "^wrk.*"
+            },
+            "required": true
+          }
+        ],
+        "summary": "Restore session into workspace",
+        "description": "Replay a session's sync events into the target workspace in batches.",
+        "responses": {
+          "200": {
+            "description": "Session replay started",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "type": "object",
+                  "properties": {
+                    "total": {
+                      "type": "integer",
+                      "minimum": 0,
+                      "maximum": 9007199254740991
+                    }
+                  },
+                  "required": ["total"]
+                }
+              }
+            }
+          },
+          "400": {
+            "description": "Bad request",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/BadRequestError"
+                }
+              }
+            }
+          }
+        },
+        "requestBody": {
+          "content": {
+            "application/json": {
+              "schema": {
+                "type": "object",
+                "properties": {
+                  "sessionID": {
+                    "type": "string",
+                    "pattern": "^ses.*"
+                  }
+                },
+                "required": ["sessionID"]
+              }
+            }
+          }
+        },
+        "x-codeSamples": [
+          {
+            "lang": "js",
+            "source": "import { createOpencodeClient } from \"@opencode-ai/sdk\n\nconst client = createOpencodeClient()\nawait client.experimental.workspace.sessionRestore({\n  ...\n})"
+          }
+        ]
+      }
+    },
     "/experimental/worktree": {
       "post": {
         "operationId": "worktree.create",
@@ -5143,6 +5227,202 @@
         ]
       }
     },
+    "/sync/replay": {
+      "post": {
+        "operationId": "sync.replay",
+        "parameters": [
+          {
+            "in": "query",
+            "name": "directory",
+            "schema": {
+              "type": "string"
+            }
+          },
+          {
+            "in": "query",
+            "name": "workspace",
+            "schema": {
+              "type": "string"
+            }
+          }
+        ],
+        "summary": "Replay sync events",
+        "description": "Validate and replay a complete sync event history.",
+        "responses": {
+          "200": {
+            "description": "Replayed sync events",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "type": "object",
+                  "properties": {
+                    "sessionID": {
+                      "type": "string"
+                    }
+                  },
+                  "required": ["sessionID"]
+                }
+              }
+            }
+          },
+          "400": {
+            "description": "Bad request",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/BadRequestError"
+                }
+              }
+            }
+          }
+        },
+        "requestBody": {
+          "content": {
+            "application/json": {
+              "schema": {
+                "type": "object",
+                "properties": {
+                  "directory": {
+                    "type": "string"
+                  },
+                  "events": {
+                    "minItems": 1,
+                    "type": "array",
+                    "items": {
+                      "type": "object",
+                      "properties": {
+                        "id": {
+                          "type": "string"
+                        },
+                        "aggregateID": {
+                          "type": "string"
+                        },
+                        "seq": {
+                          "type": "integer",
+                          "minimum": 0,
+                          "maximum": 9007199254740991
+                        },
+                        "type": {
+                          "type": "string"
+                        },
+                        "data": {
+                          "type": "object",
+                          "propertyNames": {
+                            "type": "string"
+                          },
+                          "additionalProperties": {}
+                        }
+                      },
+                      "required": ["id", "aggregateID", "seq", "type", "data"]
+                    }
+                  }
+                },
+                "required": ["directory", "events"]
+              }
+            }
+          }
+        },
+        "x-codeSamples": [
+          {
+            "lang": "js",
+            "source": "import { createOpencodeClient } from \"@opencode-ai/sdk\n\nconst client = createOpencodeClient()\nawait client.sync.replay({\n  ...\n})"
+          }
+        ]
+      }
+    },
+    "/sync/history": {
+      "get": {
+        "operationId": "sync.history.list",
+        "parameters": [
+          {
+            "in": "query",
+            "name": "directory",
+            "schema": {
+              "type": "string"
+            }
+          },
+          {
+            "in": "query",
+            "name": "workspace",
+            "schema": {
+              "type": "string"
+            }
+          }
+        ],
+        "summary": "List sync events",
+        "description": "List sync events for all aggregates. Keys are aggregate IDs the client already knows about, values are the last known sequence ID. Events with seq > value are returned for those aggregates. Aggregates not listed in the input get their full history.",
+        "responses": {
+          "200": {
+            "description": "Sync events",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "type": "array",
+                  "items": {
+                    "type": "object",
+                    "properties": {
+                      "id": {
+                        "type": "string"
+                      },
+                      "aggregate_id": {
+                        "type": "string"
+                      },
+                      "seq": {
+                        "type": "number"
+                      },
+                      "type": {
+                        "type": "string"
+                      },
+                      "data": {
+                        "type": "object",
+                        "propertyNames": {
+                          "type": "string"
+                        },
+                        "additionalProperties": {}
+                      }
+                    },
+                    "required": ["id", "aggregate_id", "seq", "type", "data"]
+                  }
+                }
+              }
+            }
+          },
+          "400": {
+            "description": "Bad request",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/BadRequestError"
+                }
+              }
+            }
+          }
+        },
+        "requestBody": {
+          "content": {
+            "application/json": {
+              "schema": {
+                "type": "object",
+                "propertyNames": {
+                  "type": "string"
+                },
+                "additionalProperties": {
+                  "type": "integer",
+                  "minimum": 0,
+                  "maximum": 9007199254740991
+                }
+              }
+            }
+          }
+        },
+        "x-codeSamples": [
+          {
+            "lang": "js",
+            "source": "import { createOpencodeClient } from \"@opencode-ai/sdk\n\nconst client = createOpencodeClient()\nawait client.sync.history.list({\n  ...\n})"
+          }
+        ]
+      }
+    },
     "/find": {
       "get": {
         "operationId": "find.text",
@@ -8514,6 +8794,40 @@
         },
         "required": ["type", "properties"]
       },
+      "Event.workspace.restore": {
+        "type": "object",
+        "properties": {
+          "type": {
+            "type": "string",
+            "const": "workspace.restore"
+          },
+          "properties": {
+            "type": "object",
+            "properties": {
+              "workspaceID": {
+                "type": "string",
+                "pattern": "^wrk.*"
+              },
+              "sessionID": {
+                "type": "string",
+                "pattern": "^ses.*"
+              },
+              "total": {
+                "type": "integer",
+                "minimum": 0,
+                "maximum": 9007199254740991
+              },
+              "step": {
+                "type": "integer",
+                "minimum": 0,
+                "maximum": 9007199254740991
+              }
+            },
+            "required": ["workspaceID", "sessionID", "total", "step"]
+          }
+        },
+        "required": ["type", "properties"]
+      },
       "Event.workspace.status": {
         "type": "object",
         "properties": {
@@ -10524,6 +10838,9 @@
                 "$ref": "#/components/schemas/Event.workspace.failed"
               },
               {
+                "$ref": "#/components/schemas/Event.workspace.restore"
+              },
+              {
                 "$ref": "#/components/schemas/Event.workspace.status"
               },
               {
@@ -12781,6 +13098,9 @@
             "$ref": "#/components/schemas/Event.workspace.failed"
           },
           {
+            "$ref": "#/components/schemas/Event.workspace.restore"
+          },
+          {
             "$ref": "#/components/schemas/Event.workspace.status"
           },
           {