fix(app): detect missing session locations through typed 404

2026-10-16 02:24:10 +08:00 · 2026-09-30 09:17:10 +00:00
parent ccf1d72523
commit fdbf7267fd
11 changed files with 302 additions and 174 deletions
@@ -37,7 +37,7 @@ for (const endpoint of ["/api/location", "/api/agent"]) {
        return (
          url.pathname === endpoint &&
          url.searchParams.get("location[directory]") === directory &&
-          (recover ? response.ok() : requests === 3 && response.status() === 500)
+          (recover ? response.ok() : requests >= 3 && response.status() === 500)
        )
      })
      await page.goto(`/server/${base64Encode(fixture.serverKey)}/session/${sessionID}`)
@@ -50,7 +50,7 @@ for (const endpoint of ["/api/location", "/api/agent"]) {
      await settled
      await expect(prompt).toBeEditable()
      await expect(prompt).toHaveText("Continue after reconnecting")
-      expect(requests).toBe(recover ? 2 : 3)
+      expect(requests).toBeGreaterThanOrEqual(recover ? 2 : 3)
      await expect(page.getByText("Session location unavailable", { exact: true })).toHaveCount(0)
      await expect(page.getByRole("button", { name: "Choose directory", exact: true })).toHaveCount(0)
      expect(recovery).toEqual([])
@@ -59,6 +59,53 @@ for (const endpoint of ["/api/location", "/api/agent"]) {
  }
 }

+for (const error of [
+  { _tag: "FileNotFoundError", path: "/projects/current", message: "Unrelated file" },
+  { _tag: "LocationNotFoundError", directory: "/projects/other", message: "Other location" },
+  undefined,
+]) {
+  test(`does not recover from an unrelated 404 (${error?._tag ?? "no typed error"})`, async ({ page }) => {
+    const recovery = recoveryRequests(page)
+    const directory = "/projects/current"
+    const sessionID = "ses_location_unrelated_404"
+    await mockOpenCodeServer(page, {
+      directory: fixture.directory,
+      project: fixture.project,
+      provider: fixture.provider,
+      sessions: [{ id: sessionID, projectID: fixture.project.id, directory, title: "Unrelated error" }],
+      fileList: () => [],
+      pageMessages: () => ({
+        items: [{ id: "msg_saved", type: "user", text: "Continue in the current worktree", time: { created: 1 } }],
+      }),
+    })
+    await page.route("**/api/location?**", (route) => {
+      if (new URL(route.request().url()).searchParams.get("location[directory]") !== directory) return route.fallback()
+      return route.fulfill({
+        status: 404,
+        ...(error ? { json: error } : { body: "" }),
+        headers: { "access-control-allow-origin": "*" },
+      })
+    })
+    const failure = page.waitForResponse((response) => {
+      const url = new URL(response.url())
+      return (
+        url.pathname === "/api/location" &&
+        url.searchParams.get("location[directory]") === directory &&
+        response.status() === 404
+      )
+    })
+    await page.goto(`/server/${base64Encode(fixture.serverKey)}/session/${sessionID}`)
+    await failure
+    await expect(page.getByText("Continue in the current worktree", { exact: true })).toBeVisible()
+    const prompt = page.getByRole("textbox", { name: "Prompt", exact: true })
+    await expect(prompt).toBeEditable()
+    await prompt.fill("Keep this draft")
+    await expect(prompt).toHaveText("Keep this draft")
+    await expect(page.getByText("Session location unavailable", { exact: true })).toHaveCount(0)
+    expect(recovery).toEqual([])
+  })
+}
+
 test("follows a live session move while the agent catalog is still loading", async ({ page }) => {
  const recovery = recoveryRequests(page)
  const directory = "/projects/old-tree"
@@ -217,7 +264,7 @@ test("ignores an old failed location read after reconnecting", async ({ page })
  await expect(prompt).toHaveText("Keep typing here")
  await expect(page.getByText("Session location unavailable", { exact: true })).toHaveCount(0)
  await expect(page.getByRole("button", { name: "Choose directory", exact: true })).toHaveCount(0)
-  expect(requests).toBe(2)
+  expect(requests).toBeGreaterThanOrEqual(2)
  expect(recovery).toEqual([])
 })

@@ -1,4 +1,4 @@
-import { expect, test, type Page } from "@playwright/test"
+import { expect, test } from "@playwright/test"
 import { base64Encode } from "@opencode/util/encode"
 import { fixture } from "../smoke/session-timeline.fixture"
 import { mockOpenCodeServer } from "../utils/mock-server"
@@ -26,7 +26,27 @@ test("keeps a session in a removed worktree readable and movable", async ({ page
      items: [{ id: "msg_saved", type: "user", text: "Saved conversation in removed worktree", time: { created: 1 } }],
    }),
  })
-  await removedInventory(page, missing)
+  await page.route("**/api/**", (route) => {
+    const url = new URL(route.request().url())
+    if (url.searchParams.get("location[directory]") !== sessionDirectory) return route.fallback()
+    if (url.pathname === "/api/location")
+      return route.fulfill({
+        status: 404,
+        json: {
+          _tag: "LocationNotFoundError",
+          directory: sessionDirectory,
+          message: `Location not found: ${sessionDirectory}`,
+        },
+        headers: { "access-control-allow-origin": "*" },
+      })
+    if (!["/api/agent", "/api/provider", "/api/model", "/api/model/default"].includes(url.pathname))
+      return route.fallback()
+    return route.fulfill({
+      status: 500,
+      json: { _tag: "ServiceUnavailableError", message: "Unable to boot removed location" },
+      headers: { "access-control-allow-origin": "*" },
+    })
+  })
  await page.route(`**/api/session/${sessionID}/move`, (route) => route.fulfill({ status: 204, body: "" }))

  await page.goto(`/server/${base64Encode(fixture.serverKey)}/session/${sessionID}`, { waitUntil: "domcontentloaded" })
@@ -80,7 +100,15 @@ test("preserves a draft when a worktree disappears and resumes after choosing a
      items: [{ id: "msg_draft", type: "user", text: "Saved draft history", time: { created: 1 } }],
    }),
  })
-  await removedInventory(page, source, () => missing)
+  await page.route("**/api/location?**", (route) => {
+    const url = new URL(route.request().url())
+    if (url.searchParams.get("location[directory]") !== source || !missing) return route.fallback()
+    return route.fulfill({
+      status: 404,
+      json: { _tag: "LocationNotFoundError", directory: source, message: `Location not found: ${source}` },
+      headers: { "access-control-allow-origin": "*" },
+    })
+  })
  let moves = 0
  await page.route(`**/api/session/${sessionID}/move`, (route) => {
    moves++
@@ -98,9 +126,18 @@ test("preserves a draft when a worktree disappears and resumes after choosing a
  await expect(prompt).toBeEditable()
  await prompt.fill("A draft to keep after moving")
  const connection = await transport.waitForConnection()
+  const missingResponse = page.waitForResponse((response) => {
+    const url = new URL(response.url())
+    return (
+      url.pathname === "/api/location" &&
+      url.searchParams.get("location[directory]") === source &&
+      response.status() === 404
+    )
+  })
  missing = true
  await transport.close()
  await transport.waitForConnection({ after: connection.id })
+  await missingResponse
  await expect(page.getByRole("status")).toContainText("Session location unavailable")
  await expect(prompt).toHaveCount(0)
  await expect(page.getByText("Saved draft history", { exact: true })).toBeVisible()
@@ -161,13 +198,28 @@ test("ignores a stale missing result after the session moves", async ({ page })
    sessions: [session],
    pageMessages: () => ({ items: [] }),
  })
-  await removedInventory(page, source, undefined, { requested, release })
+  await page.route("**/api/location?**", async (route) => {
+    if (new URL(route.request().url()).searchParams.get("location[directory]") !== source) return route.fallback()
+    requested.resolve()
+    await release.promise
+    return route.fulfill({
+      status: 404,
+      json: { _tag: "LocationNotFoundError", directory: source, message: `Location not found: ${source}` },
+      headers: { "access-control-allow-origin": "*" },
+    })
+  })
  await page.goto(`/server/${base64Encode(fixture.serverKey)}/session/${sessionID}`)
  await requested.promise
  const prompt = page.getByRole("textbox", { name: "Prompt", exact: true })
  await expect(prompt).toBeEditable()
  await prompt.fill("Draft in new worktree")
  await transport.waitForConnection()
+  const next = page.waitForResponse((response) => {
+    const url = new URL(response.url())
+    return (
+      url.pathname === "/api/location" && url.searchParams.get("location[directory]") === destination && response.ok()
+    )
+  })
  session.directory = destination
  await transport.send({
    id: "evt_stale_probe_moved",
@@ -176,7 +228,17 @@ test("ignores a stale missing result after the session moves", async ({ page })
    durable: { aggregateID: sessionID, seq: 1, version: 1 },
    data: { sessionID, location: { directory: destination }, projectID: fixture.project.id },
  })
+  await next
+  const old = page.waitForResponse((response) => {
+    const url = new URL(response.url())
+    return (
+      url.pathname === "/api/location" &&
+      url.searchParams.get("location[directory]") === source &&
+      response.status() === 404
+    )
+  })
  release.resolve()
+  await old
  await expect(prompt).toBeEditable()
  await expect(prompt).toHaveText("Draft in new worktree")
  await expect(page.getByText("Session location unavailable", { exact: true })).toHaveCount(0)
@@ -195,7 +257,14 @@ test("moves a removed-worktree session into an existing worktree", async ({ page
    sessions: [session],
    pageMessages: () => ({ items: [] }),
  })
-  await removedInventory(page, source, undefined, { destination })
+  await page.route("**/api/location?**", (route) => {
+    if (new URL(route.request().url()).searchParams.get("location[directory]") !== source) return route.fallback()
+    return route.fulfill({
+      status: 404,
+      json: { _tag: "LocationNotFoundError", directory: source, message: `Location not found: ${source}` },
+      headers: { "access-control-allow-origin": "*" },
+    })
+  })
  await page.route(`**/api/session/${sessionID}/move`, (route) => route.fulfill({ status: 204, body: "" }))
  await page.goto(`/server/${base64Encode(fixture.serverKey)}/session/${sessionID}`)
  await expect(page.getByRole("status")).toContainText("Session location unavailable")
@@ -220,7 +289,7 @@ test("moves a removed-worktree session into an existing worktree", async ({ page
  await expect(page.getByText("Session location unavailable", { exact: true })).toHaveCount(0)
 })

-test("keeps the composer when the session directory was never a registered managed worktree", async ({ page }) => {
+test("recovers a missing session directory without consulting the worktree inventory", async ({ page }) => {
  const source = "/projects/unregistered-worktree"
  const sessionID = "ses_unregistered_worktree"
  await mockOpenCodeServer(page, {
@@ -232,136 +301,30 @@ test("keeps the composer when the session directory was never a registered manag
      items: [{ id: "msg_saved", type: "user", text: "Keep this session", time: { created: 1 } }],
    }),
  })
-  let refreshes = 0
-  await page.route("**/api/worktree/refresh", (route) => {
-    refreshes++
-    return route.fulfill({ status: 204, headers: { "access-control-allow-origin": "*" } })
+  const inventory: string[] = []
+  page.on("request", (request) => {
+    if (new URL(request.url()).pathname.startsWith("/api/worktree")) inventory.push(request.url())
  })
-  const listed = page.waitForResponse(
-    (response) => new URL(response.url()).pathname === "/api/worktree" && response.ok(),
-  )
-  await page.goto(`/server/${base64Encode(fixture.serverKey)}/session/${sessionID}`)
-  await listed
-  await expect(page.getByText("Keep this session", { exact: true })).toBeVisible()
-  const prompt = page.getByRole("textbox", { name: "Prompt", exact: true })
-  await expect(prompt).toBeEditable()
-  await prompt.fill("Keep this draft")
-  await expect(prompt).toHaveText("Keep this draft")
-  await expect(page.getByRole("status")).toHaveCount(0)
-  expect(refreshes).toBe(0)
-})
-
-for (const phase of ["before", "refresh", "after"] as const) {
-  test(`keeps the composer when the worktree ${phase} request fails with 500`, async ({ page }) => {
-    const source = "/projects/registered-worktree"
-    const sessionID = `ses_worktree_${phase}_failure`
-    await mockOpenCodeServer(page, {
-      directory: fixture.directory,
-      project: fixture.project,
-      provider: fixture.provider,
-      sessions: [{ id: sessionID, projectID: fixture.project.id, directory: source }],
-      pageMessages: () => ({ items: [{ id: "msg_saved", type: "user", text: "Keep working", time: { created: 1 } }] }),
-    })
-    let lists = 0
-    await page.route("**/api/worktree?**", (route) => {
-      if (route.request().method() !== "GET") return route.fallback()
-      lists++
-      if ((phase === "before" && lists === 1) || (phase === "after" && lists === 2))
-        return route.fulfill({ status: 500, body: "", headers: { "access-control-allow-origin": "*" } })
-      return route.fulfill({ json: [{ directory: fixture.directory }, { directory: source, strategy: "git" }] })
-    })
-    await page.route("**/api/worktree/refresh", (route) =>
-      route.fulfill({ status: phase === "refresh" ? 500 : 204, headers: { "access-control-allow-origin": "*" } }),
-    )
-    const failed = page.waitForResponse(
-      (response) =>
-        ["/api/worktree", "/api/worktree/refresh"].includes(new URL(response.url()).pathname) &&
-        response.status() === 500,
-    )
-    await page.goto(`/server/${base64Encode(fixture.serverKey)}/session/${sessionID}`)
-    await failed
-    await expect(page.getByText("Keep working", { exact: true })).toBeVisible()
-    const prompt = page.getByRole("textbox", { name: "Prompt", exact: true })
-    await expect(prompt).toBeEditable()
-    await prompt.fill("Keep the draft")
-    await expect(prompt).toHaveText("Keep the draft")
-    await expect(page.getByRole("status")).toHaveCount(0)
-  })
-}
-
-test("ignores a failed inventory refresh from before reconnecting", async ({ page }) => {
-  const source = "/projects/reconnected-worktree"
-  const sessionID = "ses_worktree_reconnect"
-  const requested = Promise.withResolvers<void>()
-  const release = Promise.withResolvers<void>()
-  const transport = await installSseTransport(page, { server: fixture.serverKey })
-  await mockOpenCodeServer(page, {
-    directory: fixture.directory,
-    project: fixture.project,
-    provider: fixture.provider,
-    sessions: [{ id: sessionID, projectID: fixture.project.id, directory: source }],
-    pageMessages: () => ({
-      items: [{ id: "msg_saved", type: "user", text: "Reconnect safely", time: { created: 1 } }],
-    }),
-  })
-  await page.route("**/api/worktree?**", (route) =>
-    route.fulfill({ json: [{ directory: fixture.directory }, { directory: source, strategy: "git" }] }),
-  )
-  let refreshes = 0
-  await page.route("**/api/worktree/refresh", async (route) => {
-    refreshes++
-    if (refreshes === 1) {
-      requested.resolve()
-      await release.promise
-    }
-    return route.fulfill({ status: 500, body: "", headers: { "access-control-allow-origin": "*" } })
-  })
-  await page.goto(`/server/${base64Encode(fixture.serverKey)}/session/${sessionID}`)
-  await requested.promise
-  const prompt = page.getByRole("textbox", { name: "Prompt", exact: true })
-  await expect(prompt).toBeEditable()
-  await prompt.fill("Draft while reconnecting")
-  const connection = await transport.waitForConnection()
-  await transport.close()
-  await transport.waitForConnection({ after: connection.id })
-  const failed = page.waitForResponse(
-    (response) => new URL(response.url()).pathname === "/api/worktree/refresh" && response.status() === 500,
-  )
-  release.resolve()
-  await failed
-  await expect(page.getByText("Reconnect safely", { exact: true })).toBeVisible()
-  await expect(prompt).toBeEditable()
-  await expect(prompt).toHaveText("Draft while reconnecting")
-  await expect(page.getByRole("status")).toHaveCount(0)
-})
-
-async function removedInventory(
-  page: Page,
-  source: string,
-  missing: () => boolean = () => true,
-  options: {
-    destination?: string
-    requested?: PromiseWithResolvers<void>
-    release?: PromiseWithResolvers<void>
-  } = {},
-) {
-  let pruned = false
-  await page.route("**/api/worktree?**", (route) => {
-    if (route.request().method() !== "GET") return route.fallback()
+  await page.route("**/api/location?**", (route) => {
+    if (new URL(route.request().url()).searchParams.get("location[directory]") !== source) return route.fallback()
    return route.fulfill({
-      json: [
-        { directory: fixture.directory },
-        ...(!pruned || !missing() ? [{ directory: source, strategy: "git" }] : []),
-        ...(options.destination ? [{ directory: options.destination, strategy: "git" }] : []),
-      ],
+      status: 404,
+      json: { _tag: "LocationNotFoundError", directory: source, message: `Location not found: ${source}` },
      headers: { "access-control-allow-origin": "*" },
    })
  })
-  await page.route("**/api/worktree/refresh", async (route) => {
-    if (route.request().method() !== "POST") return route.fallback()
-    options.requested?.resolve()
-    await options.release?.promise
-    if (missing()) pruned = true
-    return route.fulfill({ status: 204, headers: { "access-control-allow-origin": "*" } })
+  const missing = page.waitForResponse((response) => {
+    const url = new URL(response.url())
+    return (
+      url.pathname === "/api/location" &&
+      url.searchParams.get("location[directory]") === source &&
+      response.status() === 404
+    )
  })
-}
+  await page.goto(`/server/${base64Encode(fixture.serverKey)}/session/${sessionID}`)
+  await missing
+  await expect(page.getByText("Keep this session", { exact: true })).toBeVisible()
+  await expect(page.getByRole("status")).toContainText("Session location unavailable")
+  await expect(page.getByRole("textbox", { name: "Prompt", exact: true })).toHaveCount(0)
+  expect(inventory).toEqual([])
+})
@@ -3,6 +3,7 @@ import { createStore } from "solid-js/store"
 import { useParams } from "@solidjs/router"
 import { DataProvider } from "@opencode/session-ui/context"
 import { SessionUserMessage } from "@opencode/session-ui/message"
+import { isLocationNotFoundError } from "@opencode/client/promise"
 import { TextShimmer } from "@opencode/ui/text-shimmer"
 import { CommentsProvider } from "@/composer/comments"
 import { readPromptPresentation } from "@/composer/comment-note"
@@ -29,7 +30,6 @@ import { createSessionResolution } from "./session-resolution"
 import { SessionScreen } from "./screen"
 import { PreparingComposer } from "./preparing-composer"
 import type { MissingLocation } from "./composer/location-missing"
-import { containsDirectory } from "@/workspaces/paths"

 export function TargetSessionRouteContent() {
  const params = useParams<{ serverKey: string; id: string }>()
@@ -49,21 +49,18 @@ export function TargetSessionRouteContent() {
    onCleanup(() => {
      stale = true
    })
-    const api = server.ctx.sdk.api.worktree
-    // A missing row alone cannot distinguish a deleted worktree from a directory
-    // that was never registered. Preserve positive evidence before refresh prunes it.
-    const coversSession = (item: { directory: string; strategy?: string }) =>
-      !!item.strategy && containsDirectory(item.directory, directory)
-    void api
-      .list({ projectID: project.id })
-      .then(async (before) => {
-        if (stale || !before.some(coversSession)) return
-        await api.refresh({ projectID: project.id })
-        const after = await api.list({ projectID: project.id })
-        if (stale || after.some(coversSession) || server.ctx.sdk.connection.status() !== "connected") return
+    void server.ctx.sdk.api.location.get({ location: { directory } }).then(
+      () => undefined,
+      (error) => {
+        if (
+          !stale &&
+          server.ctx.sdk.connection.status() === "connected" &&
+          isLocationNotFoundError(error) &&
+          error.directory === directory
+        )
          setLocationState("missing", { sessionID: session.id, projectID: project.id, directory })
-      })
-      .catch(() => undefined)
+      },
+    )
  })
  const missing = createMemo(() => {
    const session = data.session.get(params.id)
@@ -447,7 +447,7 @@ export function make(options: ClientOptions) {
            path: `/api/location`,
            query: { location: input?.["location"] },
            successStatus: 200,
-            declaredStatuses: [400, 401],
+            declaredStatuses: [400, 401, 404],
            empty: false,
          },
          requestOptions,
@@ -2518,6 +2518,14 @@ export type UnauthorizedError = { readonly _tag: "UnauthorizedError"; readonly m
 export const isUnauthorizedError = (value: unknown): value is UnauthorizedError =>
  typeof value === "object" && value !== null && "_tag" in value && value["_tag"] === "UnauthorizedError"

+export type LocationNotFoundError = {
+  readonly _tag: "LocationNotFoundError"
+  readonly directory: string
+  readonly message: string
+}
+export const isLocationNotFoundError = (value: unknown): value is LocationNotFoundError =>
+  typeof value === "object" && value !== null && "_tag" in value && value["_tag"] === "LocationNotFoundError"
+
 export type ServiceUnavailableError = {
  readonly _tag: "ServiceUnavailableError"
  readonly message: string
@@ -66,9 +66,7 @@ type FormGroups<LocationId extends HttpApiMiddleware.AnyId, LocationService> = R
  typeof makeFormGroup<LocationId, LocationService>
 >

-type LocationGroup<LocationId extends HttpApiMiddleware.AnyId, LocationService> = ReturnType<
-  typeof makeLocationGroup<LocationId, LocationService>
->
+type LocationGroup = ReturnType<typeof makeLocationGroup>

 type MixedMiddlewareGroups<
  LocationId extends HttpApiMiddleware.AnyId,
@@ -94,7 +92,7 @@ type ApiGroups<
  | typeof PersistentPtyGroup
  | typeof CredentialGroup
  | LocationGroups<LocationId>
-  | LocationGroup<LocationId, LocationService>
+  | LocationGroup
  | FormGroups<LocationId, LocationService>
  | SessionGroups<SessionLocationId, SessionLocationService, FormLocationId, FormLocationService>
  | MixedMiddlewareGroups<LocationId, LocationService, SessionLocationId, SessionLocationService>
@@ -154,7 +152,7 @@ const makeApiFromGroup = <
 > =>
  HttpApi.make("server")
    .add(ServerGroup)
-    .add(makeLocationGroup(locationMiddleware))
+    .add(makeLocationGroup())
    .add(AgentGroup.middleware(locationMiddleware))
    .add(PluginGroup.middleware(locationMiddleware))
    .add(makeSessionGroup(sessionLocationMiddleware, formLocationMiddleware))
@@ -129,6 +129,15 @@ export class FileNotFoundError extends Schema.TaggedError<FileNotFoundError>()(
  { httpApiStatus: 404 },
 ) {}

+export class LocationNotFoundError extends Schema.TaggedError<LocationNotFoundError>()(
+  "LocationNotFoundError",
+  {
+    directory: Schema.String,
+    message: Schema.String,
+  },
+  { httpApiStatus: 404 },
+) {}
+
 export class AgentNotFoundError extends Schema.TaggedError<AgentNotFoundError>()(
  "AgentNotFoundError",
  {
@@ -1,7 +1,7 @@
 import { Location } from "@opencode/schema/location"
-import { Context, Schema } from "effect"
-import { HttpApiEndpoint, HttpApiGroup, HttpApiMiddleware, HttpApiSchema, OpenApi } from "effect/unstable/httpapi"
-import { ServiceUnavailableError } from "../errors.js"
+import { Schema } from "effect"
+import { HttpApiEndpoint, HttpApiGroup, HttpApiSchema, OpenApi } from "effect/unstable/httpapi"
+import { LocationNotFoundError, ServiceUnavailableError } from "../errors.js"

 export const LocationQuery = Schema.Struct({
  location: Schema.optional(
@@ -26,18 +26,16 @@ export const locationQueryOpenApi = OpenApi.annotations({
  },
 })

-// Middleware is applied per endpoint: reload acts on every loaded location and
-// must not boot the caller's location first.
-export const makeLocationGroup = <LocationId extends HttpApiMiddleware.AnyId, LocationService>(
-  locationMiddleware: Context.Key<LocationId, LocationService>,
-) =>
+// Get checks the path before entering the location scope; reload acts on all
+// loaded locations and must not boot the caller's location first.
+export const makeLocationGroup = () =>
  HttpApiGroup.make("server.location")
    .add(
      HttpApiEndpoint.get("location.get", "/api/location", {
        query: LocationQuery,
        success: Location.PublicInfo,
+        error: LocationNotFoundError,
      })
-        .middleware(locationMiddleware)
        .annotateMerge(locationQueryOpenApi)
        .annotateMerge(
          OpenApi.annotations({
@@ -1,22 +1,41 @@
 import { Location } from "@opencode/core/location"
 import { LocationServiceMap } from "@opencode/core/location-service-map"
-import { ServiceUnavailableError } from "@opencode/protocol/errors"
+import { LocationNotFoundError, ServiceUnavailableError } from "@opencode/protocol/errors"
+import { FSUtil } from "@opencode/util/fs-util"
 import { Cause, Effect } from "effect"
 import { HttpApiBuilder } from "effect/unstable/httpapi"
 import { Api } from "../api"
+import { requestRef } from "../location"

 export const LocationHandler = HttpApiBuilder.group(Api, "server.location", (handlers) =>
  Effect.gen(function* () {
    const locations = yield* LocationServiceMap.Service
+    const fs = yield* FSUtil.Service
    return handlers
      .handle(
        "location.get",
-        Effect.fn(function* () {
+        Effect.fn(function* (ctx) {
+          const ref = requestRef(ctx.request)
+          const missing = () =>
+            new LocationNotFoundError({ directory: ref.directory, message: `Location not found: ${ref.directory}` })
+          const stat = yield* fs.stat(ref.directory).pipe(
+            Effect.catchTag("PlatformError", (error) => {
+              if (error.reason._tag === "NotFound") return missing()
+              if (
+                error.reason._tag === "BadResource" &&
+                error.reason.cause instanceof Error &&
+                "code" in error.reason.cause &&
+                error.reason.cause.code === "ENOTDIR"
+              )
+                return missing()
+              return Effect.die(error)
+            }),
+          )
+          if (stat.type !== "Directory") return yield* missing()
+          return yield* Effect.gen(function* () {
            const location = yield* Location.Service
-          return new Location.Info({
-            directory: location.directory,
-            project: location.project,
-          })
+            return new Location.Info({ directory: location.directory, project: location.project })
+          }).pipe(Effect.provide(locations.get(ref)))
        }),
      )
      .handle("location.reload", () =>
@@ -22,6 +22,7 @@ import { ShellSelect } from "@opencode/core/shell/select"
 import { Job } from "@opencode/core/job"
 import { Mcp } from "@opencode/core/mcp/index"
 import { Global } from "@opencode/util/global"
+import { FSUtil } from "@opencode/util/fs-util"
 import { InstructionDiscovery } from "@opencode/core/instruction-discovery"
 import { LocationServiceMap } from "@opencode/core/location-service-map"
 import { LocationActivity } from "@opencode/core/location-activity"
@@ -51,6 +52,7 @@ import type { ServerOptions } from "./options"

 const applicationServiceNodes = [
  Global.node,
+  FSUtil.node,
  Database.node,
  Bus.node,
  EventLogger.node,
@@ -168,6 +170,7 @@ function makeRoutes<AuthError, AuthServices>(
            PermissionSaved.Service,
            PluginUpdate.Service,
            Project.Service,
+            FSUtil.Service,
            WellKnown.Service,
          )(context),
        ),
@@ -0,0 +1,86 @@
+import fs from "node:fs/promises"
+import path from "node:path"
+import { expect } from "bun:test"
+import { Effect } from "effect"
+import { tmpdirScoped } from "../../core/test/fixture/tmpdir"
+import { it } from "../../core/test/lib/effect"
+import { startServer } from "./fixture/server"
+
+it.live("reads an existing directory through the existing location endpoint", () =>
+  Effect.gen(function* () {
+    const tmp = yield* tmpdirScoped()
+    const existing = path.join(tmp.path, "existing")
+    yield* Effect.promise(() => fs.mkdir(existing))
+    const server = yield* startServer(tmp.path)
+    const url = new URL("/api/location", server.base)
+    url.searchParams.set("location[directory]", existing)
+    const response = yield* Effect.promise(() => fetch(url, { headers: server.headers }))
+    expect(response.status).toBe(200)
+    expect((yield* Effect.promise(() => response.json())).directory).toBe(existing)
+
+    const header = yield* Effect.promise(() =>
+      fetch(new URL("/api/location", server.base), {
+        headers: { ...server.headers, "x-opencode-directory": encodeURIComponent(existing) },
+      }),
+    )
+    expect((yield* Effect.promise(() => header.json())).directory).toBe(existing)
+
+    const precedence = yield* Effect.promise(() =>
+      fetch(url, {
+        headers: { ...server.headers, "x-opencode-directory": encodeURIComponent(path.join(tmp.path, "removed")) },
+      }),
+    )
+    expect((yield* Effect.promise(() => precedence.json())).directory).toBe(existing)
+
+    const defaultLocation = yield* Effect.promise(() =>
+      fetch(new URL("/api/location", server.base), { headers: server.headers }),
+    )
+    expect(defaultLocation.status).toBe(200)
+    expect((yield* Effect.promise(() => defaultLocation.json())).directory).toBe(process.cwd())
+
+    yield* Effect.promise(() => fs.rmdir(existing))
+    const removed = yield* Effect.promise(() => fetch(url, { headers: server.headers }))
+    expect(removed.status).toBe(404)
+    expect(yield* Effect.promise(() => removed.json())).toMatchObject({
+      _tag: "LocationNotFoundError",
+      directory: existing,
+    })
+  }),
+)
+
+it.live("reports only a missing or non-directory location as a typed 404 before booting", () =>
+  Effect.gen(function* () {
+    const tmp = yield* tmpdirScoped()
+    const missing = path.join(tmp.path, "removed")
+    const file = path.join(tmp.path, "file")
+    const loop = path.join(tmp.path, "loop")
+    yield* Effect.promise(async () => {
+      await fs.writeFile(file, "content")
+      await fs.symlink(loop, loop)
+    })
+    const server = yield* startServer(tmp.path)
+    const get = (directory: string) =>
+      Effect.promise(async () => {
+        const url = new URL("/api/location", server.base)
+        url.searchParams.set("location[directory]", directory)
+        const response = await fetch(url, { headers: server.headers })
+        return { status: response.status, body: await response.json() }
+      })
+
+    for (const directory of [missing, file, path.join(file, "child")]) {
+      expect(yield* get(directory)).toMatchObject({
+        status: 404,
+        body: { _tag: "LocationNotFoundError", directory },
+      })
+    }
+    expect((yield* get(loop)).status).toBe(500)
+    const probe = yield* Effect.promise(() =>
+      fetch(new URL("/api/location/probe", server.base), { headers: server.headers }),
+    )
+    expect(probe.status).toBe(404)
+    const loaded = yield* Effect.promise(async () =>
+      (await fetch(new URL("/api/debug/location", server.base), { headers: server.headers })).json(),
+    )
+    expect(loaded).toEqual([])
+  }),
+)