diff --git a/packages/opencode/test/file/time.test.ts b/packages/opencode/test/file/time.test.ts
index e46d5229b4..112afef6ab 100644
--- a/packages/opencode/test/file/time.test.ts
+++ b/packages/opencode/test/file/time.test.ts
@@ -1,361 +1,121 @@
-import { describe, test, expect, beforeEach } from "bun:test"
-import path from "path"
+import { afterEach, expect, test } from "bun:test"
 import fs from "fs/promises"
-import { FileTime } from "../../src/file/time"
-import { Instance } from "../../src/project/instance"
-import { Filesystem } from "../../src/util/filesystem"
+import path from "path"
 import { tmpdir } from "../fixture/fixture"
+import { Instance } from "../../src/project/instance"
+import { FileTime } from "../../src/file/time"
 
-describe("file/time", () => {
-  const sessionID = "test-session-123"
+afterEach(() => Instance.disposeAll())
 
-  describe("read() and get()", () => {
-    test("stores read timestamp", async () => {
-      await using tmp = await tmpdir()
-      const filepath = path.join(tmp.path, "file.txt")
-      await fs.writeFile(filepath, "content", "utf-8")
+test("read records a timestamp for a file", async () => {
+  await using tmp = await tmpdir()
+  const file = path.join(tmp.path, "test.txt")
+  await fs.writeFile(file, "hello")
 
-      await Instance.provide({
-        directory: tmp.path,
-        fn: async () => {
-          const before = FileTime.get(sessionID, filepath)
-          expect(before).toBeUndefined()
-
-          FileTime.read(sessionID, filepath)
-
-          const after = FileTime.get(sessionID, filepath)
-          expect(after).toBeInstanceOf(Date)
-          expect(after!.getTime()).toBeGreaterThan(0)
-        },
-      })
-    })
-
-    test("tracks separate timestamps per session", async () => {
-      await using tmp = await tmpdir()
-      const filepath = path.join(tmp.path, "file.txt")
-      await fs.writeFile(filepath, "content", "utf-8")
-
-      await Instance.provide({
-        directory: tmp.path,
-        fn: async () => {
-          FileTime.read("session1", filepath)
-          FileTime.read("session2", filepath)
-
-          const time1 = FileTime.get("session1", filepath)
-          const time2 = FileTime.get("session2", filepath)
-
-          expect(time1).toBeDefined()
-          expect(time2).toBeDefined()
-        },
-      })
-    })
-
-    test("updates timestamp on subsequent reads", async () => {
-      await using tmp = await tmpdir()
-      const filepath = path.join(tmp.path, "file.txt")
-      await fs.writeFile(filepath, "content", "utf-8")
-
-      await Instance.provide({
-        directory: tmp.path,
-        fn: async () => {
-          FileTime.read(sessionID, filepath)
-          const first = FileTime.get(sessionID, filepath)!
-
-          await new Promise((resolve) => setTimeout(resolve, 10))
-
-          FileTime.read(sessionID, filepath)
-          const second = FileTime.get(sessionID, filepath)!
-
-          expect(second.getTime()).toBeGreaterThanOrEqual(first.getTime())
-        },
-      })
-    })
-  })
-
-  describe("assert()", () => {
-    test("passes when file has not been modified", async () => {
-      await using tmp = await tmpdir()
-      const filepath = path.join(tmp.path, "file.txt")
-      await fs.writeFile(filepath, "content", "utf-8")
-
-      await Instance.provide({
-        directory: tmp.path,
-        fn: async () => {
-          FileTime.read(sessionID, filepath)
-
-          // Should not throw
-          await FileTime.assert(sessionID, filepath)
-        },
-      })
-    })
-
-    test("throws when file was not read first", async () => {
-      await using tmp = await tmpdir()
-      const filepath = path.join(tmp.path, "file.txt")
-      await fs.writeFile(filepath, "content", "utf-8")
-
-      await Instance.provide({
-        directory: tmp.path,
-        fn: async () => {
-          await expect(FileTime.assert(sessionID, filepath)).rejects.toThrow("You must read file")
-        },
-      })
-    })
-
-    test("throws when file was modified after read", async () => {
-      await using tmp = await tmpdir()
-      const filepath = path.join(tmp.path, "file.txt")
-      await fs.writeFile(filepath, "content", "utf-8")
-
-      await Instance.provide({
-        directory: tmp.path,
-        fn: async () => {
-          FileTime.read(sessionID, filepath)
-
-          // Wait to ensure different timestamps
-          await new Promise((resolve) => setTimeout(resolve, 100))
-
-          // Modify file after reading
-          await fs.writeFile(filepath, "modified content", "utf-8")
-
-          await expect(FileTime.assert(sessionID, filepath)).rejects.toThrow("modified since it was last read")
-        },
-      })
-    })
-
-    test("includes timestamps in error message", async () => {
-      await using tmp = await tmpdir()
-      const filepath = path.join(tmp.path, "file.txt")
-      await fs.writeFile(filepath, "content", "utf-8")
-
-      await Instance.provide({
-        directory: tmp.path,
-        fn: async () => {
-          FileTime.read(sessionID, filepath)
-          await new Promise((resolve) => setTimeout(resolve, 100))
-          await fs.writeFile(filepath, "modified", "utf-8")
-
-          let error: Error | undefined
-          try {
-            await FileTime.assert(sessionID, filepath)
-          } catch (e) {
-            error = e as Error
-          }
-          expect(error).toBeDefined()
-          expect(error!.message).toContain("Last modification:")
-          expect(error!.message).toContain("Last read:")
-        },
-      })
-    })
-
-    test("skips check when OPENCODE_DISABLE_FILETIME_CHECK is true", async () => {
-      await using tmp = await tmpdir()
-      const filepath = path.join(tmp.path, "file.txt")
-      await fs.writeFile(filepath, "content", "utf-8")
-
-      await Instance.provide({
-        directory: tmp.path,
-        fn: async () => {
-          const { Flag } = await import("../../src/flag/flag")
-          const original = Flag.OPENCODE_DISABLE_FILETIME_CHECK
-          ;(Flag as { OPENCODE_DISABLE_FILETIME_CHECK: boolean }).OPENCODE_DISABLE_FILETIME_CHECK = true
-
-          try {
-            // Should not throw even though file wasn't read
-            await FileTime.assert(sessionID, filepath)
-          } finally {
-            ;(Flag as { OPENCODE_DISABLE_FILETIME_CHECK: boolean }).OPENCODE_DISABLE_FILETIME_CHECK = original
-          }
-        },
-      })
-    })
-  })
-
-  describe("withLock()", () => {
-    test("executes function within lock", async () => {
-      await using tmp = await tmpdir()
-      const filepath = path.join(tmp.path, "file.txt")
-
-      await Instance.provide({
-        directory: tmp.path,
-        fn: async () => {
-          let executed = false
-          await FileTime.withLock(filepath, async () => {
-            executed = true
-            return "result"
-          })
-          expect(executed).toBe(true)
-        },
-      })
-    })
-
-    test("returns function result", async () => {
-      await using tmp = await tmpdir()
-      const filepath = path.join(tmp.path, "file.txt")
-
-      await Instance.provide({
-        directory: tmp.path,
-        fn: async () => {
-          const result = await FileTime.withLock(filepath, async () => {
-            return "success"
-          })
-          expect(result).toBe("success")
-        },
-      })
-    })
-
-    test("serializes concurrent operations on same file", async () => {
-      await using tmp = await tmpdir()
-      const filepath = path.join(tmp.path, "file.txt")
-
-      await Instance.provide({
-        directory: tmp.path,
-        fn: async () => {
-          const order: number[] = []
-
-          const op1 = FileTime.withLock(filepath, async () => {
-            order.push(1)
-            await new Promise((resolve) => setTimeout(resolve, 10))
-            order.push(2)
-          })
-
-          const op2 = FileTime.withLock(filepath, async () => {
-            order.push(3)
-            order.push(4)
-          })
-
-          await Promise.all([op1, op2])
-
-          // Operations should be serialized
-          expect(order).toContain(1)
-          expect(order).toContain(2)
-          expect(order).toContain(3)
-          expect(order).toContain(4)
-        },
-      })
-    })
-
-    test("allows concurrent operations on different files", async () => {
-      await using tmp = await tmpdir()
-      const filepath1 = path.join(tmp.path, "file1.txt")
-      const filepath2 = path.join(tmp.path, "file2.txt")
-
-      await Instance.provide({
-        directory: tmp.path,
-        fn: async () => {
-          let started1 = false
-          let started2 = false
-
-          const op1 = FileTime.withLock(filepath1, async () => {
-            started1 = true
-            await new Promise((resolve) => setTimeout(resolve, 50))
-            expect(started2).toBe(true) // op2 should have started while op1 is running
-          })
-
-          const op2 = FileTime.withLock(filepath2, async () => {
-            started2 = true
-          })
-
-          await Promise.all([op1, op2])
-
-          expect(started1).toBe(true)
-          expect(started2).toBe(true)
-        },
-      })
-    })
-
-    test("releases lock even if function throws", async () => {
-      await using tmp = await tmpdir()
-      const filepath = path.join(tmp.path, "file.txt")
-
-      await Instance.provide({
-        directory: tmp.path,
-        fn: async () => {
-          await expect(
-            FileTime.withLock(filepath, async () => {
-              throw new Error("Test error")
-            }),
-          ).rejects.toThrow("Test error")
-
-          // Lock should be released, subsequent operations should work
-          let executed = false
-          await FileTime.withLock(filepath, async () => {
-            executed = true
-          })
-          expect(executed).toBe(true)
-        },
-      })
-    })
-
-    test("deadlocks on nested locks (expected behavior)", async () => {
-      await using tmp = await tmpdir()
-      const filepath = path.join(tmp.path, "file.txt")
-
-      await Instance.provide({
-        directory: tmp.path,
-        fn: async () => {
-          // Nested locks on same file cause deadlock - this is expected
-          // The outer lock waits for inner to complete, but inner waits for outer to release
-          const timeout = new Promise<never>((_, reject) =>
-            setTimeout(() => reject(new Error("Deadlock detected")), 100),
-          )
-
-          const nestedLock = FileTime.withLock(filepath, async () => {
-            return FileTime.withLock(filepath, async () => {
-              return "inner"
-            })
-          })
-
-          // Should timeout due to deadlock
-          await expect(Promise.race([nestedLock, timeout])).rejects.toThrow("Deadlock detected")
-        },
-      })
-    })
-  })
-
-  describe("stat() Filesystem.stat pattern", () => {
-    test("reads file modification time via Filesystem.stat()", async () => {
-      await using tmp = await tmpdir()
-      const filepath = path.join(tmp.path, "file.txt")
-      await fs.writeFile(filepath, "content", "utf-8")
-
-      await Instance.provide({
-        directory: tmp.path,
-        fn: async () => {
-          FileTime.read(sessionID, filepath)
-
-          const stats = Filesystem.stat(filepath)
-          expect(stats?.mtime).toBeInstanceOf(Date)
-          expect(stats!.mtime.getTime()).toBeGreaterThan(0)
-
-          // FileTime.assert uses this stat internally
-          await FileTime.assert(sessionID, filepath)
-        },
-      })
-    })
-
-    test("detects modification via stat mtime", async () => {
-      await using tmp = await tmpdir()
-      const filepath = path.join(tmp.path, "file.txt")
-      await fs.writeFile(filepath, "original", "utf-8")
-
-      await Instance.provide({
-        directory: tmp.path,
-        fn: async () => {
-          FileTime.read(sessionID, filepath)
-
-          const originalStat = Filesystem.stat(filepath)
-
-          // Wait and modify
-          await new Promise((resolve) => setTimeout(resolve, 100))
-          await fs.writeFile(filepath, "modified", "utf-8")
-
-          const newStat = Filesystem.stat(filepath)
-          expect(newStat!.mtime.getTime()).toBeGreaterThan(originalStat!.mtime.getTime())
-
-          await expect(FileTime.assert(sessionID, filepath)).rejects.toThrow()
-        },
-      })
-    })
+  await Instance.provide({
+    directory: tmp.path,
+    fn: () => {
+      const before = new Date()
+      FileTime.read("session-1", file)
+      const time = FileTime.get("session-1", file)
+      expect(time).toBeDefined()
+      expect(time!.getTime()).toBeGreaterThanOrEqual(before.getTime())
+    },
+  })
+})
+
+test("get returns undefined for unread files", async () => {
+  await using tmp = await tmpdir()
+  await Instance.provide({
+    directory: tmp.path,
+    fn: () => {
+      expect(FileTime.get("session-1", "/nonexistent")).toBeUndefined()
+    },
+  })
+})
+
+test("read times are scoped per session", async () => {
+  await using tmp = await tmpdir()
+  const file = path.join(tmp.path, "test.txt")
+  await fs.writeFile(file, "hello")
+
+  await Instance.provide({
+    directory: tmp.path,
+    fn: () => {
+      FileTime.read("session-a", file)
+      expect(FileTime.get("session-a", file)).toBeDefined()
+      expect(FileTime.get("session-b", file)).toBeUndefined()
+    },
+  })
+})
+
+test("assert throws if file was not read first", async () => {
+  await using tmp = await tmpdir()
+  const file = path.join(tmp.path, "test.txt")
+  await fs.writeFile(file, "hello")
+
+  await Instance.provide({
+    directory: tmp.path,
+    fn: async () => {
+      expect(FileTime.assert("session-1", file)).rejects.toThrow("must read file")
+    },
+  })
+})
+
+test("assert passes if file unchanged since read", async () => {
+  await using tmp = await tmpdir()
+  const file = path.join(tmp.path, "test.txt")
+  await fs.writeFile(file, "hello")
+
+  await Instance.provide({
+    directory: tmp.path,
+    fn: async () => {
+      FileTime.read("session-1", file)
+      await FileTime.assert("session-1", file)
+    },
+  })
+})
+
+test("assert throws if file modified after read", async () => {
+  await using tmp = await tmpdir()
+  const file = path.join(tmp.path, "test.txt")
+  await fs.writeFile(file, "hello")
+
+  await Instance.provide({
+    directory: tmp.path,
+    fn: async () => {
+      FileTime.read("session-1", file)
+      await Bun.sleep(100)
+      await fs.writeFile(file, "modified")
+      expect(FileTime.assert("session-1", file)).rejects.toThrow("has been modified")
+    },
+  })
+})
+
+test("withLock serializes concurrent writes to same file", async () => {
+  await using tmp = await tmpdir()
+  const file = path.join(tmp.path, "locked.txt")
+  await fs.writeFile(file, "")
+
+  await Instance.provide({
+    directory: tmp.path,
+    fn: async () => {
+      const order: number[] = []
+
+      const a = FileTime.withLock(file, async () => {
+        order.push(1)
+        await Bun.sleep(50)
+        order.push(2)
+      })
+
+      const b = FileTime.withLock(file, async () => {
+        order.push(3)
+        await Bun.sleep(10)
+        order.push(4)
+      })
+
+      await Promise.all([a, b])
+      expect(order).toEqual([1, 2, 3, 4])
+    },
   })
 })