diff --git a/packages/opencode/src/tool/edit.ts b/packages/opencode/src/tool/edit.ts
index 9505dd9eab..8ead6c9eea 100644
--- a/packages/opencode/src/tool/edit.ts
+++ b/packages/opencode/src/tool/edit.ts
@@ -5,6 +5,7 @@
 
 import z from "zod"
 import * as path from "path"
+import { Effect } from "effect"
 import { Tool } from "./tool"
 import { LSP } from "../lsp"
 import { createTwoFilesPatch, diffLines } from "diff"
@@ -17,7 +18,7 @@ import { FileTime } from "../file/time"
 import { Filesystem } from "../util/filesystem"
 import { Instance } from "../project/instance"
 import { Snapshot } from "@/snapshot"
-import { assertExternalDirectory } from "./external-directory"
+import { assertExternalDirectoryEffect } from "./external-directory"
 
 const MAX_DIAGNOSTICS_PER_FILE = 20
 
@@ -34,136 +35,161 @@ function convertToLineEnding(text: string, ending: "\n" | "\r\n"): string {
   return text.replaceAll("\n", "\r\n")
 }
 
-export const EditTool = Tool.define("edit", {
-  description: DESCRIPTION,
-  parameters: z.object({
-    filePath: z.string().describe("The absolute path to the file to modify"),
-    oldString: z.string().describe("The text to replace"),
-    newString: z.string().describe("The text to replace it with (must be different from oldString)"),
-    replaceAll: z.boolean().optional().describe("Replace all occurrences of oldString (default false)"),
-  }),
-  async execute(params, ctx) {
-    if (!params.filePath) {
-      throw new Error("filePath is required")
-    }
+const Parameters = z.object({
+  filePath: z.string().describe("The absolute path to the file to modify"),
+  oldString: z.string().describe("The text to replace"),
+  newString: z.string().describe("The text to replace it with (must be different from oldString)"),
+  replaceAll: z.boolean().optional().describe("Replace all occurrences of oldString (default false)"),
+})
 
-    if (params.oldString === params.newString) {
-      throw new Error("No changes to apply: oldString and newString are identical.")
-    }
-
-    const filePath = path.isAbsolute(params.filePath) ? params.filePath : path.join(Instance.directory, params.filePath)
-    await assertExternalDirectory(ctx, filePath)
-
-    let diff = ""
-    let contentOld = ""
-    let contentNew = ""
-    await FileTime.withLock(filePath, async () => {
-      if (params.oldString === "") {
-        const existed = await Filesystem.exists(filePath)
-        contentNew = params.newString
-        diff = trimDiff(createTwoFilesPatch(filePath, filePath, contentOld, contentNew))
-        await ctx.ask({
-          permission: "edit",
-          patterns: [path.relative(Instance.worktree, filePath)],
-          always: ["*"],
-          metadata: {
-            filepath: filePath,
-            diff,
-          },
-        })
-        await Filesystem.write(filePath, params.newString)
-        await Format.file(filePath)
-        Bus.publish(File.Event.Edited, { file: filePath })
-        await Bus.publish(FileWatcher.Event.Updated, {
-          file: filePath,
-          event: existed ? "change" : "add",
-        })
-        await FileTime.read(ctx.sessionID, filePath)
-        return
-      }
-
-      const stats = Filesystem.stat(filePath)
-      if (!stats) throw new Error(`File ${filePath} not found`)
-      if (stats.isDirectory()) throw new Error(`Path is a directory, not a file: ${filePath}`)
-      await FileTime.assert(ctx.sessionID, filePath)
-      contentOld = await Filesystem.readText(filePath)
-
-      const ending = detectLineEnding(contentOld)
-      const old = convertToLineEnding(normalizeLineEndings(params.oldString), ending)
-      const next = convertToLineEnding(normalizeLineEndings(params.newString), ending)
-
-      contentNew = replace(contentOld, old, next, params.replaceAll)
-
-      diff = trimDiff(
-        createTwoFilesPatch(filePath, filePath, normalizeLineEndings(contentOld), normalizeLineEndings(contentNew)),
-      )
-      await ctx.ask({
-        permission: "edit",
-        patterns: [path.relative(Instance.worktree, filePath)],
-        always: ["*"],
-        metadata: {
-          filepath: filePath,
-          diff,
-        },
-      })
-
-      await Filesystem.write(filePath, contentNew)
-      await Format.file(filePath)
-      Bus.publish(File.Event.Edited, { file: filePath })
-      await Bus.publish(FileWatcher.Event.Updated, {
-        file: filePath,
-        event: "change",
-      })
-      contentNew = await Filesystem.readText(filePath)
-      diff = trimDiff(
-        createTwoFilesPatch(filePath, filePath, normalizeLineEndings(contentOld), normalizeLineEndings(contentNew)),
-      )
-      await FileTime.read(ctx.sessionID, filePath)
-    })
-
-    const filediff: Snapshot.FileDiff = {
-      file: filePath,
-      patch: diff,
-      additions: 0,
-      deletions: 0,
-    }
-    for (const change of diffLines(contentOld, contentNew)) {
-      if (change.added) filediff.additions += change.count || 0
-      if (change.removed) filediff.deletions += change.count || 0
-    }
-
-    ctx.metadata({
-      metadata: {
-        diff,
-        filediff,
-        diagnostics: {},
-      },
-    })
-
-    let output = "Edit applied successfully."
-    await LSP.touchFile(filePath, true)
-    const diagnostics = await LSP.diagnostics()
-    const normalizedFilePath = Filesystem.normalizePath(filePath)
-    const issues = diagnostics[normalizedFilePath] ?? []
-    const errors = issues.filter((item) => item.severity === 1)
-    if (errors.length > 0) {
-      const limited = errors.slice(0, MAX_DIAGNOSTICS_PER_FILE)
-      const suffix =
-        errors.length > MAX_DIAGNOSTICS_PER_FILE ? `\n... and ${errors.length - MAX_DIAGNOSTICS_PER_FILE} more` : ""
-      output += `\n\nLSP errors detected in this file, please fix:\n<diagnostics file="${filePath}">\n${limited.map(LSP.Diagnostic.pretty).join("\n")}${suffix}\n</diagnostics>`
-    }
+export const EditTool = Tool.defineEffect(
+  "edit",
+  Effect.gen(function* () {
+    const lsp = yield* LSP.Service
+    const filetime = yield* FileTime.Service
 
     return {
-      metadata: {
-        diagnostics,
-        diff,
-        filediff,
-      },
-      title: `${path.relative(Instance.worktree, filePath)}`,
-      output,
+      description: DESCRIPTION,
+      parameters: Parameters,
+      execute: (params: z.infer<typeof Parameters>, ctx: Tool.Context) =>
+        Effect.gen(function* () {
+          if (!params.filePath) {
+            throw new Error("filePath is required")
+          }
+
+          if (params.oldString === params.newString) {
+            throw new Error("No changes to apply: oldString and newString are identical.")
+          }
+
+          const filePath = path.isAbsolute(params.filePath)
+            ? params.filePath
+            : path.join(Instance.directory, params.filePath)
+          yield* assertExternalDirectoryEffect(ctx, filePath)
+
+          let diff = ""
+          let contentOld = ""
+          let contentNew = ""
+          yield* filetime.withLock(filePath, async () => {
+              if (params.oldString === "") {
+                const existed = await Filesystem.exists(filePath)
+                contentNew = params.newString
+                diff = trimDiff(createTwoFilesPatch(filePath, filePath, contentOld, contentNew))
+                await ctx.ask({
+                  permission: "edit",
+                  patterns: [path.relative(Instance.worktree, filePath)],
+                  always: ["*"],
+                  metadata: {
+                    filepath: filePath,
+                    diff,
+                  },
+                })
+                await Filesystem.write(filePath, params.newString)
+                await Format.file(filePath)
+                Bus.publish(File.Event.Edited, { file: filePath })
+                await Bus.publish(FileWatcher.Event.Updated, {
+                  file: filePath,
+                  event: existed ? "change" : "add",
+                })
+                await FileTime.read(ctx.sessionID, filePath)
+                return
+              }
+
+              const stats = Filesystem.stat(filePath)
+              if (!stats) throw new Error(`File ${filePath} not found`)
+              if (stats.isDirectory()) throw new Error(`Path is a directory, not a file: ${filePath}`)
+              await FileTime.assert(ctx.sessionID, filePath)
+              contentOld = await Filesystem.readText(filePath)
+
+              const ending = detectLineEnding(contentOld)
+              const old = convertToLineEnding(normalizeLineEndings(params.oldString), ending)
+              const next = convertToLineEnding(normalizeLineEndings(params.newString), ending)
+
+              contentNew = replace(contentOld, old, next, params.replaceAll)
+
+              diff = trimDiff(
+                createTwoFilesPatch(
+                  filePath,
+                  filePath,
+                  normalizeLineEndings(contentOld),
+                  normalizeLineEndings(contentNew),
+                ),
+              )
+              await ctx.ask({
+                permission: "edit",
+                patterns: [path.relative(Instance.worktree, filePath)],
+                always: ["*"],
+                metadata: {
+                  filepath: filePath,
+                  diff,
+                },
+              })
+
+              await Filesystem.write(filePath, contentNew)
+              await Format.file(filePath)
+              Bus.publish(File.Event.Edited, { file: filePath })
+              await Bus.publish(FileWatcher.Event.Updated, {
+                file: filePath,
+                event: "change",
+              })
+              contentNew = await Filesystem.readText(filePath)
+              diff = trimDiff(
+                createTwoFilesPatch(
+                  filePath,
+                  filePath,
+                  normalizeLineEndings(contentOld),
+                  normalizeLineEndings(contentNew),
+                ),
+              )
+              await FileTime.read(ctx.sessionID, filePath)
+            })
+
+          const filediff: Snapshot.FileDiff = {
+            file: filePath,
+            patch: diff,
+            additions: 0,
+            deletions: 0,
+          }
+          for (const change of diffLines(contentOld, contentNew)) {
+            if (change.added) filediff.additions += change.count || 0
+            if (change.removed) filediff.deletions += change.count || 0
+          }
+
+          ctx.metadata({
+            metadata: {
+              diff,
+              filediff,
+              diagnostics: {},
+            },
+          })
+
+          let output = "Edit applied successfully."
+          yield* lsp.touchFile(filePath, true)
+          const diagnostics = yield* lsp.diagnostics()
+          const normalizedFilePath = Filesystem.normalizePath(filePath)
+          const issues = diagnostics[normalizedFilePath] ?? []
+          const errors = issues.filter((item) => item.severity === 1)
+          if (errors.length > 0) {
+            const limited = errors.slice(0, MAX_DIAGNOSTICS_PER_FILE)
+            const suffix =
+              errors.length > MAX_DIAGNOSTICS_PER_FILE
+                ? `\n... and ${errors.length - MAX_DIAGNOSTICS_PER_FILE} more`
+                : ""
+            output += `\n\nLSP errors detected in this file, please fix:\n<diagnostics file="${filePath}">\n${limited.map(LSP.Diagnostic.pretty).join("\n")}${suffix}\n</diagnostics>`
+          }
+
+          return {
+            metadata: {
+              diagnostics,
+              diff,
+              filediff,
+            },
+            title: `${path.relative(Instance.worktree, filePath)}`,
+            output,
+          }
+        }).pipe(Effect.orDie, Effect.runPromise),
     }
-  },
-})
+  }),
+)
 
 export type Replacer = (content: string, find: string) => Generator<string, void, unknown>
 
diff --git a/packages/opencode/src/tool/multiedit.ts b/packages/opencode/src/tool/multiedit.ts
index 7f562f4737..5a52d0f0af 100644
--- a/packages/opencode/src/tool/multiedit.ts
+++ b/packages/opencode/src/tool/multiedit.ts
@@ -1,46 +1,57 @@
 import z from "zod"
+import { Effect } from "effect"
 import { Tool } from "./tool"
 import { EditTool } from "./edit"
 import DESCRIPTION from "./multiedit.txt"
 import path from "path"
 import { Instance } from "../project/instance"
 
-export const MultiEditTool = Tool.define("multiedit", {
-  description: DESCRIPTION,
-  parameters: z.object({
-    filePath: z.string().describe("The absolute path to the file to modify"),
-    edits: z
-      .array(
-        z.object({
-          filePath: z.string().describe("The absolute path to the file to modify"),
-          oldString: z.string().describe("The text to replace"),
-          newString: z.string().describe("The text to replace it with (must be different from oldString)"),
-          replaceAll: z.boolean().optional().describe("Replace all occurrences of oldString (default false)"),
-        }),
-      )
-      .describe("Array of edit operations to perform sequentially on the file"),
-  }),
-  async execute(params, ctx) {
-    const tool = await EditTool.init()
-    const results = []
-    for (const [, edit] of params.edits.entries()) {
-      const result = await tool.execute(
-        {
-          filePath: params.filePath,
-          oldString: edit.oldString,
-          newString: edit.newString,
-          replaceAll: edit.replaceAll,
-        },
-        ctx,
-      )
-      results.push(result)
-    }
+export const MultiEditTool = Tool.defineEffect(
+  "multiedit",
+  Effect.gen(function* () {
+    const editInfo = yield* EditTool
+    const edit = yield* Effect.promise(() => editInfo.init())
+
     return {
-      title: path.relative(Instance.worktree, params.filePath),
-      metadata: {
-        results: results.map((r) => r.metadata),
-      },
-      output: results.at(-1)!.output,
+      description: DESCRIPTION,
+      parameters: z.object({
+        filePath: z.string().describe("The absolute path to the file to modify"),
+        edits: z
+          .array(
+            z.object({
+              filePath: z.string().describe("The absolute path to the file to modify"),
+              oldString: z.string().describe("The text to replace"),
+              newString: z.string().describe("The text to replace it with (must be different from oldString)"),
+              replaceAll: z.boolean().optional().describe("Replace all occurrences of oldString (default false)"),
+            }),
+          )
+          .describe("Array of edit operations to perform sequentially on the file"),
+      }),
+      execute: (params: { filePath: string; edits: Array<{ filePath: string; oldString: string; newString: string; replaceAll?: boolean }> }, ctx: Tool.Context) =>
+        Effect.gen(function* () {
+          const results = []
+          for (const [, entry] of params.edits.entries()) {
+            const result = yield* Effect.promise(() =>
+              edit.execute(
+                {
+                  filePath: params.filePath,
+                  oldString: entry.oldString,
+                  newString: entry.newString,
+                  replaceAll: entry.replaceAll,
+                },
+                ctx,
+              ),
+            )
+            results.push(result)
+          }
+          return {
+            title: path.relative(Instance.worktree, params.filePath),
+            metadata: {
+              results: results.map((r) => r.metadata),
+            },
+            output: results.at(-1)!.output,
+          }
+        }).pipe(Effect.orDie, Effect.runPromise),
     }
-  },
-})
+  }),
+)
diff --git a/packages/opencode/src/tool/registry.ts b/packages/opencode/src/tool/registry.ts
index bd27802ff8..bbc154371c 100644
--- a/packages/opencode/src/tool/registry.ts
+++ b/packages/opencode/src/tool/registry.ts
@@ -111,6 +111,7 @@ export namespace ToolRegistry {
       const codesearch = yield* CodeSearchTool
       const globtool = yield* GlobTool
       const writetool = yield* WriteTool
+      const edit = yield* EditTool
 
       const state = yield* InstanceState.make<State>(
         Effect.fn("ToolRegistry.state")(function* (ctx) {
@@ -173,7 +174,7 @@ export namespace ToolRegistry {
             read: Tool.init(read),
             glob: Tool.init(globtool),
             grep: Tool.init(GrepTool),
-            edit: Tool.init(EditTool),
+            edit: Tool.init(edit),
             write: Tool.init(writetool),
             task: Tool.init(task),
             fetch: Tool.init(webfetch),
diff --git a/packages/opencode/test/tool/edit.test.ts b/packages/opencode/test/tool/edit.test.ts
index 96d41400e3..220fe299b3 100644
--- a/packages/opencode/test/tool/edit.test.ts
+++ b/packages/opencode/test/tool/edit.test.ts
@@ -1,10 +1,12 @@
-import { afterEach, describe, test, expect } from "bun:test"
+import { afterAll, afterEach, describe, test, expect } from "bun:test"
 import path from "path"
 import fs from "fs/promises"
+import { Effect, Layer, ManagedRuntime } from "effect"
 import { EditTool } from "../../src/tool/edit"
 import { Instance } from "../../src/project/instance"
 import { tmpdir } from "../fixture/fixture"
 import { FileTime } from "../../src/file/time"
+import { LSP } from "../../src/lsp"
 import { SessionID, MessageID } from "../../src/session/schema"
 
 const ctx = {
@@ -27,6 +29,22 @@ async function touch(file: string, time: number) {
   await fs.utimes(file, date, date)
 }
 
+const runtime = ManagedRuntime.make(
+  Layer.mergeAll(LSP.defaultLayer, FileTime.defaultLayer),
+)
+
+afterAll(async () => {
+  await runtime.dispose()
+})
+
+const resolve = () =>
+  runtime.runPromise(
+    Effect.gen(function* () {
+      const info = yield* EditTool
+      return yield* Effect.promise(() => info.init())
+    }),
+  )
+
 describe("tool.edit", () => {
   describe("creating new files", () => {
     test("creates new file when oldString is empty", async () => {
@@ -36,7 +54,7 @@ describe("tool.edit", () => {
       await Instance.provide({
         directory: tmp.path,
         fn: async () => {
-          const edit = await EditTool.init()
+          const edit = await resolve()
           const result = await edit.execute(
             {
               filePath: filepath,
@@ -61,7 +79,7 @@ describe("tool.edit", () => {
       await Instance.provide({
         directory: tmp.path,
         fn: async () => {
-          const edit = await EditTool.init()
+          const edit = await resolve()
           await edit.execute(
             {
               filePath: filepath,
@@ -91,7 +109,7 @@ describe("tool.edit", () => {
           const events: string[] = []
           const unsubUpdated = Bus.subscribe(FileWatcher.Event.Updated, () => events.push("updated"))
 
-          const edit = await EditTool.init()
+          const edit = await resolve()
           await edit.execute(
             {
               filePath: filepath,
@@ -119,7 +137,7 @@ describe("tool.edit", () => {
         fn: async () => {
           await FileTime.read(ctx.sessionID, filepath)
 
-          const edit = await EditTool.init()
+          const edit = await resolve()
           const result = await edit.execute(
             {
               filePath: filepath,
@@ -146,7 +164,7 @@ describe("tool.edit", () => {
         fn: async () => {
           await FileTime.read(ctx.sessionID, filepath)
 
-          const edit = await EditTool.init()
+          const edit = await resolve()
           await expect(
             edit.execute(
               {
@@ -169,7 +187,7 @@ describe("tool.edit", () => {
       await Instance.provide({
         directory: tmp.path,
         fn: async () => {
-          const edit = await EditTool.init()
+          const edit = await resolve()
           await expect(
             edit.execute(
               {
@@ -194,7 +212,7 @@ describe("tool.edit", () => {
         fn: async () => {
           await FileTime.read(ctx.sessionID, filepath)
 
-          const edit = await EditTool.init()
+          const edit = await resolve()
           await expect(
             edit.execute(
               {
@@ -217,7 +235,7 @@ describe("tool.edit", () => {
       await Instance.provide({
         directory: tmp.path,
         fn: async () => {
-          const edit = await EditTool.init()
+          const edit = await resolve()
           await expect(
             edit.execute(
               {
@@ -249,7 +267,7 @@ describe("tool.edit", () => {
           await touch(filepath, 2_000)
 
           // Try to edit with the new content
-          const edit = await EditTool.init()
+          const edit = await resolve()
           await expect(
             edit.execute(
               {
@@ -274,7 +292,7 @@ describe("tool.edit", () => {
         fn: async () => {
           await FileTime.read(ctx.sessionID, filepath)
 
-          const edit = await EditTool.init()
+          const edit = await resolve()
           await edit.execute(
             {
               filePath: filepath,
@@ -307,7 +325,7 @@ describe("tool.edit", () => {
           const events: string[] = []
           const unsubUpdated = Bus.subscribe(FileWatcher.Event.Updated, () => events.push("updated"))
 
-          const edit = await EditTool.init()
+          const edit = await resolve()
           await edit.execute(
             {
               filePath: filepath,
@@ -335,7 +353,7 @@ describe("tool.edit", () => {
         fn: async () => {
           await FileTime.read(ctx.sessionID, filepath)
 
-          const edit = await EditTool.init()
+          const edit = await resolve()
           await edit.execute(
             {
               filePath: filepath,
@@ -361,7 +379,7 @@ describe("tool.edit", () => {
         fn: async () => {
           await FileTime.read(ctx.sessionID, filepath)
 
-          const edit = await EditTool.init()
+          const edit = await resolve()
           await edit.execute(
             {
               filePath: filepath,
@@ -385,7 +403,7 @@ describe("tool.edit", () => {
       await Instance.provide({
         directory: tmp.path,
         fn: async () => {
-          const edit = await EditTool.init()
+          const edit = await resolve()
           await expect(
             edit.execute(
               {
@@ -410,7 +428,7 @@ describe("tool.edit", () => {
         fn: async () => {
           await FileTime.read(ctx.sessionID, dirpath)
 
-          const edit = await EditTool.init()
+          const edit = await resolve()
           await expect(
             edit.execute(
               {
@@ -435,7 +453,7 @@ describe("tool.edit", () => {
         fn: async () => {
           await FileTime.read(ctx.sessionID, filepath)
 
-          const edit = await EditTool.init()
+          const edit = await resolve()
           const result = await edit.execute(
             {
               filePath: filepath,
@@ -502,7 +520,7 @@ describe("tool.edit", () => {
       return await Instance.provide({
         directory: tmp.path,
         fn: async () => {
-          const edit = await EditTool.init()
+          const edit = await resolve()
           const filePath = path.join(tmp.path, "test.txt")
           await FileTime.read(ctx.sessionID, filePath)
           await edit.execute(
@@ -647,7 +665,7 @@ describe("tool.edit", () => {
         fn: async () => {
           await FileTime.read(ctx.sessionID, filepath)
 
-          const edit = await EditTool.init()
+          const edit = await resolve()
 
           // Two concurrent edits
           const promise1 = edit.execute(