chore: merge dev into v2 (#35591)

Co-authored-by: Frank <frank@anoma.ly>
Co-authored-by: Aarav Sareen <96787824+arvsrn@users.noreply.github.com>
Co-authored-by: Brendan Allan <git@brendonovich.dev>
Co-authored-by: opencode-agent[bot] <opencode-agent[bot]@users.noreply.github.com>
Co-authored-by: Jack <jack@anoma.ly>
Co-authored-by: Brendan Allan <14191578+Brendonovich@users.noreply.github.com>
Co-authored-by: Shoubhit Dash <shoubhit2005@gmail.com>
Co-authored-by: opencode-agent[bot] <219766164+opencode-agent[bot]@users.noreply.github.com>
Co-authored-by: James Long <longster@gmail.com>
Co-authored-by: Dustin Deus <deusdustin@gmail.com>
Co-authored-by: starptech <starptech@starptechs-MBP.fritz.box>
Co-authored-by: Luke Parker <10430890+Hona@users.noreply.github.com>
Co-authored-by: 𝓛𝓲𝓽𝓽𝓵𝓮 𝓕𝓻𝓪𝓷𝓴 <little-frank@opencord.local>
Co-authored-by: Dax <mail@thdxr.com>
Co-authored-by: usrnk1 <7547651+usrnk1@users.noreply.github.com>
Co-authored-by: Jay <53023+jayair@users.noreply.github.com>
Co-authored-by: runvip <164729189+runvip@users.noreply.github.com>
Co-authored-by: opencode <opencode@sst.dev>
Co-authored-by: Julian Coy <julian@ex-machina.co>
Co-authored-by: Vladimir Glafirov <vglafirov@gitlab.com>
Co-authored-by: Adam <2363879+adamdotdevin@users.noreply.github.com>
Co-authored-by: Kit Langton <kit.langton@gmail.com>
Co-authored-by: Simon Klee <hello@simonklee.dk>
Co-authored-by: Jay <air@live.ca>
Co-authored-by: David Hill <1879069+iamdavidhill@users.noreply.github.com>

packages/opencode/src/cli/cmd/tui.ts

@@ -132,6 +132,8 @@ export const TuiThreadCommand = cmd({
       const config = await TuiConfig.get()
 
       const network = resolveNetworkOptionsNoConfig(args)
+      const external = hasArg("--port") || hasArg("--hostname") || network.mdns === true
+      const headers = external ? ServerAuth.headers() : undefined
       const url = (await client.call("server", network)).url
 
       try {
@@ -139,6 +141,7 @@ export const TuiThreadCommand = cmd({
           url,
           sessionID: args.session,
           directory: cwd,
+          headers,
         })
       } catch (error) {
         UI.error(errorMessage(error))
@@ -154,10 +157,10 @@ export const TuiThreadCommand = cmd({
         const { Effect } = await import("effect")
         const { run } = await import("../tui/layer")
         const { createLegacyTuiPluginHost } = await import("@/plugin/tui/runtime")
-        await Effect.runPromise(
+         await Effect.runPromise(
           run({
-            client: createOpencodeClient({ baseUrl: url, directory: cwd }),
-            api: OpenCode.make({ baseUrl: url }),
+            client: createOpencodeClient({ baseUrl: url, headers, directory: cwd }),
+            api: OpenCode.make({ baseUrl: url, headers }),
             async onSnapshot() {
               const tui = writeHeapSnapshot("tui.heapsnapshot")
               const server = await client.call("snapshot", undefined)

packages/opencode/src/effect/runtime-flags.ts

@@ -45,6 +45,7 @@ export class Service extends ConfigService.Service<Service>()("@opencode/Runtime
   experimentalLspTool: enabledByExperimental("OPENCODE_EXPERIMENTAL_LSP_TOOL"),
   experimentalOxfmt: enabledByExperimental("OPENCODE_EXPERIMENTAL_OXFMT"),
   experimentalPlanMode: enabledByExperimental("OPENCODE_EXPERIMENTAL_PLAN_MODE"),
+  experimentalCodeMode: enabledByExperimental("OPENCODE_EXPERIMENTAL_CODE_MODE"),
   experimentalEventSystem: enabledByExperimental("OPENCODE_EXPERIMENTAL_EVENT_SYSTEM"),
   experimentalWorkspaces: enabledByExperimental("OPENCODE_EXPERIMENTAL_WORKSPACES"),
   experimentalIconDiscovery: enabledByExperimental("OPENCODE_EXPERIMENTAL_ICON_DISCOVERY"),

packages/opencode/src/mcp/browser.ts

@@ -0,0 +1,37 @@
+import { LayerNode } from "@opencode-ai/core/effect/layer-node"
+import { Context, Effect, Layer } from "effect"
+import open from "open"
+
+export interface Interface {
+  readonly open: (url: string) => Effect.Effect<void, Error>
+}
+
+export class Service extends Context.Service<Service, Interface>()("@opencode/McpBrowser") {}
+
+const layer = Layer.succeed(
+  Service,
+  Service.of({
+    open: Effect.fn("McpBrowser.open")(function* (url: string) {
+      const subprocess = yield* Effect.tryPromise({
+        try: () => open(url),
+        catch: (error) => (error instanceof Error ? error : new Error(String(error))),
+      })
+      yield* Effect.callback<void, Error>((resume) => {
+        const timer = setTimeout(() => resume(Effect.void), 500)
+        subprocess.on("error", (error) => {
+          clearTimeout(timer)
+          resume(Effect.fail(error))
+        })
+        subprocess.on("exit", (code) => {
+          if (code === null || code === 0) return
+          clearTimeout(timer)
+          resume(Effect.fail(new Error(`Browser open failed with exit code ${code}`)))
+        })
+      })
+    }),
+  }),
+)
+
+export const node = LayerNode.make({ service: Service, layer, deps: [] })
+
+export * as McpBrowser from "./browser"

packages/opencode/src/mcp/index.ts

@@ -1,7 +1,6 @@
 import path from "node:path"
 import { pathToFileURL } from "node:url"
 import { LayerNode } from "@opencode-ai/core/effect/layer-node"
-import { type Tool } from "ai"
 import { ConfigV1 } from "@opencode-ai/core/v1/config/config"
 import { serviceUse } from "@opencode-ai/core/effect/service-use"
 import { Client, type ClientOptions } from "@modelcontextprotocol/sdk/client/index.js"
@@ -27,7 +26,6 @@ import { McpOAuthCallback } from "./oauth-callback"
 import { McpAuth } from "./auth"
 import { EventV2Bridge } from "@/event-v2-bridge"
 import { TuiEvent } from "@/server/tui-event"
-import open from "open"
 import { Cause, Effect, Exit, Layer, Context, Schema, Stream } from "effect"
 import { EffectBridge } from "@/effect/bridge"
 import { InstanceState } from "@/effect/instance-state"
@@ -35,6 +33,7 @@ import { ChildProcess, ChildProcessSpawner } from "effect/unstable/process"
 import { CrossSpawnSpawner } from "@opencode-ai/core/cross-spawn-spawner"
 import { McpCatalog } from "./catalog"
 import { McpEvent } from "@opencode-ai/schema/mcp-event"
+import { McpBrowser } from "./browser"
 
 const DEFAULT_TIMEOUT = 30_000
 const CLIENT_OPTIONS = {
@@ -154,11 +153,19 @@ export interface ServerInstructions {
   tools: string[]
 }
 
+/** An MCP tool in its native shape; consumers adapt it to their own tool format. */
+export interface McpTool {
+  /** Shared cached definition; consumers must copy rather than mutate it. */
+  readonly def: MCPToolDef
+  readonly client: MCPClient
+  readonly timeout?: number
+}
+
 export interface Interface {
   readonly status: () => Effect.Effect<Record<string, Status>>
   readonly clients: () => Effect.Effect<Record<string, MCPClient>>
   readonly instructions: () => Effect.Effect<ServerInstructions[]>
-  readonly tools: () => Effect.Effect<Record<string, Tool>>
+  readonly tools: () => Effect.Effect<Record<string, McpTool>>
   readonly prompts: () => Effect.Effect<Record<string, PromptInfo & { client: string }>>
   readonly resources: (clientName?: string) => Effect.Effect<Record<string, ResourceInfo & { client: string }>>
   readonly resourceTemplates: (
@@ -200,6 +207,7 @@ const layer = Layer.effect(
     const spawner = yield* ChildProcessSpawner.ChildProcessSpawner
     const auth = yield* McpAuth.Service
     const events = yield* EventV2Bridge.Service
+    const browser = yield* McpBrowser.Service
 
     type Transport = StdioClientTransport | StreamableHTTPClientTransport | SSEClientTransport
 
@@ -656,7 +664,7 @@ const layer = Layer.effect(
     }
 
     const tools = Effect.fn("MCP.tools")(function* () {
-      const result: Record<string, Tool> = {}
+      const result: Record<string, McpTool> = {}
       const s = yield* InstanceState.get(state)
 
       const cfg = yield* cfgSvc.get()
@@ -672,9 +680,8 @@ const layer = Layer.effect(
           continue
         }
         const timeout = requestTimeout(s, clientName, mcpConfig, defaultTimeout)
-        for (const mcpTool of listed) {
-          const key = McpCatalog.toolName(clientName, mcpTool.name)
-          result[key] = McpCatalog.convertTool(mcpTool, client, timeout)
+        for (const def of listed) {
+          result[McpCatalog.toolName(clientName, def.name)] = { def, client, timeout }
         }
       }
       return result
@@ -891,22 +898,7 @@ const layer = Layer.effect(
       const callbackPromise = McpOAuthCallback.waitForCallback(result.oauthState, mcpName)
       onAuthorization?.(result.authorizationUrl)
 
-      yield* Effect.tryPromise(() => open(result.authorizationUrl)).pipe(
-        Effect.flatMap((subprocess) =>
-          Effect.callback<void, Error>((resume) => {
-            const timer = setTimeout(() => resume(Effect.void), 500)
-            subprocess.on("error", (err) => {
-              clearTimeout(timer)
-              resume(Effect.fail(err))
-            })
-            subprocess.on("exit", (code) => {
-              if (code !== null && code !== 0) {
-                clearTimeout(timer)
-                resume(Effect.fail(new Error(`Browser open failed with exit code ${code}`)))
-              }
-            })
-          }),
-        ),
+      yield* browser.open(result.authorizationUrl).pipe(
         Effect.catch(() => {
           return events.publish(BrowserOpenFailed, { mcpName, url: result.authorizationUrl }).pipe(Effect.ignore)
         }),
@@ -1006,7 +998,7 @@ export type AuthStatus = "authenticated" | "expired" | "not_authenticated"
 export const node = LayerNode.make({
   service: Service,
   layer: layer,
-  deps: [CrossSpawnSpawner.node, McpAuth.node, EventV2Bridge.node, Config.node],
+  deps: [CrossSpawnSpawner.node, McpAuth.node, EventV2Bridge.node, Config.node, McpBrowser.node],
 })
 
 export * as MCP from "."

packages/opencode/src/permission/index.ts

@@ -213,6 +213,11 @@ export function disabled(tools: string[], ruleset: PermissionV1.Ruleset): Set<st
   )
 }
 
+export function visibleTools<T>(tools: Record<string, T>, ruleset: PermissionV1.Ruleset): Record<string, T> {
+  const hidden = disabled(Object.keys(tools), ruleset)
+  return Object.fromEntries(Object.entries(tools).filter(([name]) => !hidden.has(name)))
+}
+
 export const node = LayerNode.make({ service: Service, layer: layer, deps: [EventV2Bridge.node] })
 
 export * as Permission from "."

packages/opencode/src/plugin/github-copilot/models.ts

@@ -72,6 +72,10 @@ type SelectableItem = Item & {
     }
   }
 }
+type CopilotEndpoint = "chat" | "responses" | "messages"
+type CopilotModel = Omit<Model, "api"> & {
+  api: Model["api"] & { endpoint?: CopilotEndpoint }
+}
 const decodeModels = Schema.decodeUnknownSync(schema)
 const decodeItem = Schema.decodeUnknownOption(item)
 
@@ -86,17 +90,25 @@ function build(key: string, remote: SelectableItem, url: string, prev?: Model):
     (remote.capabilities.limits.vision?.supported_media_types ?? []).some((item) => item.startsWith("image/"))
 
   const isMsgApi = remote.supported_endpoints?.includes("/v1/messages")
+  const endpoint: CopilotEndpoint | undefined = isMsgApi
+    ? "messages"
+    : remote.supported_endpoints?.includes("/responses")
+      ? "responses"
+      : remote.supported_endpoints?.includes("/chat/completions")
+        ? "chat"
+        : undefined
   const prices = remote.billing?.token_prices
   // Copilot prices are AIC per billing batch; OpenCode stores USD per million tokens.
   const usdPerMillion = prices ? 10_000 / prices.batch_size : 0
 
-  const model: Model = {
+  const model: CopilotModel = {
     id: key,
     providerID: "github-copilot",
     api: {
       id: remote.id,
       url: isMsgApi ? `${url}/v1` : url,
       npm: isMsgApi ? "@ai-sdk/anthropic" : "@ai-sdk/github-copilot",
+      ...(endpoint ? { endpoint } : {}),
     },
     // API response wins
     status: "active",

packages/opencode/src/provider/provider.ts

@@ -218,8 +218,12 @@ function custom(dep: CustomDep): Record<string, CustomLoader> {
     "github-copilot": () =>
       Effect.succeed({
         autoload: false,
-        async getModel(sdk: any, modelID: string, _options?: Record<string, any>) {
+        async getModel(sdk: any, modelID: string, _options?: Record<string, any>, model?: Model) {
           if (sdk.responses === undefined && sdk.chat === undefined) return sdk.languageModel(modelID)
+          if (model && "endpoint" in model.api) {
+            if (model.api.endpoint === "responses" && sdk.responses) return sdk.responses(modelID)
+            if (model.api.endpoint === "chat" && sdk.chat) return sdk.chat(modelID)
+          }
           const match = /^gpt-(\d+)/.exec(modelID)
           if (match && Number(match[1]) >= 5 && !modelID.startsWith("gpt-5-mini")) return sdk.responses(modelID)
           return sdk.chat(modelID)

packages/opencode/src/provider/transform.ts

@@ -1240,9 +1240,6 @@ export function smallOptions(model: Provider.Model) {
     return mergeDeep(base, small)
   }
   if (model.providerID === "openrouter" || model.providerID === "llmgateway") {
-    if (model.providerID === "openrouter" && small.reasoning?.effort === "low") {
-      return { reasoning: { effort: "none" } }
-    }
     if (Object.keys(small).length === 0 && model.api.id.includes("google")) {
       return { reasoning: { enabled: false } }
     }

packages/opencode/src/server/routes/instance/httpapi/handlers/experimental.ts

@@ -137,8 +137,9 @@ export const experimentalHandlers = HttpApiBuilder.group(InstanceHttpApi, "exper
 
     const session = Effect.fn("ExperimentalHttpApi.session")(function* (ctx: { query: typeof SessionListQuery.Type }) {
       const limit = ctx.query.limit ?? 100
+      const directory = ctx.query.directory ? yield* InstanceState.directory : undefined
       const all = yield* sessions.listGlobal({
-        directory: ctx.query.directory,
+        directory,
         roots: ctx.query.roots,
         start: ctx.query.start,
         cursor: ctx.query.cursor,

packages/opencode/src/server/routes/instance/httpapi/handlers/session.ts

@@ -18,6 +18,7 @@ import { MessageID, PartID, SessionID } from "@/session/schema"
 import { NamedError } from "@opencode-ai/core/util/error"
 import { Cause, Effect, Option, Schema, Scope } from "effect"
 import * as Stream from "effect/Stream"
+import { InstanceState } from "@/effect/instance-state"
 import { HttpServerRequest, HttpServerResponse } from "effect/unstable/http"
 import { HttpApiBuilder, HttpApiError, HttpApiSchema } from "effect/unstable/httpapi"
 import { InstanceHttpApi } from "../api"
@@ -61,8 +62,9 @@ export const sessionHandlers = HttpApiBuilder.group(InstanceHttpApi, "session",
     const scope = yield* Scope.Scope
 
     const list = Effect.fn("SessionHttpApi.list")(function* (ctx: { query: typeof ListQuery.Type }) {
+      const directory = ctx.query.directory ? yield* InstanceState.directory : undefined
       return yield* session.list({
-        directory: ctx.query.scope === "project" ? undefined : ctx.query.directory,
+        directory: ctx.query.scope === "project" ? undefined : directory,
         scope: ctx.query.scope,
         path: ctx.query.path,
         roots: ctx.query.roots,

packages/opencode/src/session/processor.ts

@@ -192,6 +192,8 @@ const layer = Layer.effect(
             status: "error",
             input: match.part.state.input,
             error: errorMessage(error),
+            // Keep metadata streamed while running so failures retain progress detail (e.g. execute's child calls).
+            metadata: match.part.state.metadata,
             time: { start: match.part.state.time.start, end: Date.now() },
           },
         })

packages/opencode/src/session/prompt.ts

@@ -1237,6 +1237,7 @@ const layer = Layer.effect(
               Effect.provideService(ToolRegistry.Service, registry),
               Effect.provideService(MCP.Service, mcp),
               Effect.provideService(Truncate.Service, truncate),
+              Effect.provideService(RuntimeFlags.Service, flags),
             )
 
             if (lastUser.format?.type === "json_schema") {

packages/opencode/src/session/tools.ts

@@ -3,6 +3,7 @@ import { SessionV1 } from "@opencode-ai/core/v1/session"
 import { Provider } from "@/provider/provider"
 import { ProviderTransform } from "@/provider/transform"
 import { MCP } from "@/mcp"
+import { McpCatalog } from "@/mcp/catalog"
 import { Permission } from "@/permission"
 import { Tool } from "@/tool/tool"
 import { ToolJsonSchema } from "@/tool/json-schema"
@@ -21,6 +22,7 @@ import { EffectBridge } from "@/effect/bridge"
 import { ProviderV2 } from "@opencode-ai/core/provider"
 import { ModelV2 } from "@opencode-ai/core/model"
 import { isRecord } from "@/util/record"
+import { RuntimeFlags } from "@/effect/runtime-flags"
 
 const MCP_RESOURCE_TOOLS = {
   list: "list_mcp_resources",
@@ -52,6 +54,7 @@ export const resolve = Effect.fn("SessionTools.resolve")(function* (input: {
   const registry = yield* ToolRegistry.Service
   const mcp = yield* MCP.Service
   const truncate = yield* Truncate.Service
+  const flags = yield* RuntimeFlags.Service
 
   const context = (args: Record<string, unknown>, options: ToolExecutionOptions): Tool.Context => ({
     sessionID: input.session.id,
@@ -90,6 +93,7 @@ export const resolve = Effect.fn("SessionTools.resolve")(function* (input: {
     modelID: ModelV2.ID.make(input.model.api.id),
     providerID: input.model.providerID,
     agent: input.agent,
+    permission: input.session.permission,
   })) {
     const schema = ProviderTransform.schema(input.model, ToolJsonSchema.fromTool(item))
     tools[item.id] = tool({
@@ -381,7 +385,10 @@ export const resolve = Effect.fn("SessionTools.resolve")(function* (input: {
     })
   }
 
-  for (const [key, item] of Object.entries(yield* mcp.tools())) {
+  if (flags.experimentalCodeMode) return tools
+
+  for (const [key, entry] of Object.entries(yield* mcp.tools())) {
+    const item = McpCatalog.convertTool(entry.def, entry.client, entry.timeout)
     const execute = item.execute
     if (!execute) continue
 

packages/opencode/src/tool/code-mode.ts

@@ -0,0 +1,310 @@
+import * as Tool from "./tool"
+import { CallToolResultSchema, type CallToolResult } from "@modelcontextprotocol/sdk/types.js"
+import { Cause, Effect, Schema } from "effect"
+import { CodeMode, Tool as SandboxTool, toolError } from "@opencode-ai/codemode"
+import { MCP } from "@/mcp"
+import { McpCatalog } from "@/mcp/catalog"
+import { Agent } from "@/agent/agent"
+import { Session } from "@/session/session"
+import { Permission } from "@/permission"
+import { Plugin } from "@/plugin"
+
+export const CODE_MODE_TOOL = "execute"
+
+const DESCRIPTION = "Run a confined orchestration script with access to connected MCP tools."
+
+export const Parameters = Schema.Struct({
+  code: Schema.String.annotate({
+    description: "Script body executed by the confined interpreter.",
+  }),
+})
+
+type CallEntry = { tool: string; status: "running" | "completed" | "error"; input?: Record<string, unknown> }
+
+type Metadata = {
+  toolCalls: CallEntry[]
+  error?: boolean
+}
+
+type Attachment = NonNullable<Tool.ExecuteResult["attachments"]>[number]
+
+type CatalogEntry = {
+  path: string
+  key: string
+  server: string
+  local: string
+  tool: MCP.McpTool
+}
+
+function groupByServer(mcpTools: Record<string, MCP.McpTool>, servers: readonly string[]): Map<string, CatalogEntry[]> {
+  const byLongest = [...servers].sort((a, b) => b.length - a.length)
+  const groups = new Map<string, CatalogEntry[]>()
+  for (const key of Object.keys(mcpTools).sort((a, b) => a.localeCompare(b))) {
+    const server =
+      byLongest.find((name) => key.startsWith(name + "_")) ?? (key.includes("_") ? key.slice(0, key.indexOf("_")) : key)
+    const local = server && key.startsWith(server + "_") ? key.slice(server.length + 1) : key
+    const entry: CatalogEntry = {
+      path: `${server}.${local}`,
+      key,
+      server,
+      local,
+      tool: mcpTools[key]!,
+    }
+    groups.set(server, [...(groups.get(server) ?? []), entry])
+  }
+  return groups
+}
+
+export function describeCatalog(mcpTools: Record<string, MCP.McpTool>, servers: readonly string[]): string {
+  return CodeMode.make({
+    tools: toolTree(
+      [...groupByServer(mcpTools, servers).values()].flat(),
+      () => () => Effect.fail(toolError("Tool preview is not executable.")),
+    ),
+  }).instructions()
+}
+
+const lastSegment = (uri: string) => {
+  const trimmed = uri.split(/[?#]/, 1)[0]!.replace(/\/+$/, "")
+  const segment = trimmed.slice(trimmed.lastIndexOf("/") + 1)
+  return segment.length > 0 ? segment : undefined
+}
+
+const dataUrl = (mime: string, base64: string) => `data:${mime};base64,${base64}`
+
+function projectMcpResult(result: CallToolResult, collect: (attachment: Attachment) => void): unknown {
+  const text: string[] = []
+  let files = 0
+  let images = 0
+  const push = (attachment: Attachment) => {
+    files += 1
+    if (attachment.mime.startsWith("image/")) images += 1
+    collect(attachment)
+  }
+  for (const block of result.content) {
+    switch (block.type) {
+      case "text":
+        text.push(block.text)
+        break
+      case "image":
+      case "audio":
+        push({ type: "file", mime: block.mimeType, url: dataUrl(block.mimeType, block.data) })
+        break
+      case "resource": {
+        if ("text" in block.resource) {
+          text.push(block.resource.text)
+          break
+        }
+        const mime = block.resource.mimeType ?? "application/octet-stream"
+        push({ type: "file", mime, url: dataUrl(mime, block.resource.blob), filename: lastSegment(block.resource.uri) })
+        break
+      }
+      case "resource_link":
+        // A link is a reference, not fetchable media; hand it to the program instead of the attachment channel.
+        text.push(`${block.name}: ${block.uri}`)
+        break
+    }
+  }
+
+  if (result.structuredContent !== undefined && result.structuredContent !== null) return result.structuredContent
+  if (text.length > 0) return text.join("\n")
+  if (files > 0) {
+    const noun = files === images ? "image" : "file"
+    return `[${files} ${noun}${files === 1 ? "" : "s"} attached to the result]`
+  }
+  return null
+}
+
+type Run = (input: unknown) => Effect.Effect<unknown, unknown>
+
+function toolTree(catalog: readonly CatalogEntry[], run: (entry: CatalogEntry) => Run) {
+  const tree: Record<string, Record<string, SandboxTool.Definition>> = {}
+  for (const entry of catalog) {
+    const namespace = (tree[entry.server] ??= {})
+    namespace[entry.local] = SandboxTool.make({
+      description: entry.tool.def.description ?? "",
+      input: entry.tool.def.inputSchema as SandboxTool.JsonSchema,
+      output: entry.tool.def.outputSchema as SandboxTool.JsonSchema | undefined,
+      run: run(entry),
+    })
+  }
+  return tree
+}
+
+const invokeChildTool = Effect.fn("CodeMode.invokeChildTool")(function* (input: {
+  plugin: Plugin.Interface
+  entry: CatalogEntry
+  args: Record<string, unknown>
+  callID: string
+  ctx: Tool.Context
+}) {
+  yield* input.plugin.trigger(
+    "tool.execute.before",
+    { tool: input.entry.key, sessionID: input.ctx.sessionID, callID: input.callID },
+    { args: input.args },
+  )
+  const result: CallToolResult = yield* Effect.gen(function* () {
+    yield* input.ctx.ask({ permission: input.entry.key, metadata: {}, patterns: ["*"], always: ["*"] })
+    // Deliberately mirrors McpCatalog.convertTool's transport call so the MCP service stays free of tool-loop concerns.
+    return yield* Effect.promise(async () => {
+      const raw = await input.entry.tool.client.callTool(
+        { name: input.entry.tool.def.name, arguments: input.args },
+        CallToolResultSchema,
+        {
+          resetTimeoutOnProgress: true,
+          signal: input.ctx.abort,
+          timeout: input.entry.tool.timeout,
+          // The MCP SDK only sends a progress token when this hook is present, enabling timeout resets.
+          onprogress: () => {},
+        },
+      )
+      if (raw.isError)
+        throw new Error(
+          raw.content
+            .flatMap((item) => (item.type === "text" ? [item.text] : []))
+            .filter((text) => text.trim())
+            .join("\n\n") || "MCP tool returned an error",
+        )
+      return raw
+    })
+  }).pipe(
+    Effect.withSpan("Tool.execute", {
+      attributes: {
+        "tool.name": input.entry.key,
+        "tool.call_id": input.callID,
+        "session.id": input.ctx.sessionID,
+        "message.id": input.ctx.messageID,
+      },
+    }),
+  )
+  yield* input.plugin.trigger(
+    "tool.execute.after",
+    { tool: input.entry.key, sessionID: input.ctx.sessionID, callID: input.callID, args: input.args },
+    result,
+  )
+  return result
+})
+
+export const CodeModeTool = Tool.define(
+  CODE_MODE_TOOL,
+  Effect.gen(function* () {
+    const mcp = yield* MCP.Service
+    const agents = yield* Agent.Service
+    const sessions = yield* Session.Service
+    const plugin = yield* Plugin.Service
+
+    const init: Tool.DefWithoutID<typeof Parameters, Metadata> = {
+      description: DESCRIPTION,
+      parameters: Parameters,
+      execute: Effect.fn("CodeMode.execute")(function* (params, ctx) {
+        if (ctx.abort.aborted) {
+          return {
+            title: CODE_MODE_TOOL,
+            metadata: { toolCalls: [], error: true },
+            output: "Execution cancelled.",
+          } satisfies Tool.ExecuteResult<Metadata>
+        }
+        const agent = yield* agents.get(ctx.agent)
+        const session = yield* sessions.get(ctx.sessionID).pipe(Effect.orDie)
+        const ruleset = Permission.merge(agent.permission, session.permission ?? [])
+        const mcpTools = Permission.visibleTools(yield* mcp.tools(), ruleset)
+        const servers = Object.keys(yield* mcp.clients()).map(McpCatalog.sanitize)
+        const catalog = [...groupByServer(mcpTools, servers).values()].flat()
+
+        const calls: CallEntry[] = []
+        const attachments: Attachment[] = []
+        const publish = () =>
+          ctx.metadata({ title: CODE_MODE_TOOL, metadata: { toolCalls: calls.map((c) => ({ ...c })) } })
+
+        let childCalls = 0
+        const callTool = (entry: CatalogEntry) => (input: unknown) =>
+          Effect.gen(function* () {
+            childCalls += 1
+            const result = yield* invokeChildTool({
+              plugin,
+              entry,
+              args: (input ?? {}) as Record<string, unknown>,
+              callID: `${ctx.callID ?? entry.key}/${childCalls}`,
+              ctx,
+            })
+            return projectMcpResult(result, (attachment: Attachment) => void attachments.push(attachment))
+          }).pipe(
+            Effect.catchCause((cause) => {
+              if (Cause.hasInterruptsOnly(cause)) return Effect.interrupt
+              const error = Cause.squash(cause)
+              return Effect.fail(toolError(error instanceof Error ? error.message : String(error), error))
+            }),
+          )
+
+        const runtime = CodeMode.make({
+          tools: toolTree(catalog, callTool),
+          onToolCallStart: ({ index, name, input }) =>
+            Effect.suspend(() => {
+              const shown = (() => {
+                if (input === null || input === undefined) return
+                if (typeof input === "object" && !Array.isArray(input)) {
+                  const value = input as Record<string, unknown>
+                  return Object.keys(value).length > 0 ? value : undefined
+                }
+                return { input }
+              })()
+              calls[index] = { tool: name, status: "running", ...(shown ? { input: shown } : {}) }
+              return publish()
+            }),
+          onToolCallEnd: ({ index, outcome }) =>
+            Effect.suspend(() => {
+              const current = calls[index]
+              if (current) calls[index] = { ...current, status: outcome === "success" ? "completed" : "error" }
+              return publish()
+            }),
+        })
+
+        const abort = Effect.callback<void>((resume) => {
+          if (ctx.abort.aborted) return resume(Effect.void)
+          const handler = () => resume(Effect.void)
+          ctx.abort.addEventListener("abort", handler, { once: true })
+          return Effect.sync(() => ctx.abort.removeEventListener("abort", handler))
+        })
+        const cancelled = (): CodeMode.Result => ({
+          ok: false,
+          error: { kind: "ExecutionFailure", message: "Execution cancelled." },
+          toolCalls: calls.map((call) => ({ name: call.tool })),
+        })
+
+        const result = yield* Effect.raceFirst(runtime.execute(params.code), abort.pipe(Effect.map(cancelled)))
+        const logs = result.logs ?? []
+        const withLogs = (text: string) => {
+          if (logs.length === 0) return text
+          return text.length > 0 ? `${text}\n\nLogs:\n${logs.join("\n")}` : `Logs:\n${logs.join("\n")}`
+        }
+
+        if (!result.ok) {
+          if (ctx.abort.aborted) {
+            return {
+              title: CODE_MODE_TOOL,
+              metadata: { toolCalls: calls, error: true },
+              output: "Execution cancelled.",
+            } satisfies Tool.ExecuteResult<Metadata>
+          }
+          const hints = (result.error.suggestions ?? []).filter((hint) => !result.error.message.includes(hint))
+          return yield* Effect.fail(new Error(withLogs([result.error.message, ...hints].join("\n"))))
+        }
+
+        // The interpreter validates returned values as plain JSON, so stringify cannot throw;
+        // it yields undefined only for a program that returns undefined.
+        const output =
+          typeof result.value === "string"
+            ? result.value
+            : (JSON.stringify(result.value, null, 2) ?? String(result.value))
+
+        return {
+          title: CODE_MODE_TOOL,
+          metadata: { toolCalls: calls },
+          output: withLogs(output),
+          ...(attachments.length > 0 ? { attachments } : {}),
+        } satisfies Tool.ExecuteResult<Metadata>
+      }, Effect.orDie),
+    }
+    return init
+  }),
+)

packages/opencode/src/tool/registry.ts

@@ -51,6 +51,9 @@ import { Job } from "@/job"
 import { RuntimeFlags } from "@/effect/runtime-flags"
 import { ProviderV2 } from "@opencode-ai/core/provider"
 import { ModelV2 } from "@opencode-ai/core/model"
+import { MCP } from "@/mcp"
+import { PermissionV1 } from "@opencode-ai/core/v1/permission"
+import { McpCatalog } from "@/mcp/catalog"
 
 export function webSearchEnabled(providerID: ProviderV2.ID, flags = { exa: false, parallel: false }) {
   return providerID === ProviderV2.ID.opencode || flags.exa || flags.parallel
@@ -74,6 +77,7 @@ export interface Interface {
     providerID: ProviderV2.ID
     modelID: ModelV2.ID
     agent: Agent.Info
+    permission?: PermissionV1.Ruleset
   }) => Effect.Effect<Tool.Def[]>
 }
 
@@ -87,6 +91,7 @@ const layer = Layer.effect(
     const agents = yield* Agent.Service
     const truncate = yield* Truncate.Service
     const flags = yield* RuntimeFlags.Service
+    const mcp = yield* MCP.Service
 
     const invalid = yield* InvalidTool
     const task = yield* TaskTool
@@ -105,6 +110,8 @@ const layer = Layer.effect(
     const patchtool = yield* ApplyPatchTool
     const skilltool = yield* SkillTool
     const agent = yield* Agent.Service
+    const codeMode = flags.experimentalCodeMode ? yield* Effect.promise(() => import("./code-mode")) : undefined
+    const codeModeTool = codeMode ? yield* codeMode.CodeModeTool : undefined
 
     const state = yield* InstanceState.make<State>(
       Effect.fn("ToolRegistry.state")(function* (ctx) {
@@ -211,6 +218,7 @@ const layer = Layer.effect(
           question: Tool.init(question),
           lsp: Tool.init(lsptool),
           plan: Tool.init(plan),
+          ...(codeModeTool ? { execute: Tool.init(codeModeTool) } : {}),
         })
 
         return {
@@ -230,6 +238,7 @@ const layer = Layer.effect(
             tool.search,
             tool.skill,
             tool.patch,
+            ...(tool.execute ? [tool.execute] : []),
             ...(flags.experimentalLspTool ? [tool.lsp] : []),
             ...(flags.experimentalPlanMode && flags.client === "cli" ? [tool.plan] : []),
           ],
@@ -263,6 +272,17 @@ const layer = Layer.effect(
       return ["Available agent types and the tools they have access to:", description].join("\n")
     })
 
+    const describeCodeMode = Effect.fn("ToolRegistry.describeCodeMode")(function* (input: {
+      agent: Agent.Info
+      permission?: PermissionV1.Ruleset
+    }) {
+      if (!codeMode) return
+      const ruleset = Permission.merge(input.agent.permission, input.permission ?? [])
+      const tools = Permission.visibleTools(yield* mcp.tools(), ruleset)
+      if (Object.keys(tools).length === 0) return
+      return codeMode.describeCatalog(tools, Object.keys(yield* mcp.clients()).map(McpCatalog.sanitize))
+    })
+
     const tools: Interface["tools"] = Effect.fn("ToolRegistry.tools")(function* (input) {
       const filtered = (yield* all()).filter((tool) => {
         if (tool.id === WebSearchTool.id) {
@@ -277,8 +297,13 @@ const layer = Layer.effect(
         return true
       })
 
+      const codeModeDescription = filtered.some((tool) => tool.id === "execute")
+        ? yield* describeCodeMode(input)
+        : undefined
+      const visible = filtered.filter((tool) => tool.id !== "execute" || codeModeDescription)
+
       return yield* Effect.forEach(
-        filtered,
+        visible,
         Effect.fnUntraced(function* (tool: Tool.Def) {
           const output = {
             description: tool.description,
@@ -292,7 +317,11 @@ const layer = Layer.effect(
               : undefined
           return {
             id: tool.id,
-            description: [output.description, tool.id === TaskTool.id ? yield* describeTask(input.agent) : undefined]
+            description: [
+              output.description,
+              tool.id === TaskTool.id ? yield* describeTask(input.agent) : undefined,
+              tool.id === "execute" ? codeModeDescription : undefined,
+            ]
               .filter(Boolean)
               .join("\n"),
             parameters: output.parameters,
@@ -412,6 +441,7 @@ export const node = LayerNode.make({
     Format.node,
     Truncate.node,
     RuntimeFlags.node,
+    MCP.node,
     Database.node,
     Ripgrep.node,
   ],