diff --git a/packages/opencode/src/cli/cmd/tui/component/prompt/index.tsx b/packages/opencode/src/cli/cmd/tui/component/prompt/index.tsx
index 730da20c265..108117076dc 100644
--- a/packages/opencode/src/cli/cmd/tui/component/prompt/index.tsx
+++ b/packages/opencode/src/cli/cmd/tui/component/prompt/index.tsx
@@ -432,6 +432,20 @@ export function Prompt(props: PromptProps) {
   }
 
   command.register(() => [
+    {
+      title: "Add directory to context",
+      value: "context.addDir",
+      category: "Session",
+      slash: { name: "add-dir" },
+      onSelect: (dialog) => {
+        dialog.clear()
+        const newText = "/add-dir "
+        const cursor = input.logicalCursor
+        input.deleteRange(0, 0, cursor.row, cursor.col)
+        input.insertText(newText)
+        input.cursorOffset = Bun.stringWidth(newText)
+      },
+    },
     {
       title: "Stash prompt",
       value: "prompt.stash",
@@ -543,6 +557,22 @@ export function Prompt(props: PromptProps) {
         command: inputText,
       })
       setStore("mode", "normal")
+    } else if (inputText.startsWith("/add-dir ")) {
+      const dirPath = inputText.slice("/add-dir ".length).trim()
+      if (!dirPath) {
+        toast.show({ title: "Usage: /add-dir <path>", message: "Please provide a directory path", variant: "error" })
+        return
+      }
+      const result = await sdk.client.session.addDir({ path: dirPath, sessionID })
+      if (result.error) {
+        toast.error(result.error)
+        return
+      }
+      const resolved = result.data!.path
+      input.clear()
+      setStore("prompt", { input: "", parts: [] })
+      toast.show({ title: "Directory added", message: resolved, variant: "success" })
+      return
     } else if (
       inputText.startsWith("/") &&
       iife(() => {
diff --git a/packages/opencode/src/permission/next.ts b/packages/opencode/src/permission/next.ts
index f95aaf34525..f56a6d64d3d 100644
--- a/packages/opencode/src/permission/next.ts
+++ b/packages/opencode/src/permission/next.ts
@@ -266,4 +266,21 @@ export namespace PermissionNext {
   export async function list() {
     return state().then((x) => Object.values(x.pending).map((x) => x.info))
   }
+
+  export const grant = fn(
+    z.object({
+      permission: z.string(),
+      patterns: z.string().array(),
+    }),
+    async (input) => {
+      const s = await state()
+      for (const pattern of input.patterns) {
+        s.approved.push({
+          permission: input.permission,
+          pattern,
+          action: "allow",
+        })
+      }
+    },
+  )
 }
diff --git a/packages/opencode/src/server/routes/session.ts b/packages/opencode/src/server/routes/session.ts
index a98624dfae2..43c734149f4 100644
--- a/packages/opencode/src/server/routes/session.ts
+++ b/packages/opencode/src/server/routes/session.ts
@@ -2,6 +2,8 @@ import { Hono } from "hono"
 import { stream } from "hono/streaming"
 import { describeRoute, validator, resolver } from "hono-openapi"
 import z from "zod"
+import * as path from "node:path"
+import * as fs from "node:fs/promises"
 import { Session } from "../../session"
 import { MessageV2 } from "../../session/message-v2"
 import { SessionPrompt } from "../../session/prompt"
@@ -16,6 +18,9 @@ import { Log } from "../../util/log"
 import { PermissionNext } from "@/permission/next"
 import { errors } from "../error"
 import { lazy } from "../../util/lazy"
+import { Instance } from "../../project/instance"
+import { Ripgrep } from "../../file/ripgrep"
+import { IGNORE_PATTERNS } from "../../tool/ls"
 
 const log = Log.create({ service: "server" })
 
@@ -931,5 +936,78 @@ export const SessionRoutes = lazy(() =>
         })
         return c.json(true)
       },
+    )
+    .post(
+      "/add-dir",
+      describeRoute({
+        summary: "Add directory to context",
+        description:
+          "Add a directory to the conversation context. If the directory is outside the project, grants external_directory permission.",
+        operationId: "session.addDir",
+        responses: {
+          200: {
+            description: "Directory added successfully",
+            content: {
+              "application/json": {
+                schema: resolver(
+                  z.object({
+                    path: z.string(),
+                    granted: z.boolean(),
+                  }),
+                ),
+              },
+            },
+          },
+          ...errors(400),
+        },
+      }),
+      validator(
+        "json",
+        z.object({
+          path: z.string(),
+          sessionID: z.string(),
+        }),
+      ),
+      async (c) => {
+        const body = c.req.valid("json")
+        const input = body.path
+
+        const expanded = input.startsWith("~/")
+          ? path.join(process.env.HOME || process.env.USERPROFILE || "", input.slice(2))
+          : input.startsWith("~")
+            ? path.join(process.env.HOME || process.env.USERPROFILE || "", input.slice(1))
+            : input
+
+        const absolute = path.isAbsolute(expanded) ? expanded : path.resolve(Instance.directory, expanded)
+
+        const info = await fs.stat(absolute).catch(() => null)
+        if (!info) return c.json({ error: "Directory does not exist" }, 400)
+        if (!info.isDirectory()) return c.json({ error: "Path is not a directory" }, 400)
+
+        const resolved = await fs.realpath(absolute)
+        const granted = !Instance.containsPath(resolved)
+        if (granted) {
+          await PermissionNext.grant({
+            permission: "external_directory",
+            patterns: [path.join(resolved, "*")],
+          })
+        }
+
+        const globs = IGNORE_PATTERNS.map((p) => `!${p}*`)
+        const files: string[] = []
+        for await (const file of Ripgrep.files({ cwd: resolved, glob: globs })) {
+          files.push(file)
+          if (files.length >= 100) break
+        }
+        const listing = files.sort().join("\n")
+
+        await SessionPrompt.prompt({
+          sessionID: body.sessionID,
+          noReply: true,
+          parts: [{ type: "text", text: `Added directory to context: ${resolved}\n\n${listing}` }],
+        })
+
+        return c.json({ path: resolved, granted })
+      },
     ),
 )
diff --git a/packages/sdk/js/src/v2/gen/sdk.gen.ts b/packages/sdk/js/src/v2/gen/sdk.gen.ts
index 59b7f06963b..dd3a4c2adcb 100644
--- a/packages/sdk/js/src/v2/gen/sdk.gen.ts
+++ b/packages/sdk/js/src/v2/gen/sdk.gen.ts
@@ -93,6 +93,8 @@ import type {
   QuestionReplyResponses,
   SessionAbortErrors,
   SessionAbortResponses,
+  SessionAddDirErrors,
+  SessionAddDirResponses,
   SessionChildrenErrors,
   SessionChildrenResponses,
   SessionCommandErrors,
@@ -1654,6 +1656,43 @@ export class Session extends HeyApiClient {
       ...params,
     })
   }
+
+  /**
+   * Add directory to context
+   *
+   * Add a directory to the conversation context. If the directory is outside the project, grants external_directory permission.
+   */
+  public addDir<ThrowOnError extends boolean = false>(
+    parameters?: {
+      directory?: string
+      path?: string
+      sessionID?: string
+    },
+    options?: Options<never, ThrowOnError>,
+  ) {
+    const params = buildClientParams(
+      [parameters],
+      [
+        {
+          args: [
+            { in: "query", key: "directory" },
+            { in: "body", key: "path" },
+            { in: "body", key: "sessionID" },
+          ],
+        },
+      ],
+    )
+    return (options?.client ?? this.client).post<SessionAddDirResponses, SessionAddDirErrors, ThrowOnError>({
+      url: "/session/add-dir",
+      ...options,
+      ...params,
+      headers: {
+        "Content-Type": "application/json",
+        ...options?.headers,
+        ...params.headers,
+      },
+    })
+  }
 }
 
 export class Part extends HeyApiClient {
diff --git a/packages/sdk/js/src/v2/gen/types.gen.ts b/packages/sdk/js/src/v2/gen/types.gen.ts
index 75540f90724..c203c3359e2 100644
--- a/packages/sdk/js/src/v2/gen/types.gen.ts
+++ b/packages/sdk/js/src/v2/gen/types.gen.ts
@@ -3710,6 +3710,39 @@ export type PermissionListResponses = {
 
 export type PermissionListResponse = PermissionListResponses[keyof PermissionListResponses]
 
+export type SessionAddDirData = {
+  body?: {
+    path: string
+    sessionID: string
+  }
+  path?: never
+  query?: {
+    directory?: string
+  }
+  url: "/session/add-dir"
+}
+
+export type SessionAddDirErrors = {
+  /**
+   * Bad request
+   */
+  400: BadRequestError
+}
+
+export type SessionAddDirError = SessionAddDirErrors[keyof SessionAddDirErrors]
+
+export type SessionAddDirResponses = {
+  /**
+   * Directory added successfully
+   */
+  200: {
+    path: string
+    granted: boolean
+  }
+}
+
+export type SessionAddDirResponse = SessionAddDirResponses[keyof SessionAddDirResponses]
+
 export type QuestionListData = {
   body?: never
   path?: never