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 249a48d358b..d2e06afaa69 100644
--- a/packages/opencode/src/cli/cmd/tui/component/prompt/index.tsx
+++ b/packages/opencode/src/cli/cmd/tui/component/prompt/index.tsx
@@ -837,7 +837,7 @@ export function Prompt(props: PromptProps) {
               textColor={keybind.leader ? theme.textMuted : theme.text}
               focusedTextColor={keybind.leader ? theme.textMuted : theme.text}
               minHeight={1}
-              maxHeight={6}
+              maxHeight={sync.data.config.experimental?.max_prompt_input_lines ?? 6}
               onContentChange={() => {
                 const value = input.plainText
                 setStore("prompt", "input", value)
diff --git a/packages/opencode/src/config/config.ts b/packages/opencode/src/config/config.ts
index 47afdfd7d0f..7023e0c0c2a 100644
--- a/packages/opencode/src/config/config.ts
+++ b/packages/opencode/src/config/config.ts
@@ -1225,6 +1225,14 @@ export namespace Config {
             .positive()
             .optional()
             .describe("Timeout in milliseconds for model context protocol (MCP) requests"),
+          max_prompt_input_lines: z
+            .number()
+            .int()
+            .min(1)
+            .max(99)
+            .optional()
+            .default(6)
+            .describe("Maximum number of lines for the prompt input text box (1-99, default: 6)"),
         })
         .optional(),
     })
diff --git a/packages/sdk/js/src/v2/gen/types.gen.ts b/packages/sdk/js/src/v2/gen/types.gen.ts
index ec797f2ba81..881e6fbe01b 100644
--- a/packages/sdk/js/src/v2/gen/types.gen.ts
+++ b/packages/sdk/js/src/v2/gen/types.gen.ts
@@ -1503,6 +1503,10 @@ export type Config = {
      * Timeout in milliseconds for model context protocol (MCP) requests
      */
     mcp_timeout?: number
+    /**
+     * Maximum number of lines for the prompt input text box (1-99, default: 6)
+     */
+    max_prompt_input_lines?: number
   }
 }