feat(api): Probe for @ mentions in TUI append to prompt API

packages/opencode/src/cli/cmd/tui/component/prompt/index.tsx

@@ -120,7 +120,33 @@ export function Prompt(props: PromptProps) {
 
   event.on(TuiEvent.PromptAppend.type, (evt) => {
     if (!input || input.isDestroyed) return
+    const oldLength = input.plainText.length
     input.insertText(evt.properties.text)
+
+    if (evt.properties.parts.length > 0) {
+      for (const part of evt.properties.parts) {
+        const extmarkId =
+          part.source &&
+          input.extmarks.create({
+            start: oldLength + (part.type === "file" ? part.source.text.start : part.source.start),
+            end: oldLength + (part.type === "file" ? part.source.text.end : part.source.end),
+            virtual: true,
+            styleId: part.type === "agent" ? agentStyleId : fileStyleId,
+            typeId: promptPartTypeId,
+          })
+
+        setStore(
+          produce((draft) => {
+            const partIndex = draft.prompt.parts.length
+            draft.prompt.parts.push(part)
+            if (extmarkId !== undefined) {
+              draft.extmarkToPartIndex.set(extmarkId, partIndex)
+            }
+          }),
+        )
+      }
+    }
+
     setTimeout(() => {
       // setTimeout is a workaround and needs to be addressed properly
       if (!input || input.isDestroyed) return

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

@@ -1,10 +1,22 @@
 import { BusEvent } from "@/bus/bus-event"
 import { Bus } from "@/bus"
 import { SessionID } from "@/session/schema"
+import { MessageV2 } from "@/session/message-v2"
 import z from "zod"
 
 export const TuiEvent = {
-  PromptAppend: BusEvent.define("tui.prompt.append", z.object({ text: z.string() })),
+  PromptAppend: BusEvent.define(
+    "tui.prompt.append",
+    z.object({
+      text: z.string(),
+      parts: z.array(
+        z.union([
+          MessageV2.AgentPart.omit({ id: true, sessionID: true, messageID: true }),
+          MessageV2.FilePart.omit({ id: true, sessionID: true, messageID: true }),
+        ]),
+      ),
+    }),
+  ),
   CommandExecute: BusEvent.define(
     "tui.command.execute",
     z.object({

packages/opencode/src/server/routes/tui.ts

@@ -3,6 +3,7 @@ import { describeRoute, validator, resolver } from "hono-openapi"
 import z from "zod"
 import { Bus } from "../../bus"
 import { Session } from "../../session"
+import { SessionPrompt } from "../../session/prompt"
 import { TuiEvent } from "@/cli/cmd/tui/event"
 import { AsyncQueue } from "../../util/queue"
 import { errors } from "../error"
@@ -95,9 +96,15 @@ export const TuiRoutes = lazy(() =>
           ...errors(400),
         },
       }),
-      validator("json", TuiEvent.PromptAppend.properties),
+      validator("json", z.object({ text: z.string() })),
       async (c) => {
-        await Bus.publish(TuiEvent.PromptAppend, c.req.valid("json"))
+        const { text } = c.req.valid("json")
+        await Bus.publish(TuiEvent.PromptAppend, {
+          text,
+          parts: (await SessionPrompt.resolvePromptParts(text)).filter(
+            (part) => part.type === "agent" || part.type === "file",
+          ),
+        })
         return c.json(true)
       },
     )

packages/opencode/src/session/prompt.ts

@@ -132,15 +132,34 @@ export namespace SessionPrompt {
             const info = yield* fsys.stat(filepath).pipe(Effect.option)
             if (Option.isNone(info)) {
               const found = yield* agents.get(name)
-              if (found) parts.push({ type: "agent", name: found.name })
+              if (found) {
+                parts.push({
+                  type: "agent" as const,
+                  name: found.name,
+                  source: {
+                    start: match.index!,
+                    end: match.index! + match[0].length,
+                    value: match[0],
+                  },
+                })
+              }
               return
             }
             const stat = info.value
             parts.push({
-              type: "file",
-              url: pathToFileURL(filepath).href,
-              filename: name,
+              type: "file" as const,
               mime: stat.type === "Directory" ? "application/x-directory" : "text/plain",
+              filename: name,
+              url: pathToFileURL(filepath).href,
+              source: {
+                type: "file" as const,
+                path: name,
+                text: {
+                  start: match.index!,
+                  end: match.index! + match[0].length,
+                  value: match[0],
+                },
+              },
             })
           }),
           { concurrency: "unbounded", discard: true },

packages/sdk/js/src/gen/types.gen.ts

@@ -615,6 +615,24 @@ export type EventTuiPromptAppend = {
   type: "tui.prompt.append"
   properties: {
     text: string
+    parts: Array<
+      | {
+          type: "agent"
+          name: string
+          source?: {
+            value: string
+            start: number
+            end: number
+          }
+        }
+      | {
+          type: "file"
+          mime: string
+          filename?: string
+          url: string
+          source?: FilePartSource
+        }
+    >
   }
 }
 

packages/sdk/js/src/v2/gen/types.gen.ts

@@ -241,6 +241,24 @@ export type EventTuiPromptAppend = {
   type: "tui.prompt.append"
   properties: {
     text: string
+    parts: Array<
+      | {
+          type: "agent"
+          name: string
+          source?: {
+            value: string
+            start: number
+            end: number
+          }
+        }
+      | {
+          type: "file"
+          mime: string
+          filename?: string
+          url: string
+          source?: FilePartSource
+        }
+    >
   }
 }