feat: support reference file mentions

packages/app/src/components/prompt-input.tsx

@@ -564,6 +564,9 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
       .filter((agent) => !agent.hidden && agent.mode !== "primary")
       .map((agent): AtOption => ({ type: "agent", name: agent.name, display: agent.name })),
   )
+  const referenceAgentNames = createMemo(() =>
+    sync.data.agent.filter((agent) => agent.options.reference !== undefined).map((agent) => agent.name),
+  )
   const agentNames = createMemo(() => local.agent.list().map((agent) => agent.name))
 
   const handleAtSelect = (option: AtOption | undefined) => {
@@ -589,6 +592,9 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
   } = useFilteredList<AtOption>({
     items: async (query) => {
       const agents = agentList()
+      const reference = referenceAgentNames().find(
+        (name) => query.startsWith(`${name}:/`) || query.startsWith(`${name}/`),
+      )
       const open = recent()
       const seen = new Set(open)
       const pinned: AtOption[] = open.map((path) => ({ type: "file", path, display: path, recent: true }))
@@ -597,6 +603,7 @@ export const PromptInput: Component<PromptInputProps> = (props) => {
       const fileOptions: AtOption[] = paths
         .filter((path) => !seen.has(path))
         .map((path) => ({ type: "file", path, display: path }))
+      if (reference) return fileOptions
       return [...agents, ...pinned, ...fileOptions]
     },
     key: atKey,

packages/app/src/components/prompt-input/build-request-parts.test.ts

@@ -124,6 +124,33 @@ describe("buildRequestParts", () => {
     expect(files.some((part) => part.type === "file" && part.url === "file:///repo/src/shared.ts")).toBe(true)
   })
 
+  test("builds reference file URLs for configured repo paths", () => {
+    const result = buildRequestParts({
+      prompt: [{ type: "file", path: "effect:/src/Effect.ts", content: "@effect:/src/Effect.ts", start: 0, end: 22 }],
+      context: [
+        {
+          key: "ctx:reference-comment",
+          type: "file",
+          path: "src/review.ts",
+          comment: "Compare with @effect:/src/Context.ts.",
+        },
+      ],
+      images: [],
+      text: "@effect:/src/Effect.ts",
+      messageID: "msg_reference",
+      sessionID: "ses_reference",
+      sessionDirectory: "/repo",
+    })
+
+    const files = result.requestParts.filter((part) => part.type === "file")
+    expect(files.some((part) => part.type === "file" && part.url === "opencode-reference://effect/src/Effect.ts")).toBe(
+      true,
+    )
+    expect(
+      files.some((part) => part.type === "file" && part.url === "opencode-reference://effect/src/Context.ts"),
+    ).toBe(true)
+  })
+
   test("handles Windows paths correctly (simulated on macOS)", () => {
     const prompt: Prompt = [{ type: "file", path: "src\\foo.ts", content: "@src\\foo.ts", start: 0, end: 11 }]
 

packages/app/src/components/prompt-input/build-request-parts.ts

@@ -41,6 +41,22 @@ const fileQuery = (selection: FileSelection | undefined) =>
 
 const mention = /(^|[\s([{"'])@(\S+)/g
 
+const referencePath = (value: string) => {
+  const match = value.match(/^([^:/\\]+):\/(.*)$/)
+  if (!match) return
+  if (/^[A-Za-z]$/.test(match[1]!)) return
+  return { name: match[1]!, path: match[2] ?? "" }
+}
+
+const referenceUrl = (value: string, selection?: FileSelection) => {
+  const reference = referencePath(value)
+  if (!reference) return
+  return `opencode-reference://${encodeURIComponent(reference.name)}/${reference.path
+    .split("/")
+    .map(encodeURIComponent)
+    .join("/")}${fileQuery(selection)}`
+}
+
 const parseCommentMentions = (comment: string) => {
   return Array.from(comment.matchAll(mention)).flatMap((match) => {
     const path = (match[2] ?? "").replace(/[.,!?;:)}\]"']+$/, "")
@@ -97,25 +113,34 @@ export function buildRequestParts(input: BuildRequestPartsInput) {
     },
   ]
 
-  const files = input.prompt.filter(isFileAttachment).map((attachment) => {
-    const path = absolute(input.sessionDirectory, attachment.path)
+  const filePart = (file: string, selection?: FileSelection, source?: FileAttachmentPart) => {
+    const url = referenceUrl(file, selection)
+    const filepath = url ? file : absolute(input.sessionDirectory, file)
     return {
       id: Identifier.ascending("part"),
       type: "file",
       mime: "text/plain",
-      url: `file://${encodeFilePath(path)}${fileQuery(attachment.selection)}`,
-      filename: getFilename(attachment.path),
-      source: {
-        type: "file",
-        text: {
-          value: attachment.content,
-          start: attachment.start,
-          end: attachment.end,
-        },
-        path,
-      },
+      url: url ?? `file://${encodeFilePath(filepath)}${fileQuery(selection)}`,
+      filename: getFilename(file),
+      ...(source
+        ? {
+            source: {
+              type: "file" as const,
+              text: {
+                value: source.content,
+                start: source.start,
+                end: source.end,
+              },
+              path: filepath,
+            },
+          }
+        : {}),
     } satisfies PromptRequestPart
-  })
+  }
+
+  const files = input.prompt
+    .filter(isFileAttachment)
+    .map((attachment) => filePart(attachment.path, attachment.selection, attachment))
 
   const agents = input.prompt.filter(isAgentAttachment).map((attachment) => {
     return {
@@ -133,34 +158,20 @@ export function buildRequestParts(input: BuildRequestPartsInput) {
   const used = new Set(files.map((part) => part.url))
   const context = input.context.flatMap((item) => {
     const path = absolute(input.sessionDirectory, item.path)
-    const url = `file://${encodeFilePath(path)}${fileQuery(item.selection)}`
+    const url = referenceUrl(item.path, item.selection) ?? `file://${encodeFilePath(path)}${fileQuery(item.selection)}`
     const comment = item.comment?.trim()
     if (!comment && used.has(url)) return []
     used.add(url)
 
-    const filePart = {
-      id: Identifier.ascending("part"),
-      type: "file",
-      mime: "text/plain",
-      url,
-      filename: getFilename(item.path),
-    } satisfies PromptRequestPart
+    const contextFilePart = filePart(item.path, item.selection)
 
-    if (!comment) return [filePart]
+    if (!comment) return [contextFilePart]
 
     const mentions = parseCommentMentions(comment).flatMap((path) => {
-      const url = `file://${encodeFilePath(absolute(input.sessionDirectory, path))}`
+      const url = referenceUrl(path) ?? `file://${encodeFilePath(absolute(input.sessionDirectory, path))}`
       if (used.has(url)) return []
       used.add(url)
-      return [
-        {
-          id: Identifier.ascending("part"),
-          type: "file",
-          mime: "text/plain",
-          url,
-          filename: getFilename(path),
-        } satisfies PromptRequestPart,
-      ]
+      return [filePart(path)]
     })
 
     return [
@@ -177,7 +188,7 @@ export function buildRequestParts(input: BuildRequestPartsInput) {
           origin: item.commentOrigin,
         }),
       } satisfies PromptRequestPart,
-      filePart,
+      contextFilePart,
       ...mentions,
     ]
   })