fix: link only the repo head in message titles, keep the subject plain

AGENTS.md

@@ -136,9 +136,14 @@ tests/                   # bun test unit tests (webhook, formatter, discord, tel
 
 ## Message Format Spec
 
-- Every embed title must start with the repo, then optional `#number`, then `: subject`:
+- Every message title must start with the repo, then optional `#number`, then `: subject`:
   `{repo}{#number}: {subject}` (e.g. `acme/widget#7: Add feature`). Repo comes from
   `payload.repository.full_name`; fall back to `t("common.repository")` when missing.
+- Only the repo head is hyperlinked (never the whole title). Drivers split the title via
+  `splitMessageTitle`/`repoUrlFromMessage` (`server/lib/formatters/helpers.ts`): the Discord
+  embed title is `{repo}{#number}` linked to the repository URL and `: {subject}` renders as
+  the first description line; Telegram keeps the one-line title with an inline repo link and
+  a plain subject. Messages without a `: ` separator keep the legacy whole-title link.
 - Do NOT use `"Comment on org/repo"` / `"Review on org/repo"` prefixes. Comments, reviews
   and inline comments use the same `{repo}{#number}: {title}` title as their parent object.
 - All event-specific emoji live in `server/lib/formatters/` (via the `emojiPrefix` helper), never in

server/lib/drivers/discord/render.ts

@@ -1,4 +1,5 @@
 import type { FormattedMessage, NeutralActionStyle, NeutralMessage } from "../../types";
+import { repoUrlFromMessage, splitMessageTitle } from "../../formatters/helpers";
 
 function toStyle(style: NeutralActionStyle): number {
   switch (style) {
@@ -15,14 +16,26 @@ export function renderNeutralMessage(message: NeutralMessage): FormattedMessage
   const content = message.mentionRoleIds?.length
     ? message.mentionRoleIds.map((id) => `<@&${id}>`).join(" ")
     : undefined;
+
+  // Discord embed titles can only be linked as a whole, so only the repo head
+  // goes into the title (linked to the repository); the `: subject` text is
+  // rendered as the first line of the description, unlinked.
+  const { head, subject } = splitMessageTitle(message.title);
+  const repoUrl = repoUrlFromMessage(message.url);
+  const description = subject
+    ? message.description
+      ? `${subject}\n${message.description}`
+      : subject
+    : message.description;
+
   return {
     content,
     embeds: [
       {
-        title: message.title,
-        url: message.url,
+        title: head,
+        url: subject ? repoUrl : message.url,
         color: message.color,
-        description: message.description,
+        description,
         author: message.author
           ? {
               name: message.author.name,

server/lib/drivers/telegram/render.ts

@@ -1,4 +1,5 @@
 import type { NeutralMessage } from "../../types";
+import { repoUrlFromMessage, splitMessageTitle } from "../../formatters/helpers";
 
 function esc(s: string): string {
   return s
@@ -32,10 +33,16 @@ function formatTimestamp(ts?: string): string {
 export function renderNeutralMessage(message: NeutralMessage): string {
   const parts: string[] = [];
 
-  const title = message.url
-    ? `<a href="${esc(message.url)}">${mdToHtml(message.title)}</a>`
-    : mdToHtml(message.title);
-  parts.push(`<b>${title}</b>`);
+  // HTML allows partial links, so keep the `{repo}{#number}: {subject}` line
+  // intact with only the repo head linked (the subject stays plain text).
+  const { head, subject } = splitMessageTitle(message.title);
+  const repoUrl = repoUrlFromMessage(message.url);
+  const title = subject
+    ? `<b>${repoUrl ? `<a href="${esc(repoUrl)}">${mdToHtml(head)}</a>` : mdToHtml(head)}: ${mdToHtml(subject)}</b>`
+    : message.url
+      ? `<b><a href="${esc(message.url)}">${mdToHtml(message.title)}</a></b>`
+      : `<b>${mdToHtml(message.title)}</b>`;
+  parts.push(title);
 
   if (message.author) {
     const name = mdToHtml(message.author.name);

server/lib/formatters/helpers.ts

@@ -12,6 +12,42 @@ export function makeT(tr?: Translations): T {
   return (key, params) => translate(key, params, undefined, tr);
 }
 
+export interface TitleParts {
+  /** `{repo}` or `{repo}#{number}` — what embed titles link (the repo). */
+  head: string;
+  /** Text after `": "`, undefined when the title has no `: ` separator. */
+  subject?: string;
+}
+
+/**
+ * Split a `{repo}{#number}: {subject}` title into the repo head and the
+ * subject. Discord embed titles can only link as a whole, so drivers render
+ * the head as the linked title and the subject as plain text (description /
+ * unlinked remainder) to avoid hyperlinking the whole title.
+ */
+export function splitMessageTitle(title: string): TitleParts {
+  const idx = title.indexOf(": ");
+  if (idx <= 0) return { head: title };
+  return { head: title.slice(0, idx), subject: title.slice(idx + 2) };
+}
+
+/**
+ * Repository URL derived from an event URL (origin + owner + repo). Returns
+ * undefined when there is no URL to derive from — callers then render the
+ * title without a link.
+ */
+export function repoUrlFromMessage(url: string | undefined): string | undefined {
+  if (!url) return undefined;
+  try {
+    const parsed = new URL(url);
+    const segments = parsed.pathname.split("/").filter(Boolean);
+    if (segments.length >= 2) return `${parsed.origin}/${segments[0]}/${segments[1]}`;
+  } catch {
+    // not a parseable URL — no link
+  }
+  return undefined;
+}
+
 export function buildMessage(
   partial: Omit<Partial<NeutralMessage>, "title"> & { title: string },
   t: T,

tests/discord.test.ts

@@ -309,7 +309,8 @@ describe("dispatchEvent fallback routing", () => {
     const logBody = JSON.parse(sent[1]!.body) as {
       embeds?: Array<{ title?: string; color?: number; fields?: Array<{ value: string }> }>;
     };
-    expect(logBody.embeds?.[0]?.title).toBe("owner/repo: push");
+    expect(logBody.embeds?.[0]?.title).toBe("owner/repo");
+    expect(logBody.embeds?.[0]?.description).toContain("push");
     expect(logBody.embeds?.[0]?.color).toBe(0x3fb950);
     expect(logBody.embeds?.[0]?.fields?.[0]?.value).toContain("✅ Push Route → 111");
     expect(logBody.embeds?.[0]?.fields?.[1]?.value).toBe("deliv-1");
@@ -460,8 +461,6 @@ describe("dispatchEvent fallback routing", () => {
       const parsed = JSON.parse(b) as { embeds?: Array<{ title?: string }> };
       return parsed.embeds?.[0]?.title ?? "";
     });
-    expect(titles.sort()).toEqual(
-      ["owner/repo: 推送了 1 个提交", "owner/repo: Pushed 1 commit"].sort(),
-    );
+    expect(titles.sort()).toEqual(["owner/repo", "owner/repo"].sort());
   });
 });

tests/telegram.test.ts

@@ -25,7 +25,7 @@ describe("telegram renderNeutralMessage", () => {
     };
     const out = renderNeutralMessage(message);
     expect(out).toContain(
-      '<b><a href="https://github.com/acme/widget">acme/widget: Add feature</a></b>',
+      '<b><a href="https://github.com/acme/widget">acme/widget</a>: Add feature</b>',
     );
     expect(out).toContain("<b>Status</b>: success");
     expect(out).toContain("<i>acme/widget</i>");

tests/webhook-tenant.test.ts

@@ -236,9 +236,9 @@ describe("processWebhook", () => {
     const parsed = JSON.parse(sent[0]!.body) as {
       embeds?: Array<{ title?: string; color?: number; description?: string }>;
     };
-    expect(parsed.embeds?.[0]?.title).toBe("acme/widget: Deploy failed");
+    expect(parsed.embeds?.[0]?.title).toBe("acme/widget");
     expect(parsed.embeds?.[0]?.color).toBe(0xf85149);
-    expect(parsed.embeds?.[0]?.description).toBe("prod down");
+    expect(parsed.embeds?.[0]?.description).toBe("Deploy failed\nprod down");
   });
 
   it("rejects custom webhooks without a signature header", async () => {