From 107935dc512a43ae415a716963728de1d885b4c3 Mon Sep 17 00:00:00 2001
From: Rai Butera <rai@rbutera.com>
Date: Mon, 9 Mar 2026 14:40:32 +0000
Subject: [PATCH] fix(discord): preserve fast-path chunk settings

---
 src/discord/monitor/reply-delivery.test.ts | 20 ++++++++++++++++++++
 src/discord/monitor/reply-delivery.ts      | 19 ++++++++++++++++++-
 2 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/src/discord/monitor/reply-delivery.test.ts b/src/discord/monitor/reply-delivery.test.ts
index 3274a669cf2..8b19372cdfe 100644
--- a/src/discord/monitor/reply-delivery.test.ts
+++ b/src/discord/monitor/reply-delivery.test.ts
@@ -256,6 +256,26 @@ describe("deliverDiscordReply", () => {
     expect(sendDiscordTextMock.mock.calls[1]?.[1]).toBe("789");
   });
 
+  it("passes maxLinesPerMessage and chunkMode through the fast path", async () => {
+    const fakeRest = {} as import("@buape/carbon").RequestClient;
+
+    await deliverDiscordReply({
+      replies: [{ text: Array.from({ length: 18 }, (_, index) => `line ${index + 1}`).join("\n") }],
+      target: "channel:789",
+      token: "token",
+      rest: fakeRest,
+      runtime,
+      textLimit: 2000,
+      maxLinesPerMessage: 120,
+      chunkMode: "newline",
+    });
+
+    expect(sendMessageDiscordMock).not.toHaveBeenCalled();
+    expect(sendDiscordTextMock).toHaveBeenCalledTimes(1);
+    expect(sendDiscordTextMock.mock.calls[0]?.[5]).toBe(120);
+    expect(sendDiscordTextMock.mock.calls[0]?.[8]).toBe("newline");
+  });
+
   it("falls back to sendMessageDiscord when rest is not provided", async () => {
     await deliverDiscordReply({
       replies: [{ text: "single chunk" }],
diff --git a/src/discord/monitor/reply-delivery.ts b/src/discord/monitor/reply-delivery.ts
index 11fc1733ef1..d3e7ef9bf61 100644
--- a/src/discord/monitor/reply-delivery.ts
+++ b/src/discord/monitor/reply-delivery.ts
@@ -130,9 +130,11 @@ async function sendDiscordChunkWithFallback(params: {
   text: string;
   token: string;
   accountId?: string;
+  maxLinesPerMessage?: number;
   rest?: RequestClient;
   replyTo?: string;
   binding?: DiscordThreadBindingLookupRecord;
+  chunkMode?: ChunkMode;
   username?: string;
   avatarUrl?: string;
   /** Pre-resolved channel ID to bypass redundant resolution per chunk. */
@@ -169,7 +171,18 @@ async function sendDiscordChunkWithFallback(params: {
   if (params.channelId && params.request && params.rest) {
     const { channelId, request, rest } = params;
     await sendWithRetry(
-      () => sendDiscordText(rest, channelId, text, params.replyTo, request),
+      () =>
+        sendDiscordText(
+          rest,
+          channelId,
+          text,
+          params.replyTo,
+          request,
+          params.maxLinesPerMessage,
+          undefined,
+          undefined,
+          params.chunkMode,
+        ),
       params.retryConfig,
     );
     return;
@@ -294,8 +307,10 @@ export async function deliverDiscordReply(params: {
           token: params.token,
           rest: params.rest,
           accountId: params.accountId,
+          maxLinesPerMessage: params.maxLinesPerMessage,
           replyTo,
           binding,
+          chunkMode: params.chunkMode,
           username: persona.username,
           avatarUrl: persona.avatarUrl,
           channelId,
@@ -329,8 +344,10 @@ export async function deliverDiscordReply(params: {
         token: params.token,
         rest: params.rest,
         accountId: params.accountId,
+        maxLinesPerMessage: params.maxLinesPerMessage,
         replyTo: resolveReplyTo(),
         binding,
+        chunkMode: params.chunkMode,
         username: persona.username,
         avatarUrl: persona.avatarUrl,
         channelId,