fix(auto-reply): tighten block streaming defaults

src/agents/pi-embedded-block-chunker.ts

@@ -53,6 +53,14 @@ export class EmbeddedBlockChunker {
     const maxChars = Math.max(minChars, Math.floor(this.#chunking.maxChars));
     if (this.#buffer.length < minChars && !force) return;
 
+    if (force && this.#buffer.length <= maxChars) {
+      if (this.#buffer.trim().length > 0) {
+        emit(this.#buffer);
+      }
+      this.#buffer = "";
+      return;
+    }
+
     while (
       this.#buffer.length >= minChars ||
       (force && this.#buffer.length > 0)

src/agents/pi-embedded-subscribe.test.ts

@@ -784,7 +784,7 @@ describe("subscribeEmbeddedPiSession", () => {
       blockReplyBreak: "message_end",
       blockReplyChunking: {
         minChars: 5,
-        maxChars: 40,
+        maxChars: 25,
         breakPreference: "paragraph",
       },
     });
@@ -836,7 +836,7 @@ describe("subscribeEmbeddedPiSession", () => {
       blockReplyBreak: "message_end",
       blockReplyChunking: {
         minChars: 5,
-        maxChars: 50,
+        maxChars: 25,
         breakPreference: "paragraph",
       },
     });
@@ -939,7 +939,7 @@ describe("subscribeEmbeddedPiSession", () => {
       blockReplyBreak: "message_end",
       blockReplyChunking: {
         minChars: 5,
-        maxChars: 40,
+        maxChars: 25,
         breakPreference: "paragraph",
       },
     });
@@ -986,7 +986,7 @@ describe("subscribeEmbeddedPiSession", () => {
       blockReplyBreak: "message_end",
       blockReplyChunking: {
         minChars: 5,
-        maxChars: 45,
+        maxChars: 30,
         breakPreference: "paragraph",
       },
     });
@@ -1035,7 +1035,7 @@ describe("subscribeEmbeddedPiSession", () => {
       blockReplyBreak: "message_end",
       blockReplyChunking: {
         minChars: 10,
-        maxChars: 50,
+        maxChars: 30,
         breakPreference: "paragraph",
       },
     });

src/auto-reply/reply.ts

@@ -470,20 +470,26 @@ export async function getReplyFromConfig(
       (agentCfg?.elevatedDefault as ElevatedLevel | undefined) ??
       "on")
     : "off";
+  const providerKey = sessionCtx.Provider?.trim().toLowerCase();
+  const explicitBlockStreamingEnable = opts?.disableBlockStreaming === false;
   const resolvedBlockStreaming =
     opts?.disableBlockStreaming === true
       ? "off"
       : opts?.disableBlockStreaming === false
         ? "on"
-        : agentCfg?.blockStreamingDefault === "off"
-          ? "off"
-          : "on";
+        : agentCfg?.blockStreamingDefault === "on"
+          ? "on"
+          : "off";
   const resolvedBlockStreamingBreak: "text_end" | "message_end" =
     agentCfg?.blockStreamingBreak === "message_end"
       ? "message_end"
       : "text_end";
+  const allowBlockStreaming =
+    providerKey === "telegram" || explicitBlockStreamingEnable;
   const blockStreamingEnabled =
-    resolvedBlockStreaming === "on" && opts?.disableBlockStreaming !== true;
+    resolvedBlockStreaming === "on" &&
+    opts?.disableBlockStreaming !== true &&
+    allowBlockStreaming;
   const blockReplyChunking = blockStreamingEnabled
     ? resolveBlockStreamingChunking(
         cfg,

src/auto-reply/reply/block-streaming.ts

@@ -5,6 +5,13 @@ import { resolveTextChunkLimit, type TextChunkProvider } from "../chunk.js";
 const DEFAULT_BLOCK_STREAM_MIN = 800;
 const DEFAULT_BLOCK_STREAM_MAX = 1200;
 const DEFAULT_BLOCK_STREAM_COALESCE_IDLE_MS = 1000;
+const PROVIDER_COALESCE_DEFAULTS: Partial<
+  Record<TextChunkProvider, { minChars: number; idleMs: number }>
+> = {
+  signal: { minChars: 1500, idleMs: 1000 },
+  slack: { minChars: 1500, idleMs: 1000 },
+  discord: { minChars: 1500, idleMs: 1000 },
+};
 
 const BLOCK_CHUNK_PROVIDERS = new Set<TextChunkProvider>([
   "whatsapp",
@@ -77,6 +84,9 @@ export function resolveBlockStreamingCoalescing(
   const providerKey = normalizeChunkProvider(provider);
   const textLimit = resolveTextChunkLimit(cfg, providerKey, accountId);
   const normalizedAccountId = normalizeAccountId(accountId);
+  const providerDefaults = providerKey
+    ? PROVIDER_COALESCE_DEFAULTS[providerKey]
+    : undefined;
   const providerCfg = (() => {
     if (!cfg || !providerKey) return undefined;
     if (providerKey === "whatsapp") {
@@ -125,7 +135,10 @@ export function resolveBlockStreamingCoalescing(
   const minRequested = Math.max(
     1,
     Math.floor(
-      coalesceCfg?.minChars ?? chunking?.minChars ?? DEFAULT_BLOCK_STREAM_MIN,
+      coalesceCfg?.minChars ??
+        providerDefaults?.minChars ??
+        chunking?.minChars ??
+        DEFAULT_BLOCK_STREAM_MIN,
     ),
   );
   const maxRequested = Math.max(
@@ -136,7 +149,11 @@ export function resolveBlockStreamingCoalescing(
   const minChars = Math.min(minRequested, maxChars);
   const idleMs = Math.max(
     0,
-    Math.floor(coalesceCfg?.idleMs ?? DEFAULT_BLOCK_STREAM_COALESCE_IDLE_MS),
+    Math.floor(
+      coalesceCfg?.idleMs ??
+        providerDefaults?.idleMs ??
+        DEFAULT_BLOCK_STREAM_COALESCE_IDLE_MS,
+    ),
   );
   const preference = chunking?.breakPreference ?? "paragraph";
   const joiner =

src/config/schema.ts

@@ -116,7 +116,7 @@ const FIELD_LABELS: Record<string, string> = {
   "talk.apiKey": "Talk API Key",
   "telegram.botToken": "Telegram Bot Token",
   "telegram.dmPolicy": "Telegram DM Policy",
-  "telegram.streamMode": "Telegram Stream Mode",
+  "telegram.streamMode": "Telegram Draft Stream Mode",
   "telegram.retry.attempts": "Telegram Retry Attempts",
   "telegram.retry.minDelayMs": "Telegram Retry Min Delay (ms)",
   "telegram.retry.maxDelayMs": "Telegram Retry Max Delay (ms)",
@@ -193,7 +193,7 @@ const FIELD_HELP: Record<string, string> = {
   "telegram.dmPolicy":
     'Direct message access control ("pairing" recommended). "open" requires telegram.allowFrom=["*"].',
   "telegram.streamMode":
-    "Draft streaming mode for Telegram replies (off | partial | block). Requires private topics + sendMessageDraft.",
+    "Draft streaming mode for Telegram replies (off | partial | block). Separate from block streaming; requires private topics + sendMessageDraft.",
   "telegram.retry.attempts":
     "Max retry attempts for outbound Telegram API calls (default: 3).",
   "telegram.retry.minDelayMs":