feat: send session prompt once

src/auto-reply/reply.ts

@@ -134,10 +134,13 @@ export async function getReplyFromConfig(
 	);
 	const sessionScope = sessionCfg?.scope ?? "per-sender";
 	const storePath = resolveStorePath(sessionCfg?.store);
+	let sessionStore: ReturnType<typeof loadSessionStore> | undefined;
+	let sessionKey: string | undefined;
 
 	let sessionId: string | undefined;
 	let isNewSession = false;
 	let bodyStripped: string | undefined;
+	let systemSent = false;
 
 	if (sessionCfg) {
 		const trimmedBody = (ctx.Body ?? "").trim();
@@ -156,21 +159,23 @@ export async function getReplyFromConfig(
 			}
 		}
 
-		const sessionKey = deriveSessionKey(sessionScope, ctx);
-		const store = loadSessionStore(storePath);
-		const entry = store[sessionKey];
+		sessionKey = deriveSessionKey(sessionScope, ctx);
+		sessionStore = loadSessionStore(storePath);
+		const entry = sessionStore[sessionKey];
 		const idleMs = idleMinutes * 60_000;
 		const freshEntry = entry && Date.now() - entry.updatedAt <= idleMs;
 
 		if (!isNewSession && freshEntry) {
 			sessionId = entry.sessionId;
+			systemSent = entry.systemSent ?? false;
 		} else {
 			sessionId = crypto.randomUUID();
 			isNewSession = true;
+			systemSent = false;
 		}
 
-		store[sessionKey] = { sessionId, updatedAt: Date.now() };
-		await saveSessionStore(storePath, store);
+		sessionStore[sessionKey] = { sessionId, updatedAt: Date.now(), systemSent };
+		await saveSessionStore(storePath, sessionStore);
 	}
 
 	const sessionCtx: TemplateContext = {
@@ -193,12 +198,43 @@ export async function getReplyFromConfig(
 	}
 
 	// Optional prefix injected before Body for templating/command prompts.
+	const sendSystemOnce = sessionCfg?.sendSystemOnce === true;
+	const isFirstTurnInSession = isNewSession || !systemSent;
+	const sessionIntro =
+		isFirstTurnInSession && sessionCfg?.sessionIntro
+			? applyTemplate(sessionCfg.sessionIntro, sessionCtx)
+			: "";
 	const bodyPrefix = reply?.bodyPrefix
 		? applyTemplate(reply.bodyPrefix, sessionCtx)
 		: "";
-	const prefixedBodyBase = bodyPrefix
-		? `${bodyPrefix}${sessionCtx.BodyStripped ?? sessionCtx.Body ?? ""}`
-		: (sessionCtx.BodyStripped ?? sessionCtx.Body);
+	const baseBody = sessionCtx.BodyStripped ?? sessionCtx.Body ?? "";
+	const prefixedBodyBase = (() => {
+		let body = baseBody;
+		if (!sendSystemOnce || isFirstTurnInSession) {
+			body = bodyPrefix ? `${bodyPrefix}${body}` : body;
+		}
+		if (sessionIntro) {
+			body = `${sessionIntro}\n\n${body}`;
+		}
+		return body;
+	})();
+	if (
+		sessionCfg &&
+		sendSystemOnce &&
+		isFirstTurnInSession &&
+		sessionStore &&
+		sessionKey
+	) {
+		sessionStore[sessionKey] = {
+			...(sessionStore[sessionKey] ?? {}),
+			sessionId: sessionId ?? crypto.randomUUID(),
+			updatedAt: Date.now(),
+			systemSent: true,
+		};
+		await saveSessionStore(storePath, sessionStore);
+		systemSent = true;
+	}
+
 	const prefixedBody =
 		transcribedText && reply?.mode === "command"
 			? [prefixedBodyBase, `Transcript:\n${transcribedText}`]
@@ -241,9 +277,10 @@ export async function getReplyFromConfig(
 	if (reply.mode === "command" && reply.command?.length) {
 		await onReplyStart();
 		let argv = reply.command.map((part) => applyTemplate(part, templatingCtx));
-		const templatePrefix = reply.template
-			? applyTemplate(reply.template, templatingCtx)
-			: "";
+		const templatePrefix =
+			reply.template && (!sendSystemOnce || isFirstTurnInSession || !systemSent)
+				? applyTemplate(reply.template, templatingCtx)
+				: "";
 		if (templatePrefix && argv.length > 0) {
 			argv = [argv[0], templatePrefix, ...argv.slice(1)];
 		}

src/config/config.ts

@@ -17,6 +17,8 @@ export type SessionConfig = {
 	sessionArgNew?: string[];
 	sessionArgResume?: string[];
 	sessionArgBeforeBody?: boolean;
+	sendSystemOnce?: boolean;
+	sessionIntro?: string;
 };
 
 export type LoggingConfig = {
@@ -73,6 +75,8 @@ const ReplySchema = z
 				sessionArgNew: z.array(z.string()).optional(),
 				sessionArgResume: z.array(z.string()).optional(),
 				sessionArgBeforeBody: z.boolean().optional(),
+				sendSystemOnce: z.boolean().optional(),
+				sessionIntro: z.string().optional(),
 			})
 			.optional(),
 		claudeOutputFormat: z

src/config/sessions.ts

@@ -8,7 +8,11 @@ import { CONFIG_DIR, normalizeE164 } from "../utils.js";
 
 export type SessionScope = "per-sender" | "global";
 
-export type SessionEntry = { sessionId: string; updatedAt: number };
+export type SessionEntry = {
+	sessionId: string;
+	updatedAt: number;
+	systemSent?: boolean;
+};
 
 export const SESSION_STORE_DEFAULT = path.join(CONFIG_DIR, "sessions.json");
 export const DEFAULT_RESET_TRIGGER = "/new";

src/index.core.test.ts

@@ -1,5 +1,6 @@
 import crypto from "node:crypto";
 import net from "node:net";
+import fs from "node:fs";
 import os from "node:os";
 import path from "node:path";
 import type { MessageInstance } from "twilio/lib/rest/api/v2010/account/message.js";
@@ -499,6 +500,64 @@ describe("config and templating", () => {
 		expect(argvSecond[2]).toBe("--resume");
 	});
 
+	it("only sends system prompt once per session when configured", async () => {
+		const tmpStore = path.join(os.tmpdir(), `warelay-store-${Date.now()}.json`);
+		vi.spyOn(crypto, "randomUUID").mockReturnValue("sid-1");
+		const runSpy = vi.spyOn(index, "runCommandWithTimeout").mockResolvedValue({
+			stdout: "ok\n",
+			stderr: "",
+			code: 0,
+			signal: null,
+			killed: false,
+		});
+		const cfg = {
+			inbound: {
+				reply: {
+					mode: "command" as const,
+					command: ["echo", "{{Body}}"],
+					template: "[tmpl]",
+					bodyPrefix: "[pfx] ",
+					session: {
+						sendSystemOnce: true,
+						sessionIntro: "SYS",
+						store: tmpStore,
+						sessionArgNew: ["--sid", "{{SessionId}}"],
+						sessionArgResume: ["--resume", "{{SessionId}}"],
+					},
+				},
+			},
+		};
+
+		await index.getReplyFromConfig(
+			{ Body: "/new hi", From: "+1", To: "+2" },
+			undefined,
+			cfg,
+			runSpy,
+		);
+		await index.getReplyFromConfig(
+			{ Body: "next", From: "+1", To: "+2" },
+			undefined,
+			cfg,
+			runSpy,
+		);
+
+		const firstArgv = runSpy.mock.calls[0][0];
+		expect(firstArgv).toEqual([
+			"echo",
+			"[tmpl]",
+			"--sid",
+			"sid-1",
+			"SYS\n\n[pfx] hi",
+		]);
+
+		const secondArgv = runSpy.mock.calls[1][0];
+		expect(secondArgv).toEqual(["echo", "--resume", "sid-1", "next"]);
+
+		const persisted = JSON.parse(fs.readFileSync(tmpStore, "utf-8"));
+		const firstEntry = Object.values(persisted)[0] as { systemSent?: boolean };
+		expect(firstEntry.systemSent).toBe(true);
+	});
+
 	it("injects Claude output format + print flag when configured", async () => {
 		const runSpy = vi.spyOn(index, "runCommandWithTimeout").mockResolvedValue({
 			stdout: "ok",