diff --git a/src/config/types.agent-defaults.ts b/src/config/types.agent-defaults.ts
index 9c6ce0211..478a86979 100644
--- a/src/config/types.agent-defaults.ts
+++ b/src/config/types.agent-defaults.ts
@@ -89,6 +89,10 @@ export type CliBackendConfig = {
   imageMode?: "repeat" | "list";
   /** Serialize runs for this CLI. */
   serialize?: boolean;
+  /** Directory where this CLI stores session transcripts (for reading history). */
+  transcriptDir?: string;
+  /** Pattern for transcript file names (use {sessionId} placeholder, defaults to {sessionId}.jsonl). */
+  transcriptPattern?: string;
 };
 
 export type AgentDefaultsConfig = {
diff --git a/src/config/zod-schema.core.ts b/src/config/zod-schema.core.ts
index 4a8c80bcc..f74564eea 100644
--- a/src/config/zod-schema.core.ts
+++ b/src/config/zod-schema.core.ts
@@ -266,6 +266,8 @@ export const CliBackendSchema = z
     imageArg: z.string().optional(),
     imageMode: z.union([z.literal("repeat"), z.literal("list")]).optional(),
     serialize: z.boolean().optional(),
+    transcriptDir: z.string().optional(),
+    transcriptPattern: z.string().optional(),
   })
   .strict();
 
diff --git a/src/gateway/server-chat.ts b/src/gateway/server-chat.ts
index 8c67767a6..ee9070c01 100644
--- a/src/gateway/server-chat.ts
+++ b/src/gateway/server-chat.ts
@@ -2,6 +2,7 @@ import { normalizeVerboseLevel } from "../auto-reply/thinking.js";
 import { loadConfig } from "../config/config.js";
 import { type AgentEventPayload, getAgentRunContext } from "../infra/agent-events.js";
 import { resolveHeartbeatVisibility } from "../infra/heartbeat-visibility.js";
+import { appendAssistantTranscriptEntry } from "./session-utils.fs.js";
 import { loadSessionEntry } from "./session-utils.js";
 import { formatForLog } from "./ws-log.js";
 
@@ -168,6 +169,22 @@ export function createAgentEventHandler({
     chatRunState.buffers.delete(clientRunId);
     chatRunState.deltaSentAt.delete(clientRunId);
     if (jobState === "done") {
+      // Write transcript for CLI provider runs (which don't write their own gateway transcripts)
+      if (text) {
+        try {
+          const { storePath, entry } = loadSessionEntry(sessionKey);
+          const sessionId = entry?.sessionId ?? clientRunId;
+          appendAssistantTranscriptEntry({
+            message: text,
+            sessionId,
+            storePath,
+            sessionFile: entry?.sessionFile,
+            createIfMissing: true,
+          });
+        } catch {
+          // Transcript write failure shouldn't block the response
+        }
+      }
       const payload = {
         runId: clientRunId,
         sessionKey,
diff --git a/src/gateway/session-utils.fs.test.ts b/src/gateway/session-utils.fs.test.ts
index 3cbbd4343..91835c637 100644
--- a/src/gateway/session-utils.fs.test.ts
+++ b/src/gateway/session-utils.fs.test.ts
@@ -3,9 +3,11 @@ import os from "node:os";
 import path from "node:path";
 import { afterEach, beforeEach, describe, expect, test } from "vitest";
 import {
+  appendAssistantTranscriptEntry,
   readFirstUserMessageFromTranscript,
   readLastMessagePreviewFromTranscript,
   readSessionPreviewItemsFromTranscript,
+  resolveSessionTranscriptCandidates,
 } from "./session-utils.fs.js";
 
 describe("readFirstUserMessageFromTranscript", () => {
@@ -404,3 +406,197 @@ describe("readSessionPreviewItemsFromTranscript", () => {
     expect(result[0]?.text.endsWith("...")).toBe(true);
   });
 });
+
+describe("appendAssistantTranscriptEntry", () => {
+  let tmpDir: string;
+  let storePath: string;
+
+  beforeEach(() => {
+    tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), "moltbot-append-test-"));
+    storePath = path.join(tmpDir, "sessions.json");
+  });
+
+  afterEach(() => {
+    fs.rmSync(tmpDir, { recursive: true, force: true });
+  });
+
+  test("creates transcript file when createIfMissing is true", () => {
+    const sessionId = "new-session-1";
+    const result = appendAssistantTranscriptEntry({
+      message: "Hello from assistant",
+      sessionId,
+      storePath,
+      createIfMissing: true,
+    });
+
+    expect(result.ok).toBe(true);
+    expect(result.messageId).toBeDefined();
+    expect(result.message).toBeDefined();
+    expect(result.message?.role).toBe("assistant");
+
+    const transcriptPath = path.join(tmpDir, `${sessionId}.jsonl`);
+    expect(fs.existsSync(transcriptPath)).toBe(true);
+
+    const content = fs.readFileSync(transcriptPath, "utf-8");
+    const lines = content.split("\n").filter(Boolean);
+    expect(lines.length).toBe(2); // header + message
+  });
+
+  test("fails when transcript does not exist and createIfMissing is false", () => {
+    const sessionId = "nonexistent-session";
+    const result = appendAssistantTranscriptEntry({
+      message: "Hello",
+      sessionId,
+      storePath,
+      createIfMissing: false,
+    });
+
+    expect(result.ok).toBe(false);
+    expect(result.error).toContain("not found");
+  });
+
+  test("appends to existing transcript file", () => {
+    const sessionId = "existing-session";
+    const transcriptPath = path.join(tmpDir, `${sessionId}.jsonl`);
+    const header = JSON.stringify({ type: "session", version: 1, id: sessionId });
+    fs.writeFileSync(transcriptPath, `${header}\n`, "utf-8");
+
+    const result = appendAssistantTranscriptEntry({
+      message: "New assistant message",
+      sessionId,
+      storePath,
+      createIfMissing: false,
+    });
+
+    expect(result.ok).toBe(true);
+
+    const content = fs.readFileSync(transcriptPath, "utf-8");
+    const lines = content.split("\n").filter(Boolean);
+    expect(lines.length).toBe(2);
+
+    const lastLine = JSON.parse(lines[1]);
+    expect(lastLine.message.role).toBe("assistant");
+    expect(lastLine.message.content[0].text).toBe("New assistant message");
+  });
+
+  test("includes label prefix when provided", () => {
+    const sessionId = "labeled-session";
+    const result = appendAssistantTranscriptEntry({
+      message: "Message content",
+      label: "webchat",
+      sessionId,
+      storePath,
+      createIfMissing: true,
+    });
+
+    expect(result.ok).toBe(true);
+    expect(result.message?.content[0].text).toContain("[webchat]");
+    expect(result.message?.content[0].text).toContain("Message content");
+  });
+
+  test("returns error when storePath is undefined and no sessionFile", () => {
+    const result = appendAssistantTranscriptEntry({
+      message: "Hello",
+      sessionId: "test",
+      storePath: undefined,
+      createIfMissing: true,
+    });
+
+    expect(result.ok).toBe(false);
+    expect(result.error).toContain("not resolved");
+  });
+});
+
+describe("resolveSessionTranscriptCandidates with CLI config", () => {
+  let tmpDir: string;
+
+  beforeEach(() => {
+    tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), "moltbot-candidates-test-"));
+  });
+
+  afterEach(() => {
+    fs.rmSync(tmpDir, { recursive: true, force: true });
+  });
+
+  test("includes CLI transcript path when cliConfig is provided", () => {
+    const sessionId = "cli-session";
+    const storePath = path.join(tmpDir, "sessions.json");
+
+    const candidates = resolveSessionTranscriptCandidates(
+      sessionId,
+      storePath,
+      undefined,
+      undefined,
+      {
+        transcriptDir: tmpDir,
+        transcriptPattern: "{sessionId}.jsonl",
+      },
+    );
+
+    expect(candidates).toContain(path.join(tmpDir, `${sessionId}.jsonl`));
+  });
+
+  test("uses default pattern when transcriptPattern is not provided", () => {
+    const sessionId = "default-pattern-session";
+    const storePath = path.join(tmpDir, "sessions.json");
+
+    const candidates = resolveSessionTranscriptCandidates(
+      sessionId,
+      storePath,
+      undefined,
+      undefined,
+      {
+        transcriptDir: tmpDir,
+      },
+    );
+
+    expect(candidates).toContain(path.join(tmpDir, `${sessionId}.jsonl`));
+  });
+
+  test("expands tilde in transcriptDir", () => {
+    const sessionId = "tilde-session";
+    const storePath = path.join(tmpDir, "sessions.json");
+    const homeDir = os.homedir();
+
+    const candidates = resolveSessionTranscriptCandidates(
+      sessionId,
+      storePath,
+      undefined,
+      undefined,
+      {
+        transcriptDir: "~/.test-cli-logs",
+      },
+    );
+
+    const expectedPath = path.join(homeDir, ".test-cli-logs", `${sessionId}.jsonl`);
+    expect(candidates).toContain(expectedPath);
+  });
+
+  test("does not add CLI path when cliConfig is undefined", () => {
+    const sessionId = "no-cli-session";
+    const storePath = path.join(tmpDir, "sessions.json");
+
+    const candidates = resolveSessionTranscriptCandidates(sessionId, storePath);
+
+    // Should only have storePath-derived path and default clawdbot path
+    expect(candidates.length).toBe(2);
+  });
+
+  test("supports custom transcript pattern", () => {
+    const sessionId = "custom-pattern";
+    const storePath = path.join(tmpDir, "sessions.json");
+
+    const candidates = resolveSessionTranscriptCandidates(
+      sessionId,
+      storePath,
+      undefined,
+      undefined,
+      {
+        transcriptDir: tmpDir,
+        transcriptPattern: "logs-{sessionId}.json",
+      },
+    );
+
+    expect(candidates).toContain(path.join(tmpDir, `logs-${sessionId}.json`));
+  });
+});
diff --git a/src/gateway/session-utils.fs.ts b/src/gateway/session-utils.fs.ts
index d6453ace6..97f42888f 100644
--- a/src/gateway/session-utils.fs.ts
+++ b/src/gateway/session-utils.fs.ts
@@ -1,7 +1,9 @@
+import { randomUUID } from "node:crypto";
 import fs from "node:fs";
 import os from "node:os";
 import path from "node:path";
 
+import { CURRENT_SESSION_VERSION } from "@mariozechner/pi-coding-agent";
 import { resolveSessionTranscriptPath } from "../config/sessions.js";
 import { stripEnvelope } from "./chat-sanitize.js";
 import type { SessionPreviewItem } from "./session-utils.types.js";
@@ -32,11 +34,17 @@ export function readSessionMessages(
   return messages;
 }
 
+export type CliTranscriptConfig = {
+  transcriptDir?: string;
+  transcriptPattern?: string;
+};
+
 export function resolveSessionTranscriptCandidates(
   sessionId: string,
   storePath: string | undefined,
   sessionFile?: string,
   agentId?: string,
+  cliConfig?: CliTranscriptConfig,
 ): string[] {
   const candidates: string[] = [];
   if (sessionFile) candidates.push(sessionFile);
@@ -47,6 +55,15 @@ export function resolveSessionTranscriptCandidates(
   if (agentId) {
     candidates.push(resolveSessionTranscriptPath(sessionId, agentId));
   }
+  // Check CLI-configured transcript location if provided
+  if (cliConfig?.transcriptDir) {
+    const pattern = cliConfig.transcriptPattern ?? "{sessionId}.jsonl";
+    const fileName = pattern.replace("{sessionId}", sessionId);
+    const expandedDir = cliConfig.transcriptDir.startsWith("~")
+      ? path.join(os.homedir(), cliConfig.transcriptDir.slice(1))
+      : cliConfig.transcriptDir;
+    candidates.push(path.join(expandedDir, fileName));
+  }
   candidates.push(path.join(os.homedir(), ".clawdbot", "sessions", `${sessionId}.jsonl`));
   return candidates;
 }
@@ -58,6 +75,101 @@ export function archiveFileOnDisk(filePath: string, reason: string): string {
   return archived;
 }
 
+export type TranscriptAppendResult = {
+  ok: boolean;
+  messageId?: string;
+  message?: Record<string, unknown>;
+  error?: string;
+};
+
+function resolveTranscriptWritePath(params: {
+  sessionId: string;
+  storePath: string | undefined;
+  sessionFile?: string;
+}): string | null {
+  const { sessionId, storePath, sessionFile } = params;
+  if (sessionFile) return sessionFile;
+  if (!storePath) return null;
+  return path.join(path.dirname(storePath), `${sessionId}.jsonl`);
+}
+
+function ensureTranscriptFile(params: { transcriptPath: string; sessionId: string }): {
+  ok: boolean;
+  error?: string;
+} {
+  if (fs.existsSync(params.transcriptPath)) return { ok: true };
+  try {
+    fs.mkdirSync(path.dirname(params.transcriptPath), { recursive: true });
+    const header = {
+      type: "session",
+      version: CURRENT_SESSION_VERSION,
+      id: params.sessionId,
+      timestamp: new Date().toISOString(),
+      cwd: process.cwd(),
+    };
+    fs.writeFileSync(params.transcriptPath, `${JSON.stringify(header)}\n`, "utf-8");
+    return { ok: true };
+  } catch (err) {
+    return { ok: false, error: err instanceof Error ? err.message : String(err) };
+  }
+}
+
+export function appendAssistantTranscriptEntry(params: {
+  message: string;
+  label?: string;
+  sessionId: string;
+  storePath: string | undefined;
+  sessionFile?: string;
+  createIfMissing?: boolean;
+}): TranscriptAppendResult {
+  const transcriptPath = resolveTranscriptWritePath({
+    sessionId: params.sessionId,
+    storePath: params.storePath,
+    sessionFile: params.sessionFile,
+  });
+  if (!transcriptPath) {
+    return { ok: false, error: "transcript path not resolved" };
+  }
+
+  if (!fs.existsSync(transcriptPath)) {
+    if (!params.createIfMissing) {
+      return { ok: false, error: "transcript file not found" };
+    }
+    const ensured = ensureTranscriptFile({
+      transcriptPath,
+      sessionId: params.sessionId,
+    });
+    if (!ensured.ok) {
+      return { ok: false, error: ensured.error ?? "failed to create transcript file" };
+    }
+  }
+
+  const now = Date.now();
+  const messageId = randomUUID().slice(0, 8);
+  const labelPrefix = params.label ? `[${params.label}]\n\n` : "";
+  const messageBody: Record<string, unknown> = {
+    role: "assistant",
+    content: [{ type: "text", text: `${labelPrefix}${params.message}` }],
+    timestamp: now,
+    stopReason: "injected",
+    usage: { input: 0, output: 0, totalTokens: 0 },
+  };
+  const transcriptEntry = {
+    type: "message",
+    id: messageId,
+    timestamp: new Date(now).toISOString(),
+    message: messageBody,
+  };
+
+  try {
+    fs.appendFileSync(transcriptPath, `${JSON.stringify(transcriptEntry)}\n`, "utf-8");
+  } catch (err) {
+    return { ok: false, error: err instanceof Error ? err.message : String(err) };
+  }
+
+  return { ok: true, messageId, message: transcriptEntry.message };
+}
+
 function jsonUtf8Bytes(value: unknown): number {
   try {
     return Buffer.byteLength(JSON.stringify(value), "utf8");
diff --git a/src/gateway/session-utils.ts b/src/gateway/session-utils.ts
index 164be999e..24add4376 100644
--- a/src/gateway/session-utils.ts
+++ b/src/gateway/session-utils.ts
@@ -34,6 +34,7 @@ import type {
 } from "./session-utils.types.js";
 
 export {
+  appendAssistantTranscriptEntry,
   archiveFileOnDisk,
   capArrayByJsonBytes,
   readFirstUserMessageFromTranscript,
@@ -42,6 +43,7 @@ export {
   readSessionMessages,
   resolveSessionTranscriptCandidates,
 } from "./session-utils.fs.js";
+export type { CliTranscriptConfig, TranscriptAppendResult } from "./session-utils.fs.js";
 export type {
   GatewayAgentRow,
   GatewaySessionRow,