fix: use stream-json output for Claude CLI backend to prevent watchdog timeouts

The Claude CLI backend uses `--output-format json`, which produces no
stdout until the entire request completes. When session context is large
(100K+ tokens) or API response is slow, the no-output watchdog timer
(max 180s for resume sessions) kills the process before it finishes,
resulting in "CLI produced no output for 180s and was terminated" errors.

Switch to `--output-format stream-json --verbose` so Claude CLI emits
NDJSON events throughout processing (init, assistant, rate_limit, result).
Each event resets the watchdog timer, which is the intended behavior —
the watchdog detects truly stuck processes, not slow-but-progressing ones.

Changes:
- cli-backends.ts: `json` → `stream-json --verbose`, `output: "jsonl"`
- helpers.ts: teach parseCliJsonl to extract text from Claude's
  `{"type":"result","result":"..."}` NDJSON line

Note: `--verbose` is required for stream-json in `-p` (print) mode.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -38,6 +38,7 @@ Docs: https://docs.openclaw.ai
 - CLI/onboarding: show the Kimi Code API key option again in the Moonshot setup menu so the interactive picker includes all Kimi setup paths together. Fixes #54412 Thanks @sparkyrider
 - Agents/status: use provider-aware context window lookup for fresh Anthropic 4.6 model overrides so `/status` shows the correct 1.0m window instead of an underreported shared-cache minimum. (#54796) Thanks @neeravmakwana.
 - Agents/errors: surface provider quota/reset details when available, but keep HTML/Cloudflare rate-limit pages on the generic fallback so raw error pages are not shown to users. (#54512) Thanks @bugkill3r.
+- Claude CLI: switch the bundled Claude CLI backend to `stream-json` output so watchdogs see progress on long runs, and keep session/usage metadata even when Claude finishes with an empty result line. (#49698) Thanks @felear2022.
 - Agents/embedded replies: surface mid-turn 429 and overload failures when embedded runs end without a user-visible reply, while preserving successful media-only replies that still use legacy `mediaUrl`. (#50930) Thanks @infichen.
 - WhatsApp/allowFrom: show a specific allowFrom policy error for valid blocked targets instead of the misleading `<E.164|group JID>` format hint. Thanks @mcaxtr.
 - Agents/cooldowns: scope rate-limit cooldowns per model so one 429 no longer blocks every model on the same auth profile, replace the exponential 1 min -> 1 h escalation with a stepped 30 s / 1 min / 5 min ladder, and surface a user-facing countdown message when all models are rate-limited. (#49834) Thanks @kiranvk-2011.

extensions/anthropic/cli-backend.ts

@@ -78,17 +78,25 @@ export function buildAnthropicCliBackend(): CliBackendPlugin {
     bundleMcp: true,
     config: {
       command: "claude",
-      args: ["-p", "--output-format", "json", "--permission-mode", "bypassPermissions"],
+      args: [
+        "-p",
+        "--output-format",
+        "stream-json",
+        "--verbose",
+        "--permission-mode",
+        "bypassPermissions",
+      ],
       resumeArgs: [
         "-p",
         "--output-format",
-        "json",
+        "stream-json",
+        "--verbose",
         "--permission-mode",
         "bypassPermissions",
         "--resume",
         "{sessionId}",
       ],
-      output: "json",
+      output: "jsonl",
       input: "arg",
       modelArg: "--model",
       modelAliases: CLAUDE_MODEL_ALIASES,

src/agents/cli-backends.test.ts

@@ -92,9 +92,14 @@ describe("resolveCliBackendConfig claude-cli defaults", () => {
     const resolved = resolveCliBackendConfig("claude-cli");
 
     expect(resolved).not.toBeNull();
+    expect(resolved?.config.output).toBe("jsonl");
+    expect(resolved?.config.args).toContain("stream-json");
+    expect(resolved?.config.args).toContain("--verbose");
     expect(resolved?.config.args).toContain("--permission-mode");
     expect(resolved?.config.args).toContain("bypassPermissions");
     expect(resolved?.config.args).not.toContain("--dangerously-skip-permissions");
+    expect(resolved?.config.resumeArgs).toContain("stream-json");
+    expect(resolved?.config.resumeArgs).toContain("--verbose");
     expect(resolved?.config.resumeArgs).toContain("--permission-mode");
     expect(resolved?.config.resumeArgs).toContain("bypassPermissions");
     expect(resolved?.config.resumeArgs).not.toContain("--dangerously-skip-permissions");

src/agents/cli-runner.helpers.test.ts

@@ -1,7 +1,7 @@
 import type { ImageContent } from "@mariozechner/pi-ai";
 import { beforeEach, describe, expect, it, vi } from "vitest";
 import { MAX_IMAGE_BYTES } from "../media/constants.js";
-import { buildCliArgs, loadPromptRefImages } from "./cli-runner/helpers.js";
+import { buildCliArgs, loadPromptRefImages, parseCliJsonl } from "./cli-runner/helpers.js";
 import * as promptImageUtils from "./pi-embedded-runner/run/images.js";
 import type { SandboxFsBridge } from "./sandbox/fs-bridge.js";
 import * as toolImages from "./tool-images.js";
@@ -118,3 +118,74 @@ describe("buildCliArgs", () => {
     ).toEqual(["exec", "resume", "thread-123", "--model", "gpt-5.4"]);
   });
 });
+
+describe("parseCliJsonl", () => {
+  it("parses Claude stream-json result events", () => {
+    const result = parseCliJsonl(
+      [
+        JSON.stringify({ type: "init", session_id: "session-123" }),
+        JSON.stringify({
+          type: "result",
+          session_id: "session-123",
+          result: "Claude says hello",
+          usage: {
+            input_tokens: 12,
+            output_tokens: 3,
+            cache_read_input_tokens: 4,
+          },
+        }),
+      ].join("\n"),
+      {
+        command: "claude",
+        output: "jsonl",
+        sessionIdFields: ["session_id"],
+      },
+    );
+
+    expect(result).toEqual({
+      text: "Claude says hello",
+      sessionId: "session-123",
+      usage: {
+        input: 12,
+        output: 3,
+        cacheRead: 4,
+        cacheWrite: undefined,
+        total: undefined,
+      },
+    });
+  });
+
+  it("preserves Claude session metadata even when the final result text is empty", () => {
+    const result = parseCliJsonl(
+      [
+        JSON.stringify({ type: "init", session_id: "session-456" }),
+        JSON.stringify({
+          type: "result",
+          session_id: "session-456",
+          result: "   ",
+          usage: {
+            input_tokens: 18,
+            output_tokens: 0,
+          },
+        }),
+      ].join("\n"),
+      {
+        command: "claude",
+        output: "jsonl",
+        sessionIdFields: ["session_id"],
+      },
+    );
+
+    expect(result).toEqual({
+      text: "",
+      sessionId: "session-456",
+      usage: {
+        input: 18,
+        output: undefined,
+        cacheRead: undefined,
+        cacheWrite: undefined,
+        total: undefined,
+      },
+    });
+  });
+});

src/agents/cli-runner/helpers.ts

@@ -233,6 +233,22 @@ export function parseCliJsonl(raw: string, backend: CliBackendConfig): CliOutput
     if (isRecord(parsed.usage)) {
       usage = toUsage(parsed.usage) ?? usage;
     }
+
+    // Claude stream-json: {"type":"result","result":"...","session_id":"...","usage":{...}}
+    if (
+      typeof parsed.type === "string" &&
+      parsed.type === "result" &&
+      typeof parsed.result === "string"
+    ) {
+      const resultText = parsed.result.trim();
+      if (resultText) {
+        return { text: resultText, sessionId, usage };
+      }
+      // Claude may finish with an empty result after tool-only work. Keep the
+      // resolved session handle and usage instead of dropping them.
+      return { text: "", sessionId, usage };
+    }
+
     const item = isRecord(parsed.item) ? parsed.item : null;
     if (item && typeof item.text === "string") {
       const type = typeof item.type === "string" ? item.type.toLowerCase() : "";