Greptile Summary

This PR attempts to fix stdout pollution from plugin loading logs when running openclaw agent --json by calling routeLogsToStderr() at the start of agentCliCommand. The intent is correct — routeLogsToStderr() is already used successfully in completion-cli.ts for the same class of problem — but the implementation has a critical flaw that makes --json output completely broken.

• Root cause of the new bug: By the time agentCliCommand executes, enableConsoleCapture() has already patched console.log in run-main.ts. Once routeLogsToStderr() sets forceConsoleToStderr = true, all subsequent console.log calls — including the one that outputs the final JSON payload in agentViaGatewayCommand (runtime.log(JSON.stringify(response, null, 2))) — are redirected to process.stderr. The result: stdout is empty and the JSON appears on stderr.
• Why completion-cli.ts avoids this: It writes its output with process.stdout.write(script + "\n"), which bypasses the patched console.log entirely.
• Recommended fix: Change the JSON output in agentViaGatewayCommand from runtime.log(JSON.stringify(...)) to process.stdout.write(JSON.stringify(...) + "\n") so it is not subject to the stderr redirect.

Confidence Score: 1/5

• This PR introduces a regression: openclaw agent --json will produce empty stdout and JSON on stderr, making the flag non-functional.
• The fix correctly identifies that routeLogsToStderr() should be called, but the final JSON output in agentViaGatewayCommand is still emitted via runtime.log → console.log, which is already intercepted by enableConsoleCapture. With forceConsoleToStderr = true, the JSON goes to stderr. This is a clear regression — the --json flag will produce no output on stdout after the fix.
• src/commands/agent-via-gateway.ts — specifically the runtime.log(JSON.stringify(response, null, 2)) call in agentViaGatewayCommand (around line 160) needs to be changed to process.stdout.write.

This is a comment left during a code review.
Path: src/commands/agent-via-gateway.ts
Line: 184-186

Comment:
**JSON response redirected to stderr by same call**

Calling `routeLogsToStderr()` here patches `console.log` (via `enableConsoleCapture`, which runs before this point in `run-main.ts`) to write to `process.stderr` whenever `forceConsoleToStderr` is `true`. The problem is that the final JSON payload in `agentViaGatewayCommand` is emitted the same way:

```ts
// agentViaGatewayCommand (line ~160)
if (opts.json) {
  runtime.log(JSON.stringify(response, null, 2));  // calls console.log → now goes to stderr!
  return response;
}
```

`runtime.log` delegates to `console.log`, which is already patched. Once `routeLogsToStderr()` is called, *every* subsequent `console.log` call — including the one that outputs the JSON result — is redirected to `process.stderr`. This means `--json` stdout would be empty and the JSON would land on stderr instead.

Compare with `completion-cli.ts`, which writes its stdout output with `process.stdout.write(script + "\n")` directly, bypassing the console patch entirely.

The fix should write the JSON using `process.stdout.write` (or `rawConsole.log` / `loggingState.rawConsole`) so it is not subject to the `forceConsoleToStderr` redirect. For example, in `agentViaGatewayCommand`:

```ts
if (opts.json) {
  process.stdout.write(JSON.stringify(response, null, 2) + "\n");
  return response;
}
```

Without this change, `openclaw agent --json` will produce an empty stdout and the JSON on stderr — the opposite of the intended behaviour.

How can I resolve this? If you propose a fix, please make it concise.

_{Last reviewed commit: "fix(cli): route logs..."}

Noted. The concern about JSON output going to stderr via routeLogsToStderr() is valid — I will switch to process.stdout.write for structured JSON to preserve the --json contract.

Closing this as implemented after Codex review.

Current main already keeps --json CLI startup/plugin logs off stdout and writes openclaw agent --json payloads through the runtime JSON writer, so this PR’s targeted change is obsolete.

What I checked:

• Generic JSON-mode stderr routing already exists: CLI preaction detects JSON output mode and applies startup presentation before command execution; startup presentation routes logs to stderr when stdout must stay clean. (src/cli/program/preaction.ts:71, 6944d7025d9c)
• Bootstrap passes suppression into plugin loading: Command bootstrap forwards suppressDoctorStdout into plugin registry loading, so plugin-loading logs are redirected during JSON-mode startup instead of leaking to stdout. (src/cli/command-bootstrap.ts:14, 6944d7025d9c)
• Plugin loader scopes and restores stderr routing: Plugin registry loading saves and restores loggingState.forceConsoleToStderr, so the stderr redirect applies during plugin load but does not permanently hijack later command output. (src/cli/plugin-registry-loader.ts:18, 6944d7025d9c)
• Agent JSON output uses runtime JSON writer: agentViaGatewayCommand now emits JSON via writeRuntimeJson(runtime, response) rather than plain runtime.log(...), avoiding the regression called out in review. (src/commands/agent-via-gateway.ts:157, 6944d7025d9c)
• Runtime JSON writer goes to stdout for output-capable runtimes: writeRuntimeJson uses runtime.writeJson, and the default/output runtime implementation writes with process.stdout.write, preserving the stdout JSON contract even when console logs are routed to stderr. (src/runtime.ts:52, 6944d7025d9c)
• Regression tests cover the exact class of bug: Tests assert that --json mode routes logs to stderr so stdout stays clean, and specifically that plugin loading is routed to stderr during JSON mode and restored afterward. (src/cli/program/preaction.test.ts:394, 6944d7025d9c)

So I’m closing this as already implemented rather than keeping a duplicate issue open.

Review notes: reviewed against 6944d7025d9c; fix evidence: release v2026.4.22, commit 00bd2cf7a376.