feat: add Grok Build subscription CLI as a provider

README.md

@@ -202,7 +202,7 @@ notes.
 
 ## Customizing
 
-OpenWiki supports OpenAI (with an API key or a ChatGPT login), OpenRouter, Nebius Token Factory, Fireworks, Baseten, NVIDIA NIM, an OpenAI-compatible provider, AWS Bedrock, Anthropic, and Google Vertex AI (Claude models) out of the box. The onboarding default is OpenAI with `gpt-5.6-terra`, and each inference provider also includes pre-defined model options plus support for custom model IDs.
+OpenWiki supports OpenAI (with an API key or a ChatGPT login), Grok Build (subscription CLI), OpenRouter, Nebius Token Factory, Fireworks, Baseten, NVIDIA NIM, an OpenAI-compatible provider, AWS Bedrock, Anthropic, and Google Vertex AI (Claude models) out of the box. The onboarding default is OpenAI with `gpt-5.6-terra`, and each inference provider also includes pre-defined model options plus support for custom model IDs.
 
 ### Alternative base URLs
 
@@ -320,6 +320,47 @@ For CI, authenticate before the update job runs — for example with
 
 Base URLs (and all credentials) can be set in your environment or stored in `~/.openwiki/.env`.
 
+### Grok Build (subscription)
+
+The `grok-build` provider runs documentation jobs through the local [Grok Build](https://grok.com)
+CLI (`grok`) using your Grok subscription login — no xAI API key required. OpenWiki
+spawns `grok` headlessly with `--always-approve` and `--output-format streaming-json`,
+and model usage draws on the same session as interactive Grok Build.
+
+Prerequisites:
+
+1. Install the Grok Build CLI and ensure `grok` is on your `PATH` (or set
+   `OPENWIKI_GROK_BUILD_BINARY` to the full path).
+2. Run `grok login` once so the CLI has a valid subscription session.
+
+```bash
+OPENWIKI_PROVIDER=grok-build openwiki code --init
+# or
+OPENWIKI_PROVIDER=grok-build openwiki personal --init
+```
+
+Optional overrides:
+
+```bash
+# Binary path when `grok` is not on PATH
+OPENWIKI_GROK_BUILD_BINARY=/path/to/grok
+
+# Model (defaults to grok-4.5)
+OPENWIKI_MODEL_ID=grok-4.5
+
+# Max agent turns for a documentation run (default 50)
+OPENWIKI_GROK_BUILD_MAX_TURNS=50
+
+# Overall run timeout in seconds (default 1800)
+OPENWIKI_AGENT_CLI_TIMEOUT_SECONDS=1800
+```
+
+**Local / subscription only.** Prefer this provider on a machine where you already
+use Grok Build interactively. It is not a drop-in for the scheduled GitHub Actions
+or GitLab CI examples, which expect a metered API key and do not have a `grok login`
+session. Runs use `--always-approve` so the CLI can write documentation files;
+treat the model like any coding agent with write access to the repo.
+
 ### Provider retry attempts
 
 OpenWiki uses LangChain's built-in retry handling for transient provider errors.

src/agent/engines/child-env.ts

@@ -0,0 +1,114 @@
+import { MANAGED_ENV_KEYS } from "../../env.js";
+import { isSecretLikeKey } from "../../diagnostics.js";
+
+/**
+ * Environment keys the agent CLI is allowed to inherit from the parent.
+ *
+ * Intentionally minimal: enough for PATH lookup, home-directory session
+ * files (`~/.grok`, `~/.gemini/antigravity-cli`), temp dirs, locale, and
+ * corporate proxy/CA setup. Everything else — especially OpenWiki-managed
+ * credentials — is dropped.
+ */
+const PASSTHROUGH_ENV_KEYS = new Set([
+  "PATH",
+  "Path",
+  "HOME",
+  "USERPROFILE",
+  "HOMEDRIVE",
+  "HOMEPATH",
+  "USER",
+  "USERNAME",
+  "LOGNAME",
+  "TMPDIR",
+  "TMP",
+  "TEMP",
+  "TERM",
+  "COLORTERM",
+  "NO_COLOR",
+  "FORCE_COLOR",
+  "SHELL",
+  "ComSpec",
+  "COMSPEC",
+  "SYSTEMROOT",
+  "SystemRoot",
+  "WINDIR",
+  "PATHEXT",
+  "PROCESSOR_ARCHITECTURE",
+  "APPDATA",
+  "LOCALAPPDATA",
+  "XDG_CONFIG_HOME",
+  "XDG_DATA_HOME",
+  "XDG_CACHE_HOME",
+  "XDG_STATE_HOME",
+  "XDG_RUNTIME_DIR",
+  "HTTP_PROXY",
+  "HTTPS_PROXY",
+  "NO_PROXY",
+  "ALL_PROXY",
+  "http_proxy",
+  "https_proxy",
+  "no_proxy",
+  "all_proxy",
+  "SSL_CERT_FILE",
+  "SSL_CERT_DIR",
+  "REQUESTS_CA_BUNDLE",
+  "CURL_CA_BUNDLE",
+  "NODE_EXTRA_CA_CERTS",
+]);
+
+const MANAGED_ENV_KEY_SET = new Set<string>(MANAGED_ENV_KEYS);
+
+/**
+ * Builds a scrubbed environment for vendor agent-CLI children.
+ *
+ * Drops every {@link MANAGED_ENV_KEYS} entry (provider keys, OAuth tokens,
+ * connector secrets), secret-like keys, and OpenWiki/LangChain config so a
+ * prompt-injected shell step or compromised binary cannot read credentials
+ * that OpenWiki loaded into `process.env`.
+ */
+export function buildAgentCliChildEnv(
+  parent: NodeJS.ProcessEnv = process.env,
+): NodeJS.ProcessEnv {
+  const env: NodeJS.ProcessEnv = {};
+
+  for (const [key, value] of Object.entries(parent)) {
+    if (value === undefined) {
+      continue;
+    }
+
+    if (!shouldPassEnvKey(key)) {
+      continue;
+    }
+
+    env[key] = value;
+  }
+
+  return env;
+}
+
+/** Exported for tests. */
+export function shouldPassEnvKey(key: string): boolean {
+  if (MANAGED_ENV_KEY_SET.has(key)) {
+    return false;
+  }
+
+  if (isSecretLikeKey(key)) {
+    return false;
+  }
+
+  // Defense in depth: never forward OpenWiki or LangChain/LangSmith vars even
+  // when they are not in MANAGED_ENV_KEYS (e.g. future keys, LANGCHAIN_ENDPOINT).
+  if (
+    key.startsWith("OPENWIKI_") ||
+    key.startsWith("LANGCHAIN_") ||
+    key.startsWith("LANGSMITH_")
+  ) {
+    return false;
+  }
+
+  if (key.startsWith("LC_")) {
+    return true;
+  }
+
+  return PASSTHROUGH_ENV_KEYS.has(key) || key === "LANG";
+}