feat(cli-tools): configure Grok Build subagent models

Add separate model selectors for Grok Build main, general-purpose,
explore, and plan agents. Each override gets an independent 9Router
custom-model slot and context_window derived from 9Router model
capabilities. Preserve and restore pre-existing config on reset.

src/app/api/cli-tools/grok-build-settings/route.js

@@ -6,24 +6,16 @@ import { promisify } from "util";
 import fs from "fs/promises";
 import path from "path";
 import os from "os";
+import { getCapabilitiesForModel } from "open-sse/providers/capabilities.js";
+import {
+  applyGrokBuildConfig,
+  GROK_SUBAGENT_TYPES,
+  parseGrokBuildConfig,
+  resetGrokBuildConfig,
+} from "@/lib/grokBuildConfig";
 
 const execAsync = promisify(exec);
 
-const PROVIDER_NAME = "9router";
-const MODEL_SLOT = "9router";
-const BUILTIN_DEFAULT = "grok-build";
-
-// [model.9router] ... until next [section] header or EOF
-const MODEL_SECTION_RE = new RegExp(
-  `^\\[model\\.${MODEL_SLOT}\\][ \\t]*\\r?\\n(?:(?!\\[)[^\\r\\n]*\\r?\\n?)*`,
-  "m"
-);
-
-const MODELS_SECTION_RE = /^\[models\][ \t]*\r?\n((?:(?!\[)[^\r\n]*\r?\n?)*)/m;
-
-// Marker written on Apply so Reset can restore the previous [models].default
-const PREV_DEFAULT_RE = /^# 9router-prev-default = "([^"]*)"[ \t]*\r?\n?/m;
-
 const getGrokDir = () => path.join(os.homedir(), ".grok");
 const getGrokConfigPath = () => path.join(getGrokDir(), "config.toml");
 const getGrokBinPath = () => path.join(getGrokDir(), "bin", "grok");
@@ -31,21 +23,16 @@ const getGrokBinPath = () => path.join(getGrokDir(), "bin", "grok");
 const checkGrokInstalled = async () => {
   try {
     const isWindows = os.platform() === "win32";
-    const command = isWindows ? "where grok" : "which grok";
-    await execAsync(command, { windowsHide: true });
+    await execAsync(isWindows ? "where grok" : "which grok", { windowsHide: true });
     return true;
   } catch {
-    try {
-      await fs.access(getGrokBinPath());
-      return true;
-    } catch {
+    for (const candidate of [getGrokBinPath(), getGrokConfigPath()]) {
       try {
-        await fs.access(getGrokConfigPath());
+        await fs.access(candidate);
         return true;
-      } catch {
-        return false;
-      }
+      } catch { /* try next */ }
     }
+    return false;
   }
 };
 
@@ -58,99 +45,32 @@ const readConfigToml = async () => {
   }
 };
 
-const getTomlField = (body, key) => {
-  const m = body.match(new RegExp(`^[ \\t]*${key}[ \\t]*=[ \\t]*"([^"]*)"`, "m"));
-  return m ? m[1] : null;
+const normalizeContextWindow = (value, model) => {
+  const explicit = Number(value);
+  if (Number.isFinite(explicit) && explicit > 0) return Math.floor(explicit);
+  const slash = model.indexOf("/");
+  const provider = slash > 0 ? model.slice(0, slash) : null;
+  const modelId = slash > 0 ? model.slice(slash + 1) : model;
+  return getCapabilitiesForModel(provider, modelId).contextWindow;
 };
 
-const parseModelSection = (toml) => {
-  const match = toml.match(MODEL_SECTION_RE);
-  if (!match) return null;
-  const body = match[0].replace(/^\[model\.[^\]]+\][ \t]*\r?\n/, "");
-  return {
-    model: getTomlField(body, "model"),
-    base_url: getTomlField(body, "base_url"),
-    name: getTomlField(body, "name"),
-    api_key: getTomlField(body, "api_key"),
-    api_backend: getTomlField(body, "api_backend"),
-  };
-};
-
-const parseModelsDefault = (toml) => {
-  const match = toml.match(MODELS_SECTION_RE);
-  if (!match) return null;
-  return getTomlField(match[1] || "", "default");
-};
-
-const buildModelSection = (model, baseUrl, apiKey) => {
-  const lines = [
-    `[model.${MODEL_SLOT}]`,
-    `model = "${model}"`,
-    `base_url = "${baseUrl}"`,
-    `name = "9Router"`,
-    `description = "Routed via 9Router gateway"`,
-    `api_backend = "chat_completions"`,
-  ];
-  if (apiKey) lines.push(`api_key = "${apiKey}"`);
-  return `${lines.join("\n")}\n`;
-};
-
-const upsertModelSection = (toml, section) => {
-  if (MODEL_SECTION_RE.test(toml)) return toml.replace(MODEL_SECTION_RE, section);
-  const needsNl = toml.length > 0 && !toml.endsWith("\n");
-  return `${toml}${needsNl ? "\n" : ""}\n${section}`;
-};
-
-const removeModelSection = (toml) =>
-  toml.replace(MODEL_SECTION_RE, "").replace(/\n{3,}/g, "\n\n");
-
-// Set or insert default = "..." inside existing [models], or create the section
-const setModelsDefault = (toml, value) => {
-  const match = toml.match(MODELS_SECTION_RE);
-  if (match) {
-    const body = match[1] || "";
-    let newBody;
-    if (/^[ \t]*default[ \t]*=/m.test(body)) {
-      newBody = body.replace(/^[ \t]*default[ \t]*=[ \t]*"[^"]*"/m, `default = "${value}"`);
-    } else {
-      newBody = `default = "${value}"\n${body}`;
-    }
-    return toml.replace(match[0], `[models]\n${newBody}`);
+const normalizeSubagentModels = (value) => {
+  if (value === undefined) return undefined; // backwards-compatible callers leave current overrides untouched
+  if (!value || typeof value !== "object" || Array.isArray(value)) return {};
+  const result = {};
+  for (const type of GROK_SUBAGENT_TYPES) {
+    const entry = value[type];
+    const model = typeof entry === "string" ? entry.trim() : entry?.model?.trim();
+    if (!model) continue; // blank means inherit the main model
+    result[type] = {
+      model,
+      contextWindow: normalizeContextWindow(entry?.contextWindow, model),
+    };
   }
-  const block = `[models]\ndefault = "${value}"\n\n`;
-  return toml.length > 0 ? block + toml : block;
+  return result;
 };
 
-// Remember the previous default once (so re-Apply does not overwrite it with "9router")
-const rememberPrevDefault = (toml) => {
-  if (PREV_DEFAULT_RE.test(toml)) return toml;
-  const current = parseModelsDefault(toml);
-  if (!current || current === MODEL_SLOT) return toml;
-  const marker = `# 9router-prev-default = "${current}"\n`;
-  // Prefer placing the marker just above [model.9router] if present, else at EOF
-  if (MODEL_SECTION_RE.test(toml)) {
-    return toml.replace(MODEL_SECTION_RE, (section) => marker + section);
-  }
-  const needsNl = toml.length > 0 && !toml.endsWith("\n");
-  return `${toml}${needsNl ? "\n" : ""}${marker}`;
-};
-
-// If default points at our slot, restore previous (or built-in) default and drop marker
-const clearModelsDefaultIfOurs = (toml) => {
-  const prevMatch = toml.match(PREV_DEFAULT_RE);
-  const restoreTo = prevMatch?.[1] || BUILTIN_DEFAULT;
-  let next = toml.replace(PREV_DEFAULT_RE, "");
-  const current = parseModelsDefault(next);
-  if (current === MODEL_SLOT) {
-    next = setModelsDefault(next, restoreTo);
-  }
-  return next;
-};
-
-const has9RouterConfig = (modelCfg) => {
-  if (!modelCfg?.base_url) return false;
-  return true;
-};
+const has9RouterConfig = (settings) => Boolean(settings?.model?.base_url);
 
 export async function GET() {
   try {
@@ -163,17 +83,11 @@ export async function GET() {
       });
     }
 
-    const toml = await readConfigToml();
-    const model = parseModelSection(toml);
-    const defaultModel = parseModelsDefault(toml);
-
+    const settings = parseGrokBuildConfig(await readConfigToml());
     return NextResponse.json({
       installed: true,
-      settings: {
-        model,
-        default: defaultModel,
-      },
-      has9Router: has9RouterConfig(model),
+      settings,
+      has9Router: has9RouterConfig(settings),
       configPath: getGrokConfigPath(),
     });
   } catch (error) {
@@ -184,29 +98,28 @@ export async function GET() {
 
 export async function POST(request) {
   try {
-    const { baseUrl, apiKey, model } = await request.json();
-    if (!baseUrl || !model) {
+    const { baseUrl, apiKey, model, contextWindow, subagentModels } = await request.json();
+    const selectedModel = typeof model === "string" ? model.trim() : "";
+    if (!baseUrl || !selectedModel) {
       return NextResponse.json({ error: "baseUrl and model are required" }, { status: 400 });
     }
 
-    const dir = getGrokDir();
-    await fs.mkdir(dir, { recursive: true });
-
+    await fs.mkdir(getGrokDir(), { recursive: true });
     const normalizedBaseUrl = baseUrl.endsWith("/v1") ? baseUrl : `${baseUrl}/v1`;
-    const keyToWrite = apiKey || "sk_9router";
-
-    let toml = await readConfigToml();
-    toml = rememberPrevDefault(toml);
-    toml = upsertModelSection(toml, buildModelSection(model, normalizedBaseUrl, keyToWrite));
-    toml = setModelsDefault(toml, MODEL_SLOT);
-
+    const toml = applyGrokBuildConfig(await readConfigToml(), {
+      baseUrl: normalizedBaseUrl,
+      apiKey: apiKey || "sk_9router",
+      model: selectedModel,
+      contextWindow: normalizeContextWindow(contextWindow, selectedModel),
+      subagentModels: normalizeSubagentModels(subagentModels),
+    });
     await fs.writeFile(getGrokConfigPath(), toml);
 
     return NextResponse.json({
       success: true,
       message: "Grok Build settings applied successfully!",
       configPath: getGrokConfigPath(),
-      modelSlot: MODEL_SLOT,
+      modelSlot: "9router",
     });
   } catch (error) {
     console.log("Error updating grok-build settings:", error);
@@ -217,7 +130,7 @@ export async function POST(request) {
 export async function DELETE() {
   try {
     const configPath = getGrokConfigPath();
-    let toml = "";
+    let toml;
     try {
       toml = await fs.readFile(configPath, "utf-8");
     } catch (error) {
@@ -227,13 +140,10 @@ export async function DELETE() {
       throw error;
     }
 
-    toml = removeModelSection(toml);
-    toml = clearModelsDefaultIfOurs(toml);
-    await fs.writeFile(configPath, toml);
-
+    await fs.writeFile(configPath, resetGrokBuildConfig(toml));
     return NextResponse.json({
       success: true,
-      message: `${PROVIDER_NAME} model slot removed from Grok Build`,
+      message: "9router model slots removed from Grok Build",
     });
   } catch (error) {
     console.log("Error resetting grok-build settings:", error);