Add bundled pi default and session token reporting

src/agents/context.ts

@@ -0,0 +1,34 @@
+// Lazy-load pi-ai model metadata so we can infer context windows when the agent
+// reports a model id. pi-coding-agent depends on @mariozechner/pi-ai, so it
+// should be present whenever CLAWDIS is installed from npm.
+
+type ModelEntry = { id: string; contextWindow?: number };
+
+const MODEL_CACHE = new Map<string, number>();
+const loadPromise = (async () => {
+  try {
+    const piAi = (await import("@mariozechner/pi-ai")) as {
+      getProviders: () => string[];
+      getModels: (provider: string) => ModelEntry[];
+    };
+    const providers = piAi.getProviders();
+    for (const p of providers) {
+      const models = piAi.getModels(p) as ModelEntry[];
+      for (const m of models) {
+        if (!m?.id) continue;
+        if (typeof m.contextWindow === "number" && m.contextWindow > 0) {
+          MODEL_CACHE.set(m.id, m.contextWindow);
+        }
+      }
+    }
+  } catch {
+    // If pi-ai isn't available, leave cache empty; lookup will fall back.
+  }
+})();
+
+export function lookupContextTokens(modelId?: string): number | undefined {
+  if (!modelId) return undefined;
+  // Best-effort: kick off loading, but don't block.
+  void loadPromise;
+  return MODEL_CACHE.get(modelId);
+}

src/agents/defaults.ts

@@ -0,0 +1,5 @@
+// Defaults for agent metadata when upstream does not supply them.
+// Model id uses pi-ai's built-in Anthropic catalog.
+export const DEFAULT_MODEL = "claude-opus-4-5";
+// Context window: Opus 4.5 supports ~200k tokens (per pi-ai models.generated.ts).
+export const DEFAULT_CONTEXT_TOKENS = 200_000;

src/agents/pi-path.ts

@@ -0,0 +1,26 @@
+import fs from "node:fs";
+import { createRequire } from "node:module";
+import path from "node:path";
+
+// Resolve the bundled pi/tau binary path from the installed dependency.
+export function resolveBundledPiBinary(): string | null {
+  try {
+    const require = createRequire(import.meta.url);
+    const pkgPath = require.resolve(
+      "@mariozechner/pi-coding-agent/package.json",
+    );
+    const pkgDir = path.dirname(pkgPath);
+    // Prefer compiled binary if present, else fall back to dist/cli.js (has shebang).
+    const binCandidates = [
+      path.join(pkgDir, "dist", "pi"),
+      path.join(pkgDir, "dist", "cli.js"),
+      path.join(pkgDir, "bin", "tau-dev.mjs"),
+    ];
+    for (const candidate of binCandidates) {
+      if (fs.existsSync(candidate)) return candidate;
+    }
+  } catch {
+    // Dependency missing or resolution failed.
+  }
+  return null;
+}