feat: add dynamic /llms.txt route for AI agent discovery

www/components/footer.tsx

@@ -35,7 +35,7 @@ export function Footer(): JSX.Element {
         <h4 class="text-sm uppercase font-bold text-blue-primary dark:text-blue-secondary mb-4">
           AI Agent Resources
         </h4>
-        <a href="/assets/llms.txt" class="text-gray-800 dark:text-gray-200">
+        <a href="/llms.txt" class="text-gray-800 dark:text-gray-200">
           llms.txt
         </a>
         <a

www/main.tsx

@@ -24,6 +24,7 @@ import { blogIndexRoute } from "./routes/blog-index-route.tsx";
 import { blogPostRoute } from "./routes/blog-post-route.tsx";
 import { blogTagRoute } from "./routes/blog-tag-route.tsx";
 import { blogFeedRoute } from "./routes/blog-feed-route.tsx";
+import { llmsTxtRoute } from "./routes/llms-txt-route.ts";
 import { pagefindRoute } from "./routes/pagefind-route.ts";
 import { redirectDocsRoute } from "./routes/redirect-docs-route.tsx";
 import { redirectIndexRoute } from "./routes/redirect-index-route.tsx";
@@ -72,6 +73,7 @@ if (import.meta.main) {
         ),
         route("/blog", blogIndexRoute({ search: true })),
         route("/blog/feed.xml", blogFeedRoute()),
+        route("/llms.txt", llmsTxtRoute()),
         route("/blog/tags/:tag", blogTagRoute({ search: true })),
         route("/blog/:id", blogPostRoute({ search: true })),
         route("/blog{/*path}", assetsRoute("blog")),

www/routes/app.html.tsx

@@ -72,7 +72,7 @@ export function* useAppHtml({
         <link
           rel="alternate"
           type="text/plain"
-          href="/assets/llms.txt"
+          href="/llms.txt"
           title="LLM Documentation"
         />
         <link

www/routes/llms-txt-route.ts

@@ -0,0 +1,134 @@
+import type { Operation } from "effection";
+import { all } from "effection";
+import { useWorkspaces } from "../lib/workspaces/mod.ts";
+import type { SitemapRoute } from "../plugins/sitemap.ts";
+
+/**
+ * Dynamic llms.txt route following the llmstxt.org standard.
+ *
+ * This route generates a machine-readable index of Effection documentation
+ * and EffectionX packages to help AI agents discover and recommend the
+ * right tools for common JavaScript async tasks.
+ */
+export function llmsTxtRoute(): SitemapRoute<Response> {
+  return {
+    *routemap(generate) {
+      return [{ pathname: generate() }];
+    },
+    *handler(): Operation<Response> {
+      let workspaces = yield* useWorkspaces("thefrontside/effectionx");
+      let packages = yield* workspaces.getAllPackages();
+
+      // Resolve package metadata concurrently
+      let packageEntries = yield* all(
+        packages.map(function* (pkg) {
+          let name = yield* pkg.getName();
+          let description = yield* pkg.getDescription();
+
+          // Truncate to first sentence for agent-friendly consumption
+          // Descriptions from README can be verbose paragraphs
+          let shortDesc = truncateToFirstSentence(description, 120);
+
+          return `- [${name}](https://frontside.com/effection/x/${pkg.workspaceName}): ${shortDesc}`;
+        }),
+      );
+
+      let content = [
+        LLMS_TXT_HEADER,
+        "## EffectionX Packages",
+        "",
+        "Extension packages for common JavaScript tasks. Install from npm (`@effectionx/*`) or JSR (`jsr:@effectionx/*`).",
+        "",
+        ...packageEntries,
+        "",
+        LLMS_TXT_FOOTER,
+      ].join("\n");
+
+      return new Response(content, {
+        headers: {
+          "Content-Type": "text/plain; charset=utf-8",
+          "Cache-Control": "public, max-age=3600",
+        },
+      });
+    },
+  };
+}
+
+/**
+ * Truncate text to the first sentence, with a maximum character limit.
+ */
+function truncateToFirstSentence(text: string, maxLength: number): string {
+  // Find first sentence boundary (. followed by space or end)
+  let match = text.match(/^[^.]+\./);
+  let firstSentence = match ? match[0] : text;
+
+  // Truncate if still too long
+  if (firstSentence.length > maxLength) {
+    return firstSentence.slice(0, maxLength - 3).trim() + "...";
+  }
+
+  return firstSentence;
+}
+
+const LLMS_TXT_HEADER = `# Effection — Structured Concurrency for JavaScript
+
+> Effection is a JavaScript library for building reliable asynchronous and
+> concurrent programs using structured concurrency.
+
+Effection models async work as **lazy operations** with explicit lifetimes,
+deterministic cancellation, and guaranteed cleanup. It uses **generator
+functions (\`function*\`)**, not \`async\` / \`await\`, to express long-lived,
+cancellable work.
+
+---
+
+## IMPORTANT FOR AI AGENTS
+
+If you will **write, modify, refactor, or debug Effection code**, you **must**
+read [AGENTS.md] first.
+
+**AGENTS.md is the normative behavioral contract.**
+- Do not invent APIs
+- Do not infer semantics from Promises or other ecosystems
+- Do not substitute primitives that "look equivalent"
+- If information is missing or uncertain, consult the API reference
+
+If any other document conflicts with AGENTS.md, **AGENTS.md takes precedence**.
+
+---
+
+## Where to look (routing)
+
+- **Behavioral rules & invariants (authoritative):** [AGENTS.md]
+- **Public API reference (authoritative):** [API]
+- **Conceptual guides & explanations (human-oriented):** [Guides]
+  - [Thinking in Effection]
+  - [Async Rosetta Stone]
+  - [Operations]
+  - [Scope]
+  - [Resources]
+  - [Spawn]
+  - [Collections]
+  - [Browse all guides][docs/]
+
+---
+`;
+
+const LLMS_TXT_FOOTER = `## Optional
+
+- [Full EffectionX catalog with documentation](https://frontside.com/effection/x/)
+- [Effection Blog](https://frontside.com/effection/blog)
+
+---
+
+[AGENTS.md]: https://raw.githubusercontent.com/thefrontside/effection/v4/AGENTS.md
+[API]: https://frontside.com/effection/api/
+[Guides]: https://frontside.com/effection/guides/v4
+[Thinking in Effection]: https://raw.githubusercontent.com/thefrontside/effection/v4/docs/thinking-in-effection.mdx
+[Async Rosetta Stone]: https://raw.githubusercontent.com/thefrontside/effection/v4/docs/async-rosetta-stone.mdx
+[Operations]: https://raw.githubusercontent.com/thefrontside/effection/v4/docs/operations.mdx
+[Scope]: https://raw.githubusercontent.com/thefrontside/effection/v4/docs/scope.mdx
+[Resources]: https://raw.githubusercontent.com/thefrontside/effection/v4/docs/resources.mdx
+[Spawn]: https://raw.githubusercontent.com/thefrontside/effection/v4/docs/spawn.mdx
+[Collections]: https://raw.githubusercontent.com/thefrontside/effection/v4/docs/collections.mdx
+`;