docs: seed the Feature Support by Chain page for the interactive matrix

.prettierignore

@@ -4,3 +4,8 @@
 **/*.md
 content/api-specs/
 pnpm-lock.yaml
+
+# Generated by UpdateFeatureSupportFromDaikonWorkflow; the generator owns its
+# one-entity-per-line format (prettier reflowing it would make every daily bot
+# write a diff)
+content/feature-support.json

content/api-reference/pricing-resources/resources/feature-support-by-chain.mdx

@@ -5,8 +5,43 @@ subtitle: Alchemy's current feature availability for each of its supported chain
 slug: reference/feature-support-by-chain
 ---
 
-<Info>
-  Check the [Chains](https://dashboard.alchemy.com/chains) page for details about product and chain support!
+See the [Chains page](https://dashboard.alchemy.com/chains) in the dashboard for Alchemy's current product and chain support.
 
-  ![](https://alchemyapi-res.cloudinary.com/image/upload/v1764179964/docs/api-reference/alchemy-transact/transaction-simulation/523fb8a9a9d899921ee1046d0ff1b389967a9976d1c6112ebbbe071ddd1ef374-image.png)
-</Info>
+{/*
+  The visible sentence above is a placeholder so this nav-listed page is
+  never blank: the stacked follow-up replaces it with the interactive
+  <FeatureSupportMatrix /> widget when the generated data lands.
+
+  Data freshness: the widget's data is server-rendered, not fetched by the
+  browser and not baked into this MDX. The docs-site renders
+  <FeatureSupportMatrix /> on the server from content/feature-support.json
+  in this repo, cached under the "feature-support" Next.js cache tag. When
+  that file changes on main — the daily Daikon bot PR merge — the
+  revalidate-content workflow calls the docs-site
+  /api/revalidate/feature-support endpoint to invalidate the tag, so the
+  statically generated page re-renders with fresh data (an hourly TTL
+  backstops a missed webhook). JSON-only daily updates therefore reach
+  readers without this MDX being edited.
+
+  The summary table below cannot drift from the JSON: the daily workflow
+  regenerates both from the same resolved data and commits them together,
+  so any change that affects the table is itself an MDX edit and
+  revalidates through the markdown path. A JSON-only commit means the
+  table's coarser product-by-chain view genuinely did not change.
+
+  The summary block is intentionally wrapped in a hidden div: it exists for
+  search engines, LLMs, and markdown consumers, while the interactive
+  <FeatureSupportMatrix /> widget is the human-facing view. The h4 keeps it
+  out of the page table of contents.
+*/}
+
+<div hidden>
+
+#### Product support by chain
+
+Every Alchemy product and the chains it supports, at a glance. A product counts as supported on a chain when at least one of its networks supports at least one of the product's methods.
+
+{/* feature-support:auto */}
+{/* feature-support:auto end */}
+
+</div>

src/content-indexer/utils/__tests__/truncate-record.test.ts

@@ -21,6 +21,54 @@ describe("truncateRecord", () => {
     expect(result.content).toBe("Short content");
   });
 
+  test("should strip non-rendered MDX comments from indexed content", () => {
+    const record: AlgoliaRecord = {
+      objectID: "abc123",
+      indexerType: "docs",
+      path: "reference/feature-support-by-chain",
+      pageType: "Guide",
+      title: "Feature Support By Chain",
+      content: [
+        "Visible intro.",
+        "{/*\n  Data freshness: operational note that never renders.\n*/}",
+        "{/* feature-support:auto */}",
+        "| Product | Chains |",
+        "{/* feature-support:auto end */}",
+        "Visible outro.",
+      ].join("\n\n"),
+      breadcrumbs: ["Reference"],
+    };
+
+    const result = truncateRecord(record);
+    expect(result.content).toContain("Visible intro.");
+    expect(result.content).toContain("Visible outro.");
+    expect(result.content).not.toContain("Data freshness");
+    expect(result.content).not.toContain("feature-support:auto");
+  });
+
+  test("should preserve JSX comments inside fenced code examples", () => {
+    const record: AlgoliaRecord = {
+      objectID: "abc123",
+      indexerType: "docs",
+      path: "wallets/react/mfa/email-otp",
+      pageType: "Guide",
+      title: "Email OTP",
+      content: [
+        "{/* operational note that never renders */}",
+        "```tsx\nreturn (\n  <div>\n    {/* OTP input component */}\n    <OtpInput />\n  </div>\n);\n```",
+        "After the example.",
+      ].join("\n\n"),
+      breadcrumbs: ["Wallets"],
+    };
+
+    const result = truncateRecord(record);
+    // The comment in the rendered code block is real page content...
+    expect(result.content).toContain("OTP input component");
+    // ...while the non-rendered MDX comment outside it is stripped.
+    expect(result.content).not.toContain("operational note");
+    expect(result.content).toContain("After the example.");
+  });
+
   test("should truncate content for oversized record", () => {
     // Create a record with content exceeding 100KB
     const largeContent = "x".repeat(150_000);

src/content-indexer/utils/truncate-record.ts

@@ -6,13 +6,33 @@ const MAX_RECORD_BYTES = 100_000; // Algolia imposes a 100KB limit on each recor
 const BUFFER_BYTES = 1_000;
 const MAX_ITERATIONS = 5;
 
+/**
+ * MDX expression comments never render on the page, but remove-markdown
+ * leaves them intact, so implementation notes and generator markers
+ * (cu:auto, feature-support:auto, data-freshness notes) would otherwise be
+ * uploaded into public search records and snippets.
+ *
+ * Fenced code blocks are skipped: a JSX comment inside a rendered code
+ * example (e.g. `{/* OTP input component *\/}` in the wallets MFA guides)
+ * is real page content that must stay searchable.
+ */
+const stripMdxComments = (content: string): string =>
+  content
+    .split(/(```[\s\S]*?```)/)
+    .map((segment, index) =>
+      // Odd indexes are the captured fenced code blocks.
+      index % 2 === 1 ? segment : segment.replace(/\{\/\*[\s\S]*?\*\/\}/g, ""),
+    )
+    .join("");
+
 /**
  * Truncate record content to ensure entire JSON payload fits within Algolia limit.
  * Also strips markdown formatting from content for better search experience.
  */
 export const truncateRecord = (rawRecord: AlgoliaRecord): AlgoliaRecord => {
-  // Strip markdown formatting to get clean, searchable text
-  const cleanedContent = removeMd(rawRecord.content);
+  // Strip non-rendered MDX comments and markdown formatting to get clean,
+  // searchable text
+  const cleanedContent = removeMd(stripMdxComments(rawRecord.content));
   const record = { ...rawRecord, content: cleanedContent };
 
   const fullRecordJson = JSON.stringify(record);