From a7bc472e874d42a1ecfa885910c675edb9ab99cc Mon Sep 17 00:00:00 2001
From: Ricardo <rick@rmendes.net>
Date: Mon, 23 Feb 2026 10:06:19 +0100
Subject: [PATCH] fix: deduplicate cross-source webmentions

webmention.io cache and conversations API can report the same
interaction (e.g. a like) with different wm-id formats. Deduplicate
by author URL + interaction type after URL filtering to prevent
the same like/reply appearing twice.
---
 eleventy.config.js | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/eleventy.config.js b/eleventy.config.js
index dd1555c..ec2f363 100644
--- a/eleventy.config.js
+++ b/eleventy.config.js
@@ -484,7 +484,21 @@ export default function (eleventyConfig) {
     }
 
     // Filter merged data matching any of our URLs
-    return merged.filter((wm) => urlsToCheck.has(wm["wm-target"]));
+    const matched = merged.filter((wm) => urlsToCheck.has(wm["wm-target"]));
+
+    // Deduplicate cross-source: same author + same interaction type = same mention
+    // (webmention.io and conversations API may both report the same like/reply)
+    const deduped = [];
+    const authorActions = new Set();
+    for (const wm of matched) {
+      const authorUrl = wm.author?.url || wm.url || "";
+      const action = wm["wm-property"] || "mention";
+      const key = `${authorUrl}::${action}`;
+      if (authorActions.has(key)) continue;
+      authorActions.add(key);
+      deduped.push(wm);
+    }
+    return deduped;
   });
 
   eleventyConfig.addFilter("webmentionsByType", function (mentions, type) {