From ca1b8f461a72f44001a9b3c858478fbe83efbb1f Mon Sep 17 00:00:00 2001
From: Reuven <cohen@ruv-mac-mini.local>
Date: Tue, 17 Mar 2026 00:47:06 -0400
Subject: [PATCH] fix(adr-115): deserialize CDX length/offset from strings

Common Crawl CDX API returns length and offset as strings, not
integers. Add custom deserialize_string_to_u64 function to handle
the type conversion.

Co-Authored-By: claude-flow <ruv@ruv.net>
---
 crates/mcp-brain-server/src/pipeline.rs | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/crates/mcp-brain-server/src/pipeline.rs b/crates/mcp-brain-server/src/pipeline.rs
index e96254c04..326e2fc1c 100644
--- a/crates/mcp-brain-server/src/pipeline.rs
+++ b/crates/mcp-brain-server/src/pipeline.rs
@@ -499,14 +499,26 @@ pub struct CdxRecord {
     pub status: String,
     #[serde(default)]
     pub mime: String,
-    #[serde(default)]
+    /// Length in bytes (CDX returns as string, we parse to u64)
+    #[serde(default, deserialize_with = "deserialize_string_to_u64")]
     pub length: u64,
-    #[serde(default)]
+    /// Offset in WARC file (CDX returns as string, we parse to u64)
+    #[serde(default, deserialize_with = "deserialize_string_to_u64")]
     pub offset: u64,
     #[serde(default)]
     pub filename: String,
 }
 
+/// Deserialize a string to u64 (CDX API returns numeric fields as strings)
+fn deserialize_string_to_u64<'de, D>(deserializer: D) -> Result<u64, D::Error>
+where
+    D: serde::Deserializer<'de>,
+{
+    use serde::Deserialize;
+    let s: String = String::deserialize(deserializer)?;
+    s.parse().map_err(serde::de::Error::custom)
+}
+
 /// Query parameters for Common Crawl CDX index.
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct CdxQuery {