From 701fcd8e2ee2af07bbef31d9dda8c41097bbe113 Mon Sep 17 00:00:00 2001
From: Ben Hoverter <32376575+benhoverter@users.noreply.github.com>
Date: Mon, 4 May 2026 12:04:31 -0700
Subject: [PATCH] channels/bridge: disable transparent decompression on image
 download
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Content-Type: text/plain; charset=UTF-8
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Discord's CDN edges occasionally advertise `content-encoding: gzip` (or
deflate/brotli) on PNG/JPEG passthroughs while the body is raw,
uncompressed image bytes. With the default `reqwest::Client::new()` and
the workspace's gzip/deflate/brotli features all enabled, reqwest's
transparent-decompression layer chokes on the PNG/JPEG header and
returns "error decoding response body" only on `bytes().await` (not on
`send()`), causing `download_image_to_blocks` to silently fall back to a
text-only block — the user's image never reaches the model.

Build the client explicitly with no_gzip/no_deflate/no_brotli so the
request advertises identity encoding and the body is read raw. Also set
a User-Agent (some CDN edges 403 clients without one) and a 30s timeout
aligned with the upstream 5 MB cap.

Repro: send an image attachment via Discord; the daemon logs
`Failed to read image bytes: error decoding response body` and the turn
appends as text-only with `appended_has_image=false`. After this fix the
PNG bytes are read and emitted as an Image content block as intended.
---
 crates/openfang-channels/src/bridge.rs | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/crates/openfang-channels/src/bridge.rs b/crates/openfang-channels/src/bridge.rs
index c0246b7f..16271d6e 100644
--- a/crates/openfang-channels/src/bridge.rs
+++ b/crates/openfang-channels/src/bridge.rs
@@ -1524,7 +1524,25 @@ async fn download_image_to_blocks(url: &str, caption: Option<&str>) -> Vec<Conte
                 }
             }
         } else {
-            let client = reqwest::Client::new();
+            // Build the client with transparent decompression DISABLED. Discord's
+            // CDN edges occasionally advertise `content-encoding: gzip` (or br)
+            // on PNG/JPEG passthroughs while the body is the raw, uncompressed
+            // image bytes. With the default reqwest client (gzip/deflate/brotli
+            // features enabled at the workspace level), this causes the
+            // decompression layer to choke on the image header and reqwest
+            // returns "error decoding response body" only on `bytes().await`,
+            // not on `send()`. Forcing identity encoding sidesteps the whole
+            // class of CDN content-encoding-flapping bugs. We also set a UA
+            // (some CDNs 403 clients without one) and a 30s timeout aligned
+            // with the upstream 5 MB cap.
+            let client = reqwest::Client::builder()
+                .no_gzip()
+                .no_deflate()
+                .no_brotli()
+                .user_agent("openfang/0.1 (+https://openfang.ai)")
+                .timeout(std::time::Duration::from_secs(30))
+                .build()
+                .unwrap_or_else(|_| reqwest::Client::new());
             let resp = match client.get(url).send().await {
                 Ok(r) => r,
                 Err(e) => {