diff --git a/.github/workflows/build-ghosttykit.yml b/.github/workflows/build-ghosttykit.yml
index 35e74d69e67..7760ac9f306 100644
--- a/.github/workflows/build-ghosttykit.yml
+++ b/.github/workflows/build-ghosttykit.yml
@@ -93,7 +93,8 @@ jobs:
           set -euo pipefail
           rm -rf GhosttyKit.xcframework
           cp -R ghostty/macos/GhosttyKit.xcframework GhosttyKit.xcframework
-          tar czf GhosttyKit.xcframework.tar.gz GhosttyKit.xcframework
+          COPYFILE_DISABLE=1 tar czf GhosttyKit.xcframework.tar.gz GhosttyKit.xcframework
+          python3 scripts/validate-xcframework-archive.py GhosttyKit.xcframework.tar.gz
 
       - name: Upload xcframework release
         if: steps.check-release.outputs.exists == 'false'
diff --git a/docs/ghostty-fork.md b/docs/ghostty-fork.md
index ed0d91d277a..86e2cc65d4b 100644
--- a/docs/ghostty-fork.md
+++ b/docs/ghostty-fork.md
@@ -12,9 +12,12 @@ When we change the fork, update this document and the parent submodule SHA.
 
 ## Current fork changes
 
-Fork main has advanced beyond the March 30, 2026 rebase onto upstream `main`
-at `3509ccf78` (`v1.3.1-457-g3509ccf78`).
-Current cmux pinned fork head: `3b684a085` (`tip-1717-g3b684a085`).
+The fork was refreshed from upstream `main` again on April 28, 2026.
+Current cmux pinned fork head: `d3117e03e`, merged into fork `main` via
+`manaflow-ai/ghostty` PR https://github.com/manaflow-ai/ghostty/pull/48
+(`xcframework-f7880c47313a8697ee7f58969564772cb70eb6e9-300-gd3117e03e`).
+This head merges upstream `659019666` and preserves the previous cmux pin
+`465a9a621`.
 
 ### 1) macOS display link restart on display changes
 
@@ -101,7 +104,12 @@ tend to conflict together during rebases.
 
 ### 7) macos-background-from-layer config flag
 
-- Commit: `ae3cc5d29` (Restore macOS layer background hook)
+- Commits:
+  - `ae3cc5d29` (Restore macOS layer background hook)
+  - `aa28e1bcb` (Add macos-background-from-layer config flag)
+  - `1a01b36d9` (Skip fullscreen bg draw call in layer-background mode)
+  - `82e20630b` (Preserve bg images in layer background mode)
+  - `465a9a621` (Restore bg-image alpha in layer background mode)
 - Files:
   - `src/config/Config.zig`
   - `src/renderer/generic.zig`
@@ -120,8 +128,20 @@ tend to conflict together during rebases.
   - Wires `.apc_start`, `.apc_put`, and `.apc_end` through the shared APC parser in `TerminalStream`.
   - Restores kitty graphics execution and APC OK/error replies for the non-termio stream path used by cmux/libghostty integrations.
 
-Fork main now carries the section 8 APC handling fix plus later upstream merges;
-the current cmux pin is the head listed above.
+### 9) Config load string C API
+
+- Commit: `f7880c473` (Add config load string C API)
+- Files:
+  - `include/ghostty.h`
+  - `src/config/CApi.zig`
+  - `src/config/Config.zig`
+- Summary:
+  - Adds a C API for loading Ghostty config from an in-memory string.
+  - Lets cmux parse generated or override config without materializing a separate config file first.
+
+The current cmux pin is the head listed above. It is reachable from the
+`manaflow-ai/ghostty` fork `main` branch and has a matching prebuilt release
+tag `xcframework-d3117e03ea19665bc83a28f7e0428c63937e6140`.
 
 ## Upstreamed fork changes
 
@@ -145,6 +165,16 @@ the current cmux pin is the head listed above.
 
 These files change frequently upstream; be careful when rebasing the fork:
 
+- April 28, 2026, upstream merge:
+  - Merged upstream `659019666` into `465a9a621` without textual conflicts.
+  - Verified with `CMUX_GHOSTTYKIT_NO_PREBUILT=1 ./scripts/ensure-ghosttykit.sh`.
+  - Verified cmux with `./scripts/reload.sh --tag gtyup`.
+  - Published `xcframework-d3117e03ea19665bc83a28f7e0428c63937e6140` and pinned
+    its archive checksum in `scripts/ghosttykit-checksums.txt`.
+  - Merged `d3117e03e` into fork `main` with https://github.com/manaflow-ai/ghostty/pull/48.
+  - Package GhosttyKit archives with `COPYFILE_DISABLE=1`; the archive validator rejects
+    macOS AppleDouble entries such as `._GhosttyKit.xcframework`.
+
 - `src/terminal/osc.zig`
   - OSC dispatch logic moves often. Re-check the integration points for the OSC 99 parser and keep
     the newer `capture`/`captureTrailing()` API usage intact.
diff --git a/ghostty b/ghostty
index 465a9a62120..d3117e03ea1 160000
--- a/ghostty
+++ b/ghostty
@@ -1 +1 @@
-Subproject commit 465a9a62120f619a826b4864a4818dae7da724a7
+Subproject commit d3117e03ea19665bc83a28f7e0428c63937e6140
diff --git a/scripts/ghosttykit-checksums.txt b/scripts/ghosttykit-checksums.txt
index 3d1068c344f..527ce931b4a 100644
--- a/scripts/ghosttykit-checksums.txt
+++ b/scripts/ghosttykit-checksums.txt
@@ -21,3 +21,4 @@ fc59b46ba67787e4fd6ad0de63e5e469592d3eae 410196d8ebb5371e2c6ed25489e7411e43f920f
 3b684a085d40ec79e8a0ae863a4f2b48ed4dba74 1d408a5ba5e7996b21a4f3346adbc971c47f3ccf7e440bd334ac5389cd2f11c8
 f7880c47313a8697ee7f58969564772cb70eb6e9 d8647cf2fa1e54912ca781db81871932a4c4becc96b58a3eda4f7e66c979cdbf
 465a9a62120f619a826b4864a4818dae7da724a7 c090450d88cee0c75c68d5631e8e9fbc6b748542c73965220ad7d11b85f79dd3
+d3117e03ea19665bc83a28f7e0428c63937e6140 dd33542f2cb0ea6bb9579067cda4faf605586664e8b5d1dce57c793e48eb2668