diff --git a/addins/cuframes.sh b/addins/cuframes.sh
new file mode 100644
index 0000000..c5d79bc
--- /dev/null
+++ b/addins/cuframes.sh
@@ -0,0 +1,13 @@
+#!/bin/bash
+# Addin: cuframes — patched FFmpeg n7.1 с input демуксером cuframes://<key>
+# плюс statically-linked libcuframes.
+#
+# Активация: ./build.sh linux64 gpl cuframes
+#
+# Переключает clone FFmpeg на наш fork с применённым patch'ем.
+
+FFMPEG_REPO_OVERRIDE="https://git.goldix.org/gx/ffmpeg-patched.git"
+GIT_BRANCH_OVERRIDE="n7.1-cuframes"
+
+# Включает scripts.d/50-libcuframes.sh (он проверяет $FFBUILD_HAS_CUFRAMES)
+export FFBUILD_HAS_CUFRAMES=1
diff --git a/images/base-linux64/Dockerfile b/images/base-linux64/Dockerfile
index f8c39c7..d702f93 100644
--- a/images/base-linux64/Dockerfile
+++ b/images/base-linux64/Dockerfile
@@ -1,13 +1,17 @@
 ARG GH_REPO=btbn/ffmpeg-builds
 FROM ghcr.io/$GH_REPO/base:latest
 
+# Pre-fetched tarballs для обхода flaky upstream URLs (zlib.net deprecated /zlib-N.tar.gz).
+# CT_LOCAL_TARBALLS_DIR=$HOME/src — там crosstool-NG ищет cache перед download.
+COPY preload/*.tar.gz /root/src/
+
 RUN --mount=src=ct-ng-config,dst=/.config \
-    git clone --filter=blob:none https://github.com/crosstool-ng/crosstool-ng.git /ct-ng && cd /ct-ng && \
+    git clone --filter=blob:none https://github.com/crosstool-ng/crosstool-ng.git /ct-ng && cd /ct-ng && git checkout 185f348 && \
     ./bootstrap && \
     ./configure --enable-local && \
     make -j$(nproc) && \
     cp /.config .config && \
-    ./ct-ng build && \
+    ( ./ct-ng build || ( echo '=== build.log tail ==='; tail -100 /ct-ng/build.log 2>/dev/null || true; echo '=== config.log tail ==='; find /ct-ng/.build -name config.log -newer /tmp -exec sh -c 'echo "==== $1 ===="; tail -80 "$1"' _ {} \; 2>/dev/null; exit 1 ) ) && \
     cd / && \
     rm -rf ct-ng
 
diff --git a/images/base-linux64/ct-ng-config b/images/base-linux64/ct-ng-config
index 3fdade0..cb22ce0 100644
--- a/images/base-linux64/ct-ng-config
+++ b/images/base-linux64/ct-ng-config
@@ -722,9 +722,10 @@ CT_GMP_PATCH_GLOBAL=y
 # CT_GMP_PATCH_LOCAL_BUNDLED is not set
 # CT_GMP_PATCH_NONE is not set
 CT_GMP_PATCH_ORDER="global"
-CT_GMP_V_6_2=y
+CT_GMP_V_6_3=y
+# CT_GMP_V_6_2 is not set
 # CT_GMP_V_6_1 is not set
-CT_GMP_VERSION="6.2.1"
+CT_GMP_VERSION="6.3.0"
 CT_GMP_MIRRORS="https://gmplib.org/download/gmp https://gmplib.org/download/gmp/archive $(CT_Mirrors GNU gmp)"
 CT_GMP_ARCHIVE_FILENAME="@{pkg_name}-@{version}"
 CT_GMP_ARCHIVE_DIRNAME="@{pkg_name}-@{version}"
diff --git a/images/base-linux64/preload/gmp-6.3.0.tar.xz b/images/base-linux64/preload/gmp-6.3.0.tar.xz
new file mode 100644
index 0000000..eed1334
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diff --git a/images/base-linux64/preload/zlib-1.2.12.tar.gz b/images/base-linux64/preload/zlib-1.2.12.tar.gz
new file mode 100644
index 0000000..4eede14
Binary files /dev/null and b/images/base-linux64/preload/zlib-1.2.12.tar.gz differ