diff --git a/.github/workflows/build-inputs.yml b/.github/workflows/build-inputs.yml
index bce39d4..6ae0769 100644
--- a/.github/workflows/build-inputs.yml
+++ b/.github/workflows/build-inputs.yml
@@ -36,6 +36,10 @@ on:
         description: 'Kconfig'
         required: false
         default: 'default'
+      merge:
+        description: 'ZMK Merge'
+        required: false
+        default: 'default'
 jobs:
   process-inputs:
     runs-on: ubuntu-latest
@@ -48,13 +52,14 @@ jobs:
       layers: ${{ steps.process-inputs.outputs.layers }}
       mapping: ${{ steps.process-inputs.outputs.mapping }}
       kconfig: ${{ steps.process-inputs.outputs.kconfig }}
+      merge: ${{ steps.process-inputs.outputs.merge }}
     steps:
       - name: Process inputs
         id: process-inputs
         run: |
           set-output()
           {
-            json=`echo "$2" | jq -cnR 'inputs | split("(,| )+";"")'`
+            json=`echo "$2" | jq -cnR 'inputs | split(",";"")'`
             echo "::set-output name=$1::$json"
           }
           set-output "board" "${{ github.event.inputs.board }}"
@@ -65,6 +70,7 @@ jobs:
           set-output "layers" "${{ github.event.inputs.layers }}"
           set-output "mapping" "${{ github.event.inputs.mapping }}"
           set-output "kconfig" "${{ github.event.inputs.kconfig }}"
+          set-output "merge" "${{ github.event.inputs.merge }}"
   build:
     uses: manna-harbour/zmk-config/.github/workflows/main.yml@82f608118a663f0cb02a3cfa4330e21d58b52a4f
     needs: process-inputs
@@ -77,3 +83,4 @@ jobs:
       layers: ${{ needs.process-inputs.outputs.layers }}
       mapping: ${{ needs.process-inputs.outputs.mapping }}
       kconfig: ${{ needs.process-inputs.outputs.kconfig }}
+      merge: ${{ needs.process-inputs.outputs.merge }}
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index ddbc262..7f9cdb4 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -29,6 +29,10 @@ on:
       kconfig:
         type: string
         default: '["default"]'
+      merge:
+        type: string
+        default: '["default"]'
+
 jobs:
   main:
     runs-on: ubuntu-latest
@@ -45,6 +49,7 @@ jobs:
         layers: ${{ fromJSON(inputs.layers) }}
         mapping: ${{ fromJSON(inputs.mapping) }}
         kconfig: ${{ fromJSON(inputs.kconfig) }}
+        merge: ${{ fromJSON(inputs.merge) }}
     steps:
       - name: Checkout
         uses: actions/checkout@v2
@@ -95,6 +100,11 @@ jobs:
             artifact_build_name="$artifact_build_name kconfig_"`echo "${{ matrix.kconfig }}" | md5sum | cut -d ' ' -f 1`
           fi
 
+          if [ -n "${{ matrix.merge }}" -a "${{ matrix.merge }}" != 'default' ]
+          then
+            artifact_build_name="$artifact_build_name merge_"`echo "${{ matrix.merge }}" | md5sum | cut -d ' ' -f 1`
+          fi
+
           outboard_dir=".github/workflows/outboards"
           if [ -n "$shield" ]
           then
@@ -140,10 +150,9 @@ jobs:
         run: |
           cp ${{ steps.variables.outputs.outboard_chekout_dir }}/${{ env.outboard_manifest }} config/west.yml
           cat config/west.yml
-      - name: Cache west modules
+      - name: Cache
+        if: true
         uses: actions/cache@v2
-        env:
-          cache-name: zephyr
         with:
           path: |
             bootloader/
@@ -151,17 +160,35 @@ jobs:
             tools/
             zephyr/
             zmk/
-          key: ${{ runner.os }}-${{ env.cache-name }}-${{ hashFiles('config/west.yml') }}
-          restore-keys: ${{ runner.os }}-${{ env.cache-name }}
+          key: ${{ runner.os }} ${{ hashFiles('config/west.yml') }} ${{ matrix.merge }}
         timeout-minutes: 2
         continue-on-error: true
-      - name: Initialize workspace (west init)
+      - name: Initialize west workspace
         run: west init -l config
-      - name: Update modules (west update)
+      - name: Update west projects
         run: west update
-      - name: Export Zephyr CMake package (west zephyr-export)
+      - name: Merge branches and update
+        if: ${{ matrix.merge != '' && matrix.merge != 'default' }}
+        run: |
+          cd zmk
+          git config user.name "${GITHUB_ACTOR}"
+          git config user.email "${GITHUB_ACTOR}@users.noreply.github.com"
+          for merge in ${{ matrix.merge }}
+          do
+            user=`echo "$merge" | cut -f 1 -d '/'`
+            repo=`echo "$merge" | cut -f 2 -d '/'`
+            branch=`echo "$merge" | cut -f 3- -d '/'`
+            remote="$user-$repo"
+            git remote add "$remote" "https://github.com/$user/$repo.git"
+            git fetch "$remote" "$branch"
+            git merge "$remote/$branch"
+            git remote remove "$remote"
+            git status
+          done
+          west update
+      - name: Export Zephyr CMake package
         run: west zephyr-export
-      - name: Build (west build)
+      - name: Build
         run: west build -s zmk/app -b ${{ matrix.board }} -- ${{ steps.variables.outputs.shield-arg }} -DZMK_CONFIG="${GITHUB_WORKSPACE}/config"
       - name: Show dts.pre.tmp
         if: ${{ failure() }}
diff --git a/readme.org b/readme.org
index 8e41be2..501b950 100644
--- a/readme.org
+++ b/readme.org
@@ -59,9 +59,11 @@ The ~shield~ option specifies the ZMK shield.
 
 The ~alphas~, ~nav~, ~clipboard~, and ~layers~ options correspond to the [[https://github.com/manna-harbour/miryoku/tree/master/docs/reference#alternative-layouts][alternative layout]] options.  The ~mapping~ option corresponds to the alternative [[#mapping][mapping]] options.  Alternative layout and mapping options are given in the documentation in the form ~MIRYOKU_OPTION=VALUE~.  To use here, convert to the form specified above.  Use ~default~ to represent the default value.  Values for these five options are case-insensitive.
 
+See the Test All workflow files for all supported values for each option.
+
 The ~kconfig~ option can be used to for [[#kconfig-configuration][Kconfig configuration]].  Join multiple lines with ~\n~.
 
-See the Test All workflow files for all supported values for each option.
+The ~merge~ option can be used to merge branches into ZMK at build time.  Branches are specified as ~<user>/<repo>/<branch>~.  To merge multiple branches, separate with space.
 
 
 **** Build Inputs
@@ -78,6 +80,8 @@ The ~Miryoku Alphas~, ~Miryoku Nav~, ~Miryoku Clipboard~, and ~Miryoku Layers~ o
 
 The ~Kconfig~ option can be used to for [[#kconfig-configuration][Kconfig configuration]].  Join multiple lines with ~\n~.
 
+The ~ZMK Merge~ option can be used to merge branches into ZMK at build time.  Branches are specified as ~<user>/<repo>/<branch>~.  To merge multiple branches, separate with space.
+
 
 ** Supported Keyboards