diff --git a/.github/workflows/github_CI.yml b/.github/workflows/github_CI.yml
new file mode 100644
index 0000000000000..5337bfd20b610
--- /dev/null
+++ b/.github/workflows/github_CI.yml
@@ -0,0 +1,74 @@
+#####################################################################
+# This triggers git Continuous Integration tests when a PR to       #
+# any branch is made. Or if a code-commit is made to any            #
+# test branch (temporarily) specified below.                        #
+#                                                                   #
+# The tests themselves are delegated to a gitlab CI runner          #
+# controlled by the .gitlab-ci.yml file at                          #
+# https://gitlab.cern.ch/cms-l1tk/cmssw_CI .                        #
+# N.B. .gitlab-ci.yml must be update if the CMSSW version changes.  #
+#                                                                   # 
+# Communication between the github & gitlab CIs is done via scripts #
+# at https://github.com/cms-L1TK/gitlab-mirror-and-ci-action        #
+#####################################################################
+
+name: PR validation with GitLab CI
+ 
+on: # Controls when the action will run.
+  workflow_dispatch:
+  push: # Please specify your branch down here if you want CI to run for each push to it.
+    branches: [myBranchUnderTest]
+  pull_request: # Run CI if someone makes a PR to any branch
+    # branches: [L1TK-dev-12_0_0_pre4] # Optionally only run CI if PR is to this branch.
+    
+env:
+  mirror_repo: "https://gitlab.cern.ch/cms-l1tk/cmssw_CI" # gitlab mirror
+  current_branch: "unitialized"
+
+jobs:
+  trigger_gitlab_CI: # https://github.com/marketplace/actions/mirror-to-gitlab-and-run-gitlab-ci
+    name: trigger_gitlab_CI
+    runs-on: ubuntu-latest
+    steps:
+
+    - name: DebugPrint
+      run: |
+        echo "github.ref = ${{ github.ref }}"
+
+    - name: Redefine branch on pull_request
+      if: github.event_name == 'pull_request'
+      run: |
+        # Sets env. variable $current_branch
+        echo "current_branch=$(echo ${{ github.head_ref }})" >> $GITHUB_ENV
+
+    - name: Redefine branch on push
+      if: github.event_name == 'push'
+      run: |
+        # Sets env. variable $current_branch
+        echo "current_branch=$(echo ${{ github.ref }} | sed -E 's|refs/[a-zA-Z]+/||')" >> $GITHUB_ENV
+
+    - name: Trigger gitlab CI run
+      # Communicate between gitlab & github, and trigger gitlab CI run.
+      # (Forked from https://github.com/SvanBoxel/gitlab-mirror-and-ci-action).
+      uses: cms-L1TK/gitlab-mirror-and-ci-action@master
+      env:
+        GITLAB_HOSTNAME: "gitlab.cern.ch"
+        GITLAB_USERNAME: "cms-l1tk"   
+        GITLAB_PASSWORD: ${{ secrets.GITLAB_L1TK_CMSSW_CI_TOKEN }} # Generate token here: https://gitlab.cern.ch/cms-l1tk/cmssw_CI/-/settings/access_tokens and add it to GitHub secrets https://github.com/cms-L1TK/cmssw/settings/secrets/actions   
+        GITLAB_PROJECT_ID: "124851" # ID visible at https://gitlab.cern.ch/cms-l1tk/cmssw 
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }} # https://help.github.com/en/articles/virtual-environments-for-github-actions#github_token-secret
+        MIRROR_REPO: ${{ env.mirror_repo }} # gitlab mirror.
+        IS_CMSSW: "true" # Is repo CMSSW or something else (e.g. HLS)?
+        CHECKOUT_BRANCH: ${{ env.current_branch }} # Needed so push to gitlab can work
+        REMOVE_BRANCH: "true" # Refreshes branch on mirror, which triggers CI run there.
+        REBASE_MASTER: "false" # If true would rebase to "master", which isn't used in cms-L1TK.
+        RETURN_FILE: "pipeline_url.txt" # Output file with gitlab pipeline url
+
+    - name: print summary
+      if: always()
+      run: |
+        echo ""
+        echo "==========================================================="
+        echo "DETAILED OUTPUT FROM CMSSW COMPILATION & RUN AVAILABLE "
+        echo "AT FOLLOWING GITLAB CI URL:"
+        cat pipeline_url.txt
diff --git a/L1Trigger/TrackFindingTracklet/test/makeHists.csh b/L1Trigger/TrackFindingTracklet/test/makeHists.csh
index 6ad4919784a6b..8458faad0cc78 100755
--- a/L1Trigger/TrackFindingTracklet/test/makeHists.csh
+++ b/L1Trigger/TrackFindingTracklet/test/makeHists.csh
@@ -13,7 +13,7 @@
 ###########################################################################
 
 if ($#argv == 0) then
-  set inputFullFileName = "TTbar_PU200_D49.root"
+  set inputFullFileName = "TTbar_PU200_D76.root"
 else
   set inputFullFileName = $1
 endif
diff --git a/L1Trigger/TrackFindingTracklet/test/skimForCI_cfg.py b/L1Trigger/TrackFindingTracklet/test/skimForCI_cfg.py
new file mode 100644
index 0000000000000..d21f0528f2d9d
--- /dev/null
+++ b/L1Trigger/TrackFindingTracklet/test/skimForCI_cfg.py
@@ -0,0 +1,73 @@
+#-----------------------------------------------------------
+# This job skims a MC dataset, selecting only products
+# that are needed to run the L1 tracking & measure its
+# performance. 
+#
+# It is typically used to create small datasets that
+# the git CI runs on to check new code.
+#
+# Whenever the L1 tracking group switches to a new default
+# MC dataset, this skim should be run on ttbar+0PU MC, 
+# and the skimmed dataset placed in
+# https://gitlab.cern.ch/cms-l1tk/cmssw_CI .
+#-----------------------------------------------------------
+
+############################################################
+# define basic process
+############################################################
+
+import FWCore.ParameterSet.Config as cms
+import FWCore.Utilities.FileUtils as FileUtils
+import os
+process = cms.Process("SKIM")
+
+ 
+############################################################
+# import standard configurations
+############################################################
+
+process.load('Configuration.StandardSequences.Services_cff')
+process.load('FWCore.MessageService.MessageLogger_cfi')
+process.load('Configuration.EventContent.EventContent_cff')
+process.load('Configuration.StandardSequences.MagneticField_cff')
+
+# D49 geometry (T15 tracker)
+process.load('Configuration.Geometry.GeometryExtended2026D76Reco_cff')
+process.load('Configuration.Geometry.GeometryExtended2026D76_cff')
+
+process.load('Configuration.StandardSequences.EndOfProcess_cff')
+
+
+process.maxEvents = cms.untracked.PSet(input = cms.untracked.int32(1000))
+
+#--- To use MCsamples scripts, defining functions get*data*() for easy MC access,
+#--- follow instructions in https://github.com/cms-L1TK/MCsamples
+
+from MCsamples.Scripts.getCMSdata_cfi import *
+
+# Read data from card files (defines getCMSdataFromCards()):
+from MCsamples.RelVal_1130_D76.PU0_TTbar_14TeV_cfi import *
+inputMC = getCMSdataFromCards()
+
+process.source = cms.Source("PoolSource", fileNames = cms.untracked.vstring(*inputMC))
+
+process.output = cms.OutputModule("PoolOutputModule",
+    splitLevel = cms.untracked.int32(0),
+    eventAutoFlushCompressedSize = cms.untracked.int32(5242880),
+    outputCommands = cms.untracked.vstring('drop *'),
+    fileName = cms.untracked.string('/tmp/skimmedForCI.root'),
+    dataset = cms.untracked.PSet(
+        filterName = cms.untracked.string(''),
+        dataTier = cms.untracked.string('GEN-SIM-DIGI-RAW')
+    )
+)
+
+process.output.outputCommands.append('keep  *_*_*Level1TTTracks*_*')
+process.output.outputCommands.append('keep  *_*_*StubAccepted*_*')
+process.output.outputCommands.append('keep  *_*_*ClusterAccepted*_*')
+process.output.outputCommands.append('keep  *_*_*MergedTrackTruth*_*')
+process.output.outputCommands.append('keep  *_genParticles_*_*')
+
+process.pd = cms.EndPath(process.output)
+
+process.schedule = cms.Schedule(process.pd)