diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 201938f..eba7923 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -2,21 +2,24 @@ name: 'Get Cover Build'
 on: ['pull_request']
 
 jobs:
-  build: # make sure build/ci work properly
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v3
-      - run: |
-          npm install
-      - run: |
-          npm run all
+  # build: # make sure build/ci work properly
+  #   runs-on: ubuntu-latest
+  #   steps:
+  #     - uses: actions/checkout@v3
+  #     - run: |
+  #         npm install
+  #     - run: |
+  #         npm run all
   test: # make sure the action works on a clean machine without building
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3
+        with:
+          ref: ${{ github.head_ref }}
       - uses: ./
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
           thresholdNew: 0.8
           thresholdModified: 0.0
           coverageFile: coverage.xml
+          diffCoverageFile: diff-coverage.json
diff --git a/action.yml b/action.yml
index f81bc10..1ac39d5 100644
--- a/action.yml
+++ b/action.yml
@@ -8,6 +8,9 @@ inputs:
   token:
     required: true
     description: 'github token'
+  diffCoverageFile:
+    required: false
+    description: 'local path to a diff coverage xml file like the output of diff-cover coverage.xml'
   thresholdAll:
     required: false
     description: the coverage threshold for average over all files [0,1]
@@ -27,5 +30,5 @@ runs:
   using: 'node20'
   main: 'dist/index.js'
 branding:
-   icon: 'umbrella'
-   color: 'purple'
+  icon: 'umbrella'
+  color: 'purple'
diff --git a/diff-coverage.json b/diff-coverage.json
new file mode 100644
index 0000000..39f5cc5
--- /dev/null
+++ b/diff-coverage.json
@@ -0,0 +1,32 @@
+{
+    "report_name": "XML",
+    "diff_name": "origin/develop...HEAD, staged and unstaged changes",
+    "src_stats": {
+        "src/coverage.ts": {
+            "percent_covered": 69.9090909090909,
+            "violation_lines": [],
+            "covered_lines": [
+                12,
+                367,
+                370,
+                371,
+                372,
+                373,
+                378,
+                379,
+                380,
+                381
+            ],
+            "violations": [
+                [
+                    368,
+                    null
+                ]
+            ]
+        }
+    },
+    "total_num_lines": 45,
+    "total_num_violations": 34,
+    "total_percent_covered": 24,
+    "num_changed_lines": 95
+}
\ No newline at end of file
diff --git a/src/coverage.ts b/src/coverage.ts
index 6589089..7bd3cde 100644
--- a/src/coverage.ts
+++ b/src/coverage.ts
@@ -23,14 +23,18 @@ export type FilesCoverage = {
   modifiedCover?: Coverage[]
 }
 
-export function parseCoverageReport(report: string, files: CommitsComparison): FilesCoverage {
+export function parseCoverageReport(report: string, diffReport: string, files: CommitsComparison): FilesCoverage {
   const threshAll = parseFloat(core.getInput('thresholdAll'))
   const avgCover = parseAverageCoverage(report, threshAll)
 
   const source = core.getInput('sourceDir') || parseSource(report)
   const threshModified = parseFloat(core.getInput('thresholdModified'))
-  const modifiedCover = parseFilesCoverage(report, source, files.modifiedFiles, threshModified)
-
+  let modifiedCover: Coverage[] | undefined
+  if (diffReport === '') {
+    modifiedCover = parseFilesCoverage(report, source, files.modifiedFiles, threshModified)
+  } else {
+    modifiedCover = parseFilesCoverage(diffReport, source, files.modifiedFiles, threshModified)
+  }
   const threshNew = parseFloat(core.getInput('thresholdNew'))
   const newCover = parseFilesCoverage(report, source, files.newFiles, threshNew)
   return {averageCover: avgCover, newCover, modifiedCover}
@@ -56,6 +60,22 @@ export function parseFilesCoverage(
   return coverages?.filter(cover => cover.cover >= 0)
 }
 
+export function parseDiffCoverageReport(
+  report: string,
+  source: string,
+  files: string[] | undefined,
+  threshold: number
+): Coverage[] | undefined {
+  const jsonReport = JSON.parse(report)
+  const coverages = files?.map(file => {
+    const fileName = escapeRegExp(file.replace(`${source}/`, ''))
+    const fileReport = jsonReport.src_stats[fileName]
+    const cover = fileReport?.percent_covered ?? -1
+    return {file, cover, pass: cover >= threshold}
+  })
+  return coverages?.filter(cover => cover.cover >= 0)
+}
+
 export function parseSource(report: string): string {
   const regex = new RegExp(`.*<source>(?<source>.*)</source>.*`)
   const match = report.match(regex)
diff --git a/src/index.ts b/src/index.ts
index 8c1f1fc..104ebee 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -8,7 +8,10 @@ import readFile from './readFile'
 async function run(): Promise<void> {
   try {
     const coverageFile: string = core.getInput('coverageFile', {required: true})
-    core.debug(`coverageFile: ${coverageFile}`)
+    core.info(`coverageFile: ${coverageFile}`)
+
+    const diffCoverageFile: string = core.getInput('diffCoverageFile')
+    core.info(`diffCoverageFile: ${diffCoverageFile}`)
 
     const eventName = context.eventName
     if (eventName !== 'pull_request') {
@@ -21,10 +24,11 @@ async function run(): Promise<void> {
 
     core.info(`comparing commits: base ${base} <> head ${head}`)
     const files = await compareCommits(base, head)
-    core.info(`git new files: ${JSON.stringify(files.newFiles)} modified files: ${JSON.stringify(files.modifiedFiles)}`)
+    core.info(`can you see me ? git new files: ${JSON.stringify(files.newFiles)} modified files: ${JSON.stringify(files.modifiedFiles)}`)
 
     const report = readFile(coverageFile)
-    const filesCoverage = parseCoverageReport(report, files)
+    const diffReport = readFile(diffCoverageFile)
+    const filesCoverage = parseCoverageReport(report, diffReport, files)
     const passOverall = scorePr(filesCoverage)
 
     if (!passOverall) {