diff --git a/.github/workflows/nightly.yaml b/.github/workflows/nightly.yaml
index ecaa419f1..4759d1933 100644
--- a/.github/workflows/nightly.yaml
+++ b/.github/workflows/nightly.yaml
@@ -15,7 +15,11 @@ jobs:
     uses: ./.github/workflows/regression_reusable.yaml
     with:
       env-path: runner/env_nightly
+      testrun_name: nightly
+      report-history: true
     secrets:
+      TCACHE_BASIC_AUTH: ${{ secrets.TCACHE_BASIC_AUTH }}
+      TCACHE_URL: ${{ secrets.TCACHE_URL }}
       CI_FAIL_MAILS: ${{ secrets.NIGHTLY_FAIL_MAILS }}
       GMAIL_USERNAME: ${{ secrets.GMAIL_USERNAME }}
       GMAIL_PASSWORD: ${{ secrets.GMAIL_PASSWORD }}
diff --git a/.github/workflows/nightly_cli.yaml b/.github/workflows/nightly_cli.yaml
index 6cd42e75c..ed89afeca 100644
--- a/.github/workflows/nightly_cli.yaml
+++ b/.github/workflows/nightly_cli.yaml
@@ -15,7 +15,11 @@ jobs:
     uses: ./.github/workflows/regression_reusable.yaml
     with:
       env-path: runner/env_nightly_cli
+      testrun_name: nightly-cli
+      report-history: true
     secrets:
+      TCACHE_BASIC_AUTH: ${{ secrets.TCACHE_BASIC_AUTH }}
+      TCACHE_URL: ${{ secrets.TCACHE_URL }}
       CI_FAIL_MAILS: ${{ secrets.NIGHTLY_FAIL_MAILS }}
       GMAIL_USERNAME: ${{ secrets.GMAIL_USERNAME }}
       GMAIL_PASSWORD: ${{ secrets.GMAIL_PASSWORD }}
diff --git a/.github/workflows/nightly_dbsync.yaml b/.github/workflows/nightly_dbsync.yaml
index c3ceb0484..2e2f59da1 100644
--- a/.github/workflows/nightly_dbsync.yaml
+++ b/.github/workflows/nightly_dbsync.yaml
@@ -15,7 +15,11 @@ jobs:
     uses: ./.github/workflows/regression_reusable.yaml
     with:
       env-path: runner/env_nightly_dbsync
+      testrun_name: nightly-dbsync
+      report-history: true
     secrets:
+      TCACHE_BASIC_AUTH: ${{ secrets.TCACHE_BASIC_AUTH }}
+      TCACHE_URL: ${{ secrets.TCACHE_URL }}
       CI_FAIL_MAILS: ${{ secrets.NIGHTLY_FAIL_MAILS }}
       GMAIL_USERNAME: ${{ secrets.GMAIL_USERNAME }}
       GMAIL_PASSWORD: ${{ secrets.GMAIL_PASSWORD }}
diff --git a/.github/workflows/regression.yaml b/.github/workflows/regression.yaml
index dc8ee3a54..c00b8d349 100644
--- a/.github/workflows/regression.yaml
+++ b/.github/workflows/regression.yaml
@@ -60,6 +60,10 @@ on:
         type: boolean
         default: false
         description: "Skip tests that already passed (internal)"
+      report-history:
+        type: boolean
+        default: false
+        description: "TEMP-SMOKE-TEST: revert before merge"
 
 run-name: ${{ inputs.testrun_name && 'Run:' || ''}} ${{ inputs.testrun_name }} ${{ (inputs.testrun_name && inputs.skip_passed) && ':repeat:' || '' }}
 
@@ -81,6 +85,7 @@ jobs:
       byron_cluster: ${{ inputs.byron_cluster }}
       testrun_name: ${{ inputs.testrun_name }}
       skip_passed: ${{ inputs.skip_passed }}
+      report-history: ${{ inputs.report-history }}
       env-path: runner/env_regression
     secrets:
       TCACHE_BASIC_AUTH: ${{ secrets.TCACHE_BASIC_AUTH }}
diff --git a/.github/workflows/regression_reusable.yaml b/.github/workflows/regression_reusable.yaml
index 2f8e39c99..89c75ba28 100644
--- a/.github/workflows/regression_reusable.yaml
+++ b/.github/workflows/regression_reusable.yaml
@@ -51,6 +51,10 @@ on:
         required: false
         type: boolean
         default: false
+      report-history:
+        required: false
+        type: boolean
+        default: false
     secrets:
       TCACHE_BASIC_AUTH:
         required: false
@@ -231,6 +235,28 @@ jobs:
             testrun_name_strip="${CI_TESTRUN_NAME//[!a-zA-Z0-9_-]/}"
             curl -s -X PUT --fail-with-body -u "$TCACHE_BASIC_AUTH" "$TCACHE_URL/${testrun_name_strip}/${{ github.run_number }}/import" -F "junitxml=@run_workdir/testrun-report.xml"
           fi
+      - name: Report nightly history
+        # PUTs to /history, separate from /import above. Gated on
+        # report-history so only nightly runs persist JUnit XML.
+        if: (success() || failure()) && inputs.testrun_name && inputs.report-history # TEMP-SMOKE-TEST: revert to failure() before merge
+        env:
+          TCACHE_BASIC_AUTH: ${{ secrets.TCACHE_BASIC_AUTH }}
+          TCACHE_URL: ${{ secrets.TCACHE_URL }}
+        run: |
+          if [ -n "$TCACHE_BASIC_AUTH" ] && [ -n "$TCACHE_URL" ] && [ -e run_workdir/testrun-report.xml ]; then
+            testrun_name_strip="${CI_TESTRUN_NAME//[!a-zA-Z0-9_-]/}"
+            curl -s -X PUT --fail-with-body -u "$TCACHE_BASIC_AUTH" "$TCACHE_URL/history/${testrun_name_strip}/${{ github.run_number }}" -F "junitxml=@run_workdir/testrun-report.xml"
+          fi
+      - name: TEMP-SMOKE-TEST verify tcache history
+        # Remove before merge. Prints the /history listing so we can confirm
+        # the PUT above actually landed, from the job log alone.
+        if: (success() || failure()) && inputs.testrun_name && inputs.report-history
+        env:
+          TCACHE_BASIC_AUTH: ${{ secrets.TCACHE_BASIC_AUTH }}
+          TCACHE_URL: ${{ secrets.TCACHE_URL }}
+        run: |
+          testrun_name_strip="${CI_TESTRUN_NAME//[!a-zA-Z0-9_-]/}"
+          curl -s -u "$TCACHE_BASIC_AUTH" "$TCACHE_URL/history/${testrun_name_strip}?days=1"
       - name: ↟ Upload testing artifacts on failure
         uses: actions/upload-artifact@v7
         if: failure()