diff --git a/.nova/last_run.txt b/.nova/last_run.txt
new file mode 100644
index 00000000..2b9f9864
--- /dev/null
+++ b/.nova/last_run.txt
@@ -0,0 +1 @@
+1757781984
diff --git a/.nova/test-results.json b/.nova/test-results.json
new file mode 100644
index 00000000..7f9242d8
--- /dev/null
+++ b/.nova/test-results.json
@@ -0,0 +1,274 @@
+{
+    "created": 1757781985.026093,
+    "duration": 0.014173030853271484,
+    "exitcode": 5,
+    "root": "/private/var/folders/22/fzs3nrw505z_m71cghqjc7j80000gn/T/nova-fix-uy1kqqsb/repo",
+    "environment": {},
+    "summary": { "total": 0, "collected": 0 },
+    "collectors": [
+        {
+            "nodeid": "",
+            "outcome": "passed",
+            "result": [{ "nodeid": ".", "type": "Dir" }]
+        },
+        { "nodeid": "docs/_static/css", "outcome": "passed", "result": [] },
+        {
+            "nodeid": "docs/_static",
+            "outcome": "passed",
+            "result": [{ "nodeid": "docs/_static/css", "type": "Dir" }]
+        },
+        {
+            "nodeid": "docs/_templates/autosummary",
+            "outcome": "passed",
+            "result": []
+        },
+        {
+            "nodeid": "docs/_templates",
+            "outcome": "passed",
+            "result": [
+                { "nodeid": "docs/_templates/autosummary", "type": "Dir" }
+            ]
+        },
+        { "nodeid": "docs/extensions", "outcome": "passed", "result": [] },
+        { "nodeid": "docs/notebooks/data", "outcome": "passed", "result": [] },
+        { "nodeid": "docs/notebooks/img", "outcome": "passed", "result": [] },
+        {
+            "nodeid": "docs/notebooks",
+            "outcome": "passed",
+            "result": [
+                { "nodeid": "docs/notebooks/data", "type": "Dir" },
+                { "nodeid": "docs/notebooks/img", "type": "Dir" }
+            ]
+        },
+        {
+            "nodeid": "docs",
+            "outcome": "passed",
+            "result": [
+                { "nodeid": "docs/_static", "type": "Dir" },
+                { "nodeid": "docs/_templates", "type": "Dir" },
+                { "nodeid": "docs/extensions", "type": "Dir" },
+                { "nodeid": "docs/notebooks", "type": "Dir" }
+            ]
+        },
+        {
+            "nodeid": "tutorial-registry/tutorials/ATAC-preprocessing",
+            "outcome": "passed",
+            "result": []
+        },
+        {
+            "nodeid": "tutorial-registry/tutorials/CITEseq-integration",
+            "outcome": "passed",
+            "result": []
+        },
+        {
+            "nodeid": "tutorial-registry/tutorials/Joint-analysis-of-multiomic-data-with-MultiVI",
+            "outcome": "passed",
+            "result": []
+        },
+        {
+            "nodeid": "tutorial-registry/tutorials/RNA-velocity",
+            "outcome": "passed",
+            "result": []
+        },
+        {
+            "nodeid": "tutorial-registry/tutorials/advanced-plotting",
+            "outcome": "passed",
+            "result": []
+        },
+        {
+            "nodeid": "tutorial-registry/tutorials/anndata-getting-started",
+            "outcome": "passed",
+            "result": []
+        },
+        {
+            "nodeid": "tutorial-registry/tutorials/anndata-mudata-axes",
+            "outcome": "passed",
+            "result": []
+        },
+        {
+            "nodeid": "tutorial-registry/tutorials/bentotools-subcellular-resolution",
+            "outcome": "passed",
+            "result": []
+        },
+        {
+            "nodeid": "tutorial-registry/tutorials/cellcharter-spatial-transcriptomics",
+            "outcome": "passed",
+            "result": []
+        },
+        {
+            "nodeid": "tutorial-registry/tutorials/compositional-analysis",
+            "outcome": "passed",
+            "result": []
+        },
+        {
+            "nodeid": "tutorial-registry/tutorials/concatenation-of-multimodal-data",
+            "outcome": "passed",
+            "result": []
+        },
+        {
+            "nodeid": "tutorial-registry/tutorials/concatenation-of-unimodal-data",
+            "outcome": "passed",
+            "result": []
+        },
+        {
+            "nodeid": "tutorial-registry/tutorials/decoupler-pseudobulk-de",
+            "outcome": "passed",
+            "result": []
+        },
+        {
+            "nodeid": "tutorial-registry/tutorials/interoperability",
+            "outcome": "passed",
+            "result": []
+        },
+        {
+            "nodeid": "tutorial-registry/tutorials/perturbation-modeling",
+            "outcome": "passed",
+            "result": []
+        },
+        {
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+            "outcome": "passed",
+            "result": []
+        },
+        {
+            "nodeid": "tutorial-registry/tutorials/preprocessing-and-clustering",
+            "outcome": "passed",
+            "result": []
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+        {
+            "nodeid": "tutorial-registry/tutorials/pseudotemporal-ordering",
+            "outcome": "passed",
+            "result": []
+        },
+        {
+            "nodeid": "tutorial-registry/tutorials/scirpy-tcr",
+            "outcome": "passed",
+            "result": []
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+            "nodeid": "tutorial-registry/tutorials/scverse-objects-in-backed-mode",
+            "outcome": "passed",
+            "result": []
+        },
+        {
+            "nodeid": "tutorial-registry/tutorials/scvi-batch-effect-removal",
+            "outcome": "passed",
+            "result": []
+        },
+        {
+            "nodeid": "tutorial-registry/tutorials/squidpy-spatial",
+            "outcome": "passed",
+            "result": []
+        },
+        {
+            "nodeid": "tutorial-registry/tutorials",
+            "outcome": "passed",
+            "result": [
+                {
+                    "nodeid": "tutorial-registry/tutorials/ATAC-preprocessing",
+                    "type": "Dir"
+                },
+                {
+                    "nodeid": "tutorial-registry/tutorials/CITEseq-integration",
+                    "type": "Dir"
+                },
+                {
+                    "nodeid": "tutorial-registry/tutorials/Joint-analysis-of-multiomic-data-with-MultiVI",
+                    "type": "Dir"
+                },
+                {
+                    "nodeid": "tutorial-registry/tutorials/RNA-velocity",
+                    "type": "Dir"
+                },
+                {
+                    "nodeid": "tutorial-registry/tutorials/advanced-plotting",
+                    "type": "Dir"
+                },
+                {
+                    "nodeid": "tutorial-registry/tutorials/anndata-getting-started",
+                    "type": "Dir"
+                },
+                {
+                    "nodeid": "tutorial-registry/tutorials/anndata-mudata-axes",
+                    "type": "Dir"
+                },
+                {
+                    "nodeid": "tutorial-registry/tutorials/bentotools-subcellular-resolution",
+                    "type": "Dir"
+                },
+                {
+                    "nodeid": "tutorial-registry/tutorials/cellcharter-spatial-transcriptomics",
+                    "type": "Dir"
+                },
+                {
+                    "nodeid": "tutorial-registry/tutorials/compositional-analysis",
+                    "type": "Dir"
+                },
+                {
+                    "nodeid": "tutorial-registry/tutorials/concatenation-of-multimodal-data",
+                    "type": "Dir"
+                },
+                {
+                    "nodeid": "tutorial-registry/tutorials/concatenation-of-unimodal-data",
+                    "type": "Dir"
+                },
+                {
+                    "nodeid": "tutorial-registry/tutorials/decoupler-pseudobulk-de",
+                    "type": "Dir"
+                },
+                {
+                    "nodeid": "tutorial-registry/tutorials/interoperability",
+                    "type": "Dir"
+                },
+                {
+                    "nodeid": "tutorial-registry/tutorials/perturbation-modeling",
+                    "type": "Dir"
+                },
+                {
+                    "nodeid": "tutorial-registry/tutorials/plotting-in-scanpy",
+                    "type": "Dir"
+                },
+                {
+                    "nodeid": "tutorial-registry/tutorials/preprocessing-and-clustering",
+                    "type": "Dir"
+                },
+                {
+                    "nodeid": "tutorial-registry/tutorials/pseudotemporal-ordering",
+                    "type": "Dir"
+                },
+                {
+                    "nodeid": "tutorial-registry/tutorials/scirpy-tcr",
+                    "type": "Dir"
+                },
+                {
+                    "nodeid": "tutorial-registry/tutorials/scverse-objects-in-backed-mode",
+                    "type": "Dir"
+                },
+                {
+                    "nodeid": "tutorial-registry/tutorials/scvi-batch-effect-removal",
+                    "type": "Dir"
+                },
+                {
+                    "nodeid": "tutorial-registry/tutorials/squidpy-spatial",
+                    "type": "Dir"
+                }
+            ]
+        },
+        {
+            "nodeid": "tutorial-registry",
+            "outcome": "passed",
+            "result": [
+                { "nodeid": "tutorial-registry/tutorials", "type": "Dir" }
+            ]
+        },
+        {
+            "nodeid": ".",
+            "outcome": "passed",
+            "result": [
+                { "nodeid": "docs", "type": "Dir" },
+                { "nodeid": "tutorial-registry", "type": "Dir" }
+            ]
+        }
+    ],
+    "tests": []
+}
diff --git a/tutorial-registry/tutorials/decoupler-pseudobulk-de/meta.yaml b/tutorial-registry/tutorials/decoupler-pseudobulk-de/meta.yaml
index 00fa11d2..b787a309 100644
--- a/tutorial-registry/tutorials/decoupler-pseudobulk-de/meta.yaml
+++ b/tutorial-registry/tutorials/decoupler-pseudobulk-de/meta.yaml
@@ -2,7 +2,7 @@ name: Pseudo-bulk differential expression and functional analysis
 description: |
   This notebook showcases decoupler for pathway and TF enrichment on ~5k
   Blood myeloid cells from healthy and COVID-19 infected patients.
-link: https://decoupler-py.readthedocs.io/en/latest/notebooks/pseudobulk.html
+link: https://decoupler.readthedocs.io/en/latest/notebooks/scell/rna_psbk.html
 image: icon.png
 primary_category: scRNA-seq
 order: 30
diff --git a/tutorial-registry/validate.py b/tutorial-registry/validate.py
index d83e6207..451280f4 100755
--- a/tutorial-registry/validate.py
+++ b/tutorial-registry/validate.py
@@ -22,8 +22,11 @@
 HERE = Path(__file__).absolute().parent
 
 
+HEADERS = {"User-Agent": "scverse tutorial registry (https://github.com/scverse/scverse-tutorials)"}
+
+
 def _check_url_exists(url: str) -> None:
-    response = httpx.get(url)
+    response = httpx.head(url, headers=HEADERS)
     if response.status_code != 200:
         raise ValueError(f"URL {url} is not reachable (error {response.status_code}). ")