CELLxGENE Census Data Query
Query and analyze 200M+ cells of public single-cell and spatial transcriptomics data from the CZ CELLxGENE Census without downloading full datasets.
Data & AnalyticsAdvanced★ 33,030⑂ 3,248AI score 8/10Last updated: Aug 9, 2026
What it does
The CZ CELLxGENE Census is a versioned, standardized collection of public single-cell and spatial transcriptomics data. This skill teaches Claude to use the cellxgene-census Python API correctly so you pull only the slice you need instead of whole datasets.
- Filter on standardized metadata: cell type, tissue, disease, assay, donor
- Fetch raw expression matrices into AnnData, or stream large slices out-of-core
- List datasets, summary counts, and source H5AD download URIs
- Access pre-computed embeddings and spatial Census data
- Integrate with Scanpy and train PyTorch models via TileDB-SOMA-ML
- Reproducibility best practices (pin
census_version, filteris_primary_data == True) plus a troubleshooting section
Who it's for
- Bioinformaticians and grad students working with scRNA-seq
- Anyone building reference atlases by comparing many public datasets
- ML engineers training cell-type classifiers at million-cell scale
- Users who need public reference data (for your own local data, use scanpy/scvi-tools instead)
Examples
- "Show me the cell type composition of lung tissue" → metadata-only
get_obsquery followed byvalue_counts(). - "Compare CD4/CD8A expression in T cells from COVID-19 donors" → explore metadata first, then load a narrow AnnData slice and analyze with Scanpy.
- "How do macrophages differ across lung, liver, and brain?" → cross-tissue query plus
rank_genes_groupsfor tissue-specific markers.
· · · Install guide · · ·
Install in the Claude app (no terminal)
- Download the ZIP with the button below.
- In Claude, open Settings → Capabilities and turn on 'Code execution and file creation'. (one time)
- Go to Customize → Skills → + → 'Upload a skill' and upload the ZIP.
Install in Claude Code
Let Claude do it — paste this into Claude Code
Install the skill I found on Claude Skill Mart. Copy the skills/cellxgene-census folder from the GitHub repo K-Dense-AI/scientific-agent-skills into my ~/.claude/skills/cellxgene-census/. When it's done, tell me in one line what this skill can do.
Install with a command instead
git clone https://github.com/K-Dense-AI/scientific-agent-skills.git && mkdir -p ~/.claude/skills && cp -r scientific-agent-skills/skills/cellxgene-census ~/.claude/skills/⚠ This is a third-party skill. Check the source repository before installing.
- Open a terminal and confirm you have Python 3.10–3.12 (
python --version). - Clone the repo:
git clone https://github.com/K-Dense-AI/scientific-agent-skills.git - Create the skills folder:
mkdir -p ~/.claude/skills - Copy the skill:
cp -r scientific-agent-skills/skills/cellxgene-census ~/.claude/skills/ - Install the library:
uv pip install "cellxgene-census==1.17.*"(for spatial work:uv pip install "cellxgene-census[spatial]==1.17.*" "spatialdata[extra]>=0.2.5"). - Restart Claude Code and try a prompt like "Query lung cell types from the CELLxGENE Census".
- No authentication is needed for public Census data, but you do need network access and enough RAM for larger queries.
View source on GitHub ↗License: MIT