cellxgene-census

cellxgene-census is a skill for Claude Code from dralkh/seerai. It costs 97 tokens per session (4,666 once invoked), scanned A, a copy of cellxgene-census, MIT.

A programmatic interface to the CZ CELLxGENE Census, a versioned public collection of single-cell and spatial gene-expression data with standardised metadata.

In plain words
What is it for?
Use it to query cells by type, tissue, or disease, inspect dataset metadata, retrieve expression data and source files, compare reference atlases, and work with embeddings or spatial data.
Why use it?
It lets researchers find and analyse relevant cells and datasets without first downloading an entire collection.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Good fit Use it to query cells by type, tissue, or disease, inspect dataset metadata, retrieve expression data and source files, compare reference atlases, and work with embeddings or spatial data.

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Install with agentmods
npx agentmods add skills/dralkh/seerai/cellxgene-census
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add dralkh/seerai --skill cellxgene-census
Clone the repo
git clone --depth 1 https://github.com/dralkh/seerai

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for cellxgene-census

README.md
[![agentmods](https://agentmods.dev/badge/skills/dralkh/seerai/cellxgene-census/github.svg)](https://agentmods.dev/skills/dralkh/seerai/cellxgene-census)
Your own site
<a href="https://agentmods.dev/skills/dralkh/seerai/cellxgene-census"><img src="https://agentmods.dev/badge/skills/dralkh/seerai/cellxgene-census/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for cellxgene-census

Your own site · 80×15
<a href="https://agentmods.dev/skills/dralkh/seerai/cellxgene-census"><img src="https://agentmods.dev/badge/skills/dralkh/seerai/cellxgene-census.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 97 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,666 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin 86% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00097 $0.04666
Opus 5 $0.00048 $0.02333
Sonnet 5 $0.00019 $0.00933
Haiku 4.5 $0.00010 $0.00467

Measured 13d ago against content hash 54e49ca66e7b, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

cellxgene-census scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 13d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

86% identical to cellxgene-census — 317 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

skills/cellxgene-census/SKILL.md · 560 lines

How it starts

The opening of the file, as written. The whole thing — 560 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CZ CELLxGENE Census

Overview

The CZ CELLxGENE Census provides programmatic access to a comprehensive, versioned collection of standardized single-cell and spatial transcriptomics data from CZ CELLxGENE Discover. This skill enables efficient querying and analysis of public Census releases without downloading whole datasets first.

The Census includes:

  • 217+ million total cells and 125+ million unique cells in the 2025-11-08 stable LTS release
  • 1,845 datasets in the 2025-11-08 stable LTS release
  • Human, mouse, marmoset, rhesus macaque, and chimpanzee data in the current schema
  • Standardized metadata (cell types, tissues, diseases, donors)
  • Raw gene expression matrices and source H5AD lookup/download helpers
  • Pre-calculated summary counts, embeddings, and spatial data
  • Integration with AnnData, Scanpy, TileDB-SOMA, TileDB-SOMA-ML, and other analysis tools

When to Use This Skill

This skill should be used when:

  • Querying single-cell expression data by cell type, tissue, or disease
  • Exploring available single-cell datasets and metadata
  • Training machine learning models on single-cell data
  • Performing large-scale cross-dataset analyses
  • Integrating Census data with scanpy or other analysis frameworks
  • Computing statistics across millions of cells
  • Accessing pre-calculated embeddings or model predictions

Installation and Setup

Install the Census API:

uv pip install "cellxgene-census==1.17.*"

For spatial workflows:

uv pip install "cellxgene-census[spatial]==1.17.*" "spatialdata[extra]>=0.2.5"

For PyTorch model training, use TileDB-SOMA-ML. The old cellxgene_census.experimental.ml loaders are deprecated:

uv pip install "cellxgene-census==1.17.*" tiledbsoma-ml

Core Workflow Patterns

1. Opening the Census

Always use the context manager to ensure proper resource cleanup:

import cellxgene_census

# Open latest stable version
with cellxgene_census.open_soma() as census:
    # Work with census data

# Open the current LTS version for reproducibility
with cellxgene_census.open_soma(census_version="2025-11-08") as census:
    # Work with census data

Read the full file on GitHub · 560 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 13d ago First seen · 560 lines · 97 tokens per session scan A 54e49ca66e7b

Subscribe to this mod's changes

cellxgene-census is a skill published in the GitHub repository dralkh/seerai (77 stars, last pushed 2mo ago), licensed MIT. It adds 97 tokens to every session and 4,666 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 0 findings. It is 86% identical to cellxgene-census, differing in 317 lines, and is treated as a copy.

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