scvelo

scvelo is a skill for Claude Code, Codex from synthetic-sciences/openscience. It costs 56 tokens per session (3,003 once invoked), scanned A, a copy of scvelo, Apache-2.0.

A Python-based method for analysing RNA velocity in single-cell RNA sequencing data. It compares unspliced and spliced RNA to estimate which way cells are changing and to place them along a likely developmental timeline.

In plain words
What is it for?
Use it to infer cell trajectories, study cell-fate decisions, estimate latent time, and identify genes associated with changes in cell state.
Why use it?
A single sequencing snapshot does not directly show how cells transition, so this analysis provides clues about direction and possible future cell states.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to infer cell trajectories, study cell-fate decisions, estimate latent time, and identify genes associated with changes in cell state.

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Install with agentmods
npx agentmods add skills/synthetic-sciences/openscience/scvelo
About the project

synthetic-sciences/openscience is an AI workbench that carries out scientific research by reading papers, forming hypotheses, writing and running code, conducting experiments, analyzing results, and preparing reports. Researchers use it for work in machine learning, biology, physics, and chemistry with remote or local models. Catalogue add-ons extend its scientific workflows through skills and instructions.

synthetic-sciences/openscience · 4,025 stars · on GitHub · openscience.sh

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 synthetic-sciences/openscience --skill scvelo
Clone the repo
git clone --depth 1 https://github.com/synthetic-sciences/openscience

Made for: Claude Code, Codex.

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 scvelo

README.md
[![agentmods](https://agentmods.dev/badge/skills/synthetic-sciences/openscience/scvelo/github.svg)](https://agentmods.dev/skills/synthetic-sciences/openscience/scvelo)
Your own site
<a href="https://agentmods.dev/skills/synthetic-sciences/openscience/scvelo"><img src="https://agentmods.dev/badge/skills/synthetic-sciences/openscience/scvelo/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 scvelo

Your own site · 80×15
<a href="https://agentmods.dev/skills/synthetic-sciences/openscience/scvelo"><img src="https://agentmods.dev/badge/skills/synthetic-sciences/openscience/scvelo.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 56 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,003 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 97% 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 $0.00056 $0.03003
Opus 5.5 $0.00022 $0.01201
Sonnet 5.5 $0.00011 $0.00601
Haiku 4.5 $0.00006 $0.00300

Measured 1mo ago against content hash 03c33dfc97c8, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

scvelo 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 1mo ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/rna_velocity_workflow.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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

97% identical to scvelo — 452 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.

backend/cli/skills/biology/scvelo/SKILL.md · 336 lines

How it starts

The opening of the file, as written. The whole thing — 336 lines — stays where its author put it; the contents beside it link to each section on GitHub.

scVelo — RNA Velocity Analysis

Overview

scVelo is the leading Python package for RNA velocity analysis in single-cell RNA-seq data. It infers cell state transitions by modeling the kinetics of mRNA splicing — using the ratio of unspliced (pre-mRNA) to spliced (mature mRNA) abundances to determine whether a gene is being upregulated or downregulated in each cell. This allows reconstruction of developmental trajectories and identification of cell fate decisions without requiring time-course data.

Installation: uv pip install scvelo

Key resources:

When to Use This Skill

Use scVelo when:

  • Trajectory inference from snapshot data: Determine which direction cells are differentiating
  • Cell fate prediction: Identify progenitor cells and their downstream fates
  • Driver gene identification: Find genes whose dynamics best explain observed trajectories
  • Developmental biology: Model hematopoiesis, neurogenesis, epithelial-to-mesenchymal transitions
  • Latent time estimation: Order cells along a pseudotime derived from splicing dynamics
  • Complement to Scanpy: Add directional information to UMAP embeddings

Prerequisites

scVelo requires count matrices for both unspliced and spliced RNA. These are generated by:

  1. STARsolo or kallisto|bustools with lamanno mode
  2. velocyto CLI: velocyto run10x / velocyto run
  3. alevin-fry / simpleaf with spliced/unspliced output

Data is stored in an AnnData object with layers["spliced"] and layers["unspliced"].

Standard RNA Velocity Workflow

1. Setup and Data Loading

import scvelo as scv
import scanpy as sc
import numpy as np
import matplotlib.pyplot as plt

# Configure settings
scv.settings.verbosity = 3       # Show computation steps
scv.settings.presenter_view = True
scv.settings.set_figure_params('scvelo')

# Load data (AnnData with spliced/unspliced layers)
# Option A: Load from loom (velocyto output)
adata = scv.read("cellranger_output.loom", cache=True)

# Option B: Merge velocyto loom with Scanpy-processed AnnData
adata_processed = sc.read_h5ad("processed.h5ad")  # Has UMAP, clusters
adata_velocity = scv.read("velocyto.loom")
adata = scv.utils.merge(adata_processed, adata_velocity)

# Verify layers
print(adata)
# obs × var: N × G
# layers: 'spliced', 'unspliced' (required)
# obsm['X_umap'] (required for visualization)

Read the full file on GitHub · 336 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. 1mo ago Changed · +5 lines 03c33dfc97c8
  2. 1mo ago First seen · 331 lines · 56 tokens per session scan A a868f47965db

Subscribe to this mod's changes

scvelo is a skill published in the GitHub repository synthetic-sciences/openscience (4,025 stars, last pushed today), licensed Apache-2.0. It adds 56 tokens to every session and 3,003 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 97% identical to scvelo, differing in 452 lines, and is treated as a copy.

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