query-ensembl

Query Ensembl REST API for gene annotations, sequences, variants, and homology.

401|53|Updated Feb 26, 2026
One-click install
npx skills add https://github.com/Runchuan-BU/BioClaw --skill query-ensembl
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: query-ensembl
Source: https://github.com/Runchuan-BU/BioClaw/tree/main/.claude/skills/query-ensembl
Command: npx skills add https://github.com/Runchuan-BU/BioClaw --skill query-ensembl

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

This Skill provides programmatic access to Ensembl data so users can quickly retrieve gene coordinates, sequences, variant annotations, and homology information without manual navigation of web pages.

Core Features & Use Cases

  • Gene and ID lookup: Resolve gene symbols to Ensembl IDs and genomic coordinates with transcript and exon details.
  • Sequence retrieval: Fetch genomic, cDNA, or protein sequences by Ensembl ID or region.
  • Variant and region queries: Look up rsIDs and return variant annotations and overlapping genomic features.
  • Homology and cross-species comparison: Retrieve orthologs and paralogs across supported species.
  • Use Case: Retrieve BRCA2 genomic coordinates, list transcripts and exons, get the canonical protein sequence, and find mouse orthologs.

Quick Start

Ask the skill to look up BRCA2 gene coordinates in homo_sapiens and return transcripts and the protein sequence.

Frequently Asked Questions about query-ensembl

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I retrieve gene coordinates and transcript details from Ensembl?

To retrieve gene coordinates, you can query Ensembl using a gene symbol or Ensembl ID to resolve genomic locations, transcripts, and exon details. This Skill handles REST API lookups and returns JSON-formatted genomic annotations for common model organisms.

Can I fetch genomic and cDNA sequences by Ensembl ID or genomic region?

Yes, you can fetch genomic, cDNA, or protein sequences by querying Ensembl IDs or specific genomic regions. The Skill queries sequence endpoints and returns the requested sequence data formatted in JSON.

How do I look up rsID variant annotations and overlapping genomic features?

You can look up rsIDs to return variant annotations and overlapping genomic features by querying Ensembl variation and overlap endpoints. The Skill processes these REST API requests and retrieves the corresponding variant details.

Does this Ensembl query approach support cross-species homology and ortholog lookup?

Yes, cross-species homology is supported. You can retrieve orthologs and paralogs across supported species by querying Ensembl homology endpoints, which return the comparative genomic relationships in JSON format.

What are the limitations when querying large genomic regions from Ensembl?

When querying large genomic regions from Ensembl, you must respect region size limits imposed by the REST API. The Skill processes overlap and sequence retrieval requests while adhering to these constraints to ensure successful JSON responses.

How do I find mouse orthologs for a human gene using Ensembl?

To find mouse orthologs, query the Ensembl homology endpoints with a human gene symbol or Ensembl ID. The Skill retrieves cross-species ortholog data, returning the corresponding mouse gene annotations and comparative details.