---
title: VarSome API
description: VarSome's high-performance API enables variant annotation from over 140 integrated databases. Start your project immediately, without incurring the significant overheads of multiple integrations and manual updates.
---
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VarSome's high-performance Application Programming Interface (API) enables variant annotation using data from our massive variant knowledge base. You can start your project immediately and without incurring the significant overheads of multiple integrations and manual updates.
[Get a Quote](https://landing.varsome.com/varsome-api#VAPI-lander-inboundform)
[Flexible Pricing](https://docs.varsome.com/en/varsome-api-cost-calculation)
Our Engine Your Workflow
## Works with All Programming Languages
VarSome API works with any programming language, including Python, R, Java, and C++. It provides programmatic access to the full VarSome database, allowing you to retrieve annotations, classifications, and population data directly into your own pipelines.
[](https://landing.varsome.com/hs/cta/wi/redirect?encryptedPayload=AVxigLLU%2FElGbcLyvWeefSpLD1wWT%2FJOT4tY801X6LpfZfam5UUH36SWj3IycI4RPWVJsPoHkFs%2BHtRq1zzwkB0iJUQfO7HFgRpPXksfhQmrn%2FoLRHy%2FrU4TLXSz1XXEU1L4r%2BOesS3TN%2FxelTYpVAp8DJVedYmWPPPw1lKTxPUFKhveAQ8mGFeUPJyLNUJNnsOssOnAKY4D%2Fw%3D%3D&webInteractiveContentId=193664865920&portalId=4384097)
## Fast Annotation for WGS & WES
Receive full annotations at \>600 variants per second on a normal internet connection. Enabling the allele-frequency filter skips variants with a gnomAD frequency above your chosen threshold, reducing the data processed and increasing throughput up to 4x.
[](https://landing.varsome.com/hs/cta/wi/redirect?encryptedPayload=AVxigLJvLmvDfZAqlaytv8IVCb%2B9tQ3RD81Nl5ri1ETGmlNNNkTDJ9aAh9UAmT3xtzcGI7szQUt%2FG9A5oigkn67qxvA3ty%2FgAvrx6gON60qbfuy%2BbL9Fzfg8Xu0larMs2tNQ5PoWNYJC6yv5UN8A2H%2FCDyR5gIwvgr1dwzhxQXkHxEFjpT0CbdfX8lLQ2MimvJE%3D&webInteractiveContentId=193119870234&portalId=4384097)
## A Working Example
Make use of our reference API client for Python that demonstrates how to annotate a VCF. This reference shows how to structure batched calls and apply the relevant filters to maintain high performance in production. You can clone this repository and adapt the code to suit you.
[](https://landing.varsome.com/hs/cta/wi/redirect?encryptedPayload=AVxigLKkH%2FmqXcEs6o%2BOga%2B6EZ6QhzyJeLIB6xQCTvrWhTq0LSD%2BswAZNjoUZ46Gn0Xt4lZyMxNRW7AScVEreX6Xm4W6ajTZz9LTPvuJKVC29HeNO61JHjZlqUmrTD7Nnh51KErXSfLa4BrJQ%2BlcIUkbU3egQ9UV85DWwW0ekGZQbGes6rVES5e7GNN72RT0XS2JX7AMSYoGWrvWuBheyuEaFJjFxtwmYo63vHDs&webInteractiveContentId=193119870259&portalId=4384097)
Why VarSome?
## Automated Classification with Full Transparency
**Get germline and somatic classifications returned with full transparency**, including the criteria triggered and supporting literature references. The API automates the process but does not remove your control. You decide how results are reviewed, interpreted, and used in your workflow.
## Supports Long Reads and Structural Variants
VarSome API supports the **annotation of SNVs, CNVs, structural variants, and repeat expansions.** It works with data from long-read platforms such as **PacBio and Oxford Nanopore Technologies**, enabling the detection of variants in non-coding or structurally complex regions that may be missed by standard short-read sequencing.
## API Environments
**The VarSome API is available in three environments**, each designed for different use cases and stability requirements.
The Stable environment is a frozen version with updates released quarterly, suitable for production use. This environment offers high data quality and consistency, but may lag behind the latest updates by up to six months. It is unthrottled and included in all subscriber plans.
The Live environment provides access to the most up-to-date data, including recent user community contributions. It is updated monthly or at our discretion and is ideal for exploratory or flexible use. Like Stable, it is unthrottled and available to subscribers.
The Staging environment mirrors the upcoming Stable release and is intended for testing and validation. It is frozen at least four weeks before a Stable release to allow for compatibility testing. During this time, it may still receive updates if bugs are found. After release, Staging is updated again to reflect Live or internal development versions. Access is throttled and limited to subscribers.
Choosing the right environment helps ensure your integration remains reliable and predictable.
## Flexible Pricing
**Pricing scales with usage, and you only pay for the data you request.** To keep costs low, you can filter by allele frequency, limit to coding or splice-site variants, or select only the annotations you need. High-volume users benefit from lower rates, while monthly caps and dedicated instances are also available
## Scales with Your Workflow
From single-sample clinical interpretation to large-scale cohort annotation, the API scales to match your workload. **Submit up to 200 variants in a single request and configure it for high-throughput use with batch processing**, **smart filtering, and usage cap controls.**
## Standardized Interpretation
Use VarSome’s API to apply consistent interpretation logic across your lab or organisation. Whether centralised or distributed, it ensures **reproducible results, alignment with ACMG and AMP guidelines, and up-to-date classification rules in every request.**
API Environments to Suit You
## Stable
A frozen, production-grade API version. It’s updated quarterly and retains high data quality. It may lag behind the live data by up to 6 months.
## Live
The actively maintained Live environment offers the most up-to-date data and support for community contributions, with updates at VarSome’s discretion.
## Staging
A test instance reflecting the upcoming Stable release. It’s used for validation before release, may have partial data, and is throttled.
Behind the API
The VarSome API was designed to make variant interpretation faster, more consistent, and easier to integrate. In this conversation, our CSO joins members of the VarSome Development Team to discuss how our API supports clinical and research pipelines, and how automation, transparency, and reproducibility come together to advance precision medicine at scale.
Mentioned 5000+ Times in Literature
## Integration of VarSome API in an existing bioinformatic pipeline for automated ACMG interpretation of clinical variants – [Sorrentino et al. 2021.](https://www.europeanreview.org/wp/wp-content/uploads/1-6.pdf)
## PacMAGI: A pipeline including accurate indel detection for the analysis of PacBio sequencing data applied to RPE65 – [Sorrentino et al. 2022.](https://www.sciencedirect.com/science/article/pii/S0378111922003730)
## Variant selection and interpretation: an example of modified VarSome classifier of ACMG guidelines in the diagnostic setting – [Cristofoli et al. 2021.](https://www.mdpi.com/2073-4425/12/12/1885)
## Want to read more? [Click here](https://scholar.google.com/scholar?hl=en&as_sdt=0%2C5&q=%22varsome%22&oq=%22) for the list of publications.
VarSome API Plans
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EPFL Innovation Park - I,
1015 Lausanne,
Switzerland
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