Ptarmigan-1 documentation
Ptarmigan-1 predicts which compounds engage a protein target from the protein's sequence alone, with no structure needed. Pick a human protein and a compound library, run a screen, and every compound in the library comes back ranked by predicted engagement. The method is described in the Ptarmigan-1 preprint.
To try it now, the quickstart runs a first screen in the web app for a few cents.
Ways to use it
| You want to | Use | Guide |
|---|---|---|
| Run screens and explore results in your browser | The web app at https://ptarmigan.app | Using the web app |
| Let an AI agent screen for you | MCP, with an API key | Using an agent |
| Script screens from a shell | The REST API with curl | REST with curl |
| Analyse results in Python or a notebook | The REST API with httpx | Python, which links a getting-started notebook to download |
All four use the same account, libraries and balance. A screen started in one shows up in the others.
Concepts
Target. The protein you screen against. Search by gene, name or UniProt accession. You can screen only the human proteins Ptarmigan-1 provides; adding your own protein is not supported yet.
Library. A set of compounds, each a SMILES string with an optional id and name. Use a provided library, or upload your own; see Library files.
Screen. One target against one library. A screen is queued, runs, and ranks every compound in the library. It is charged only when it completes; a screen that fails or is cancelled costs nothing.
Predicted engagement. A number between 0 and 1: how likely the compound is to engage the target. A screen lists compounds from highest to lowest predicted engagement; see Reading the results.
Tokens and cost. A screen costs one token per compound. The price per token is on the pricing page, with what is free, and every estimate shows a screen's cost before anything is spent.
Balance. Screens are paid from a prepaid balance in dollars. A new account
starts with $250 of promotional funds, which are spent first. You
can add funds by card from the Billing page. Funds expire 6 months
after they are added. Funds are dated to the start of the hour (UTC) in which
they were added, so a grant's granted_at and expires_at in
/api/v1/balance fall on the hour: funds bought at 21:29 show 21:00.
Results. A completed screen's full ranking stays available in the app for 6 months. Download it to keep it for longer.
Reference
- API reference: every REST route, generated from the API itself.
- Errors: every error code, and what to do when you get one.
- https://ptarmigan.app/llms.txt: a short guide written for AI agents.