Peptide Library

About Peptide Library

Peptide Library offers a versioned REST API providing access to the research data, vendor information, and pricing behind the Peptide Library app. The API covers peptide profiles (names, aliases, mechanism, chemistry, evidence level, safety, and regulatory status), cited studies with PubMed, DOI, and ClinicalTrials.gov identifiers and evidence classifications, a vendor directory with location, ratings, catalog size, and shipping destinations, and current listed prices by compound and form with last-seen timestamps. It does not return dosing, regimen, cycle, reconstitution, or injection information.

Research and study endpoints are accessible without an API key; vendor, product, and price endpoints require a key obtained through a developer dashboard, with access controlled by scopes (research:read, studies:read, vendors:read, products:read, pricing:read). Keys are shown once, stored as a hash, and intended for server-side use via bearer token authentication. The API has an OpenAPI 3.1 specification, an interactive playground, TypeScript and Python SDKs, a Postman collection, and an MCP server for connecting AI assistants such as Claude, ChatGPT, and Cursor to the research data.

Plans include a public no-key tier (300 requests/minute, research and studies only), a free Developer tier (5,000 requests/month, 60/minute, all endpoints a key's scopes allow), a Pro Developer tier (100,000 requests/month, 600/minute, for commercial integrations, not yet on sale), and a custom Enterprise tier. Rate limits count vendor, product, and price requests; exceeding them returns a 429 response with Retry-After, and nothing is billed automatically. Vendor links in API responses may be affiliate links, disclosed in the response, that can earn a commission without affecting listing order. The API is intended for research and educational use and states it is not medical advice or a recommendation to use any substance.

Key features

• REST API for peptide research profiles, studies, vendor directory, and product pricing
• MCP server to connect Claude, ChatGPT, Cursor and other AI assistants to the research data
• TypeScript and Python SDKs with pagination, retries and typed errors
• Interactive playground and Postman collection for building and testing requests
• Scoped API keys (research:read, studies:read, vendors:read, products:read, pricing:read)
• OpenAPI 3.1 spec with versioned endpoints

Frequently asked questions