# IBorrowDesk

> IBorrowDesk tracks the stock-loan data Interactive Brokers publishes: the
> annualised borrow fee, the rebate, and the shares available to short, for
> tens of thousands of US and international securities, recorded several times
> an hour since 2015. The website is free to browse. Programmatic access is the
> paid, API-key v2 API described here.

Automated clients should use the v2 API. The site's other `/api/` endpoints
are the web app's internal interface: they block scripted user agents, are
rate-limited per network, and carry no stability guarantee.

## For AI agents

- [Agent Skill](https://www.iborrowdesk.com/api/v2/agent-skill/SKILL.md): instructions for calling the API, choosing a series, keeping cost down and handling errors. Works with Claude Code, Codex and other agents that read SKILL.md files
- [Agent Skill (zip)](https://www.iborrowdesk.com/api/v2/agent-skill.zip): the skill packaged for installing in Claude, Codex and other agents
- [Field reference](https://www.iborrowdesk.com/api/v2/agent-skill/REFERENCE.md): units, response fields, and the errors to branch on

## API

- [OpenAPI 3 spec](https://www.iborrowdesk.com/api/v2/openapi.json): the authoritative contract
- [Coverage and limits](https://www.iborrowdesk.com/api/v2/coverage): free, no key needed. Read the live per-request limits here rather than hardcoding them
- [Developer console](https://www.iborrowdesk.com/developer): API keys, usage and units. Needs an account with the API plan
- [Plans](https://www.iborrowdesk.com/plans): the API plan is $29/month with 5,000 units included, and unit packs top it up

Quick facts:

- Base URL `https://www.iborrowdesk.com` (www only). Auth `Authorization: Bearer ibd_...`
- `GET /api/v2/daily/borrow?symbols=GME,AMC&start=2025-01-01`: daily open/high/low/close of fee, rebate and availability, back to 2015. One unit per symbol per 365 days of history returned. Omit `start` for all-time
- `GET /api/v2/intraday/borrow?symbols=TSLA&start=2026-10-01&end=2026-10-20`: 15-minute readings, at most 31 days per call. One unit per symbol per call that returns data
- Up to 100 symbols per call. Non-US tickers take a venue suffix (`VOD.LN`, `7203.JP`, `AAPL.CA`). Join on `figi`, not the ticker
- Requests that return no data cost nothing. Errors are JSON `{"error", "message"}`. 402 `units_exhausted` and 403 `no_api_access` are not retryable

## Website

- [Home](https://www.iborrowdesk.com/): most expensive borrows, fee movers, leaderboards
- [Stock report](https://www.iborrowdesk.com/report/GME): one stock's borrow history, at /report/{SYMBOL}
- [FAQ](https://www.iborrowdesk.com/faq)
- [Terms](https://www.iborrowdesk.com/terms)