API access
Get a Tower of Babel API key: a free key by email, paid tiers above it — server-side search, full-text delivery, and bulk snapshots of the library of 2,557,923 works. The texts themselves stay free on this site either way; a key buys the maintained pipe, the throughput, and someone standing behind it, never access.
Tiers
Keyless catalog — Free
No published limit. The static surface documented on the API page: the full catalog JSON, shards, and predictable .txt URLs. No key, no sign-up. Unchanged — this is the discovery layer and it stays open.
Free key — Free
200 requests/day. A key by email for API v1: catalog search and metadata for your own projects. Non-commercial use. The key is shown only in the email that delivers it.
Pro — $19/mo ($190/yr)
5,000 requests/day. API v1 with full-text delivery and a commercial-use licence for a single project. For builders, researchers, and small products that need the pipe, not the scrape.
Commercial — $149/mo ($1,490/yr)
25,000 requests/day. Everything in Pro at commercial scale: bulk snapshot packages and a commercial-use licence covering multiple projects.
Get a free key
Enter your email on this page in the app and a free key is sent to it — shown only in that email, stored here only as a hash. Asking for a new key revokes the previous free key for that address.
Billing is managed through Stripe — the receipt for any payment includes a manage-billing link. Refunds: cancel within 7 days of a charge and that charge is refunded in full — email us from the address on the subscription and we will process it; the API key stays active until the end of the paid period unless you ask us to revoke it sooner.