All API endpoints conform to the pattern `[PREFIX]LETTER[/ZETTEL-ID]`, where:



The following letters are currently in use:

| Letter | Without zettel identifier | With [zettel identifier](00001006050000) | Mnemonic |
| :-: | --- | --- | --- |
| `a` | POST: [client authentication](00001012050200) |  | __A__uthenticate |
|  | PUT: [renew access token](00001012050400) |  |  |
| `r` |  | GET: [references](00001012053800) | __R__eference |
| `x` | GET: [retrieve administrative data](00001012070500) |  | E__x__ecute |
|  | POST: [execute command](00001012080100) |  |  |
| `z` | GET: [list zettel](00001012051200)/[query zettel](00001012051400) | GET: [retrieve zettel](00001012053300) | __Z__ettel |
|  | POST: [create new zettel](00001012053200) | PUT: [update zettel](00001012054200) |  |
|  |  | DELETE: [delete zettel](00001012054600) |  |

The full URL will contain either the “http” or “https” scheme, a host name, and an optional port number.

The API examples will assume the “http” schema, the local host “127.0.0.1”, the default port “23123”, and the default empty `PREFIX` “/”.
Therefore, all URLs in the API documentation will begin with “http://127.0.0.1:23123/”.