# Users and what they may do

Who the users are, and what each may do, is the swarm's: a registry in the document,
the same on every node. How a user proves who it is stays each node's: its
`--htpasswd`, or a reverse proxy naming the user (`--user-header`, [`trust.md`](trust.md)).

## The registry

`_continuum/users/<name>`, one entry per user. It is protocol data: every member holds
it, a remake's snapshot carries it into the next epoch, and it holds no secrets (no
password hashes: every member reads the document).

```json
{ "since": 1762400000000, "by": "continuum:3f…",
  "caps": { "8c41e2…": { "path": [], "rights": ["read", "write"],
                        "by": "continuum:3f…", "since": 1762400000000 } },
  "disabled": false }
```

* **Names** are what `--htpasswd` and the proxy give: 1 to 64 of `A-Z a-z 0-9 . _ @ -`.
* **Capabilities** (`caps`): each a path, as segments as the store's API takes them,
  and the rights it gives there and below: `read`, `write`. A capability covers its
  path segment by segment (`servers/eu` covers `servers/eu/0`, not `servers/europe`).
  One outside protocol data never covers protocol data: `[]` is all of the swarm's
  data, `["_continuum"]` protocol data, managing users included (`_continuum/users`).
  They are kept by a random ID, so two capabilities granted at once both hold, and
  revoking one removes it alone. Each names who granted it (`by`: a user as
  `user:<name>`, or the node that recorded it) and when (`since`).
* **`disabled`**: the entry stays (who wrote what stays readable), and gives nothing.
  An entry that doesn't read as above gives less, never more: a capability that
  doesn't read is left out, and anything but `false` disables.

## A new swarm

Its genesis node records the first users, with the swarm ID, in its first change:

* those of `--bootstrap-users`, each with everything (`[]` and `["_continuum"]`);
* unset: the users of its `--htpasswd` with `[]`, and those of them, or of the
  proxy's, in `--protocol-writers` with `["_continuum"]` too.

A swarm nobody could manage doesn't start: with none of them with `["_continuum"]`,
`--genesis` is refused, naming both options.