# REST API

The fatcat HTTP API is mostly a classic REST CRUD (Create, Read, Update,
Delete) API, with a few twists.

A declarative specification of all API endpoints, JSON data models, and
response types is available in OpenAPI 2.0 format. Code generation tools are
used to generate both server-side type-safe endpoint routes and client-side
libraries. Auto-generated reference documentation is, for now, available at
<https://api.qa.fatcat.wiki>.

All API traffic is over HTTPS; there is no insecure HTTP endpoint, even for
read-only operations. To start, all endpoints accept and return only JSON
serialized content.

## Entity Endpoints/Actions

Actions could, in theory, be directed at any of:

    entities (ident)
    revision
    edit

A design decision to be made is how much to abstract away the distinction
between these three types (particularly the identifier/revision distinction).

Top-level entity actions (resulting in edits):

    create (new rev)
    redirect
    split
    update (new rev)
    delete

On existing entity edits (within a group):

    update
    delete

An edit group as a whole can be:

    create
    submit
    accept

Other per-entity endpoints:

    match (by field/context)
    lookup (by external persistent identifier)

## Editgroups

All mutating entity operations (create, update, delete) accept an
`editgroup_id` query parameter. If the parameter isn't set, the editor's
"currently active" editgroup will be used, or a new editgroup will be created
from scratch. It's generally preferable to manually create an editgroup and use
the `id` in edit requests; the allows appropriate metadata to be set. The
"currently active" editgroup behavior may be removed in the future.

## Sub-Entity Expansion

To reduce the need for multiple GET queries when looking for common related
metadata, it is possible to include linked entities in responses using the
`expand` query parameter. For example, by default the `release` model only
includes an optional `container_id` field which points to a container entity.
If the `expand` parameter is set:

    https://api.qa.fatcat.wiki/v0/release/aaaaaaaaaaaaarceaaaaaaaaam?expand=container

Then the full container model will be included under the `container` field.
Multiple expand parameters can be passed, comma-separated.

## Authentication and Authorization

There are two editor types: bots and humans. Additionally, either type of
editor may have additional privileges which allow them to, eg, directly accept
editgroups (as opposed to submitting edits for review).

All mutating API calls (POST, PUT, DELETE HTTP verbs) require token-based
authentication using an HTTP Bearer token. If you can't generate such a token
from the web interface (because that feature hasn't been implemented), look for
a public demo token for experimentation, or ask an administrator for a token.

## Autoaccept Flag

Currently only on batch creation (POST) for entities.

For all bulk operations, optional 'editgroup' query parameter overrides
individual editgroup parameters.

If autoaccept flag is set and editgroup is not, a new editgroup is
automatically created and overrides for all entities inserted. Note
that this is different behavior from the "use current or create new"
default behavior for regular creation.

Unfortunately, "true" and "false" are the only values acceptable for boolean
rust/openapi2 query parameters

## QA Instance

The intent is to run a public "sandbox" QA instance of the catalog, using a
subset of the full catalog, running the most recent development branch of the
API specification. This instance can be used by developers for prototyping and
experimentation, though note that all data is periodically wiped, and this
endpoint is more likely to have bugs or be offline.