Expand README

Author: alukach

README.md

@@ -10,6 +10,25 @@ STAC Auth Proxy is a proxy API that mediates between the client and and some int
 - 🔐 Selectively apply OIDC auth to some or all endpoints & methods
 - 📖 Augments [OpenAPI](https://swagger.io/specification/) with auth information, keeping auto-generated docs (e.g. [Swagger UI](https://swagger.io/tools/swagger-ui/)) accurate
 
+### CQL2 Filters
+
+| Method   | Endpoint                                       | Action | Filter | Strategy                                                                                                   |
+| -------- | ---------------------------------------------- | ------ | ------ | ---------------------------------------------------------------------------------------------------------- |
+| `POST`   | `/search`                                      | Read   | Item   | Append body with generated CQL2 query.                                                                     |
+| `GET`    | `/search`                                      | Read   | Item   | Append query params with generated CQL2 query.                                                             |
+| `GET`    | `/collections/{collection_id}/items`           | Read   | Item   | Append query params with generated CQL2 query.                                                             |
+| `POST`   | `/collections/{collection_id}/items`           | Create | Item   | Validate body with generated CQL2 query.                                                                   |
+| `PUT`    | `/collections/{collection_id}/items/{item_id}` | Update | Item   | Fetch STAC Item and validate CQL2 query; merge STAC Item with body and validate with generated CQL2 query. |
+| `DELETE` | `/collections/{collection_id}/items/{item_id}` | Delete | Item   | Fetch STAC Item and validate with CQL2 query.                                                              |
+
+#### Recipes
+
+Only return collections that are mentioned in a `collections` array encoded within the auth token.
+
+```
+"A_CONTAINEDBY(id, ('{{ token.collections | join(\"', '\") }}' ))"
+```
+
 ## Installation
 
 Set up connection to upstream STAC API and the OpenID Connect provider by setting the following environment variables: