Update README.md

README.md

@@ -1 +1,59 @@
 # Google Drive fsspec implementation
+
+This is an implementation of the fsspec interface for Google Drive.
+
+This software is in alpha stage and should not be relied upon in production settings.
+
+## Installation
+
+You can install it directly from source using pip:
+
+```sh
+pip install git+https://github.com/fsspec/gdrivefs
+```
+
+> [!IMPORTANT]  
+> gdrivefs is *not* released on PyPI. Note that there is a project on PyPI with the name `gdrivefs` which is unrelated and does not implement fsspec. See #21.
+
+## Usage
+
+As gdrivefs implements the fsspec interface, most documentation can be found at https://filesystem-spec.readthedocs.io/en/latest/usage.html.
+
+### Authentication
+
+There are several methods to authenticate gdrivefs against Google Drive.
+
+1. Service account credentials
+
+    In this method, you providea dict containing the service account credentials obtainend in GCP console. The dict content is the same as the json file downloaded from GCP console. More details can be found here: <https://cloud.google.com/iam/docs/service-account-creds#key-types>. This credential can be useful when integrating with other GCP services, and when you don't want the user to be prompted to authenticate.
+
+    ```python
+    fs = GoogleDriveFileSystem(creds=service_account_credentials)
+    ```
+
+2. OAuth with user credentials
+
+    A browser will be opened to complete the OAuth authentication flow. Afterwards, the access token will be stored locally and you can re-use it in subsequent sessions.
+
+    ```python
+    # use this the first time you run
+    token = 'browser'
+    # use this on subsequent attempts
+    #token = 'cache'
+    fs = gdrivefs.GoogleDriveFileSystem(token=token)
+    ```
+
+3. Anonymous (read-only) access
+
+    If you want to interact with files that are shared publicly ("anyone with the link"), then you do not need to authenticate to Google Drive.
+
+    ```python
+    token = 'anon'
+    fs = gdrivefs.GoogleDriveFileSystem(token=token)
+    ```
+
+See [GoogleDriveFileSystem](https://github.com/fsspec/gdrivefs/blob/master/gdrivefs/core.py#L41) docstring for more details.
+
+## Other implementations
+
+- [PyDrive2](https://github.com/iterative/PyDrive2?tab=readme-ov-file#fsspec-filesystem) also provides an fsspec-compatible Google Drive API.