Create README.md

README.md

@@ -0,0 +1,107 @@
+# Vapi Java Library
+[![fern shield](https://img.shields.io/badge/%F0%9F%8C%BF-SDK%20generated%20by%20Fern-brightgreen)](https://github.com/fern-api/fern)
+
+The Vapi Java SDK provides convenient access to the Vapi API from Java or Kotlin.
+
+## Installation
+
+### Gradle
+
+Add the dependency in your `build.gradle`:
+
+```groovy
+dependencies {
+    implementation 'com.vapi:vapi-java:0.x.x'
+}
+```
+
+### Maven
+
+Add the dependency in your `pom.xml`:
+
+```xml
+<dependency>
+    <groupId>com.vapi</groupId>
+    <artifactId>vapi-java</artifactId>
+    <version>0.x.x</version>
+</dependency>
+```
+
+## Usage
+
+Instantiate and use the client with the following:
+
+```java
+import com.vapi.api.Vapi;
+
+Vapi vapi = Vapi.builder()
+  .token("YOUR_TOKEN") 
+  .build();
+
+vapi.call.create();
+```
+
+## Exception Handling
+
+When the API returns a non-success status code (4xx or 5xx response), a subclass of `VapiException`
+will be thrown.
+
+```java
+import com.vapi.api.core.VapiException;
+
+try {
+    vapi.call.create();
+} catch (VapiException e) {
+    System.out.println(e.message());
+}
+```
+
+The SDK also supports error handling for first class exceptions with strongly typed body fields. 
+
+```java
+import com.vapi.api.errors.InvalidRequestError;
+
+try {
+    vapi.call.create();
+} catch (InvalidRequestError e) {
+    System.out.println(e.message());
+    System.out.println(e.getBody().getMissingField());
+}
+```
+
+## Advanced
+
+### Callbacks
+
+You can register `callbacks` with the Vapi client and the callbacks will be invoked
+after events have been sent or failed to send. 
+
+```java
+vapi.addCallback((event, statusCode) -> {
+  if (statusCode >= 400) {
+    // do something with event in error case    
+  }    
+});
+```
+
+### Retries
+
+The SDK is instrumented with automatic retries with exponential backoff. A request will be retried as long
+as the request is deemed retriable and the number of retry attempts has not grown larger than the configured
+retry limit (default: 2).
+
+A request is deemed retriable when any of the following HTTP status codes is returned:
+
+- [408](https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/408) (Timeout)
+- [429](https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/429) (Too Many Requests)
+- [5XX](https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/500) (Internal Server Errors)
+
+## Contributing
+
+While we value open-source contributions to this SDK, this library is generated programmatically.
+Additions made directly to this library would have to be moved over to our generation code,
+otherwise they would be overwritten upon the next generated release. Feel free to open a PR as
+a proof of concept, but know that we will not be able to merge it as-is. We suggest opening
+an issue first to discuss with us!
+
+On the other hand, contributions to the README are always very welcome!