Update calling modes
# Guide on Asynchronous processing
-By default functions are accessed synchronously via the following route:
+Asynchronous function calls can be queued up using the following route:
```
$ curl --data "message" http://gateway/function/{function_name}
```
-As of [PR #131](https://github.com/openfaas/faas/pull/131) asynchronous invocation is available for testing.
+Summary of modes for calling functions via API Gateway:
+
+| Mode | Method | URL | Body | Headers | Query string
+| -------------|--------|------------------------------------------------|------|--------- |------------------- |
+| Synchronous | POST | http://gateway/function/{function_name} | Yes | Yes | Yes |
+| Synchronous | GET | http://gateway/function/{function_name} | Yes | Yes | Yes |
+| Asynchronous | POST | http://gateway/async-function/{function_name} | Yes | Yes | Yes [#369](https://github.com/openfaas/faas/issues/369) |
+| Asynchronous | GET | Not supported | - | - | - |
+
+This work was carried out under [PR #131](https://github.com/openfaas/faas/pull/131).
*Logical flow for synchronous functions:*
