Launch the node TCP server for FastAGI:

```
~$ node path/to/fastagi.js
```

Add a context for FastAGI testing:

```
[fastagi-test]
exten => _5XXX,1,Answer()
exten => _5XXX,n,AGI(agi://127.0.0.1/hello)
exten => _5XXX,n,Hangup()
```

Include this in your default context:

```
include => fastagi-test
```

When you dial a 4-digit extension beginning with 5 the test will execute.