Streaming JSON

The Amp CLI has two new flags: --stream-json and --stream-json-input.

They can be used together with the --execute flag to turn on structured JSON output and input, respectively.

Here is an example:

$ amp --execute "what is 2+2?" --stream-json

This would print something like the following on stdout:

{"type":"system","subtype":"init","cwd":"/Users/mrnugget/work/amp","session_id":"T-2775dc92-90ed-4f85-8b73-8f9766029e83","tools":["oracle","..."],"mcp_servers":[]}
{"type":"user","message":{"role":"user","content":[{"type":"text","text":"what is 2+2?"}]},"parent_tool_use_id":null,"session_id":"T-2775dc92-90ed-4f85-8b73-8f9766029e83"}
{"type":"assistant","message":{"type":"message","role":"assistant","content":[{"type":"text","text":"2 + 2 equals 4."}],"stop_reason":"end_turn","usage":{"input_tokens":12783,"cache_creation_input_tokens":367,"cache_read_input_tokens":12416,"output_tokens":8,"max_tokens":224000,"service_tier":"standard"}},"parent_tool_use_id":null,"session_id":"T-2775dc92-90ed-4f85-8b73-8f9766029e83"}
{"type":"result","subtype":"success","duration_ms":2906,"is_error":false,"num_turns":1,"result":"2 + 2 equals 4.","session_id":"T-2775dc92-90ed-4f85-8b73-8f9766029e83"}

Structured input can be provided on stdin with the --stream-json-input flag:

$ echo '{
  "type": "user",
  "message": {
    "role": "user",
    "content": [
      {
        "type": "text",
        "text": "what is 2+2?"
      }
    ]
  }
}' | amp -x --stream-json --stream-json-input

If --stream-json-input is set, the Amp CLI will process user messages as soon as they are received on stdin and exit as soon as stdin is closed and the agent has ended its turns.

Combined with amp threads continue [thread], multi-turn conversations can even happen across multiple invocations of the CLI:

$ amp -x "what is 2+2?" --stream-json
...
$ amp threads continue -x "and now add 7 to that" --stream-json
...
{"type":"result","result":"11.", "subtype":"success","duration_ms":2906,"is_error":false,"num_turns":2,"session_id":"T-2775dc92-90ed-4f85-8b73-8f9766029e83"}

See the Manual for more details and the Appendix for the full schema.