Programmatic chat: the /agent/run contract

curl -N -X POST http://127.0.0.1:8000/agent/run \
  -H "Content-Type: application/json" \
  -d '{
    "threadId": "demo-1",
    "runId": "run-1",
    "state": {},
    "messages": [
      {"id":"msg-1","role":"user","content":"Hello"}
    ],
    "tools": [],
    "context": [],
    "forwardedProps": {}
  }'

from typing import TypedDict
from langgraph.graph import StateGraph, START, END

class InputState(TypedDict):
    user_input: str

class OutputState(TypedDict):
    graph_output: str

class OverallState(TypedDict):
    user_input: str
    intermediate: str
    graph_output: str

builder = StateGraph(
    OverallState,
    input_schema=InputState,
    output_schema=OutputState,
)

{
  "messages": [
    {
      "id": "msg-1",
      "role": "user",
      "content": "{\"user_input\": \"Hello\"}"
    }
  ]
}

class AgentState(TypedDict, total=False):
    messages: list[BaseMessage]
    intent: str
    draft: str
    response: str

builder = StateGraph(AgentState)  # no input_schema, chat mode

import json
import requests

with requests.post(
    "http://127.0.0.1:8000/agent/run",
    json={
        "threadId": "demo-1",
        "runId": "run-1",
        "state": {},
        "messages": [{"id": "msg-1", "role": "user", "content": "Hello"}],
        "tools": [],
        "context": [],
        "forwardedProps": {},
    },
    stream=True,
    headers={"Accept": "text/event-stream"},
) as response:
    for line in response.iter_lines():
        if not line or not line.startswith(b"data: "):
            continue
        event = json.loads(line[len(b"data: "):])
        if event.get("type") == "TextMessageContent":
            print(event["content"], end="", flush=True)