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How to stream full state of your graph

LangGraph Cloud supports multiple streaming modes. The main ones are:

  • values: This streaming mode streams back values of the graph. This is the full state of the graph after each node is called.
  • updates: This streaming mode streams back updates to the graph. This is the update to the state of the graph after each node is called.
  • messages: This streaming mode streams back messages - both complete messages (at the end of a node) as well as tokens for any messages generated inside a node. This mode is primarily meant for powering chat applications.

This guide covers stream_mode="values".

First let's set up our client and thread:

from langgraph_sdk import get_client

client = get_client(url="whatever-your-deployment-url-is")
# create thread
thread = await client.threads.create()
print(thread)

import { Client } from "@langchain/langgraph-sdk";

const client = new Client({ apiUrl: "whatever-your-deployment-url-is" });
// create thread
const thread = await client.threads.create();
console.log(thread)

Output:

{'thread_id': 'bfc68029-1f7b-400f-beab-6f9032a52da4',
 'created_at': '2024-06-24T21:30:07.980789+00:00',
 'updated_at': '2024-06-24T21:30:07.980789+00:00',
 'metadata': {}}

Now we can stream by values, which streams the full state of the graph after each node has finished executing:

input = {"messages": [{"role": "human", "content": "what's the weather in la"}]}

# stream values
async for chunk in client.runs.stream(
    thread["thread_id"],
    "agent", 
    input=input,
    stream_mode="values"
):
    print(f"Receiving new event of type: {chunk.event}...")
    print(chunk.data)
    print("\n\n")

const input = {"messages": [{"role": "human", "content": "what's the weather in la"}]}

const streamResponse = client.runs.stream(
  thread["thread_id"],
  "agent",
  {
    input,
    streamMode: "values"
  }
);
for await (const chunk of streamResponse) {
  console.log(f"Receiving new event of type: {chunk.event}...")
  console.log(chunk.data)
  console.log("\n\n")
}

Output:

Receiving new event of type: metadata...
{'run_id': 'f08791ce-0a3d-44e0-836c-ff62cd2e2786'}



Receiving new event of type: values...
{'messages': [{'role': 'human', 'content': 'what's the weather in la'}]}



Receiving new event of type: values...
{'messages': [{'content': 'what's the weather in la', 'additional_kwargs': {}, 'response_metadata': {}, 'type': 'human', 'name': None, 'id': 'faa15565-8823-4aa1-87af-e21b40526fae', 'example': False}, {'content': [{'id': 'toolu_01E5mSaZWm5rWJnCqmt63v4g', 'input': {'query': 'weather in los angeles'}, 'name': 'tavily_search_results_json', 'type': 'tool_use'}], 'additional_kwargs': {}, 'response_metadata': {}, 'type': 'ai', 'name': None, 'id': 'run-3fe1db7a-6b8d-4d83-ba07-8657190ad811', 'example': False, 'tool_calls': [{'name': 'tavily_search_results_json', 'args': {'query': 'weather in los angeles'}, 'id': 'toolu_01E5mSaZWm5rWJnCqmt63v4g'}], 'invalid_tool_calls': []}]}



Receiving new event of type: values...
{'messages': [{'content': 'what's the weather in la', 'additional_kwargs': {}, 'response_metadata': {}, 'type': 'human', 'name': None, 'id': 'faa15565-8823-4aa1-87af-e21b40526fae', 'example': False}, {'content': [{'id': 'toolu_01E5mSaZWm5rWJnCqmt63v4g', 'input': {'query': 'weather in los angeles'}, 'name': 'tavily_search_results_json', 'type': 'tool_use'}], 'additional_kwargs': {}, 'response_metadata': {}, 'type': 'ai', 'name': None, 'id': 'run-3fe1db7a-6b8d-4d83-ba07-8657190ad811', 'example': False, 'tool_calls': [{'name': 'tavily_search_results_json', 'args': {'query': 'weather in los angeles'}, 'id': 'toolu_01E5mSaZWm5rWJnCqmt63v4g'}], 'invalid_tool_calls': []}, {'content': '[{"url": "https://www.weatherapi.com/", "content": "{\'location\': {\'name\': \'Los Angeles\', \'region\': \'California\', \'country\': \'United States of America\', \'lat\': 34.05, \'lon\': -118.24, \'tz_id\': \'America/Los_Angeles\', \'localtime_epoch\': 1716310320, \'localtime\': \'2024-05-21 9:52\'}, \'current\': {\'last_updated_epoch\': 1716309900, \'last_updated\': \'2024-05-21 09:45\', \'temp_c\': 16.7, \'temp_f\': 62.1, \'is_day\': 1, \'condition\': {\'text\': \'Overcast\', \'icon\': \'//cdn.weatherapi.com/weather/64x64/day/122.png\', \'code\': 1009}, \'wind_mph\': 8.1, \'wind_kph\': 13.0, \'wind_degree\': 250, \'wind_dir\': \'WSW\', \'pressure_mb\': 1015.0, \'pressure_in\': 29.97, \'precip_mm\': 0.0, \'precip_in\': 0.0, \'humidity\': 65, \'cloud\': 100, \'feelslike_c\': 16.7, \'feelslike_f\': 62.1, \'vis_km\': 16.0, \'vis_miles\': 9.0, \'uv\': 5.0, \'gust_mph\': 12.5, \'gust_kph\': 20.2}}"}]', 'additional_kwargs': {}, 'response_metadata': {}, 'type': 'tool', 'name': 'tavily_search_results_json', 'id': '0d5dab31-5ff8-4ae2-a560-bc4bcba7c9d7', 'tool_call_id': 'toolu_01E5mSaZWm5rWJnCqmt63v4g'}]}



Receiving new event of type: values...
{'messages': [{'content': 'what's the weather in la', 'additional_kwargs': {}, 'response_metadata': {}, 'type': 'human', 'name': None, 'id': 'faa15565-8823-4aa1-87af-e21b40526fae', 'example': False}, {'content': [{'id': 'toolu_01E5mSaZWm5rWJnCqmt63v4g', 'input': {'query': 'weather in los angeles'}, 'name': 'tavily_search_results_json', 'type': 'tool_use'}], 'additional_kwargs': {}, 'response_metadata': {}, 'type': 'ai', 'name': None, 'id': 'run-3fe1db7a-6b8d-4d83-ba07-8657190ad811', 'example': False, 'tool_calls': [{'name': 'tavily_search_results_json', 'args': {'query': 'weather in los angeles'}, 'id': 'toolu_01E5mSaZWm5rWJnCqmt63v4g'}], 'invalid_tool_calls': []}, {'content': '[{"url": "https://www.weatherapi.com/", "content": "{\'location\': {\'name\': \'Los Angeles\', \'region\': \'California\', \'country\': \'United States of America\', \'lat\': 34.05, \'lon\': -118.24, \'tz_id\': \'America/Los_Angeles\', \'localtime_epoch\': 1716310320, \'localtime\': \'2024-05-21 9:52\'}, \'current\': {\'last_updated_epoch\': 1716309900, \'last_updated\': \'2024-05-21 09:45\', \'temp_c\': 16.7, \'temp_f\': 62.1, \'is_day\': 1, \'condition\': {\'text\': \'Overcast\', \'icon\': \'//cdn.weatherapi.com/weather/64x64/day/122.png\', \'code\': 1009}, \'wind_mph\': 8.1, \'wind_kph\': 13.0, \'wind_degree\': 250, \'wind_dir\': \'WSW\', \'pressure_mb\': 1015.0, \'pressure_in\': 29.97, \'precip_mm\': 0.0, \'precip_in\': 0.0, \'humidity\': 65, \'cloud\': 100, \'feelslike_c\': 16.7, \'feelslike_f\': 62.1, \'vis_km\': 16.0, \'vis_miles\': 9.0, \'uv\': 5.0, \'gust_mph\': 12.5, \'gust_kph\': 20.2}}"}]', 'additional_kwargs': {}, 'response_metadata': {}, 'type': 'tool', 'name': 'tavily_search_results_json', 'id': '0d5dab31-5ff8-4ae2-a560-bc4bcba7c9d7', 'tool_call_id': 'toolu_01E5mSaZWm5rWJnCqmt63v4g'}, {'content': 'Based on the weather API results, the current weather in Los Angeles is overcast with a temperature of around 62°F (17°C). There are light winds from the west-southwest around 8-13 mph. The humidity is 65% and visibility is good at 9 miles. Overall, mild spring weather conditions in LA.', 'additional_kwargs': {}, 'response_metadata': {}, 'type': 'ai', 'name': None, 'id': 'run-4d6d4c23-5aad-4042-b0d9-19407a9e08e3', 'example': False, 'tool_calls': [], 'invalid_tool_calls': []}]}



Receiving new event of type: end...
None

If we want to just get the final result, we can use this endpoint and just keep track of the last value we received

final_answer = None
async for chunk in client.runs.stream(
    thread["thread_id"],
    "agent",
    input=input,
    stream_mode="values"
):
    if chunk.event == "values":
        final_answer = chunk.data

let finalAnswer;
const streamResponse = client.runs.stream(
  thread["thread_id"],
  "agent",
  {
    input,
    streamMode: "values"
  }
);
for await (const chunk of streamResponse) {
  finalAnswer = chunk.data;
}

Output:

{'messages': [{'content': 'what's the weather in la',
   'additional_kwargs': {},
   'response_metadata': {},
   'type': 'human',
   'name': None,
   'id': 'e78c2f94-d810-42fc-a399-11f6bb1b1092',
   'example': False},
  {'content': [{'id': 'toolu_01SBMoAGr4U9x3ibztm2UUom',
     'input': {'query': 'weather in los angeles'},
     'name': 'tavily_search_results_json',
     'type': 'tool_use'}],
   'additional_kwargs': {},
   'response_metadata': {},
   'type': 'ai',
   'name': None,
   'id': 'run-80767ab8-09fc-40ec-9e45-657ddef5e0b1',
   'example': False,
   'tool_calls': [{'name': 'tavily_search_results_json',
     'args': {'query': 'weather in los angeles'},
     'id': 'toolu_01SBMoAGr4U9x3ibztm2UUom'}],
   'invalid_tool_calls': []},
  {'content': '[{"url": "https://www.weatherapi.com/", "content": "{\'location\': {\'name\': \'Los Angeles\', \'region\': \'California\', \'country\': \'United States of America\', \'lat\': 34.05, \'lon\': -118.24, \'tz_id\': \'America/Los_Angeles\', \'localtime_epoch\': 1716310320, \'localtime\': \'2024-05-21 9:52\'}, \'current\': {\'last_updated_epoch\': 1716309900, \'last_updated\': \'2024-05-21 09:45\', \'temp_c\': 16.7, \'temp_f\': 62.1, \'is_day\': 1, \'condition\': {\'text\': \'Overcast\', \'icon\': \'//cdn.weatherapi.com/weather/64x64/day/122.png\', \'code\': 1009}, \'wind_mph\': 8.1, \'wind_kph\': 13.0, \'wind_degree\': 250, \'wind_dir\': \'WSW\', \'pressure_mb\': 1015.0, \'pressure_in\': 29.97, \'precip_mm\': 0.0, \'precip_in\': 0.0, \'humidity\': 65, \'cloud\': 100, \'feelslike_c\': 16.7, \'feelslike_f\': 62.1, \'vis_km\': 16.0, \'vis_miles\': 9.0, \'uv\': 5.0, \'gust_mph\': 12.5, \'gust_kph\': 20.2}}"}]',
   'additional_kwargs': {},
   'response_metadata': {},
   'type': 'tool',
   'name': 'tavily_search_results_json',
   'id': 'af25e94a-c119-48c3-bbd3-096e42f472ac',
   'tool_call_id': 'toolu_01SBMoAGr4U9x3ibztm2UUom'},
  {'content': 'Based on the weather API results, the current weather in Los Angeles is overcast with a temperature of around 62°F (17°C). There are light winds from the west-southwest around 8-13 mph. The humidity is 65% and visibility is good at 9 miles. Overall, mild spring weather conditions in LA.',
   'additional_kwargs': {},
   'response_metadata': {},
   'type': 'ai',
   'name': None,
   'id': 'run-b90f0037-e56a-4f3b-ad92-00d10d079a9e',
   'example': False,
   'tool_calls': [],
   'invalid_tool_calls': []}]}

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