WEBVTT 00:00.240 --> 00:00.720 Cool. 00:00.720 --> 00:02.480 So let me go to Main.py. 00:02.640 --> 00:06.280 And here we're going to implement our Landgraaf react graph. 00:06.640 --> 00:08.640 And we'll start from the imports. 00:09.000 --> 00:13.200 Let's start by first importing from LinkedIn core. 00:13.240 --> 00:15.320 Let's import the human message. 00:15.440 --> 00:17.720 And this is the input. 00:17.760 --> 00:20.120 We're going to start our graph to run with. 00:20.760 --> 00:23.960 Now I want to import from Landgraaf. 00:24.000 --> 00:31.040 I want to import the messages date object like we had from before, which is going to hold all of our 00:31.040 --> 00:31.800 messages. 00:32.040 --> 00:36.840 And I want to also import something which is called a state graph. 00:37.080 --> 00:40.320 And this is the most generic graph we can have. 00:40.360 --> 00:44.200 And it can receive any state object that we want to give it. 00:44.400 --> 00:47.280 And this is how we're going to initialize our graph. 00:47.960 --> 00:52.400 And when we'll initialize our graph it will be much clearer later in this video. 00:53.040 --> 00:54.680 All right let's go and continue. 00:54.680 --> 00:56.880 And let's go and import our nodes. 00:57.000 --> 01:00.560 I want the run agent reasoning node and the tool node. 01:01.000 --> 01:03.280 And now we are done with the imports. 01:03.280 --> 01:03.410 Ports. 01:03.690 --> 01:07.370 So I want to start by defining some constants. 01:07.930 --> 01:11.970 And let's go and define the constant of agent reasoning. 01:13.010 --> 01:14.650 We'll call it agent reason. 01:15.130 --> 01:18.770 And let's define act as the string act. 01:18.770 --> 01:21.050 And this is simply to have cleaner code. 01:21.050 --> 01:25.250 So we won't need to rewrite those strings every time that we want to use them. 01:25.930 --> 01:31.490 And lastly let's create a new const which is called last which is going to be minus one. 01:31.490 --> 01:39.210 And this is for future when we're going to reference the last message between the user and the agent. 01:39.450 --> 01:43.130 And the last message is going to be at the minus one index. 01:43.130 --> 01:45.450 So this is some Python notation. 01:45.450 --> 01:49.610 And again this is simply for more readability when we write the code. 01:49.610 --> 01:51.130 So the code is a bit cleaner. 01:51.930 --> 01:52.490 Cool. 01:52.490 --> 01:55.490 So now it's time to finally implement our graph. 01:55.970 --> 01:59.410 Now let's define a new state graph object. 01:59.410 --> 02:01.250 Like we are auto populated here. 02:01.410 --> 02:04.010 And we want to give it the message graph. 02:04.770 --> 02:08.070 So we're going to call it flow instead of graph. 02:08.550 --> 02:10.670 And let's go and do that. 02:11.430 --> 02:15.710 And now we want to add the nodes like we're autocompleted. 02:15.710 --> 02:20.990 So we want to add the node of agent reason and the node of act. 02:21.910 --> 02:24.630 And notice how we're using those constants here. 02:25.270 --> 02:31.270 And by the way right over here cursor auto completed me this edge from start to agent reason which is 02:31.270 --> 02:32.110 correct. 02:32.110 --> 02:35.150 But I want to define it in another way. 02:35.470 --> 02:40.910 So let me go to the line where we define the agent reason node and one line below it. 02:40.910 --> 02:43.910 Let me write flow dot set entry point. 02:44.190 --> 02:46.430 And I'm going to set it to Agent Reason. 02:46.630 --> 02:50.550 And this is how I personally like to define this edge. 02:50.990 --> 02:56.270 It defines an edge from the starting node and going to the agent reason node. 02:56.710 --> 02:58.590 Anyways let me go and remove this. 02:59.350 --> 03:01.790 And now let's go and add some edges. 03:02.110 --> 03:11.080 Let's add the conditional edge from the agent reason node to the node and to the unknown depending of 03:11.120 --> 03:13.000 a certain functionality that we write. 03:13.360 --> 03:18.920 So I'm going to decide this functionality should continue function which will implement later. 03:19.280 --> 03:27.200 And the third argument is going to be a dictionary of mapping between the string end to end from the 03:27.200 --> 03:28.800 string act to act. 03:29.480 --> 03:38.280 And this mapping over here really tells Landgraf that whatever comes from the should continue function, 03:38.280 --> 03:40.560 which is going to be some kind of string. 03:40.760 --> 03:45.160 And we're going to return from that function the answering or the x ring. 03:45.520 --> 03:52.200 Then we want to map it to go to the end node or to the node with the name of act. 03:52.720 --> 03:59.800 So this is going to help us draw those dotted lines over here in the graph itself. 04:00.520 --> 04:05.280 And if we didn't write this mapping the graph would still run as we want to. 04:05.400 --> 04:08.240 But the drawing wouldn't be that explicit. 04:08.240 --> 04:11.280 So this really helps with drawing what we see over here. 04:11.760 --> 04:19.290 It defines which nodes can come after the agent reason node, and this is the node and the end node. 04:20.290 --> 04:22.370 Alrighty, let's go and implement. 04:22.370 --> 04:24.050 This should continue function. 04:24.290 --> 04:26.890 So let me go up a bit in the code. 04:27.970 --> 04:31.250 And let's go and put it right above here. 04:31.730 --> 04:36.970 And this function should continue is going to receive the state of the graph which is going to be a 04:36.970 --> 04:37.810 message state. 04:38.010 --> 04:45.090 And it's going to return us the string, which is going to annotate the node that should run after the 04:45.090 --> 04:46.170 agent reason node. 04:46.650 --> 04:50.250 So how we're going to decide we're going to check the messages. 04:50.530 --> 04:55.370 And if the last message and this is the usage of the constant here. 04:55.370 --> 05:02.250 So if the last message is going to be a tool call then we want to go to the node. 05:02.570 --> 05:06.170 And if not we want to go to end. 05:06.650 --> 05:09.370 Because if the last message is a tool call. 05:09.370 --> 05:15.620 So this means that the LM, the reasoning engine, decided that we need to invoke a tool and it has 05:15.620 --> 05:17.260 all the information of the arguments. 05:17.260 --> 05:21.180 Then we want to go and execute the tool node which will execute that tool. 05:21.580 --> 05:26.020 And if there isn't a tool call, then we simply want to end everything. 05:26.020 --> 05:32.980 Because this is a heuristic that the LM was able to answer the question with or without a tool invocation. 05:33.340 --> 05:33.780 All right. 05:33.780 --> 05:37.500 So we finished implementing those dotted lines over here in the graph. 05:37.700 --> 05:42.140 Now let's go and define the edge from act to agent reason. 05:42.140 --> 05:48.100 Because after we invoke the tool we want the agent to reason and to figure out whether it needs to return 05:48.100 --> 05:50.740 the answer or to run another tool call. 05:51.340 --> 05:53.660 And that's pretty much it for the graph. 05:53.660 --> 05:58.380 So we defined the nodes, the entry point, the edges between the nodes. 05:58.660 --> 06:00.980 And now we want to compile the graph. 06:01.300 --> 06:06.540 And let's go and print it and see that we get the same drawing that I'm showing you in the video. 06:06.820 --> 06:14.900 And for that we'll use the get graph and then draw Mermod pg function, which will print it and display 06:14.900 --> 06:15.220 it. 06:15.220 --> 06:19.320 And in the output file here which we're going to call flow PNG. 06:20.240 --> 06:24.120 Let's wait for it to run and we can see we get here an error. 06:24.560 --> 06:27.640 It seems that we cannot import messages. 06:28.120 --> 06:29.560 State message states here. 06:29.720 --> 06:31.680 And this is because I'm missing here an S. 06:31.720 --> 06:34.280 This is something a cursor made a mistake. 06:35.240 --> 06:39.920 So let me go and fix it and let's go and rerun it. 06:42.120 --> 06:47.400 And we can see we forgot to update the rest of the code to use messages state instead of message state. 06:47.400 --> 06:50.960 So let me copy that and let me put it over here. 06:51.320 --> 06:55.720 And we should also do it in the should continue function. 06:55.720 --> 06:57.520 So let me go and fix it as well. 06:58.480 --> 06:58.880 Yeah. 07:01.800 --> 07:02.840 Let me run it again. 07:02.840 --> 07:04.800 Now boom. 07:05.040 --> 07:07.840 So let's check out now the drawing of the graph. 07:08.040 --> 07:11.880 And we can see this is the graph that I showed you during this video. 07:12.440 --> 07:13.120 Awesome. 07:13.120 --> 07:16.640 So in the next video we're going to test everything. 07:16.640 --> 07:18.560 And we're going to review the traces. 07:18.560 --> 07:21.280 And we're going to see exactly how everything is working.