WEBVTT 00:00.080 --> 00:00.400 Okay. 00:00.440 --> 00:03.360 So now we're going to build the same graph that we did last time. 00:03.360 --> 00:05.080 But we're going to add in some tools. 00:05.440 --> 00:11.880 Uh, so um, one small change I'm going to make though is this time for the state object. 00:11.880 --> 00:13.800 We're not going to use a Pydantic object. 00:13.800 --> 00:15.640 We're going to use a typed dict. 00:15.800 --> 00:17.720 And it looks almost identical. 00:17.720 --> 00:22.560 It's just a it's a subclass of typed dict instead of pydantic base model. 00:22.760 --> 00:24.360 Um, but otherwise the same thing. 00:24.400 --> 00:25.600 Messages field. 00:25.640 --> 00:26.760 It's annotated. 00:26.760 --> 00:27.680 It's a list. 00:27.680 --> 00:34.280 And this is telling Landgraf that we're going to use the Add Messages reducer as a way of reducing. 00:34.320 --> 00:35.720 Otherwise it's just the same. 00:35.720 --> 00:40.400 So you can stick with Pydantic if you'd prefer, but this is a different way of doing it. 00:40.680 --> 00:44.640 Uh, so then we start the graph builder right there. 00:45.280 --> 00:47.120 And now we have something different. 00:47.120 --> 00:52.920 So it's worth keeping in mind, in your mind that when when we work with tools, there's actually two 00:52.920 --> 00:56.920 different places in our code that typically we have to worry about tools. 00:56.960 --> 01:03.480 And I've explained this up here first of all, when we're, when we're, uh, making the call to the 01:03.650 --> 01:04.650 model, to OpenAI. 01:05.010 --> 01:10.050 That's the point at which we have to look at our tools and create all of that JSON nonsense. 01:10.090 --> 01:14.730 All of the stuff to describe what the tool is, so that when we prompt the model, it knows what it 01:14.730 --> 01:15.410 can do. 01:15.530 --> 01:18.170 So that's one piece of work that has to happen. 01:18.610 --> 01:22.930 And then another piece of work is when the model then responds. 01:22.930 --> 01:27.650 We have to test to see whether is the finish reason tool calls. 01:27.770 --> 01:34.010 And if so then we have to do that stuff, which was the quite long winded handle tool call uh, method 01:34.010 --> 01:38.970 in the first week where we unpacked the tool call and then we did some clever stuff. 01:38.970 --> 01:43.890 You can either have just an if statement, or you can have something clever that goes and finds the 01:43.890 --> 01:45.370 function and calls it. 01:45.650 --> 01:50.970 But that whole piece of the puzzle, the, uh, receiving the message to call a tool from the model, 01:50.970 --> 01:53.450 is like another place where you have to do all of your coding. 01:53.490 --> 01:58.410 Those are the two points, and we'll see both those points separately in how we have to handle this 01:58.410 --> 01:59.330 with land graph. 01:59.850 --> 02:01.450 So this is the first one. 02:01.690 --> 02:09.300 When we create the model this is the chat OpenAI object which is the long chain wrapper around calling 02:09.300 --> 02:09.900 OpenAI. 02:11.060 --> 02:17.780 We also, once we've created it, we make another version of LLM, which is LLM with tools, which is 02:17.780 --> 02:21.140 after calling Bind tools to the LLM. 02:21.340 --> 02:27.260 And this is just some nice sort of magic, which is going to then figure out what are the tools that 02:27.260 --> 02:33.620 it can call and make sure that whenever we call that model, whenever we call this version of the model, 02:33.620 --> 02:36.820 it's going to to provide all of the tools it can do. 02:37.340 --> 02:38.460 So it's one of those examples. 02:38.460 --> 02:39.740 This is really powerful. 02:39.740 --> 02:40.900 It's lang chain here. 02:40.900 --> 02:47.460 And it's lang chain being really nice, making it simple to package away all of that JSON stuff and 02:47.460 --> 02:53.980 do it for us by abstracting around an LLM to have an LLM with tools which whenever you call it, it's 02:53.980 --> 02:56.580 going to automatically pass in all the tools it can call. 02:56.940 --> 03:01.900 The flip side of that is that it's it's sort of hiding from us some of the implementation and some of 03:01.900 --> 03:06.500 what's going on which which can be which can make it hard to debug and things. 03:06.500 --> 03:10.150 But but you certainly I mean hopefully you see the positives very much. 03:10.190 --> 03:11.470 It's really easy. 03:11.710 --> 03:12.910 That is done that now. 03:12.910 --> 03:18.710 Whenever we call liquid tools, it's going to automatically handle the the building of that JSON and 03:18.710 --> 03:19.710 the parsing it in. 03:20.230 --> 03:21.990 And so look look how simple this is. 03:21.990 --> 03:23.790 This is our chat bot function. 03:23.790 --> 03:29.990 This is our node our function for the chat bot which just as before we return messages. 03:30.110 --> 03:36.670 And then what we've got here is we just call invoke but not on the LM but on the LM with tools that 03:36.670 --> 03:38.110 knows already about those tools. 03:38.110 --> 03:42.310 It will build the JSON, it will parse the JSON in as the tools. 03:42.550 --> 03:43.910 So it's really clever. 03:44.110 --> 03:46.510 And then we add that node. 03:46.950 --> 03:48.950 And then there's this line here. 03:49.190 --> 03:50.550 This is part two. 03:50.590 --> 03:51.790 This is the other thing. 03:51.790 --> 03:53.990 This is handling the results back. 03:54.270 --> 03:58.110 So what's happening here is that we added that chatbot node. 03:58.110 --> 04:01.950 We're adding a second node called tools. 04:02.190 --> 04:04.470 And it is a special type of node. 04:04.470 --> 04:05.910 It's a tool node. 04:06.190 --> 04:09.750 And when you create a tool node you have to tell it okay. 04:09.790 --> 04:10.790 What are these tools. 04:10.830 --> 04:12.240 What is it that you do? 04:12.800 --> 04:20.760 And this tool node is basically like a canned node that when it's invoked, it's going to see whether 04:20.760 --> 04:26.960 any of the message is asking to call one of the tools that it's been assigned, that it was passed to 04:26.960 --> 04:28.240 it when it was created. 04:28.240 --> 04:31.640 That's the job of the tool node, and if so, it will run them. 04:32.120 --> 04:38.040 So one more time, this piece of code here is handling the request to the LM and packaging up the tools 04:38.040 --> 04:38.720 JSON. 04:39.000 --> 04:47.040 And this node here is handling what happens if a if there is a tool request, it's handling the unbundling 04:47.040 --> 04:51.800 of the request and the actual calling of the tool function. 04:51.800 --> 04:57.120 And if any of that didn't make sense, I think it hopefully will do very shortly. 04:57.320 --> 05:02.800 We're going to create the edges now and again a little bit more complicated than before. 05:03.280 --> 05:10.880 So there is an edge which is going from the chat bot to the tools from this node, which is the actual 05:10.880 --> 05:16.970 chat bot, the LM with tools to the thing that calls tools to the node that actually runs the different 05:16.970 --> 05:18.890 tools we need to connect those two. 05:19.410 --> 05:23.730 But that connection, it's a connection which which has like an if attached to it. 05:23.770 --> 05:25.450 We don't want to always call tools. 05:25.450 --> 05:33.050 We only want to call those tools if the model has returned a response that the finish reason is tool 05:33.090 --> 05:33.650 calls. 05:33.650 --> 05:36.290 We had to like code that ourselves in week one. 05:36.290 --> 05:42.290 If finish reason is tool calls so that if has to be included in here because it's only if that's true. 05:42.290 --> 05:47.330 It's only if the model returns that it wants to call tools that we actually want to to call this node. 05:47.650 --> 05:53.810 And so and so that is why when you look at this edge, it's not a normal edge. 05:53.810 --> 05:59.170 It's called a conditional edge, which means it's an edge that's only triggered in certain conditions. 05:59.210 --> 06:06.170 And like an if statement and you give it the node name, you give it the condition and you give it the 06:06.250 --> 06:07.970 the node that would then be called. 06:08.330 --> 06:14.290 And that condition called tools condition is again pre-canned with Landgraf. 06:14.290 --> 06:17.530 And of course it looks to see if the finish reason is handle tools. 06:17.930 --> 06:21.410 Uh, so, uh, sorry, the finish reason is tool calls. 06:21.570 --> 06:22.930 And so that is what. 06:22.970 --> 06:24.650 That's exactly what that does. 06:24.810 --> 06:29.890 So when I used to say that, that, uh, at the end of the day, tool calling is just an if statement. 06:29.890 --> 06:31.370 This is the if statement. 06:31.370 --> 06:34.010 This thing here is handling that if statement. 06:34.010 --> 06:38.930 And if the if statement is true then then it's calling a node called tools. 06:39.850 --> 06:40.610 Uh all right. 06:40.610 --> 06:47.330 And then the, the uh there's one more quite subtle point here, which is that you also have to make 06:47.330 --> 06:49.530 an edge between tools. 06:49.850 --> 06:56.570 Back to chatbot again, because the result of this, the result of running the tool, the output needs 06:56.570 --> 07:01.490 to get fed back into the chatbot and it needs to continue processing from there. 07:01.850 --> 07:07.210 So this is subtle and, and, uh, you know, once, once I've said it, it's probably obvious, but 07:07.210 --> 07:11.370 it's one of those things that if I hadn't said it, it's not something that would naturally have occurred 07:11.370 --> 07:11.530 to you. 07:11.530 --> 07:14.930 And if you don't do it, then things will go wrong in strange ways. 07:15.050 --> 07:16.290 So it's one of those times. 07:16.330 --> 07:18.170 Again, it's elegant, it's neat. 07:18.170 --> 07:22.620 It's great that Landgraf does that, but it can make it a bit harder to debug. 07:23.180 --> 07:23.460 All right. 07:23.460 --> 07:25.380 And then we're going to add that start edge. 07:25.660 --> 07:26.580 And then we're going to. 07:26.620 --> 07:28.140 Compile and picture it. 07:28.140 --> 07:31.220 And this will hopefully bring this together for you. 07:31.260 --> 07:32.820 Start goes to chat bot. 07:33.100 --> 07:35.540 This is a conditional line. 07:35.900 --> 07:43.620 If if the finish reason is is a tool call then it will come here because the tools condition will be 07:43.620 --> 07:44.060 true. 07:44.580 --> 07:46.340 Then it will it will be responsible. 07:46.340 --> 07:50.580 This node is a canned node that's responsible for calling the tools that are relevant. 07:50.940 --> 07:52.500 And then the results comes back. 07:52.500 --> 07:56.940 And this is a solid line because if it's got here it should always come back. 07:57.460 --> 08:02.620 And this is a dotted line because only in the event that this didn't happen then it will come to end 08:02.660 --> 08:03.300 naturally. 08:03.660 --> 08:09.100 Landgraf automatically adds an end node for any any unresolved condition like that. 08:09.660 --> 08:11.220 And so that is our graph. 08:11.220 --> 08:14.340 And I hope that seeing that graph has made it come together for you. 08:14.340 --> 08:17.060 So the two places where tools are incorporated. 08:17.060 --> 08:18.380 One is the chatbot itself. 08:18.380 --> 08:25.070 We're using the LM with tools and the other is in the conditional branch and this tools node itself. 08:25.350 --> 08:26.470 Well, I think it's enough chit chat. 08:26.510 --> 08:28.070 We should get on and run this thing. 08:28.150 --> 08:28.910 So here we go. 08:28.950 --> 08:30.110 We're going to. 08:30.310 --> 08:32.390 Oh, I think I'll make this consistent with how we've done it before. 08:32.430 --> 08:34.230 We'll call this chat not invoke graph. 08:34.230 --> 08:35.270 But it is. 08:35.310 --> 08:37.350 It is how we should think of it really. 08:37.470 --> 08:44.470 So we're going to um, we're going to, to bring up a gradient screen and we're just going to call it 08:44.470 --> 08:45.590 let's see if this works. 08:45.790 --> 08:46.230 Okay. 08:46.270 --> 08:47.430 So I'm going to say hi there. 08:50.070 --> 08:50.430 Hello. 08:50.430 --> 08:51.670 How can I assist you today. 08:51.950 --> 08:54.510 Well I'm going to do something fun here. 08:54.750 --> 09:07.830 I'm going to say uh, please send me a push notification with the current US dollar to great British 09:07.830 --> 09:09.510 pound exchange rate. 09:11.270 --> 09:17.510 So I'm hoping that it's going to look up the exchange rate, uh, by doing a web search, find it out, 09:17.550 --> 09:19.230 and then send me a push notification. 09:19.230 --> 09:20.390 This is ambitious. 09:20.390 --> 09:24.030 2 to 2 tool calls in one shot. 09:24.190 --> 09:26.480 Get that out of me and we'll see. 09:26.640 --> 09:27.960 Uh, we'll see how it does. 09:29.680 --> 09:30.640 So it's going. 09:30.680 --> 09:32.040 It's off, it's pausing. 09:32.240 --> 09:34.920 It's as you heard it certainly sent me something. 09:35.240 --> 09:40.520 The current USD GBP exchange rate is 0.78. 09:40.880 --> 09:43.680 Well, I happen to have a Google screen sitting over here. 09:43.680 --> 09:45.000 Let's bring this into view. 09:45.360 --> 09:53.040 There you will find the current US dollar GBP exchange rate is indeed 0.78. 09:53.400 --> 09:55.400 So that's cool. 09:55.400 --> 09:56.040 That's cool. 09:56.040 --> 09:56.880 I hope you agree. 09:56.920 --> 09:57.160 Sorry. 09:57.160 --> 09:58.080 Get that out of your way. 09:58.160 --> 09:59.200 I hope you agree. 09:59.440 --> 10:03.720 Uh, it's interesting to see that this has happened and that it's achieved this. 10:04.040 --> 10:10.360 And what we can see here is that we can come into Lange Smith and see the outcome of this. 10:10.360 --> 10:14.680 I'm interested that it's put that in red the four seconds that it took us. 10:14.920 --> 10:17.840 So let's go into this and see more. 10:18.200 --> 10:22.200 Please send me a push notification with the current USD GBP exchange rate. 10:22.520 --> 10:27.320 So we can see that that you can see the whole graph playing out here. 10:27.320 --> 10:32.370 And it's fascinating to see, uh, the, the, um, let's scroll down. 10:32.370 --> 10:33.970 It's doing a search right here. 10:33.970 --> 10:37.090 Click here current USD to GBP exchange rate. 10:37.210 --> 10:40.170 And that's the the result that came back. 10:40.690 --> 10:45.290 Um, this was from, from from doing the search just as we expected. 10:45.490 --> 10:49.970 And then it came back to a tools condition to a send push notification. 10:50.290 --> 10:54.610 Uh, and uh, back came the uh, the, the answer. 10:54.610 --> 10:57.250 And then that was the, uh, the conclusion. 10:57.570 --> 10:59.170 Um, there we go. 10:59.170 --> 11:01.290 And that's how it responded. 11:01.290 --> 11:09.850 So there we see the full, uh, the full chain of, of, uh, discussion happening within Lange Smith 11:09.850 --> 11:15.170 and how you can come in and debug this and see what's going on and see, indeed convince yourself that 11:15.170 --> 11:17.530 it did call the couple of tools. 11:17.650 --> 11:20.130 And this was great fun, and I hope you'll do the same thing. 11:20.170 --> 11:22.370 Come in now and run this and let it cool. 11:22.370 --> 11:28.250 Both tools go into Lange Smith and Trace through to make sure that you can also see all of these calls 11:28.250 --> 11:31.010 happening, uh, just just as we did right here.