Claude Code best practices | Code w/ Claude
00:00:00.000 | Let's get started.
00:00:06.840 | Welcome, everyone, to Cloud Code Best Practices.
00:00:12.520 | In this talk, I'm going to talk about kind of what
00:00:14.880 | Cloud Code is at a high level.
00:00:17.040 | Then we'll peer under the hood a little bit
00:00:19.480 | to kind of understand how Cloud Code works.
00:00:22.480 | And then knowing that, because it's
00:00:24.000 | useful to kind of know how your tools work,
00:00:26.160 | we're going to talk about good use cases for Cloud Code
00:00:28.680 | and also best practices we've figured out,
00:00:31.920 | both internally and from our users,
00:00:35.440 | for getting the most out of this tool.
00:00:38.000 | But before I get started, I'd like to introduce myself
00:00:40.120 | real quick and talk about how I ended up on the stage.
00:00:42.800 | So my name's Cal.
00:00:44.760 | And I joined Anthropic about a year and a half ago
00:00:48.240 | to help start up a team we call Applied AI.
00:00:51.440 | And it's the Applied AI's kind of mission--
00:00:53.960 | our team's mission is to help our customers and partners build
00:00:57.320 | great products and features on top of Cloud.
00:01:00.160 | So what that really means is I spend a lot of my day prompting
00:01:04.360 | Cloud to get the absolute best outputs out of these models.
00:01:08.440 | That said, I also love to code, and I'm definitely
00:01:11.080 | one of those coders that starts a lot of projects,
00:01:14.160 | has some crazy idea, and then just never finishes them.
00:01:16.720 | So I have this graveyard of just like code that I started,
00:01:19.720 | never really finished.
00:01:21.120 | But I'm always spinning new things up.
00:01:22.560 | And then late last year, I was in Slack,
00:01:24.720 | and I was hearing about this new tool that a few people are using.
00:01:27.560 | They were saying it was really cool.
00:01:29.600 | And so on a Friday night, I downloaded the tool that would become Cloud Code,
00:01:33.680 | and I threw it at this kind of new note-taking app that I wanted to build.
00:01:37.400 | And that whole weekend just kind of totally changed the way that I code and think about software engineering.
00:01:43.240 | I was carrying around my laptop with me all weekend.
00:01:46.240 | I was super addicted to just watching Cloud Code work.
00:01:49.240 | And I would press enter, and I'd switch over to my browser and refresh.
00:01:53.120 | And I watched this huge, powerful application come together in front of my eyes.
00:01:58.240 | And I got way farther into this thing than I ever would have on my own.
00:02:01.520 | And it just blew my mind.
00:02:03.920 | And while I was doing this, I was a little worried.
00:02:05.760 | I was like, you know, I kind of know how these things work.
00:02:08.400 | So I'm like, man, I'm using a lot of tokens.
00:02:10.680 | I hope I don't get in trouble or anyone notices.
00:02:13.040 | I'm not really contributing to Anthropic Code.
00:02:16.200 | But what I didn't know is that the Cloud Code team had built this internal leaderboard,
00:02:21.600 | tracking how much all the Anthropic employees were using this.
00:02:24.920 | And over the weekend, I had shot to the top.
00:02:27.640 | And so through that, I got to meet Boris and Kat and some of the early Cloud Code team.
00:02:32.040 | And I was able to start talking to them and say, hey, I love this tool.
00:02:36.360 | I also know a lot about prompting.
00:02:38.280 | Can I help you all out?
00:02:40.160 | And so through that, I got involved.
00:02:41.960 | And now I'm one of the core contributors on the team.
00:02:44.760 | And I do a lot of-- I work a lot on the prompting, the system prompts,
00:02:48.840 | how the tools work, the tool descriptions and tool results,
00:02:51.920 | as well as I work on how we evaluate this tool.
00:02:55.000 | So when we think about changing the prompts, how do we know
00:02:57.960 | we made things better or the same, and we didn't totally ruin Cloud Code?
00:03:02.720 | So with that said, let's kind of dive in.
00:03:05.480 | So here's my current mental model of Cloud Code
00:03:08.400 | and how I describe it to people when people ask me.
00:03:12.880 | Cloud Code is like that coworker that does everything on the terminal.
00:03:17.600 | It's the sort of person that just never touches the GUI.
00:03:20.120 | They're a whiz.
00:03:21.400 | I think of when I was a junior engineer, I had this mentor.
00:03:24.360 | And I would walk over his desk and I would say, hey, Tony,
00:03:27.720 | can you help me with this bug?
00:03:28.920 | And he would whip it over his terminal.
00:03:31.260 | And he'd be doing all these crazy bash commands
00:03:33.520 | and changing things around at Vim.
00:03:34.980 | And I'd always walk away thinking, wow, that was crazy.
00:03:37.920 | I should learn how to do that.
00:03:39.940 | I never did.
00:03:41.200 | But having Cloud Code on your computer
00:03:43.960 | is kind of like having Tony next to you all the time.
00:03:46.620 | So how does Cloud Code kind of work under the hood?
00:03:54.620 | At Anthropic, we try to always do what we call the simple thing
00:03:59.880 | that works.
00:04:01.080 | And what that means for Cloud Code is
00:04:02.760 | it's what we would consider a very pure agent.
00:04:06.740 | And Anthropic, when we talk about agents, what we really mean
00:04:10.660 | is some instructions, some powerful tools,
00:04:14.420 | and you let the model just run in a loop
00:04:16.400 | until it decides it's done.
00:04:18.400 | And that's really what Cloud Code is.
00:04:20.680 | So it's tools, powerful tools, and the tools
00:04:24.080 | that someone that was really good at a terminal
00:04:26.620 | would be able to use.
00:04:27.380 | Tools to create and edit files, to use the terminal,
00:04:30.580 | and then you can also do things like pull in other things
00:04:33.320 | with MCP.
00:04:35.120 | Now, on top of that, there's how Cloud understands the code base.
00:04:40.560 | And if you're going to build a coding agent or a coding tool
00:04:43.800 | a year ago, you'd probably have ideas like, well, OK,
00:04:47.500 | I'm going to get this user message about something
00:04:50.540 | about this code base, and I'll need to figure out
00:04:52.120 | which files are relevant.
00:04:53.380 | So maybe I'll index the whole code base and embed it
00:04:56.620 | and do this fancy, like, kind of rag retrieval thing.
00:05:00.680 | That is not how Cloud Code works.
00:05:02.140 | We don't do any sort of indexing.
00:05:03.860 | Instead, Cloud kind of explores and understands the code base
00:05:09.100 | how you, if you were new to a team and new to a code base,
00:05:11.800 | would explore a code base.
00:05:12.940 | And that is through agentic search.
00:05:15.580 | It's the same sort of search tools you or I would use,
00:05:18.040 | things like glob and grep and find.
00:05:20.600 | And it can work its way through a code base
00:05:22.820 | and understand what's going on.
00:05:24.860 | And when we talk about a genetic search,
00:05:26.620 | that really means the model can go do some searches,
00:05:29.580 | and then it can look at the results and say, hmm,
00:05:32.180 | maybe I need to figure out a few more things.
00:05:33.960 | I'm going to go do some more searching and then come back.
00:05:37.860 | And then on top of these primitives,
00:05:39.640 | on top of this agent, we have a few things.
00:05:41.860 | We have a very nice, light UI layer
00:05:44.740 | where you're going to watch Cloud Code work.
00:05:46.640 | You see all the text fly by.
00:05:48.680 | And we have this nice permission system
00:05:50.700 | that allows the agent to work and allows and kind of forces
00:05:54.660 | the human to butt in when the agent is doing something
00:05:56.880 | dangerous.
00:05:58.020 | And then on top of that, we also care a lot about security
00:06:01.060 | in this tool.
00:06:02.220 | And so because Cloud Code is just such a lightweight kind
00:06:05.460 | of layer on top of the model, and the fact
00:06:09.000 | that our model is available not just behind Anthropic APIs,
00:06:12.180 | but also with our cloud providers, AWS and GCP,
00:06:16.500 | it's very easy and native to point Cloud Code
00:06:19.140 | at one of these other services if you
00:06:21.000 | feel more comfortable consuming Cloud that way.
00:06:23.220 | Now, a lot of people ask me, hey, Kel,
00:06:28.820 | what can I use Cloud Code for?
00:06:30.400 | Like, what is it good at?
00:06:31.440 | Where is it interesting?
00:06:33.280 | And the reality is, it's kind of great at everything.
00:06:38.260 | So let's start with discovery.
00:06:40.600 | Oftentimes, in your career, you will
00:06:43.900 | be dropped into a new code base, whether that
00:06:45.880 | means you're switching teams, you're switching companies,
00:06:48.460 | I don't know, you're starting to work
00:06:49.880 | on some sort of open source project.
00:06:52.060 | And probably when you're first getting started
00:06:53.780 | and getting familiar, not very productive,
00:06:55.420 | because you're just trying to figure out
00:06:56.620 | where things are in the code base, what patterns kind
00:06:59.440 | of the team is using, things like that.
00:07:01.480 | And Cloud Code can kind of help supercharge
00:07:04.120 | that onboarding process.
00:07:06.040 | You can ask Cloud, hey, where is this feature implemented?
00:07:09.420 | Or since it's great at the terminal,
00:07:11.340 | you can say, hey, look at this file,
00:07:12.720 | and look at the Git history, and just kind of tell me
00:07:14.820 | a story about how this code has changed
00:07:17.100 | over the past couple of weeks.
00:07:20.400 | One thing you can use Cloud Code for-- and I think
00:07:22.520 | this is underrated-- is instead of just diving in
00:07:25.420 | and starting to work, you can use Cloud Code
00:07:27.220 | as a thought partner.
00:07:28.600 | So oftentimes, when I'm working with Cloud,
00:07:31.120 | and I want to implement a feature,
00:07:32.540 | or we're going to change something up, I'll open up Cloud,
00:07:34.920 | and it'll say, hey, Cloud, I'm thinking about implementing
00:07:38.100 | this feature.
00:07:39.000 | Can you just kind of search around and kind of figure out
00:07:41.580 | how we would do it, and maybe report back
00:07:43.300 | with two or three different options?
00:07:45.880 | Don't start working.
00:07:46.760 | Don't start writing any files yet.
00:07:49.440 | And Cloud will go off and use those agentic search
00:07:51.880 | capabilities and come back with a few ideas.
00:07:54.840 | And then I can work with Cloud to kind of validate things,
00:07:57.600 | and then we can jump into the project.
00:08:00.960 | Of course, Cloud Code is great at building and writing code.
00:08:04.320 | And I would say this on two different fronts.
00:08:06.640 | One, it can do the zero to one sort of stuff.
00:08:09.120 | You drop it in an empty directory, and you say, hey,
00:08:11.460 | build me an app, build me a game.
00:08:13.320 | That demos very well.
00:08:14.780 | It's very fun to do.
00:08:15.820 | It's very gratifying.
00:08:17.460 | Of course, in reality, what really matters
00:08:19.740 | is Cloud Code good working in existing code bases.
00:08:23.200 | And this is primarily what we focus on.
00:08:27.680 | And the Cloud Code team, we have in our code base
00:08:31.160 | abnormally high, I would say, unit test coverage.
00:08:34.760 | And that's because Cloud Code makes
00:08:36.420 | it so easy and just straightforward to add unit tests.
00:08:41.600 | So we have great code coverage.
00:08:43.020 | And then the other thing we have in Cloud Code,
00:08:44.740 | in our own code base, is we have great commits and PR messages.
00:08:48.200 | Because when we finish working, we'll just say, hey,
00:08:50.000 | Cloud, write the commit for me.
00:08:51.260 | They write the PR message for me.
00:08:54.240 | We also see great opportunities to use Cloud Code
00:08:58.020 | in kind of the deployments and in other parts of the lifecycle.
00:09:02.880 | And this is-- a few other people have talked about this.
00:09:05.280 | But this is using the Cloud Code SDK.
00:09:08.160 | So using it headlessly, using it programmatically,
00:09:11.240 | being able to sprinkle in a coding agent anywhere.
00:09:16.560 | And so that's things like sprinkling it into CI/CD
00:09:19.160 | to use it in GitHub, for instance, to help people programmatically.
00:09:24.820 | And then finally, it's great kind of with support and scale.
00:09:28.080 | It can help you debug errors faster.
00:09:30.420 | One thing that we saw when we started giving Cloud Code to customers
00:09:34.160 | and talking to them about it, we didn't totally predict this.
00:09:36.740 | It was a lot of customers or potential customers said, hey,
00:09:39.920 | we've been kind of putting off this large code base migration, people that are on old versions
00:09:45.580 | of Java trying to get to a new one, or a team that's on PHP and they're trying to get to React
00:09:50.900 | or Angular.
00:09:51.480 | We've talked to multiple teams like this, and having a tool like Cloud Code makes projects
00:09:56.900 | like that a little more digestible when you go to your team and you say, hey, we're going to spend a month
00:10:00.960 | of refactoring or rewriting large parts of the code base.
00:10:06.620 | And then on top of that-- and this kind of matters across all these-- is once again, remember,
00:10:11.480 | Cloud is great at the terminal.
00:10:13.280 | And that means it's going to be great at all those different CLI tools, things like Git, Docker,
00:10:18.500 | BigQuery, things like that.
00:10:20.420 | I never have to worry about, oh, I'm going to get myself-- how do I get myself out of this sticky rebase?
00:10:26.280 | I'll just fire up Cloud Code and tell it the situation and be like, hey, can you fix this for me?
00:10:30.680 | It's incredible.
00:10:33.180 | Now, let's talk about best practices.
00:10:36.980 | And the first one is not going to be a surprise, but the first one is use Cloud.MD files.
00:10:43.840 | So remember that Cloud Code, like I said, is an agent, and it has some tools.
00:10:48.720 | It has some lightweight instructions in the prompt, but it doesn't really have memory.
00:10:53.340 | And so the main way we share state across kind of sessions
00:10:57.660 | or across our team when we fire up Cloud Code in the same code base
00:11:01.560 | over and over again is this Cloud.MD file.
00:11:04.620 | So when we start Cloud, what happens is if there's this Cloud.MD file
00:11:08.780 | in the working directory, it's just plopped into context.
00:11:11.880 | It's plopped into the prompt.
00:11:13.060 | And basically what it says is, hey, Cloud, by the way,
00:11:15.500 | these are important instructions the developer left for you.
00:11:18.900 | Be sure to pay close attention to this.
00:11:21.680 | And there's various places you can put the Cloud.MD file.
00:11:24.300 | You can put it in a project and check it in so all your teammates share it.
00:11:28.220 | You could put one in your home directory if there's things you just want Cloud
00:11:31.300 | to always know about, regardless of what you're working on.
00:11:34.360 | And the things you put in here are things like, hey, by the way,
00:11:37.720 | maybe this is how you run the unit tests.
00:11:40.100 | Or just so you know, to make kind of your searching and life easier,
00:11:43.820 | here's just like an overview of kind of how this project is laid out, where the tests live,
00:11:48.580 | what different modules are, things like that.
00:11:51.360 | Or here's our style guide, all sorts of things like that to just make Cloud's life a bit easier.
00:11:56.780 | And you can build these things up over time.
00:12:01.360 | The other thing you can do which is important is permission management.
00:12:04.980 | When you're running Cloud code, there's all sorts of different kind of permission things flying by.
00:12:09.900 | Kind of out of the box, what happens when you start our tool is for read actions.
00:12:14.620 | If Cloud is searching or reading, we just let it go.
00:12:17.980 | But once it starts writing or running bash commands or doing things that could change stuff on your machine, potentially,
00:12:26.400 | that's when we kick in this UI and it says something like, yes, yes, always allow this, or no, I want to do something else.
00:12:35.520 | And using that permission management and being smart about it can help you work faster.
00:12:40.440 | So there's something called auto accept mode, where if you're working with Cloud code and you press shift tab,
00:12:46.180 | Cloud will just start working.
00:12:47.980 | There's things you can do like you can configure Cloud in the settings where specific commands,
00:12:53.100 | like on bash, like if you just are like tired of saying, yes, run NPM run test,
00:12:58.780 | you can just always approve that.
00:13:00.540 | So fiddling with your permission management is a great way to kind of speed up your workflow.
00:13:06.340 | Integration setup.
00:13:07.680 | So one thing that is going to help you get the most out of Cloud code is remember that it's great at the terminal.
00:13:13.800 | And if there's applications that you use which have kind of a way to access them through CLI-- and GitHub is a great example
00:13:20.720 | of that, they have a powerful tool called GH-- you can basically give more work to Cloud code.
00:13:27.100 | And you can do that either by just installing more CLI tools or you can attach more MCP servers.
00:13:33.720 | I would say just through experience that if you're using something like a CLI tool that's well-known
00:13:40.640 | and well-documented and you're trying to choose between the CLI tool and just installing it on your machine and grabbing an MCP server,
00:13:48.520 | I would recommend using the CLI tool.
00:13:51.440 | And then also if you internally have your own tools at Anthropic-- we have something called Koo that does a whole bunch of stuff for us--
00:13:59.440 | you can also tell Cloud about that and that's the sort of thing you'd put in Cloud.md.
00:14:03.440 | And then context management-- so remember that Claude is an agent.
00:14:10.360 | And what it does, it calls these tools and the context builds up and up over time.
00:14:16.360 | And at least for Anthropic, our models have a context window of 200,000 tokens and you can max this thing out.
00:14:22.360 | So you kind of have two options when you're in a long session with Cloud and you're working and you're going back and forth.
00:14:29.280 | You'll see in the bottom right, you'll start to get this little warning that'll say, hey, you're starting to fill out the context window.
00:14:35.280 | And kind of depending on what's going on, you have two options.
00:14:38.280 | You can run /clear and just start over and that clears everything out except for, for instance, Claude.md.
00:14:44.280 | Or you can run /compact and what'll happen is basically it's like a user message is inserted and it just says something like,
00:14:52.280 | hey, I need to go summarize everything we've been up to.
00:14:55.600 | I'm going to give this to another developer and they're going to pick up where I left off.
00:14:59.200 | And then that summary is what kind of seeds the next session and you can go from there.
00:15:03.200 | We spend a lot of time tuning this kind of compact functionality so that as you max out the context window
00:15:09.200 | and then run compact, you can start back over and keep going.
00:15:14.760 | Efficient workflows, what can you do with Cloud Code and how do you get the most out of it?
00:15:19.240 | So using planning and to-dos, I talked a little bit about this before, but one of the best things you can do is when you open up Cloud Code,
00:15:26.160 | instead of saying, hey, I need you to fix this bug, you can say, hey, I have this bug.
00:15:31.160 | Can you search around, figure out what's causing it and just like tell me a plan how we're going to fix it?
00:15:35.560 | And this can save you a lot of time because you can verify, you can read Cloud's plan and you can verify what it's going to do.
00:15:42.480 | And then the other thing that we have is we have this to-do list feature.
00:15:46.400 | So often when Cloud's working on a big task, it will create a to-do list.
00:15:51.400 | And if you're kind of paying attention, you can kind of watch this to-do list.
00:15:55.400 | And if you see anything kind of weirder in there or something that doesn't make sense,
00:15:58.400 | that's when you can press escape and say, hey, Cloud, let's change the to-do list.
00:16:01.400 | I think you're on the wrong path.
00:16:04.520 | Smart vibe coding.
00:16:06.080 | So it's very tempting and it's very powerful to just let Cloud work and press Enter and see what happens at the end.
00:16:12.400 | I think there's a few things that can help make this better.
00:16:14.880 | And there's, I think, a talk later today about just this for 30 minutes.
00:16:19.520 | But doing things like having test-driven development,
00:16:22.440 | having Cloud make small changes, run the tests, make sure they pass,
00:16:26.640 | always having Cloud do things like check the TypeScript and the linting,
00:16:30.400 | and then commit regularly.
00:16:32.160 | So that if it's kind of going off the rails, you can always fall back and try again.
00:16:37.000 | You can use screenshots to guide and debug.
00:16:39.560 | So Cloud is built on top of our models, which are multimodal.
00:16:43.460 | You can always just grab a screenshot, paste it in.
00:16:45.880 | Or if you have a file somewhere that's an image, you can just say, hey, Cloud,
00:16:49.240 | look at this mock.png, and then build the website for me or whatever.
00:16:55.520 | And then advanced techniques.
00:16:56.960 | OK, so as you're getting used to using Cloud, what are some things
00:17:00.500 | you can think about to kind of push things to the next level?
00:17:04.440 | And one of the things we see both internally and with customers
00:17:07.920 | is when you've started to use this tool for a while,
00:17:10.460 | it's going to be very tempting to use multiple Clouds at once.
00:17:14.720 | And so I know people at Anthropic and a few customers that run four Clouds at the same time.
00:17:19.260 | There's various ways to do this.
00:17:21.320 | You can have it in Tmocs or just different tabs, all sorts of crazy things.
00:17:25.860 | So I would challenge you to try getting multiple Clouds running at once
00:17:29.920 | and kind of be orchestrating all these things.
00:17:32.280 | It's quite fun.
00:17:32.960 | I can only do two, but I know people that do four.
00:17:36.960 | Use escape.
00:17:37.960 | So escape is your best friend.
00:17:40.300 | While Cloud is working, you can kind of keep an eye on what it's up to,
00:17:44.280 | and you can press escape to stop it and interject and say, hey,
00:17:47.960 | I think you're going on the wrong path or I want you to do something else.
00:17:51.520 | Knowing when the right time to press escape is versus just letting Cloud figure it out
00:17:56.160 | is key to getting the most out of the tool.
00:17:58.720 | And there's a hidden feature.
00:17:59.920 | Not too many people know about it, but if you press escape twice,
00:18:03.280 | you can actually jump back in your conversation.
00:18:05.400 | You can go back and you can kind of reset.
00:18:09.520 | Tool expansion and MCP.
00:18:11.400 | So this is taking it to the next level.
00:18:13.120 | If you feel like with Bash and with the tools that Cloud has that it still
00:18:17.440 | can't do something, this is when you should start looking at MCP servers.
00:18:22.480 | And then headless automation.
00:18:23.680 | I think this is the thing we're most excited about,
00:18:26.240 | but also we are still trying to wrap our heads around internally,
00:18:29.960 | which is how can we use Cloud programmatically?
00:18:33.360 | We have that in GitHub Actions.
00:18:35.040 | We want to figure out other creative places we can start using it.
00:18:39.280 | I would challenge you all to do the same.
00:18:43.600 | So with that said, I'm going to jump over to my computer because there's one other best
00:18:48.640 | practice, which is it's always good to stay on top of everything that's new.
00:18:54.560 | So we're shipping super fast.
00:18:56.080 | I'm just going to go over a few things that are new as of today.
00:18:59.840 | One thing is when you're in Cloud now and you fire it up, you can do /model.
00:19:06.080 | You can see what model you're running on.
00:19:07.920 | I'm on default, which happens to be Sonnet.
00:19:10.240 | We can jump over to Opus.
00:19:12.000 | You can do the same thing in /config, switch it here.
00:19:15.920 | So that's new.
00:19:19.200 | Make sure you're running the model that works for you.
00:19:21.200 | There's another thing that's new about these models,
00:19:24.560 | which is you can say something like,
00:19:26.720 | "Can you figure out what's in this project?"
00:19:30.880 | And for a long time, for a while,
00:19:32.320 | we've had this like think hard or extended thinking.
00:19:36.320 | Now, this is great, but with our past models,
00:19:40.080 | we wouldn't let our model think between tool calls.
00:19:42.560 | And that's probably when the thinking matters most.
00:19:44.560 | So starting with Cloud 4, our models now think between tool calls.
00:19:49.280 | And we can watch this happen.
00:19:50.560 | So we have Cloud in this project.
00:19:52.400 | There's a few different files in here.
00:19:53.680 | And I'm just going to tell it to think hard
00:19:55.360 | and figure out what's in this project.
00:19:57.360 | And we can watch Cloud start to work.
00:19:59.760 | And so the way you know you triggered thinking
00:20:02.320 | is you'll see kind of this lighter gray text.
00:20:05.040 | And then it'll call some file.
00:20:06.800 | It'll call some tools.
00:20:07.840 | It'll read some stuff.
00:20:09.040 | And then we see some more thinking.
00:20:11.120 | And this is awesome.
00:20:12.560 | So I encourage you, when you're working on tasks and solving bugs,
00:20:16.400 | throw a think hard in there.
00:20:17.600 | And then the other thing, and you know what?
00:20:21.920 | We'll just throw it up real quick, is I have this in VS Code.
00:20:26.720 | But of course, this is in JetBrains as well.
00:20:28.880 | But we have these new great integrations with VS Code and JetBrains.
00:20:34.320 | We can do things like, Claude's going to know what file I'm in.
00:20:37.360 | What file am I in?
00:20:38.720 | That is not what I meant to say, but Claude's going to figure it out.
00:20:44.320 | And you can do things like this.
00:20:58.080 | So these are the sort of things I would encourage you to stay on top of.
00:21:01.680 | We have a public kind of GitHub project called Claude Code under Anthropic.
00:21:07.520 | You can post issues there, but we also post our changelog there.
00:21:10.720 | And so I check this once a week and make sure that I'm on top of all the new stuff we're shipping,
00:21:15.280 | because even I can't keep up with it.
00:21:17.120 | So with that said, we have like four minutes left.
00:21:20.640 | I'm happy to answer questions about anything Claude Code related.
00:21:23.360 | We have it here.
00:21:24.480 | I can live demo some stuff if you're interested.
00:21:26.560 | Let's do a few.
00:21:29.120 | Thanks real quick.
00:21:33.840 | This might be obvious, but multiple Claude.md files in a project, I presume that's possible
00:21:40.720 | and it just figures it out or no?
00:21:42.160 | So there's a few options.
00:21:44.400 | Of course, like in the same directory, you couldn't.
00:21:48.400 | But you could have one here and one in a subdirectory.
00:21:56.320 | And I think we changed this so that all the subdirectory ones aren't read in,
00:22:00.640 | because like Anthropic, we have a monorepo.
00:22:02.960 | And people would open it at the top and blow up their context with all the Claude MDs.
00:22:07.760 | So we encourage Claude when it's searching around and it discovers Claude.md files
00:22:13.280 | in child directories that are relevant to be sure to read them.
00:22:17.920 | But by default, it just reads the Claude.md file in the current working directory when you fire it up.
00:22:23.600 | And then also you can set one in like your home directory.
00:22:26.240 | There are things you can do, though.
00:22:28.560 | We have this new thing.
00:22:29.600 | Like in your Claude.md, you can start referencing other files.
00:22:34.880 | So you could, for instance, do something like this with an @ sign.
00:22:39.520 | If you have other Claude.md files that you just kind of know you always want to read in,
00:22:44.080 | to do something like that.
00:22:47.120 | Hi, okay.
00:22:49.440 | I have not had luck getting Claude to respect my Claude.md.
00:22:54.480 | Like there's one thing particular where I'll ask it to refactor something,
00:22:58.640 | and then it will leave inline comments explaining the what of it is.
00:23:02.720 | And it's like something that's extremely obvious.
00:23:04.800 | Yes.
00:23:05.280 | And so I'll tell it like, go and remove any inline comments that describe the what of what's happening.
00:23:10.400 | And then it will remove it and then immediately do it again in like the same path.
00:23:13.920 | So do you have any strategies for dealing with that?
00:23:15.600 | So there's kind of two things that fix that.
00:23:18.880 | So that was actually kind of a model problem.
00:23:20.960 | There's nothing in the prompt.
00:23:22.160 | We have actually a lot in the prompts for 3.7 that said, whoa, do not leave comments.
00:23:27.200 | And despite that, the model just loves to leave comments.
00:23:29.600 | So it doesn't surprise me that your Claude.md didn't help much either.
00:23:32.880 | We already did a lot.
00:23:33.920 | I did a lot of work to try to tamp it down from what happens out of the box.
00:23:38.480 | So we mostly fixed that in Claude 4.
00:23:42.800 | Now, there might be some new weird behavior quirks.
00:23:45.200 | But the other thing we made better in Claude 4 is it's just better at following instructions.
00:23:49.120 | And we've gotten a lot of feedback from early testers that all of a sudden, whoa,
00:23:54.640 | my Claude.md is being followed way more closely.
00:23:57.280 | And it might be a good chance to go look in your Claude.md and decide, do I still need this stuff?
00:24:02.800 | Maybe I can take some of it out.
00:24:04.800 | Maybe I need to add a few new things.
00:24:06.880 | So moving over to the new models might be a good time to take another look at what's in there and
00:24:11.120 | see what you need and what maybe can go.
00:24:13.680 | For the record, I'm trying to think of something that you might not have thought of.
00:24:18.080 | Yes.
00:24:18.560 | We're doing multi-agent execution and parallelization.
00:24:22.240 | Can you make it so that for four agents, say, agents two and three use the context from agent one?
00:24:28.160 | Maybe agent four uses the context from agent two at a certain point?
00:24:31.360 | Yeah.
00:24:31.840 | Yeah, et cetera.
00:24:33.600 | That's interesting.
00:24:34.960 | We're trying to-- so kind of like I said at the beginning, we're trying to do the simple thing
00:24:39.360 | that works, which is just one agent that's great at coding and does everything.
00:24:43.120 | I think we want to figure that out.
00:24:46.080 | Probably what's going to happen is if you wanted to do that, you would ask all your
00:24:50.800 | agents to probably write to a shared markdown file or something like that so they can all
00:24:55.440 | kind of check in and communicate.
00:24:57.200 | Sometimes I'll be working with Claude and I'll just say, "Hey, I need you to write
00:25:03.120 | some stuff in Ticket.md for another developer."
00:25:06.160 | And then I'll fire up another Claude code and I'll be like, "Hey, read Ticket.md.
00:25:09.440 | Another developer left this note for you.
00:25:12.240 | This is what you're going to work on."
00:25:14.000 | So I would think about trying to write that state to a file and then just kind of like
00:25:18.160 | count on the model's ability to just like read files and make sense to them.
00:25:21.600 | It's probably the best you can do today and maybe we'll figure out clever ways to expose that
00:25:28.160 | in the product as something more native.
00:25:30.720 | Cool.
00:25:32.880 | All right.
00:25:35.200 | And with that said, I have some rare Claude code stickers that I found in my backpack.
00:25:41.440 | So come find me.
00:25:42.320 | I'll be hanging out over there or something.
00:25:43.920 | Happy to share them.
00:25:45.760 | Happy to share them.