Don't Panic at Claude Code Errors: All 71 Error Codes + Three Ways to Triage

When you first start using Claude Code, I’d guess most people hit the same pain point: an error fires, the conversation can’t move forward, and you don’t know what the error is or how to handle it.

There’s a textbook example right now: roughly half the people I know on official-subscription Claude Code have been getting a 401 these past couple of days, asking them to log in again. My guess is it’s tied to the privacy policy tightening up and the KYC (identity verification) that may be coming—use the end of the month to push everyone through a fresh login, then collect and verify personal information on the way in.

Don’t panic at errors: classify them first

Claude Code works by calling the Claude API, so one key thing to understand is: almost every runtime error ultimately maps to an HTTP status code. It isn’t infinite mysticism—it’s a finite set you can sort into categories.

So I took the errors scattered all over the official docs and collected them into one field guide—71 of them, in 8 categories (HTTP status codes, server errors, usage limits, auth errors, network connectivity, request errors, MCP errors, install and login). Each one is broken down the same way: the original English text, why it happens, and how to fix it. Bookmark it and take the whole thing with you—next time red text shows up in your terminal, just match it and go.

A few of the most common:

• 400: usually shows up when you plug a third-party model into Claude Code, because the request has a format or content problem.
• 401: telling you to log in again. This one genuinely spooks people, because a ban also throws a 401 telling you to log in—but on its own it’s usually just an expired credential. Don’t scare yourself.
• 403 / 404 / 413 / 429 and so on: a series of errors each pointing at something specific, all sorted out in the collection.

The three triage moves I use most

When an error shows up, a few fixes work almost everywhere. In order:

1. Hit Esc twice. That lets you find an earlier step in the conversation history, rewind to it, and take another run at it—far more effective than trying to force a correction in place.
2. Close the terminal, reopen it, and pick back up with resume. If rewinding doesn’t do it, close the terminal, open it again, and push the conversation forward with resume.
3. Have it write a to-do list and hand off. If there’s still a problem, this is the move I fall back on most: have it dump the current conversation into a to-do list, then open a fresh conversation, point it at that list, and see whether it can carry on. Usually it can.

The collection also lists the more obscure ones in full—the MCP integration errors that fire constantly, for instance, or the case where a Claude Code update leaves some file unreadable until you adjust for it. The fixes are all in there. (Worth noting: at the top of the collection I also put the official first-aid moves—/doctor clears roughly 80% of local config problems in one pass, /status shows which credential is actually in effect, and for 5xx/529 go check status.claude.com to see whether there’s an active incident.)

An aside: coding isn’t just for STEM guys anymore

I saw something interesting today: two people on a date, and instead of a movie or shopping, the guy pulls out a laptop and teaches the girl to build a project with Claude Code. How an agent calls tools, how to build a knowledge base with RAG, how to write prompts, how to configure MCP. At the end he even shows her how to put the project on her résumé and runs mock interviews with her. Lots of commenters said they envied a relationship like that.

And honestly, if the people around you are learning these frontier AI agent tools and can bring you along, that’s a genuinely great partnership. I see it most in women with deep industry experience. You don’t see them for a few days and suddenly they’ve built all kinds of interesting, creative projects with Claude Code. Meanwhile some of the guys who already knew product and code are stuck in the paths they already knew, hemming themselves in with a pile of “that won’t work, this won’t work.”

So with AI here, coding is no longer the exclusive turf of the STEM-guy stereotype. More and more women are shipping excellent products built on deep consumer insight. So what interesting thing have you built with Vibe Coding? Drop it in the comments and let’s talk. See you next episode.

Source: EP0049_audio.mp3 · ASR model gemini-2.5-pro (chunked parallel) · full text of the original recording

[00:00] Lately a lot of friends—maybe about half of the people using Claude Code on the official subscription—have been getting this 401 error, telling them to go log in again. I think it may have something to do with the privacy agreement getting stricter and the KYC thing that’s coming: they use this stretch at the end of the month to make everyone log in again, then collect and cross-check personal information. When I first started using Claude Code there was one pain point—I don’t know if this was everyone’s experience—an error comes up, and then the conversation can’t go on. I had no idea what that error was, and no idea how to handle it either. So today I’ve prepared

[00:25] a big collection of error codes: 71 errors in total that can show up in Claude Code. What its English message says, why it happens, and how to fix it—it’s all in here. Bookmark it, pack it up, take it with you. Let’s look at how to read this collection. It’s split into these eight categories: HTTP status codes, server-side errors, plus some usage limits, auth errors and so on. A fairly common one is the 400 error. There are actually a lot of different kinds of 400 error, and they usually show up when we hook a third-party model into Claude Code, because the request

[00:50] may have problems in its format or its content. And then there’s the 401 error, which has been pretty frequent these last couple of days—that’s the one telling you to go log in again. And this 401 really is scary, because if you’ve been banned, it also pops a 401 error asking you to log in. There’s also 402, 403, then 404, 413, 429 and a whole series of other errors. When these errors come up, there are a few common ways to fix them. The first is to hit Esc twice—that lets us go into the conversation history, find some earlier step, and roll the conversation back to that step. And if that doesn’t work,

[01:15] you can close the terminal, then open it again and push the conversation forward via resume. And if there’s still a problem, a method I use fairly often is to have it write the contents of that conversation into a to-do list, then start a brand new conversation and have it read the earlier to-do list and see whether it can carry on from there. Usually it can. So this big collection lists out every error that can show up in Claude Code, including that MCP integration error that pops up all the time, or when Claude Code—

[01:40] updates and that makes some file unreadable again, so you have to go tweak something to match. The fixes for all of it are in there. Something else I saw today: two people go on a date, and instead of the movies or walking around the shops, the guy pulls out his laptop and teaches the girl to build a project with Claude Code—explains how an agent calls tools, how to build a knowledge base with RAG, how to write the prompts, including how to configure MCP—and then at the end teaches her how to write these projects into her résumé, and takes her through mock interviews.

[02:05] And then a lot, a lot of people left comments saying they envy a relationship like that. And it’s true—if the person next to you right now is learning these most advanced AI agent tools and can take you along to learn with them, that really is a great partnership. Especially some of the women who have very deep experience in their industries. Honestly, you don’t see them for a few days and the next thing you know they’re building all kinds of interesting, creative projects with Claude Code. Whereas some of the men, who understood products and code before, have their thinking boxed into the old

[02:31] paths, and end up setting a lot of limits on themselves instead—can’t do this, can’t do that. So now that we have AI, this programming thing isn’t just a STEM-guy thing anymore. More and more women are building excellent products with really deep consumer insight. So what interesting products have you built with Vibe Coding? Leave a comment, let’s talk more. See you next episode, bye-bye.