Coding Agents
Claude Code error database
Find the Claude Code error you’re seeing by its message or code, and fix it: certificate and proxy problems, rate limits, sign-in, model and install errors.
25 errors
Certificates and network (8)
- SSL certificate verification failed (UNABLE_TO_GET_ISSUER_CERT_LOCALLY)Claude Code can’t trace the API’s certificate to an authority it trusts, almost always because a corporate proxy re-signs HTTPS traffic.
- Self-signed certificate detected (SELF_SIGNED_CERT_IN_CHAIN)The certificate chain ends in a self-signed root Claude Code doesn’t trust: the signature of a proxy or a private certificate authority.
- SSL certificate is not yet valid (CERT_NOT_YET_VALID)The certificate’s start date is in the future as far as your computer knows, which almost always means your system clock is wrong.
- SSL certificate has expired (CERT_HAS_EXPIRED)A certificate in the chain is past its end date, usually because your clock is ahead or a proxy is serving an expired certificate.
- SSL certificate hostname mismatch (ERR_TLS_CERT_ALTNAME_INVALID)The certificate Claude Code received is for a different hostname than the one it asked for, so something is answering in Anthropic’s place.
- curl: (60) SSL certificate problem: unable to get local issuer certificateThe Claude Code installer’s download failed certificate checks, usually because of a TLS-inspecting proxy.
- Unable to connect to APIClaude Code couldn’t open a network connection to the API at all; the code in brackets says why.
- Request timed outThe API didn’t answer before Claude Code’s deadline, from heavy load, a very long response, or a slow network or proxy.
Server and limits (5)
- API Error: 500 Internal server errorSomething failed inside the API. It isn’t caused by your prompt, settings or account, and usually clears within minutes.
- API Error: Repeated 529 Overloaded errorsThe API is temporarily at capacity for everyone. It doesn’t count against your usage limit, and switching model usually gets you going.
- API Error: Request rejected (429)You hit the rate limit of the API key, Bedrock project or Google Cloud project Claude Code is using.
- You've hit your session limitYour Claude subscription’s rolling usage allowance ran out; it comes back at the time shown.
- Credit balance is too lowClaude Code is billing a Console API key whose prepaid credits ran out, often by accident instead of your subscription.
Sign-in (4)
- Not logged in · Please run /loginClaude Code has no valid credential for this session: no saved login and no API key it can use.
- Invalid API key · Fix external API keyThe key from `ANTHROPIC_API_KEY` or your `apiKeyHelper` was rejected by the API, or blocked before sending because it’s malformed.
- OAuth token has expired / OAuth token revokedYour saved Claude login stopped working: it expired and couldn’t refresh, or it was revoked.
- API Error: 401 Invalid authentication credentialsThe API recognised your credential’s format but rejected the account or organisation behind it.
Requests and models (4)
- Prompt is too long / Context limit reachedThe conversation plus everything Claude Code sends with it no longer fits in the model’s context window.
- There's an issue with the selected modelThe configured model name isn’t recognised, or your account or provider doesn’t have access to it.
- API Error: Output blocked by content filtering policyThe API’s output filter stopped the response Claude was writing.
- Auto mode is unavailable — the server returned no safety verdictAuto mode’s safety check got no answer for ten responses in a row, so Claude Code stopped instead of acting unchecked.
Install and setup (4)
- command not found: claudeClaude Code installed, but your shell can’t find the `claude` command, almost always a PATH issue.
- Claude Code on Windows requires either Git for Windows (for bash) or PowerShellClaude Code runs natively on Windows, but it needs a shell to run commands: Git Bash or PowerShell, and it found neither.
- Raw mode is not supported on the current process.stdinClaude Code tried to show an interactive prompt while its input wasn’t a terminal, typically during a piped install.
- syntax error near unexpected token `<' when installing Claude CodeThe install URL returned a web page instead of the install script, usually because Claude Code isn’t available in your region or a proxy blocked it.
Steps
How to use the claude code error database
- Copy the error from your terminal, or just the code in brackets such as UNABLE_TO_GET_ISSUER_CERT_LOCALLY.
- Paste it into the search box and open the matching error.
- Read what it means and check the causes that fit your situation.
- Work through the fixes in order; each one says how to confirm it worked.
Method
How it works
Claude Code’s error messages are short because they appear in a terminal. Each page here expands one of them: what actually went wrong, the situations that cause it, and the fixes in the order worth trying, with the exact commands for each operating system.
Where the most common errors come from
Most reports come from three places. Corporate networks that inspect HTTPS make Claude Code distrust the connection, which shows up as certificate errors with codes like UNABLE_TO_GET_ISSUER_CERT_LOCALLY or SELF_SIGNED_CERT_IN_CHAIN. Credentials cause the next group: an ANTHROPIC_API_KEY left in the environment quietly takes priority over a subscription login, leading to low rate limits, “credit balance is too low” or 401 errors. And busy periods produce temporary 500 and 529 errors that clear on their own.
How the pages are checked
Messages are matched against Anthropic’s error reference and the text inside the Claude Code 2.1.293 build, so the wording matches what you see. Fixes follow Anthropic’s documentation, rewritten with more context. Where a page says a step was tested, it was run on a real machine. Each page shows the date it was last verified and links its sources.
Some fixes need numbers from elsewhere on this site: the context window checker helps with “prompt is too long”, and the subscription vs API calculator helps decide whether a plan or the API suits your usage limits.
FAQ
Frequently asked questions
Why does Claude Code say “SSL certificate verification failed” at work but not at home?
Most company networks inspect HTTPS traffic with a proxy that re-signs it using the company’s own root certificate. Claude Code doesn’t trust that root unless it can read it from your operating system’s store or you point NODE_EXTRA_CA_CERTS at it. The UNABLE_TO_GET_ISSUER_CERT_LOCALLY page walks through exporting the certificate on Windows, macOS and Linux.
Is it safe to set NODE_TLS_REJECT_UNAUTHORIZED=0?
No. It turns off certificate checking for everything Claude Code does, so anyone on the network path could read or alter your traffic, including your API key and code. Trust the specific certificate your company uses instead.
What’s the difference between a 429 and a 529 error?
A 429 means you hit a rate limit for the key or project you’re using. A 529 means the API is at capacity for everyone; it doesn’t count against your usage, and switching to another model usually helps.
How were these fixes checked?
Every message is checked against Anthropic’s Claude Code error reference and the strings in the Claude Code 2.1.293 build, on 2026-10-08. Fixes follow Anthropic’s documentation, and steps marked as tested were run on a real machine, such as exporting a certificate on Windows and confirming Node loads it.
The message I see is slightly different. Is it the same error?
Probably. Claude Code reworded several messages between versions, and the same failure reads differently during /login, in -p mode or in the Desktop app. Each page lists the variants it covers, including older wordings. Search for the code in brackets, such as SELF_SIGNED_CERT_IN_CHAIN, if the wording doesn’t match.
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