AI Coding Tool Errors — Claude Code, Cursor, Codex, opencode, Cline, Zed

Claude Code errors

Fixes for every error Claude Code prints: API Error 429 rate_limit_error, 401 invalid x-api-key, 529 Overloaded and the usage-limit message. Exact output, cause and fix.

• Claude Code API Error 429 (rate_limit_error) — Cause and Fix
• Claude Code API Error 401 invalid x-api-key — Fix
• Claude Code API Error 529 Overloaded — What It Means
• Claude usage limit reached in Claude Code — Reset Time and Options

Cursor errors

Fixes for Cursor errors with a custom Anthropic API key: unable to reach model provider, invalid API key on verify, 401 from the provider and rate limits. Cause and fix for each.

• Cursor: Unable to Reach the Model Provider — Causes and Fixes
• Cursor Invalid API Key (Anthropic) — Why Verify Fails
• Cursor: Request Failed With Status Code 401 — Anthropic Key Fix
• Cursor Rate Limit / 429 With Your Own Anthropic Key

Codex CLI errors

Fixes for Codex CLI failures with a custom model provider: Missing OPENAI_API_KEY, config.toml profile mistakes, auth.json login state and stream error: unexpected status 401.

• Codex CLI: Missing OPENAI_API_KEY — Custom Provider Setup
• Codex config.toml Errors — model_providers Setup That Works
• Codex auth.json / Login Errors — API Key Auth Instead
• Codex: stream error: unexpected status 401/404 — Fix

opencode errors

Fixes for opencode failures on a custom provider: AI_APICallError, models missing from the provider list, API keys that are not picked up, and silently dropped image attachments.

• opencode AI_APICallError — Causes and Fixes
• opencode Model Not Found — Declaring Custom Provider Models
• opencode API Key Not Picked Up — auth and {env} Placeholders
• opencode: This Model Does Not Support Image Input — Fix

Cline errors

Fixes for Cline errors with an Anthropic key: the API Request Failed banner, 401 invalid x-api-key, 429 rate_limit_error retry loops and the context-limit 400. Cause and fix for each.

• Cline API Request Failed — Diagnosing the Real Error
• Cline 401 invalid x-api-key (Anthropic) — Fix
• Cline 429 rate_limit_error — Stop the Retry Loop
• Cline: input length and max_tokens exceed context limit — Fix

Zed errors

Fixes for Zed assistant errors on Anthropic models: 401 invalid x-api-key, 429 rate limits, 529 Overloaded and custom api_url configuration, including the /v1/v1 404 trap.

• Zed Claude 401 invalid x-api-key — Anthropic Settings Fix
• Zed Assistant 429 rate_limit_error — Fix
• Zed: 529 Overloaded From Claude — What To Do
• Zed api_url for Anthropic — Custom Base URL Setup and the /v1/v1 404

Claude API error codes

The API-level reference: every status code and verbatim response body, organized by code rather than by tool.

Skip the broken setup

apiToken.sale serves the standard Anthropic API — same models, same SDKs, one prepaid balance. Point your tool's base URL at it, and the config on this page works as written.