Zukko Blog
Guides to Claude Code, Cursor, Codex and the Claude and GPT APIs: setup, token savings and troubleshooting.
Gateway or direct API access: which to choose
3 min · · pricing
Each option has its own price and its own risks. Both sides honestly, including where a gateway is inconvenient.
Nano Banana image generation through the API
2 min · · models
The image endpoint explained: three modes, request shape, and honest arithmetic on what an image costs.
Grok 4.6 through the API: setup and pricing
3 min · · models
Access through a shared key, a flat rate, a million-token window. Setup and what the model is worth comparing on.
How to choose a model gateway: what to look at
3 min · · pricing
Six checks before you trust an intermediary with real traffic. Each takes a couple of minutes.
GPT-6 Astra through the API: setup and cost
3 min · · models
Setup takes one line. Here is the cost and a way to judge the model on your own work rather than on reviews.
VS Code AI extensions: how they differ
2 min · · setup
There are many extensions; they differ in three things: how they connect a model, how they build context, how they ask permission.
Connecting Claude Code to an existing project
3 min · · claude-code
A first run of the agent in an unfamiliar repository: what it reads, how to set boundaries, and how a project instructions file helps.
401 Invalid API key — why your key is rejected
2 min · · errors
You pasted the key and the server still answers 401. Here are the five causes, ordered by how often they actually happen.
Claude Code keeps asking to log in to Anthropic
2 min · · claude-code
Claude Code insists on signing in to Anthropic even though your key is configured. One environment variable is to blame.
Migrating a project from the official API to a gateway
2 min · · migration
Moving to a compatible gateway is two lines of configuration and an hour of verification. Here is exactly what changes.
Cursor does not see your models after changing the base URL
2 min · · cursor
The key is in, the URL is replaced, and the model list is empty or verification fails. Four causes by frequency.
Common API connection errors and how to read them
3 min · · errors
Connecting usually takes two minutes; when it does not, the cause is almost always one of four things. How to read the server's answer.
Base URL with or without /v1 — which client needs what
2 min · · setup
The same gateway needs different base URLs in different clients. Getting the suffix wrong yields a 404 with no useful explanation.
Do you need a VPN for the Claude and GPT APIs
2 min · · access
A VPN solves the wrong problem. What is blocked is the payment, not the address — and your exit IP does not change that.
Paying for Cursor from Russia: connect your own API key
3 min · · cursor
Cursor's subscription needs a foreign card, but the editor can talk to any OpenAI-compatible API with your own key.
Claude Code from scratch: install and configure with your own key
3 min · · claude-code
Installing Claude Code and configuring it to run on your own API key, step by step, including the mistakes almost everyone makes.
Codex without a ChatGPT subscription: pointing it at another API
3 min · · codex
Codex takes its provider from a config file, so you can point it anywhere compatible. Here is the exact config and what each field does.
Claude Code without a subscription: connecting via API key
3 min · · claude-code
Claude Code works with a plain API key, not only with a subscription. Then you pay for the tokens you used, not for a month.