SubToAPI Blog

Guides and answers on the Claude API, API gateways, keys, streaming, tool use and shipping AI features.

How to Get a Claude API Key: Step-by-Step Guide

Learn how to get a Claude API key from Anthropic, set it up securely, and start making API calls — plus a faster path via SubToAPI.

2026-09-01 · 5 min read

Claude API Platform: How to Choose the Right One

A guide to evaluating a Claude API platform — what "platform" actually means, key features to check, and how to pick one for your team.

2026-09-01 · 5 min read

Claude API Docs: How to Navigate Them Efficiently

A practical guide to the Claude API docs — structure, key pages, common gaps, and how to find what you actually need fast.

2026-09-01 · 4 min read

Claude API Token: What It Means and How to Use One

"Claude API token" means two different things — an auth credential and a usage unit. Here's how each works and how to manage both.

2026-09-01 · 4 min read

Claude API Key Free: What You Actually Get for €0

Looking for a free Claude API key? Here's what Anthropic offers, how much free credit you get, how long it lasts, and what to do after it runs out.

2026-09-01 · 4 min read

Claude API Login: How Authentication Actually Works

There's no "Claude API login" screen — the API uses API keys, not sessions. Here's how authentication works and how to get set up.

2026-09-01 · 5 min read

Claude API Error: Common Codes and How to Fix Them

A practical breakdown of Claude API errors — status codes, causes, and fixes for 401, 429, 500, 529 and overloaded_error responses.

2026-09-01 · 5 min read

Claude API Models: Which One to Pick and Why

A breakdown of the Claude API models available today—capabilities, pricing tiers, and how to choose the right one for latency, cost, or quality.

2026-09-01 · 4 min read

Claude API Credits: How They Work and How to Manage Them

Learn how Claude API credits work, how to buy and top up credits, how billing is calculated, and how to avoid running out mid-project.

2026-09-01 · 5 min read

Claude API Console: What It Does and How to Use It

A guide to the Claude API console (console.anthropic.com) — creating keys, testing prompts, checking usage, and when you need more than a dashboard.

2026-09-01 · 5 min read

Claude API Usage: How to Track and Understand It

Learn what Claude API usage actually measures, how to monitor it per key or team, and how to catch spikes before they become a problem.

2026-09-01 · 5 min read

Claude API Status: How to Check It and Handle Outages

Learn how to check Claude API status, interpret incidents, and build retry logic so your app stays reliable when Anthropic has issues.

2026-09-01 · 5 min read

Claude API Cost: How to Estimate and Control It

Understand what drives Claude API cost, how to estimate spend per request, and practical ways to keep your bill predictable in production.

2026-09-01 · 5 min read

Claude API: What It Is and How to Access It

What the Claude API actually does, what you can build with it, and the different ways to get access — direct, console, or subscription-based.

2026-09-01 · 5 min read

How to Use Claude in Your App

A practical guide to using Claude in your app: authentication, requests, streaming, tool use, and production considerations for teams.

2026-09-01 · 5 min read

Claude API vs OpenAI API: Key Differences for Developers

A practical comparison of the Claude API and OpenAI API covering pricing, context windows, tool use, streaming, and how to pick between them.

2026-09-01 · 5 min read

Anthropic Claude Integration: Options and Trade-offs

A practical guide to integrating Anthropic Claude into your product, comparing the direct API, SDKs, and API gateway approaches.

2026-09-01 · 5 min read

Claude HTTP API: How It Works and How to Call It

A practical guide to Claude's HTTP API — endpoints, auth, request format, streaming, and how to call it from curl or JavaScript.

2026-08-31 · 5 min read

How to Manage LLM API Keys Without Losing Your Mind

Practical strategies to manage LLM API keys: rotation, scoping, storage, and monitoring, so you avoid leaks, overspend, and outages.

2026-08-31 · 5 min read

Claude API for Developers: A Practical Overview

What developers actually need from the Claude API — access options, auth, request patterns, and production considerations, explained clearly.

2026-08-31 · 5 min read

Build a Chatbot with Claude: A Practical Guide

Learn how to build a chatbot with Claude, from system prompts and conversation state to streaming responses and production deployment.

2026-08-31 · 5 min read

Claude API Rate Limits: How They Work and How to Avoid Them

Understand Claude API rate limits — requests per minute, tokens per minute, tiers, 429 errors — and practical ways to avoid hitting them in production.

2026-08-31 · 5 min read

Claude API Curl Example: Requests, Headers & Errors

A practical curl example for the Claude API, covering headers, request bodies, streaming, error handling, and a SubToAPI-compatible variant.

2026-08-31 · 4 min read

Claude API JavaScript Example: Requests, Streaming & Tools

A working Claude API JavaScript example covering basic requests, streaming responses, tool use, and error handling with Node.js and fetch.

2026-08-31 · 4 min read

AI API Gateway: Features That Actually Matter

What an AI API gateway does, which features are essential, and how to evaluate one before you build production traffic on top of it.

2026-08-31 · 5 min read

LLM API Gateway: What It Is and When You Need One

An LLM API gateway sits between your app and model providers, handling auth, routing, and observability. Here's how it works and how to pick one.

2026-08-31 · 5 min read

Claude Function Calling: A Practical Implementation Guide

Learn how Claude function calling works in practice, with schema examples, multi-step tool loops, error handling, and streaming patterns.

2026-08-31 · 5 min read

Claude Tool Use: How It Works and How to Implement It

Learn how Claude tool use works, how to define tools, handle tool_use blocks, and build multi-step agent workflows with real code examples.

2026-08-31 · 5 min read

Claude Streaming API: How Token Streaming Works

How the Claude streaming API delivers tokens in real time, how to implement it with SSE, and how to add it to your app in minutes.

2026-08-31 · 5 min read

Anthropic API Key: What It Is and How to Manage It

What an Anthropic API key is, where to get one, how to secure it, and what to do when console billing isn't the right fit for your team.

2026-08-31 · 5 min read

Claude API Tutorial: Build Your First Integration

A hands-on Claude API tutorial covering authentication, messages, streaming, and tool use, with working code examples for your first integration.

2026-08-31 · 5 min read

How to Use the Claude API: A Practical Setup Guide

Learn how to use the Claude API step by step: authentication, your first request, streaming, tool use, and common integration patterns for developers.

2026-08-31 · 5 min read

Claude API Pricing Explained: Costs, Tiers & Alternatives

A clear breakdown of how Claude API pricing works, what drives your bill up, and how to get predictable flat-rate access instead.

2026-08-31 · 4 min read

How to Get a Claude API Key (and How to Use It)

Step-by-step guide to getting a Claude API key from Anthropic, understanding pricing, making your first request, and keeping keys secure.

2026-08-31 · 5 min read

Turn your Claude access into an HTTPS API

SubToAPI gives you application API keys, streaming, tool use and usage insights on top of your existing Claude access — set up in minutes.

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