AI APIs for Developers: Pricing, Keys and Errors

Per-token price comparisons, OpenAI-compatible gateways that give you one key for many models, and fixes for 401, 429 and quota errors.

All APIs guides

• DeepSeek API Pricing 2026: Flash vs V4 Pro, Off-Peak Hours

  How DeepSeek's API tiers compare: deepseek-flash vs deepseek-v4-pro, peak vs off-peak hours in UTC, cache hits vs misses, and where to find official rates.

  Updated October 18, 2026
• Fix AI API Errors: 401, 429, 529 and insufficient_quota

  What each OpenAI and Anthropic API error code means, which ones retries can fix, and a copy-paste retry pattern that respects Retry-After.

  Updated October 18, 2026
• OpenAI API Pricing 2026: GPT-6 Model Tiers Explained

  How OpenAI's API tiers compare: GPT-6 Astra, GPT-6.1 Sol and Luna, Batch, Flex, Fast, Ultrafast and usage tiers, with links to the official price list.

  Updated October 18, 2026