AI API Gateway vs Direct API: Which Should You Use?
When you're building with LLMs, one of the first decisions is: should I call provider APIs directly, or use an AI API gateway? Both approaches work, but they have very different tradeoffs in cost, flexibility, and operational overhead.
Direct API Access
Calling each provider's API directly means managing separate SDKs, API keys, and billing accounts for each model you use.
✓ Lowest possible per-token cost (no intermediary markup)
✓ Full control over request parameters
✗ Multiple SDKs and API keys to manage
✗ No automatic model switching — you handle outages yourself
✗ No unified cost tracking
✗ Harder to switch models (code changes required)
AI API Gateway Access
An AI gateway (like AI24X) provides one OpenAI-compatible endpoint that routes to 26 models.
✓ One SDK, one API key, one billing account
✓ Automatic model switching — provider outages don't affect your users
✓ Built-in cost dashboard and usage tracking
✓ Switch models by changing one parameter
✗ Gateway adds small latency overhead (typically 50-200ms)
✗ Managed tiers may cost more than direct for single-model use
Side-by-Side Comparison
| Factor | Direct API | AI Gateway (AI24X) |
|---|---|---|
| Number of integrations | 1 per provider | 1 for all models |
| API keys to manage | 1 per provider | 1 for all |
| Switching on outages | ✗ Manual | ✓ Automatic |
| Model routing | ✗ Custom code | ✓ Built-in |
| Cost dashboard | ✗ Separate per provider | ✓ Unified |
| Switch models | Code changes | Change model parameter |
| Per-token cost | Lowest possible | Competitive (flat tiers) |
| Latency overhead | None | 50-200ms |
| Best for | Single-model, cost-optimized production | Multi-model, resilience, developer velocity |
When to Use Direct API
- You only use one model (e.g., only DeepSeek V3)
- You have existing direct contracts with providers
- Every millisecond of latency matters
- You have the operational capacity to manage automatic switching yourself
When to Use an AI Gateway
- You use multiple models for different tasks
- You want automatic model switching for production reliability
- You want unified billing and cost tracking
- You want to switch models without code changes
- You're building AI agents that need model diversity
Hybrid Approach: BYOK Gateway
AI24X BYOK Pro ($9.9/mo) gives you the best of both worlds: bring your existing provider API keys, get gateway features (routing, automatic switching, cost dashboard) without paying per-token markup. You keep your direct pricing while adding resilience.
Model pages: all supported models