Stop locking into one provider
If you're building on the OpenAI API, the risk isn't just price — it's lock-in. KissAPI gives you GPT-5 and GPT-5.5 and Claude Opus 4.6, Sonnet 4.6 and Haiku 4.5 behind a single OpenAI-compatible endpoint. Switch models by changing one string, not your whole stack.
Price comparison
| Model | Input / 1M | Output / 1M |
|---|---|---|
| Claude Opus 4.6 | $15.00 → $3.00 | $75.00 → $15.00 |
| Claude Sonnet 4.6 | $3.00 → $0.60 | $15.00 → $3.00 |
| Claude Haiku 4.5 | $0.80 → $0.16 | $4.00 → $0.80 |
| GPT-5 | $2.50 → $0.50 | $10.00 → $2.00 |
| GPT-5.5 | $7.50 → $1.50 | $30.00 → $6.00 |
Strikethrough = official list price. Green = KissAPI price. No subscription, pay only for tokens you use.
Truly drop-in
It's the OpenAI wire format. Change the base URL and key, keep your SDK.
curl https://api.kissapi.ai/v1/chat/completions \
-H "Authorization: Bearer $KISSAPI_KEY" \
-H "Content-Type: application/json" \
-d '{"model":"MODEL_ID","messages":[{"role":"user","content":"hi"}]}'Why provider-agnostic wins
- Benchmark GPT-5 against Claude on your own workload without new integrations
- Fail over between providers if one is degraded
- One invoice, one balance, no per-provider minimums
One key, every model
Sign up, get $1 free, and call GPT-5 and Claude from the same endpoint.
Start Free — $1 creditFAQ
Is KissAPI OpenAI-compatible?
Yes. It implements the OpenAI chat completions format, so existing OpenAI SDKs work by changing the base URL to https://api.kissapi.ai/v1 and using your KissAPI key.
Which models can I access?
GPT-5, GPT-5.5, Claude Opus 4.6, Claude Sonnet 4.6, Claude Haiku 4.5 and more — all through one key.
Is it cheaper than OpenAI directly?
Yes, models are offered at up to 80% off official list pricing, pay-as-you-go with no subscription.