Conclusion
- Supabase and Firebase are good places to keep provider keys off the client.
- No-card APIs validate an MVP, but production needs billing, quotas, observability, and fallback.
- Compatible endpoints reduce code churn when switching from free to paid providers.
- Track cost by user, workspace, function name, and route before SaaS usage scales.
What to do next
- Create one Edge Function or Cloud Function that reads baseURL, apiKey, model, and max tokens from secrets.
- Run a minimal prompt and a structured JSON response test from the deployed function runtime.
- Compare one no-card route, one low-cost provider, and one fallback on real MVP tasks.
- Add per-user/workspace quotas, timeout limits, retry limits, and daily budget alerts.
- Use OpenLLMAPI when multiple functions need one key, provider switching, route logs, and cost attribution.
Recommended paths
| Provider | Free / credits | Best for |
|---|---|---|
| OpenRouter/Groq | Free routes vary | No-card MVP smoke tests |
| DeepSeek | Verify current pricing | Low-cost SaaS tasks after prototype |
| Qwen DashScope | Signup credits vary | China-friendly compatible backend functions |
| Zhipu GLM | Signup tokens vary | Domestic fallback for backendless SaaS |
| OpenLLMAPI | Trial varies | One endpoint with logs, fallback, quotas, and per-customer cost |
Global developer checklist
- Confirm whether signup, billing, and API keys work from your country before writing production code.
- Prefer OpenAI-compatible endpoints when you may need to switch models, regions, or providers later.
- Test free credits with a real smoke prompt and record latency, error shape, streaming behavior, and quota burn.
- Keep at least one fallback route for provider outages, model deprecations, and regional access changes.
Production handoff
Give every function a budget-aware model route
Route Supabase and Firebase calls through one compatible endpoint with server-side secrets, quotas, fallback, and per-workspace cost logs.
FAQ
Can Supabase Edge Functions call OpenAI-compatible APIs?
Yes. Put baseURL, key, and model in secrets, then verify fetch/streaming behavior in the deployed edge runtime.
Can Firebase Functions use no-card APIs safely?
Yes for prototypes if keys stay in function config or secrets and public clients call only your function endpoint.
What breaks when moving from free to production?
Rate limits, cold starts, timeouts, streaming support, JSON shape, retry storms, and missing per-user budgets.
What should I log?
User/workspace id, function name, provider, model, tokens, latency, retry count, error, fallback route, and accepted outcome.