Vantafold normalises 200+ models from every major provider behind a single request and response schema. Change the model string, keep the code.
Different auth, different message shapes, different streaming formats, different tool-calling conventions. Supporting three providers means writing the same feature three times, and every new model is another migration.
Messages, tools, structured output, and streaming events have the same shape for every model. The response tells you which model answered.
A single Vantafold key replaces a drawer of provider keys. Rotate, scope, and revoke from one place.
New models appear behind the same endpoint the week they ship. Pin a version when you need stability, or track the alias.
Point your client at api.vantafold.ai and name a model — or pass model="auto" and let the router decide. Auth is one bearer token.
The gateway validates the request, applies your policy, and translates it into the provider's native format. Failures retry against your fallback list.
Output, usage, cost, and the route taken come back in the same envelope every time, with a trace ID you can look up in the dashboard.
from vantafold import Vantafold
client = Vantafold()
# The same call, whichever model answers it.
response = client.reason(
model="frontier-lg",
input="Extract the payment terms from this contract.",
response_format={"type": "json_schema", "schema": TERMS},
)
# Swapping models is a string change. Nothing else moves.
response = client.reason(
model="oss-70b-instruct",
input="Extract the payment terms from this contract.",
response_format={"type": "json_schema", "schema": TERMS},
){
"id": "req_8f2c41a9",
"model": "frontier-lg",
"output_text": "Net 30 from invoice date...",
"usage": { "input_tokens": 4210, "output_tokens": 186, "cost_usd": 0.0154 },
"route": { "requested": "auto", "selected": "frontier-lg", "attempts": 1 },
"trace_id": "tr_5b1d9e0c"
}Frontier, open-weight, fine-tuned, and private models sit side by side. Browse the full catalog for context windows and rates.
| Capability | Frontier | Open weights | Fine-tuned | Private |
|---|---|---|---|---|
| Unified request schema | Included | Included | Included | Included |
| Streaming (SSE) | Included | Included | Included | Included |
| Tool calling | Included | Included | Included | Depends on base model |
| JSON-schema output | Included | Included | Included | Included |
| Token and cost accounting | Included | Included | Included | Included |
| Automatic fallback | Included | Included | Included | Within your pool |
| Zero-retention mode | Included | Included | Included | Included |
| Provider account required | Not included | Not included | Not included | Not included |
Start on the free tier. Move to production without touching your integration.