Flexible payments
Where supported, your wallet signs a ceiling with upto, or a fixed amount with exact. The facilitator pays the payment transaction fee.
API · browser paymentsPricing, without a plan
A clear price.
For every call.
Default: provider cost × 1.03 + 0.001 USDC.
No subscription. No prepaid balance.
Growing lineup · 44 models
Compare live prices ↗Anthropic, OpenAI, Gemini and open models. Chat, vision, embeddings, images, speech, transcription and video use the same x402 payment flow.
For chat, where supported, pay actual usage within the signed ceiling (the upto payment scheme). Unit-priced endpoints use exact quotes by image, megapixel, character or second.
01
Make it your call.
Claude Fable 5.1 context: 1,000,000 tokens, including output. Choose 1–8,192 output tokens.
Estimated ceiling · upto
0.015420USDC
- Tokens · includes 3% margin
- 0.014420
- Per-call fee
- 0.001000
Estimated actual · 0.006150 USDC
Assumes 76 output tokens (30% of the limit) and the same estimated input. This is an estimate; actual tokens and the server quote determine your payment.
You sign this ceiling and pay actual usage. The charge cannot exceed the ceiling.
Contact Synal ↗Read the documentation for quotes and payment schemes before using the API.
The payment, not a platform balance
USDC stays in your wallet
until a call is paid.
Settle first
Some networks require payment before the model runs. Pay through the API with a compatible wallet. The facilitator pays the payment transaction fee.
API · browser support laterMainnet
More payment options are planned. This release uses test networks and test USDC.
Not open in this releaseWallet funding, swaps or bridging can have their own costs. They are separate from the call quote.
Keep your integration.
OpenAI and Anthropic-compatible APIs, a local paying proxy and MCP tools.
Before you pay.
What is USDC?
USDC is a digital dollar token. Synal uses it to pay for individual calls from your wallet. For this testnet release, use test USDC on the matching network.
Why does the quote include the output limit?
The quote covers your estimated prompt and all requested output tokens. With upto, you sign this ceiling and pay for tokens actually used. With exact, the quote is a fixed payment and a shorter answer does not change it.
Can I be charged twice?
The same payment authorization can settle only once. A new signature can authorize a new payment, so check an unresolved call before starting another paid attempt.
What if the call fails?
A confirmed model failure before settlement is not charged. On some networks, and for async video jobs, the payment settles before the model runs; if the model then fails, a refund is owed. A lost connection alone does not prove a refund.
Explore the payment flow ↗