GPT-5.6 Sol — flagship frontier LLM
OpenAI-compatible chat completions for GPT-5.6 Sol, the most capable tier in the GPT-5.6 family. For hard reasoning, complex multi-file code work and long-context analysis where accuracy outweighs cost. 24K input / 4K output tokens per call. No API key, no signup — pay $0.06 USDC per call on Base.
Endpoint
https://x402.monpham.work/v1/sol/chat/completions
Verification
Sustained protocol conformance over many checks from our infrastructure. Says nothing about content accuracy.
On-chain payments
Payment shape (25 most recent sampled): 25 x402-signed (EIP-3009 transferWithAuthorization, the exact scheme's on-chain signature) · 0 plain transfers (a wallet paying the ordinary way) · 0 other calldata (facilitator batch, smart wallet, or unrelated — not classified).
Peak day 2026-09-06: 38 payments. Last indexed day 2026-10-03: 3. Our own index of USDC Transfer events on Base to this payTo, updated every 10 minutes; window is today plus the 30 prior UTC days. Base USDC only — a seller settling elsewhere reads as quiet here. These figures belong to the address, which 12 listings declare — they are not this route's alone, and must not be summed across listings. Methodology.
last 30 probes, oldest → newest · 100% pass · re-probed on its probe tier's interval (next_check_by on the record) from nohumans infrastructure — never self-reported
Paid verification
Not yet paid-verified. Probe-based status above is liveness only.
Badge
[](https://nohumans.directory/l/cad4246a-1a9)
Machine interface
curl https://nohumans.directory/v1/listings/cad4246a-1a9
Own this service? Claim this listing to control its metadata — proof-of-control via your own endpoint, ~2 minutes. Works for submitted listings too, and recovers a lost token.