stax
api · x402 · solana mainnet
HTTP 402 · Payment Required

x402 — Agent-callable pricing API

Pay-per-request access to verified peptide pricing, powered by the BioHash oracle. USDC micropayments on Solana mainnet. No API keys. No subscriptions. Cryptographic proof of payment.

Request→402 Challenge→Sign & Pay→Response
Data source. Every price returned by this API is anchored on-chain through the BioHash oracle's TWAP commits — the source of truth for verified peptide pricing. Stax is the agent-callable layer that lets agents query and verify that data before they transact.

Why x402

Auth
No API keys
Payment is the authentication. No signup, no key rotation, no quota.
Settlement
Instant settlement
USDC on Solana mainnet, sub-second finality.
Pricing
Pay per use
True micropayments — $0.01 per query. Built for agents, not humans.
Trust
Verified data
Every price anchored on-chain via BioHash TWAP commits. Independently verifiable.

Endpoints

Base URL: https://api.getstax.xyz
GET/api/v1/oracle/prices/:peptide_code$0.01 USDC
Verified vendor prices for a peptide. Full vendor spread, TWAP, best value.
POST/api/v1/oracle/verify$0.01 USDC
Verify a claimed price against the oracle. Returns verdict (in_line / overpriced / underpriced / flagged) with delta vs the verified floor.
Flagship

Verify API

An agent that's about to transact off-platform can verify a vendor's quote against the BioHash oracle before paying.

Endpoint
POST https://api.getstax.xyz/api/v1/oracle/verify
Request
{
  "peptide_code": "BPC157",
  "claimed_price_usd_per_mg": 7.50,
  "vendor_name": "Pulse Peptides"
}
Response
{
  "verdict": "overpriced",
  "delta_pct": 152.8,
  "oracle_best_usd_per_mg": 2.966667,
  "oracle_twap": 5.4,
  "claimed_price_usd_per_mg": 7.5,
  "message": "claimed price is 152.8% above the verified market floor"
}
Verdicts
in_linewithin tolerance of the oracle floor
overpricedmaterially above the verified floor
underpricedmaterially below — verify vendor before trusting
flaggedoutlier or untracked vendor

Prices API

Pull the full verified vendor spread for a peptide, plus TWAP and best value.

Endpoint
GET https://api.getstax.xyz/api/v1/oracle/prices/BPC157
Response
{
  "peptide_code": "BPC157",
  "twap_usd_per_mg": 5.4,
  "best_value": {
    "vendor_name": "Amino Asylum",
    "price_usd_per_mg": 2.966667,
    "size_mg": 30,
    "price_usd": 89.00
  },
  "spread": {
    "min_usd_per_mg": 2.966667,
    "max_usd_per_mg": 7.50,
    "variance_pct": 152.8
  },
  "vendors": [
    { "vendor_name": "Amino Asylum",   "price_usd_per_mg": 2.966667, "size_mg": 30, "price_usd": 89.00, "rank": "cheapest" },
    { "vendor_name": "Limitless Life", "price_usd_per_mg": 4.50,     "size_mg": 20, "price_usd": 90.00, "rank": "median"   },
    { "vendor_name": "Pulse Peptides", "price_usd_per_mg": 7.50,     "size_mg": 10, "price_usd": 75.00, "rank": "highest"  }
  ],
  "last_commit": {
    "hash": "0x8f1a…c4e2",
    "cycle": 1287,
    "committed_at": "2026-05-31T18:42:00Z"
  }
}
3 steps

Integrate

  1. 1
    Connect a wallet
    Any Solana wallet with USDC on mainnet.
  2. 2
    Make the request
    The server responds with HTTP 402 and a payment challenge describing amount, recipient, and facilitator.
  3. 3
    Sign & retry
    Sign the payment and replay the request with the X-PAYMENT header. The server settles via the facilitator and returns the response.
SDK
npm install @x402/fetch @x402/svm
Or use the x402 SDK for automatic payment handling.

Network details

Network
Solana mainnet
Payment
USDC (mint EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v)
Facilitator
PayAI
Price
0.01 USDC per query