sFOX is a unified crypto prime brokerage and infrastructure platform for professional and institutional investors — asset managers, hedge funds, family offices, and financial institutions. It aggregates liquidity from 30+ providers across 80+ markets for smart-routed best execution, and combines that with bankruptcy-remote custody (sFOX SAFE, via SAFE Trust Company), staking, credit, and post-trade settlement in one platform. sFOX exposes a REST API, a WebSocket streaming API, and a FIX API for trading, account management, RFQ, transfers, custody, staking, market data, and reporting; a separate white-label "Connect" API covers end-user onboarding, KYC/KYB, bank linking (Plaid/Dwolla), payments, withdrawals, and SSO for businesses building crypto products.
Sfox is listed with 3 APIs on the APIs.io network, including REST API, WebSocket API, and 1 more. Tagged areas include Company, Cryptocurrency, Prime Brokerage, Trading, and Digital Asset Custody.
The Sfox catalog on APIs.io includes 1 event-driven AsyncAPI specification.
Sfox’s developer surface includes documentation, API reference, getting-started guide, engineering blog, support, signup flow, authentication, and 19 more developer resources.
Regulatory Posture applies to this provider. Its tags matched the
Securities & Market Data regime, so
Regulatory Posture carries 15 points of the composite.
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applicability map is public and we will correct it.
Create-or-Update Ergonomics could not be measured. We hold no machine-readable contract for
this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero:
never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and
several others — scorable at all.
The six quality facets above are damped to 85 points between them,
because the conditional facet above carries the other
15. That is why each facet's contribution is shown against a damped
maximum: raising a quality facet moves the composite by 85% of its nominal
weight, not 100%. The full arithmetic is at apis.io/rating/.
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Agent readiness — checks not met, largest first (exact, from this profile):
MCP Server+12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship
Idempotency+9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented)
A2A Agent Card+8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Request/Response Examples+7 pts — share of operations carrying request/response examples; else an Examples / Code Samples link
Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.
REST API for trading, order management, RFQ, account balances and transactions, transfers/deposits/withdrawals, custody (sFOX SAFE), staking, post-trade settlement, market data,...
Real-time streaming API for market data (order book, trades, ticker) and private account data (open orders, trades, balances, post-trade settlement). Authenticate then subscribe...
White-label REST + WebSocket API for businesses: end-user management, KYC/KYB and Enhanced Due Diligence, bank-account linking (Plaid), ACH (Dwolla) and wire payments, withdrawa...
Real-time streaming API for sFOX. Clients connect over WSS, authenticate with their API key (for private feeds), then subscribe/unsubscribe to feeds via a JSON control message: ...
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