Sfox
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.
Real signal across most facets with visible, nameable gaps — the contract exists but is thin, or the portal is good while governance and commercial terms are absent.
API Evangelist profiles Sfox the way a machine reads it — 8 machine-readable artifacts across 3 APIs, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.
Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — Sfox scores 51.8/100 (developing), with a separate agent-readiness read of 63/100 (agent native). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.
Kin Score
This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance.
Kin Score
How this is scored →scored 2026-07-27 · rubric v0.5
How we profile Sfox
Each block below is one kind of artifact we hold for Sfox. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.
APIs 3
Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.
Individual APIs this provider publishes, each with its own machine-readable definition.
sFOX REST API
REST API for trading, order management, RFQ, account balances and transactions, transfers/deposits/withdrawals, custody (sFOX SAFE), staking, post-trade settlement, market data,...
sFOX WebSocket API
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...
sFOX Connect API
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...
MCP Servers 1
Model Context Protocol servers expose these APIs directly to AI agents. We profile them because agent-native access is the fastest-growing way this provider's capabilities actually get used.
Model Context Protocol servers that expose these APIs to AI agents.
sfox-mcp.yml
MCP SERVERRate Limits 1
Rate limits are the difference between a demo that works and a production integration that doesn't fall over. Publishing them is an operational-transparency signal — and a hard requirement for any agent that plans its own throughput.
Documented rate limits and quota policies.
Sfox Rate Limits
RATE LIMITSEvent Specifications 1
Not every API is request/response. AsyncAPI describes the event-driven and streaming side — the webhooks and channels — so the asynchronous half of the interface is documented the same way the synchronous half is.
AsyncAPI definitions for this provider's event-driven and streaming APIs.
sFOX WebSocket API
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: ...
ASYNCAPISecurity Posture 2
Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Resources
Every other property we hold for Sfox — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.
Get Started 5
Portal, sign-up, and the first successful call
Documentation 3
Reference material describing how the API behaves
Agent Surfaces 3
MCP servers, agent skills, and machine-readable catalogs
Design & Contract 6
Pagination, idempotency, versioning, errors, and events
Access & Security 2
Authentication, authorization, and security posture
Operate 3
Status, limits, changes, and where to get help
Commercial 2
Pricing, plans, and the legal terms of use
Company 1
The organization behind the API
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