LedgerX (MIAX Derivatives Exchange)
LedgerX LLC, doing business as MIAX Derivatives Exchange (MIAXdx), is a CFTC-regulated derivatives venue registered as a Designated Contract Market (DCM), Swap Execution Facility (SEF) and Derivatives Clearing Organization (DCO). Founded in 2014 under Ledger Holdings Inc. and backed by GV and Lightspeed Venture Partners, it pioneered physically settled, federally regulated Bitcoin options and swaps for institutional and retail traders. Ledger Holdings was acquired by West Realm Shires (FTX.US) in 2021; after the FTX bankruptcy, Miami International Holdings acquired MIAXdx in May 2023, and in November 2025 MIAX agreed to sell 90% of the exchange to Robinhood Markets in partnership with Susquehanna International Group. The exchange published a public REST API for contracts, positions, trades, balances and order entry, plus a WebSocket market data feed carrying action reports, top-of-book updates and exchange heartbeats, authenticated with JWT API keys. Its physically settled DCM/SEF products were delisted in July 2024 and the public developer surface (docs, api and trade hosts, status page) is currently unreachable or inactive.
Limited machine-readable signal and partial portal coverage — documentation a human can read, but little a machine or agent can consume without scraping.
API Evangelist profiles LedgerX (MIAX Derivatives Exchange) the way a machine reads it — 6 machine-readable artifacts across 2 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 — LedgerX (MIAX Derivatives Exchange) scores 34.2/100 (thin), with a separate agent-readiness read of 30/100 (agent aware). 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 LedgerX (MIAX Derivatives Exchange)
Each block below is one kind of artifact we hold for LedgerX (MIAX Derivatives Exchange). 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 2
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.
MIAXdx Market Data and Account API
Public and authenticated REST API on api.ledgerx.com covering exchange contracts, traded contracts, contract tickers, positions, trades (own and global), upcoming exchange holid...
MIAXdx Trading API
Authenticated order-entry REST API on trade.ledgerx.com for listing resting limit orders, placing orders, cancelling a single order or all orders for an MPID, atomically cancel-...
Rate 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.
Ledgerx 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.
MIAXdx (LedgerX) Market Data Feed
WebSocket market data and account feed for MIAX Derivatives Exchange (LedgerX). NOT A PROVIDER-PUBLISHED SPEC. MIAXdx publishes no AsyncAPI document. This description was derive...
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 LedgerX (MIAX Derivatives Exchange) — 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 2
Portal, sign-up, and the first successful call
Documentation 3
Reference material describing how the API behaves
Agent Surfaces 1
MCP servers, agent skills, and machine-readable catalogs
Design & Contract 5
Pagination, idempotency, versioning, errors, and events
Build 1
SDKs, sample code, and the tooling you integrate with
Access & Security 3
Authentication, authorization, and security posture
Operate 4
Status, limits, changes, and where to get help
Company 1
The organization behind the API
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