OneChronos

OneChronos operates AI-powered "Smart Market" alternative trading systems that match institutional orders using Nobel Prize-winning combinatorial auction techniques and mathematical optimization rather than traditional price-time priority matching. Operated by OneChronos Markets LLC, a broker-dealer subsidiary of OCX Group Inc., the venue runs point-in-time periodic auctions roughly ten times per second across US equities (a dark ATS launched in 2022), spot foreign exchange, and UK/EU equities multilateral trading facilities. Subscribers connect and submit orders electronically over a modern variant of the FIX 4.2 protocol, with "expressive bidding" that lets traders encode custom constraints, spreads, pairs, portfolio and hedging strategies into each auction.

OneChronos publishes 3 APIs on the APIs.io network. Tagged areas include Company, Financial Services, Capital Markets, Trading, and Equities.

OneChronos’ developer surface includes documentation, API reference, getting-started guide, support, engineering blog, pricing, and 9 more developer resources.

🌐 Visit website 📡 Source on GitHub
23.5/100 emerging ▬ flat Agent 4/100 human only Full breakdown ↓
scored 2026-07-27 · rubric v0.5
3 APIs
CompanyFinancial ServicesCapital MarketsTradingEquitiesAlternative Trading SystemFIX ProtocolForeign ExchangeInstitutional InvestingMarket Infrastructure

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-07-27 · rubric v0.5
Composite quality — 23.5/100 · emerging
Contract Quality 0.0 / 25
Developer Ergonomics 8.3 / 20
Commercial Clarity 4.2 / 20
Operational Transparency 0.7 / 13
Governance 0.0 / 12
Discoverability 8.8 / 10
Agent readiness — 4/100 · human only
Machine-Readable Contract 0 / 18
Agentic Access Contract 0 / 15
MCP Server 0 / 12
Machine-Readable Auth 0 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 0 / 7
Typed Event Surface 0 / 6
Agent Skills 0 / 5
Well-Known Catalog 4 / 4
Consent & Bot Identity 0 / 3
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/onechronos: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 3

Individual APIs this provider publishes, each with its own machine-readable definition.

OneChronos US Equities ATS (FIX 4.2)

Order entry and execution for the OneChronos US equities dark ATS over a modern variant of the FIX 4.2 protocol. Standard and Target orders, and Expressive Bids, are submitted e...

OneChronos FX Smart Market (FIX 4.2)

Order entry for the OneChronos spot foreign exchange Smart Market over the FIX 4.2 protocol variant, applying the same combinatorial-auction matching to global FX.

OneChronos European Equities MTF (FIX 4.2)

Order entry for the OneChronos UK and EU equities multilateral trading facilities over the FIX 4.2 protocol variant.

Security Posture 1

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Onechronos Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Resources

Get Started 2

Portal, sign-up, and the first successful call

DeveloperPortal
DeveloperPortal
 GettingStarted
GettingStarted

Documentation 2

Reference material describing how the API behaves

Documentation
Documentation
 APIReference
APIReference

Agent Surfaces 2

MCP servers, agent skills, and machine-readable catalogs

WellKnown
WellKnown
 LLMsTxt
LLMsTxt

Design & Contract 1

Pagination, idempotency, versioning, errors, and events

Conformance
Conformance

Build 2

SDKs, sample code, and the tooling you integrate with

GitHubOrganization
GitHubOrganization
 Packages
Packages

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity
DomainSecurity

Operate 1

Status, limits, changes, and where to get help

Support
Support

Commercial 2

Pricing, plans, and the legal terms of use

Pricing
Pricing
 PrivacyPolicy
PrivacyPolicy

Company 2

The organization behind the API

Website
Website
 Blog
Blog

Source (apis.yml)

apis.yml Raw ↑ 
aid: onechronos
name: OneChronos
description: OneChronos operates AI-powered "Smart Market" alternative trading systems that match institutional orders using
  Nobel Prize-winning combinatorial auction techniques and mathematical optimization rather than traditional price-time priority
  matching. Operated by OneChronos Markets LLC, a broker-dealer subsidiary of OCX Group Inc., the venue runs point-in-time
  periodic auctions roughly ten times per second across US equities (a dark ATS launched in 2022), spot foreign exchange,
  and UK/EU equities multilateral trading facilities. Subscribers connect and submit orders electronically over a modern variant
  of the FIX 4.2 protocol, with "expressive bidding" that lets traders encode custom constraints, spreads, pairs, portfolio
  and hedging strategies into each auction.
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  source: []
  generated: '2026-07-22'
  method: derived
image: https://www.onechronos.com/og-image.png
url: https://raw.githubusercontent.com/api-evangelist/onechronos/refs/heads/main/apis.yml
x-type: company
x-source: vc-portfolio
x-backed-by:
- dcvc
x-tier: profiled
x-tier-reason: enriched-from-portfolio-lead
specificationVersion: '0.20'
created: '2026-07-17'
modified: '2026-07-20'
tags:
- Company
- Financial Services
- Capital Markets
- Trading
- Equities
- Alternative Trading System
- FIX Protocol
- Foreign Exchange
- Institutional Investing
- Market Infrastructure
apis:
- name: OneChronos US Equities ATS (FIX 4.2)
  description: Order entry and execution for the OneChronos US equities dark ATS over a modern variant of the FIX 4.2 protocol.
    Standard and Target orders, and Expressive Bids, are submitted electronically via FIX over TCP/IP; the ATS hosts periodic
    auctions approximately ten times per second.
  humanURL: https://www.onechronos.com/documentation/fix/fix-42/us-equities/
  properties:
  - type: Documentation
    url: https://www.onechronos.com/documentation/user-manual/us-equities/
  - type: APIReference
    url: https://www.onechronos.com/documentation/fix/fix-42/us-equities/
- name: OneChronos FX Smart Market (FIX 4.2)
  description: Order entry for the OneChronos spot foreign exchange Smart Market over the FIX 4.2 protocol variant, applying
    the same combinatorial-auction matching to global FX.
  humanURL: https://www.onechronos.com/documentation/fix/fix-42/fx/
  properties:
  - type: Documentation
    url: https://www.onechronos.com/documentation/user-manual/fx/
  - type: APIReference
    url: https://www.onechronos.com/documentation/fix/fix-42/fx/
- name: OneChronos European Equities MTF (FIX 4.2)
  description: Order entry for the OneChronos UK and EU equities multilateral trading facilities over the FIX 4.2 protocol
    variant.
  humanURL: https://www.onechronos.com/documentation/fix/fix-42/european-equities/
  properties:
  - type: APIReference
    url: https://www.onechronos.com/documentation/fix/fix-42/european-equities/
common:
- type: Website
  url: https://www.onechronos.com/
- type: DeveloperPortal
  url: https://www.onechronos.com/documentation/fix/primer/
- type: Documentation
  url: https://www.onechronos.com/documentation/user-manual/us-equities/
- type: APIReference
  url: https://www.onechronos.com/documentation/fix/fix-42/
- type: GettingStarted
  url: https://www.onechronos.com/documentation/fix/primer/
- type: Support
  url: https://www.onechronos.com/contact/
- type: Blog
  url: https://www.onechronos.com/insights/
- type: GitHubOrganization
  url: https://github.com/onechronos
- type: Pricing
  url: https://www.onechronos.com/products/us-equities/fees/
- type: PrivacyPolicy
  url: https://www.onechronos.com/legal/privacy-policy/
- type: Packages
  url: packages/onechronos-packages.yml
- type: WellKnown
  url: well-known/onechronos-well-known.yml
- type: Conformance
  url: conformance/onechronos-conformance.yml
- type: DomainSecurity
  url: security/onechronos-domain-security.yml
- type: LLMsTxt
  url: llms/onechronos-llms.txt
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
x-enrichment:
  date: '2026-07-20'
  status: enriched
  artifacts_added: 5
  pass: local-v1