PolySign

PolySign, Inc. is an Oakland / San Francisco / New York financial technology company building blockchain-enabled infrastructure for institutional digital asset capital markets and payments. Founded by Arthur Britto, David Schwartz and Jack McDonald, PolySign operates a third-generation permissioned blockchain and the AtomicNet settlement network, and was the parent of Standard Custody & Trust Company, the NYDFS-regulated digital asset custody, trading and settlement platform acquired by Ripple in 2024. PolySign publishes three OpenAPI 3.0.3 contracts for AtomicNet — the AtomicNet API Server (node interface for assets, orders, escrow and beneficiary authorizations, settlements, settlement confirmations, book transfers, partners and investors), the AtomicNet Merchant Gate Node, and the AtomicNet ABC Proxy Service (account registration, digest memorialization, signing and testnet faucet) — all authenticated with OAuth 2.0 client credentials issued by a PolySign-hosted token endpoint.

PolySign publishes 3 APIs on the APIs.io network: AtomicNet API Server, AtomicNet Merchant Gate Node, and AtomicNet ABC Proxy Service. Tagged areas include digital-assets, blockchain, institutional-custody, settlement, and escrow.

PolySign’s developer surface includes documentation, API reference, support, authentication, sandbox, and 16 more developer resources.

🌐 Visit website 📡 Source on GitHub
31.0/100 thin ▬ flat Agent 33/100 agent aware Full breakdown ↓
scored 2026-08-05 · rubric v0.9.1
3 APIs
digital-assetsblockchaininstitutional-custodysettlementescrowcapital-marketspaymentsfintechdistributed-ledgeratomicnet

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-08-05 · rubric v0.9.1
Composite quality — 31.0/100 · thin
Contract Quality 10.9 / 25
Developer Ergonomics 7.7 / 20
Commercial Clarity 0.0 / 20
Operational Transparency 0.7 / 13
Governance 1.4 / 12
Discoverability 8.3 / 10
Agent readiness — 33/100 · agent aware
Machine-Readable Contract 18 / 18
Agentic Access Contract 0 / 10
MCP Server 0 / 12
Machine-Readable Auth 10 / 10
Idempotency 0 / 9
Stable Error Semantics 8 / 8
Request/Response Examples 7 / 7
Rate-Limit Signaling 0 / 7
Typed Event Surface 0 / 6
Agent Skills 5 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3
A2A Agent Card 0 / 8
Dry-Run / Simulate Mode 0 / 4
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/polysign: 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.

AtomicNet API Server

The node-side REST interface for interacting with an AtomicNet node — registering assets and partners, publishing orders and book transfers, requesting and approving escrow and ...

AtomicNet Merchant Gate Node

The merchant-facing gate onto an AtomicNet node: submit an order, submit a book transfer, and register assets to the node, alongside the shared authentication and system health ...

AtomicNet ABC Proxy Service

Proxy service for the ABC ledger: register an ABC account against an AtomicNet ID, look up account information, memorialize a digest and verify that a digest was memorialized, s...

Security Posture 2

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

Polysign Authentication

oauth2 · 1 scheme

SECURITY

Polysign Domain Security

TLSv1.3 · DMARC

SECURITY

Scopes 1

OAuth scopes governing access to this provider's APIs.

Polysign Scopes

1 scope · clientCredentials

1 scopes

SCOPES

Resources

Get Started 1

Portal, sign-up, and the first successful call

Sandbox
Sandbox

Documentation 2

Reference material describing how the API behaves

Documentation
Documentation
 APIReference
APIReference

Agent Surfaces 2

MCP servers, agent skills, and machine-readable catalogs

LLMsTxt
LLMsTxt
 AgentSkill
AgentSkill

Design & Contract 5

Pagination, idempotency, versioning, errors, and events

Conventions
Conventions
 ErrorCatalog
ErrorCatalog
 Lifecycle
Lifecycle
 DataModel
DataModel
 Conformance
Conformance

Build 2

SDKs, sample code, and the tooling you integrate with

GitHubOrganization
GitHubOrganization
 Packages
Packages

Access & Security 3

Authentication, authorization, and security posture

Authentication
Authentication
 OAuthScopes
OAuthScopes
 DomainSecurity
DomainSecurity

Operate 1

Status, limits, changes, and where to get help

Support
Support

Commercial 1

Pricing, plans, and the legal terms of use

LegalNotice
LegalNotice

Company 3

The organization behind the API

Website
Website
 Twitter
Twitter
 LinkedIn
LinkedIn

Other 1

Properties that don't map to a standard resource type

SecondaryMarket
SecondaryMarket

Source (apis.yml)

apis.yml Raw ↑ 
aid: polysign
name: PolySign
description: PolySign, Inc. is an Oakland / San Francisco / New York financial technology company building blockchain-enabled
  infrastructure for institutional digital asset capital markets and payments. Founded by Arthur Britto, David Schwartz and
  Jack McDonald, PolySign operates a third-generation permissioned blockchain and the AtomicNet settlement network, and was
  the parent of Standard Custody & Trust Company, the NYDFS-regulated digital asset custody, trading and settlement platform
  acquired by Ripple in 2024. PolySign publishes three OpenAPI 3.0.3 contracts for AtomicNet — the AtomicNet API Server (node
  interface for assets, orders, escrow and beneficiary authorizations, settlements, settlement confirmations, book transfers,
  partners and investors), the AtomicNet Merchant Gate Node, and the AtomicNet ABC Proxy Service (account registration, digest
  memorialization, signing and testnet faucet) — all authenticated with OAuth 2.0 client credentials issued by a PolySign-hosted
  token endpoint.
image: https://www.polysign.io/images/logo.png
url: https://raw.githubusercontent.com/api-evangelist/polysign/refs/heads/main/apis.yml
x-type: company
x-source: harvest:secondary-market
specificationVersion: '0.21'
created: '2026-08-02'
modified: '2026-08-02'
tags:
- digital-assets
- blockchain
- institutional-custody
- settlement
- escrow
- capital-markets
- payments
- fintech
- distributed-ledger
- atomicnet
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
apis:
- name: AtomicNet API Server
  description: The node-side REST interface for interacting with an AtomicNet node — registering assets and partners, publishing
    orders and book transfers, requesting and approving escrow and beneficiary authorizations, publishing settlements, releasing
    settlement and book transfer confirmations, polling status updates, minting one-time investor identifiers, canonicalization
    and UID utilities, data synchronization, and system health / circuit-breaker checks. Fifty-six operations secured with
    OAuth 2.0 client credentials.
  humanURL: https://docs.polynet.sandbox.polysign.io/
  x-baseurl-note: The published OpenAPI carries no servers[] block and no public AtomicNet node host resolves in DNS — AtomicNet
    is a participant-deployed network, so the base URL is deployment-specific. All paths are rooted at /v1. Recorded rather
    than guessed.
  tags:
  - digital-assets
  - settlement
  - escrow
  - capital-markets
  - atomicnet
  - blockchain
  properties:
  - type: Documentation
    url: https://docs.polynet.sandbox.polysign.io/
  - type: APIReference
    url: https://docs.polynet.sandbox.polysign.io/
  - type: OpenAPI
    url: openapi/polysign-atomicnet-api-server-openapi.json
  - type: Overlay
    url: overlays/polysign-atomicnet-api-server-overlay.yaml
- name: AtomicNet Merchant Gate Node
  description: 'The merchant-facing gate onto an AtomicNet node: submit an order, submit a book transfer, and register assets
    to the node, alongside the shared authentication and system health surface. Eight operations secured with OAuth 2.0 client
    credentials.'
  humanURL: https://docs.polynet.sandbox.polysign.io/merchant-gate.html
  x-baseurl-note: No servers[] block is published and the node is participant-deployed; all paths are rooted at /v1.
  tags:
  - digital-assets
  - payments
  - merchant
  - atomicnet
  - settlement
  properties:
  - type: Documentation
    url: https://docs.polynet.sandbox.polysign.io/merchant-gate.html
  - type: APIReference
    url: https://docs.polynet.sandbox.polysign.io/merchant-gate.html
  - type: OpenAPI
    url: openapi/polysign-merchant-gate-openapi.json
  - type: Overlay
    url: overlays/polysign-merchant-gate-overlay.yaml
- name: AtomicNet ABC Proxy Service
  description: 'Proxy service for the ABC ledger: register an ABC account against an AtomicNet ID, look up account information,
    memorialize a digest and verify that a digest was memorialized, sign a digest and verify a signature, and create and faucet
    accounts on the ABC testnet. Fourteen operations secured with OAuth 2.0 client credentials.'
  humanURL: https://docs.polynet.sandbox.polysign.io/abc-service.html
  x-baseurl-note: No servers[] block is published and the node is participant-deployed; all paths are rooted at /v1.
  tags:
  - digital-assets
  - blockchain
  - cryptography
  - atomicnet
  - testnet
  properties:
  - type: Documentation
    url: https://docs.polynet.sandbox.polysign.io/abc-service.html
  - type: APIReference
    url: https://docs.polynet.sandbox.polysign.io/abc-service.html
  - type: OpenAPI
    url: openapi/polysign-abc-proxy-service-openapi.json
  - type: Overlay
    url: overlays/polysign-abc-proxy-service-overlay.yaml
common:
- type: Website
  url: https://www.polysign.io/
- type: SecondaryMarket
  url: https://forgeglobal.com/polysign_stock/
- type: Documentation
  url: https://docs.polynet.sandbox.polysign.io/
- type: APIReference
  url: https://docs.polynet.sandbox.polysign.io/
- type: GitHubOrganization
  url: https://github.com/PolySignInc
- type: Support
  url: https://www.polysign.io/contact.html
- type: LegalNotice
  url: https://www.polysign.io/legal.html
- type: Twitter
  url: https://twitter.com/polysigninc
- type: LinkedIn
  url: https://www.linkedin.com/company/polysign
- type: Authentication
  url: authentication/polysign-authentication.yml
- type: OAuthScopes
  url: scopes/polysign-scopes.yml
- type: Conventions
  url: conventions/polysign-conventions.yml
- type: ErrorCatalog
  url: errors/polysign-problem-types.yml
- type: Lifecycle
  url: lifecycle/polysign-lifecycle.yml
- type: DataModel
  url: data-model/polysign-data-model.yml
- type: Conformance
  url: conformance/polysign-conformance.yml
- type: DomainSecurity
  url: security/polysign-domain-security.yml
- type: Packages
  url: packages/polysign-packages.yml
- type: LLMsTxt
  url: llms/polysign-llms.txt
- type: AgentSkill
  url: skills/_index.yml
- type: Sandbox
  url: sandbox/polysign-sandbox.yml
x-enrichment:
  date: '2026-08-02'
  status: enriched
  artifacts_added: 24
  pass: local-v1