Holdyn B2B · v1

API reference

The Holdyn B2B API lets you create conditional transactions, scope participant access to individual links, and subscribe to state-change events. This reference is the authoritative contract — the Holdyn B2B dashboard uses the same endpoints, there are no privileged shortcuts.

Base URL

All requests go to https://api.holdyn.io/api/v1/b2b. The API is JSON over HTTPS and never returns 1XX or 3XX responses — success is 2XX, everything else is a typed error payload.

Base URLhttp

https://api.holdyn.io/api/v1/b2b

Authentication

Every request carries either an API key (for server-to-server integrations) or a scoped portal session (for participant-facing flows). API keys are prefixed either htst_ (test) or htlk_ (live) and passed as a bearer token:

Authenticated requestbash

curl https://api.holdyn.io/api/v1/b2b/transactions \
  -H "Authorization: Bearer htst_…"

Full details — including dashboard sessions and the portal JWT — in Authentication.

Test mode vs live mode. Keys prefixed htst_ transact against Stripe test mode and will never move real money. Live keys (htlk_) are scoped to the same account but hit production rails.

Where to go next

Pick the resource you need:

Transactions

Create, list, cancel, and release conditional transactions.

Access tokens

Scoped, hashed, revocable links for participant access.

Webhooks

Signed HMAC-SHA256 deliveries with retry policy.

Event types

Every state change Holdyn emits, catalogued.

Authentication

API keys, session JWTs, portal tokens.

Errors

Response shape, HTTP codes, and error codes.