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Open Materials Availability (OMA) is an open protocol built on Nostr that enables companies to exchange material availability, quotes, and orders directly with trading partners — without routing through a central platform or intermediary. Each company runs its own node — a server that stores and serves events. Companies connect their nodes directly to trading partners, so data flows between parties without passing through any third party. Identity is established via cryptographic keypairs: your public key is your address on the network, and your private key signs every event you publish, proving authenticity. The protocol defines three core models:
  • Listing – An offer to supply or a request to source a material
  • Quote – A bid or ask on a published listing, sent privately to the listing author
  • Response – An acceptance or rejection that closes the quoting thread

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Workflow

A typical OMA exchange follows this sequence:
  1. A company publishes a Listing to their Network Node, making it discoverable to connected partners.
  2. A trading partner discovers the listing and sends a Quote — encrypted so only the recipient can read it.
  3. The listing author replies with a Response, either accepting or rejecting the quote.
  4. If both parties accept, the thread is marked complete.

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Node Types

OMA is premised on two types of nodes:
  • Network Node — A permissioned node where companies publish listings. Trading partners can query and subscribe to material availability here.
  • Inbox Node — A private node used exclusively for quoting threads. Anyone can send events to your inbox, but only you can read what’s inside. This functions like an email inbox: publicly addressable, privately readable.