Trust Fabric integration

How gateway-to-gateway (G2G) DIDComm messaging, Verifiable Presentations, and x402 payments put Agent Stream on the Affinidi Trust Fabric.

A plain LLM proxy stops at routing and metering a call. Agent Stream carries the same trust-native capabilities as the rest of the Affinidi Trust Fabric, so identity, policy, and payments extend beyond a single appliance across organisational boundaries. Verify caller credentials with VP evidence →

Fabric

The Fabric is the set of DIDComm-based appliances that participate in mutual connectivity through Connection Points. A Fabric may include Agent Gateway appliances, Trust Registries, and other appliance types. Appliances in the Fabric exchange messages over the DIDComm connections their Connection Points establish.

How a Gateway-to-Gateway (G2G) call is routed

Gateway-to-Gateway (G2G) describes a call routed through the Fabric from one appliance to another. Agent Stream makes G2G calls when it browses or buys models from a connected peer’s model marketplace. The originating appliance forwards the call over the already-established DIDComm connection for that peer rather than opening a new connection on demand, so the call succeeds only while a Connection Point is connected to the peer.

Agent Stream
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Connection Point
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Mediator (if needed)
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Peer appliance

Connection Point

A Connection Point is the DIDComm endpoint that another Fabric-enabled appliance uses to establish and use a connection with this appliance. Connection is initiated via an out-of-band DIDComm invitation, followed by a handshake that establishes a persistent bilateral connection.

A Connection Point is distinct from an Access Point. An Access Point is the inbound endpoint for external callers reaching a Surface; a Connection Point is the appliance-to-appliance pairing endpoint for Fabric membership. Confusing the two leads to misconfiguration.

Mediator

A Mediator is a DIDComm v2.1 relay service that routes messages between appliances that cannot connect directly. Its DID document must identify the configured DID and use WSS for message sockets plus HTTPS for authentication.

Agent DID

An Agent DID is a decentralised identifier (W3C DID) that represents the appliance or an agent in Fabric identity flows.

Verifiable Presentation (VP)

A Verifiable Presentation is a signed credential bundle that proves an identity and may include caller-binding claims. On fabric traffic, when an inbound message carries a VP in its agent-identity credential extension, the receiving appliance verifies it and, when verification succeeds, passes the result to its surface policy as input.identity_binding. On an LLM Surface, a VP is inbound evidence from the caller: it arrives in a request header or a JSON body field, Agent Stream verifies it, and the result is passed to policy as input.identity_binding. Deny when no VP is presented is off by default, so an LLM Surface requires a VP only when you turn that setting on.

How x402 payments and the model marketplace work

Where it is enabled, Agent Stream layers a payment mechanism on top of a call, and can build a provisioning flow on top of that same mechanism in turn.

x402 is an HTTP 402 payments protocol for blockchain-settled, metered access, used through either an embedded or a remote facilitator: the component that verifies and settles the payment. Settlement is the step that finalises a verified payment or records it for deferred completion. This lets model or service access be monetised at the request boundary itself, rather than only through a monthly invoice.

Agent Stream can also expose a built-in model marketplace: a catalogue and purchase flow that lets a caller provision an API key for a purchased model directly, without a separate procurement step outside the appliance. A marketplace purchase is itself settled through x402, so it is a use of that payment mechanism rather than a separate, parallel one.

Why this matters

Verifiable identity, decentralised gateway-to-gateway (G2G) trust, and native payment rails are what separate Agent Stream from a proxy that only forwards and meters traffic. An organisation that already runs other Trust Fabric appliances, such as Agent Gateway, can extend the same fabric and identity model to its LLM traffic, instead of treating model governance as a separate, disconnected system.