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Metadata
FieldValue
Canonical URIhttps://docs.aion.to/extensions/aion/middleware/fulfills/1.0.0
Issueraion
Version1.0.0
ActivationThis extension is declarative. It will always be active and does not require activation.
Related ExtensionsMiddleware

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Overview

The Middleware Fulfills extension declares that a middleware agent can satisfy required extension semantics on behalf of upstream clients. This is used when a downstream agent requires an extension but an upstream middleware can provide the required data, proofs, or enforcement without client activation. Only use this extension when the middleware can fully satisfy the downstream requirements. If the client must participate (for example, signatures or payments), the downstream requirement must remain client-facing.

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Agent Card Declaration

{
  "capabilities": {
    "extensions": [
      {
        "uri": "https://docs.aion.to/extensions/aion/middleware/1.0.0",
        "description": "Access control middleware",
        "required": false
      },
      {
        "uri": "https://docs.aion.to/extensions/aion/middleware/fulfills/1.0.0",
        "description": "Provides downstream role claims",
        "required": false,
        "params": {
          "fulfills": [
            "https://docs.aion.to/extensions/aion/roles/1.0.0"
          ]
        }
      }
    ]
  }
}

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Parameters

The params.fulfills value must be a list of canonical extension URIs (string[]).
NameRequiredDescription
fulfillsrequiredList of canonical extension URIs that this middleware can satisfy on behalf of the client.

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Sequence Validation Rules

  • If a downstream agent marks extension X as required and an upstream middleware declares fulfills for X, the distribution may treat X as supported (not required) at the ingress boundary.
  • The middleware is responsible for enforcing the required semantics before forwarding the request downstream.
  • If the client activates X anyway, middleware should pass through or augment the request without breaking downstream expectations.