w3c-vcdm-issuer - SKILL.md Agent Skill

name: "w3c-vcdm-issuer" description: "Use when implementing issuer representation in W3C VCDM. Covers: issuer property requirements, syntax options, and issuer-related processing expectations." sections: - "4.7 Issuer"

4.7 Issuer

This specification defines a property for expressing the issuer of a verifiable credential.

A verifiable credential MUST have an issuer property.

      issuer

The value of the issuer property MUST be either a URL or an object containing an id property whose value is a URL; in either case, the issuer selects this URL to identify itself in a globally unambiguous way. It is RECOMMENDED that the URL be one which, if dereferenced, results in a controlled identifier document, as defined in the Controlled Identifiers v1.0 specification, about the issuer that can be used to verify the information expressed in the credential.

[Example 7](https://www.w3.org/TR/vc-data-model-2.0/#example-use-of-the-issuer-property): Use of the issuer property

  - Credential- ecdsa- ecdsa-sd- bbs- jose- cose- sd-jwt```

{ "@context": [ "https://www.w3.org/ns/credentials/v2", "https://www.w3.org/ns/credentials/examples/v2" ], "id": "http://university.example/credentials/3732", "type": ["VerifiableCredential", "ExampleDegreeCredential"], "issuer": "https://university.example/issuers/14", "validFrom": "2010-01-01T19:23:24Z", "credentialSubject": { "id": "did:example:ebfeb1f712ebc6f1c276e12ec21", "degree": { "type": "ExampleBachelorDegree", "name": "Bachelor of Science and Arts" } } }

            ```
{
  "@context": [
    "https://www.w3.org/ns/credentials/v2",
    "https://www.w3.org/ns/credentials/examples/v2"
  ],
  "id": "http://university.example/credentials/3732",
  "type": [
    "VerifiableCredential",
    "ExampleDegreeCredential"
  ],
  "issuer": "https://university.example/issuers/14",
  "validFrom": "2010-01-01T19:23:24Z",
  "credentialSubject": {
    "id": "did:example:ebfeb1f712ebc6f1c276e12ec21",
    "degree": {
      "type": "ExampleBachelorDegree",
      "name": "Bachelor of Science and Arts"
    }
  },
  "proof": {
    "type": "DataIntegrityProof",
    "created": "2025-04-27T17:58:33Z",
    "verificationMethod": "did:key:zDnaebSRtPnW6YCpxAhR5JPxJqt9UunCsBPhLEtUokUvp87nQ",
    "cryptosuite": "ecdsa-rdfc-2019",
    "proofPurpose": "assertionMethod",
    "proofValue": "z3sXkg3PHbK2YpbhQajunUvReW3Qn66mPsQQKvn4hwEG1DohgUqvXBF2oKT5Qb8tKSKjewNhsJCCcBoY6Rfye4ipw"
  }
}
```**application/vc**
            ```
{
  "@context": [
    "https://www.w3.org/ns/credentials/v2",
    "https://www.w3.org/ns/credentials/examples/v2"
  ],
  "id": "http://university.example/credentials/3732",
  "type": [
    "VerifiableCredential",
    "ExampleDegreeCredential"
  ],
  "issuer": "https://university.example/issuers/14",
  "validFrom": "2010-01-01T19:23:24Z",
  "credentialSubject": {
    "id": "did:example:ebfeb1f712ebc6f1c276e12ec21",
    "degree": {
      "type": "ExampleBachelorDegree",
      "name": "Bachelor of Science and Arts"
    }
  },
  "proof": {
    "type": "DataIntegrityProof",
    "created": "2025-04-27T17:58:33Z",
    "verificationMethod": "did:key:zDnaerJh8WwyBVVGcZKKkqRKK9iezje8ut6t9bnNChtxcWwNv",
    "cryptosuite": "ecdsa-sd-2023",
    "proofPurpose": "assertionMethod",
    "proofValue": "u2V0AhVhA91jcz-MSzf_Z-fw6VM-YN1ijTr26VBTz9H14dMiv6t5vRaGC1IKHvDtY0ZJup1pnliukZBHEXgM46Bf4EjdyIFgjgCQDMIFZRjI7aJUGGsbDYML33eEwJuub6dIF5agqeB4sTdJYIAhgKXoAudJOwmVRpO2Ab5sNIirjQdArIjp8ygMx2S5ihVhASWfZk4fYqoICvoaokYzsABtmDzpgTe8ZkI2z4MDKt1wcp0T9tBx30mk1V20Qhy2PT15nrPygrxpn8_h2Z1Jo7FhAXNmEd28tsb_VkmqckvjVBet7p8Hhq7d8DziDldJRri8-cygIdcaX0MsitDRMsclHCsO25UKSjCX96dSto_Y3FVhAeYhHIz52Lw3Fd8tO7rdPOjILauPLHFkRnmHbd8ixxKwb62gTqchavN3rv8GtKxQL9o-cLCKFm-mpQDUABuYxMVhA-vKFPcx_bNem4ufrFDr-cyjUa3r-zjLJwp9xss7XZikI3PLiiMGIBnhhGs3zCsQXvSZMX6ScPOpog6Kzl-YSj1hA7xtSv3lNDKhPKKQ-7F4WHhmfwj0F1PN_mj5jDkJcdw19eYTux4wRXgehBXRtvkuMw9iG6UFyurMFeyb-EkmQPIFnL2lzc3Vlcg"
  }
}
```**application/vc**
            ```
{
  "@context": [
    "https://www.w3.org/ns/credentials/v2",
    "https://www.w3.org/ns/credentials/examples/v2"
  ],
  "id": "http://university.example/credentials/3732",
  "type": [
    "VerifiableCredential",
    "ExampleDegreeCredential"
  ],
  "issuer": "https://university.example/issuers/14",
  "validFrom": "2010-01-01T19:23:24Z",
  "credentialSubject": {
    "id": "did:example:ebfeb1f712ebc6f1c276e12ec21",
    "degree": {
      "type": "ExampleBachelorDegree",
      "name": "Bachelor of Science and Arts"
    }
  },
  "proof": {
    "type": "DataIntegrityProof",
    "verificationMethod": "did:key:zUC78GzFRA4TWh2mqRiKro1wwRb5KDaMJ3M1AD3qGtgEbFrwWGvWbnCzArkeTZCyzBz4Panr2hLaZxsXHiBQCwBc3fRPH6xY4u5v8ZAd3dPW1aw89Rra86CVwXr3DczANggYbMD",
    "cryptosuite": "bbs-2023",
    "proofPurpose": "assertionMethod",
    "proofValue": "u2V0ChVhQs4LnYe9N1n9fBW8t7tgXy8gZA1WksN76TfdxHLUW0cJlImiaNZZbbNwAaL86-8xnTgMJgpwaMchm_8VepMSYZKjfQReWnOfwRfwz8grbaNNYQGd_DaMQQsoaryttl5TvxnFT-Vm4SkVx03K9qNJ4jhArKnv3N5iX7nvZR0OCXS-uXH4QQ9mW65QM5qlHOfE4GQVYYJVTGbTfcflzyx41E-f9kSqmf10xYzxJrGfC7b7GPY8X7VjMT__ZKSuwdH-5jak-5gkjocsHI6oxIKlLrhW1Wh5yrDCH-QC823TS8NE9VGBzIFAfUt5qazGEcJ8CxeSPxFggO3rpYlZcra0jsUsWXIoCAXrkmj3mb1o1k8CYE2Wx9d6BZy9pc3N1ZXI"
  }
}

Protected Headers

{
  "kid": "ExHkBMW9fmbkvV266mRpuP2sUY_N_EWIN1lapUzO8ro",
  "alg": "ES256"
}

application/vc

{
  "@context": [
    "https://www.w3.org/ns/credentials/v2",
    "https://www.w3.org/ns/credentials/examples/v2"
  ],
  "id": "http://university.example/credentials/3732",
  "type": [
    "VerifiableCredential",
    "ExampleDegreeCredential"
  ],
  "issuer": "https://university.example/issuers/14",
  "validFrom": "2010-01-01T19:23:24Z",
  "credentialSubject": {
    "id": "did:example:ebfeb1f712ebc6f1c276e12ec21",
    "degree": {
      "type": "ExampleBachelorDegree",
      "name": "Bachelor of Science and Arts"
    }
  }
}

application/vc+jwt

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application/vc

{
  "@context": [
    "https://www.w3.org/ns/credentials/v2",
    "https://www.w3.org/ns/credentials/examples/v2"
  ],
  "id": "http://university.example/credentials/3732",
  "type": [
    "VerifiableCredential",
    "ExampleDegreeCredential"
  ],
  "issuer": "https://university.example/issuers/14",
  "validFrom": "2010-01-01T19:23:24Z",
  "credentialSubject": {
    "id": "did:example:ebfeb1f712ebc6f1c276e12ec21",
    "degree": {
      "type": "ExampleBachelorDegree",
      "name": "Bachelor of Science and Arts"
    }
  }
}

application/vc+cose

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  - 
    Encoded
  
  - 
    Decoded
  
  - 
    Issuer Disclosures

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```

{ "kid": "ExHkBMW9fmbkvV266mRpuP2sUY_N_EWIN1lapUzO8ro", "alg": "ES256"}

      ```
{  "iat": 1745776713,  "exp": 1746986313,  "_sd_alg": "sha-256",  "@context": [    "https://www.w3.org/ns/credentials/v2",    "https://www.w3.org/ns/credentials/examples/v2"  ],  "issuer": "https://university.example/issuers/14",  "validFrom": "2010-01-01T19:23:24Z",  "credentialSubject": {    "degree": {      "name": "Bachelor of Science and Arts",      "_sd": [        "cx_BlSjQIZzn3yhTasJDxhKeYkrwKsn_-w5DaJUWMbc"      ]    },    "_sd": [      "Nroz4QPDqS8fduR4l1PhVpKyzhRs7lakueAFC2hMkhs"    ]  },  "_sd": [    "JO8FgHben-We8roP0b3OnWXkTvR2V39tSJYsvjbO-vs",    "horLRQ5jlzMpY-X7J1p5ZhxQsM6c2hxhescRqtFtPH8"  ]}