Actually I may just misinterpret the JSON. It only includes `keyType=public-key` and `keyValue=...`, I was expecting there to be `keyType=public-key` and `keyType=private-key`, but perhaps keyType is impliying the authentication method and the keyValue is my private key?

They certainly are included, but whether they're included in a way that you can use them elsewhere, vs re-importing them into the same bitwarden account (something their vault has options to do if you encrypt the export), I'm not sure. I should spin up the vaultwarden clone and see if it correctly imports it.

    {
      "passwordHistory": null,
      "revisionDate": "2025-08-04T03:02:03.600Z",
      "creationDate": "2025-08-04T03:02:03.140Z",
      "deletedDate": null,
      "id": "<UUID>",
      "organizationId": null,
      "folderId": null,
      "type": 1,
      "reprompt": 0,
      "name": "abcdef",
      "notes": null,
      "favorite": false,
      "login": {
        "uris": [
          {
            "match": null,
            "uri": "https://<URL>"
          }
        ],
        "fido2Credentials": [
          {
            "credentialId": "<UUID>",
            "keyType": "public-key",
            "keyAlgorithm": "ECDSA",
            "keyCurve": "P-256",
            "keyValue":  "<238 chars>",
            "rpId": "<URL>",
            "userHandle": "<SOME BLOB>",
            "userName": "abcdef",
            "counter": "0",
            "rpName": "abcdef",
            "userDisplayName": "abcdef",
            "discoverable": "true",
            "creationDate": "2025-08-04T03:04:34.418Z"
          }
        ],
        "username": "abcdef",
        "password": null,
        "totp": null
      },
      "collectionIds": null
    }

Seems you can only import to the same account, some hand gesturing at FIDO Credential Exchange Format & Credential Exchange Protocol which aren't yet ratified.

https://community.bitwarden.com/t/passkey-portability/59177

https://community.bitwarden.com/t/passkey-export-file/77448/...