Perseus · Carbon Accounting Provider

Perseus readiness

Each step below is checked live against the Perseus sandbox for the FSP-initiated with one permission flow. Steps marked Your turn need you to act as the SME customer.

4 / 14 stepsRe-run checks

Setup

  1. ✓

    We are listed in the Directory

    Done

    Our organisation is a member of the Perseus scheme with the Carbon Accounting Provider role.

    3 of 3 checks passed
    • ✓
      Directory returns our member record
      https://directory.core.sandbox.trust.ib1.org/m/4tnapijm
    • ✓
      Record has a legal name
      Carbon Accounting Provider (sandbox)
    • ✓
      Organisation holds the Carbon Accounting Provider role
      https://registry.core.sandbox.trust.ib1.org/scheme/perseus/role/carbon-accounting-provider
    • i
      Membership expiry is not in the public Directory API
      It is shown on the Directory web page and in the authenticated members API
    Member ID
    https://directory.core.sandbox.trust.ib1.org/m/4tnapijm
    Legal name
    Carbon Accounting Provider (sandbox)
    Directory page
    https://directory.core.sandbox.trust.ib1.org/organizations/4tnapijm/
  2. ✓

    We have registered this application

    Done

    This app is registered in the Directory under our organisation, claiming the CAP role.

    3 of 3 checks passed
    • ✓
      Directory returns our application
      https://directory.core.sandbox.trust.ib1.org/a/ciro1gll
    • ✓
      Application is published by our organisation
      https://directory.core.sandbox.trust.ib1.org/m/4tnapijm
    • ✓
      Application claims the Carbon Accounting Provider role
      https://registry.core.sandbox.trust.ib1.org/scheme/perseus/role/carbon-accounting-provider
    Application ID
    https://directory.core.sandbox.trust.ib1.org/a/ciro1gll
    Title
    Perseus Readiness Demo
  3. ✓

    We hold Directory-issued certificates

    Done

    A client certificate for mTLS with other members, and a signing certificate for provenance records.

    12 of 12 checks passed
    • ✓
      Client certificate chains to the Trust Framework root
      C=GB, O=Core Trust Framework, CN=Core (sandbox) Trust Framework client issuer
    • ✓
      Client certificate is in date
      2026-09-21 to 2027-09-21
    • ✓
      Client certificate matches our private key
    • ✓
      Client certificate names this application
      https://directory.core.sandbox.trust.ib1.org/a/ciro1gll
    • ✓
      Client certificate names our organisation
      https://directory.core.sandbox.trust.ib1.org/m/4tnapijm
    • ✓
      Client certificate carries the CAP role
      https://registry.core.sandbox.trust.ib1.org/scheme/perseus/role/carbon-accounting-provider
    • ✓
      Signing certificate chains to the Trust Framework root
      C=GB, O=Core Trust Framework, CN=Core (sandbox) Trust Framework signing issuer
    • ✓
      Signing certificate is in date
      2026-09-21 to 2027-09-21
    • ✓
      Signing certificate matches our private key
    • ✓
      Signing certificate names this application
      https://directory.core.sandbox.trust.ib1.org/a/ciro1gll
    • ✓
      Signing certificate names our organisation
      https://directory.core.sandbox.trust.ib1.org/m/4tnapijm
    • ✓
      Signing certificate carries the CAP role
      https://registry.core.sandbox.trust.ib1.org/scheme/perseus/role/carbon-accounting-provider
    Client certificate
    /tmp/perseus/certs/client/cert.pem
    Signing certificate
    /tmp/perseus/certs/signing/cert.pem
  4. ✓

    We can discover the Energy Data Provider

    Done

    The EDP is found through the Directory catalogue, and its authorisation server supports the Perseus FAPI 2 profile.

    7 of 7 checks passed
    • ✓
      Directory catalogue lists an API conforming to the energy consumption data standard
      EDP Sandbox synthetic data
    • ✓
      Our chosen EDP API is in the catalogue: EDP Sandbox synthetic data
      conformsTo https://registry.core.sandbox.trust.ib1.org/scheme/perseus/standard/energy-consumption-data/2026-03-12
    • ✓
      EDP is a Directory member with the Energy Data Provider role: Energy Data Provider (sandbox)
      https://directory.core.sandbox.trust.ib1.org/m/7a1qv915
    • ✓
      Authorisation server requires Pushed Authorization Requests (RFC 9126)
      https://mtls.perseus-demo-authentication.ib1.org/api/v1/par
    • ✓
      Clients authenticate with mTLS certificates (tls_client_auth)
    • ✓
      PKCE with S256 is supported
    • ✓
      Authorisation code flow is supported
    • i
      Metadata issuer differs from the catalogue oauthIssuer
      Metadata says https://mtls.perseus-demo-authentication.ib1.org; we will expect that value in the authorisation response iss parameter
    • i
      Directory server allowlist is empty for Perseus, so it cannot be enforced yet
    Catalogue query
    https://directory.core.sandbox.trust.ib1.org/query/data-services?conformsTo=https%3A%2F%2Fregistry.core.sandbox.trust.ib1.org%2Fscheme%2Fperseus%2Fstandard%2Fenergy-consumption-data%2F2026-03-12
    EDP
    https://directory.core.sandbox.trust.ib1.org/m/7a1qv915
    Authorisation server metadata
    https://perseus-demo-authentication.ib1.org/.well-known/oauth-authorization-server
    Allowlist
    https://directory.core.sandbox.trust.ib1.org/allowlist/perseus

User journey

  1. 5

    User arrives from the FSP start link

    Your turn

    The FSP sends the SME to our landing page with its Directory ID; we keep it to preselect the FSP.

    In production the FSP sends the SME a link to this page carrying the FSP’s Directory ID, e.g. /?fsp=https://directory…/m/<id>.

    Follow a start link from Financial Service Provider 1 (sandbox)
  2. 6

    User signs in

    Your turn

    The SME creates an account or logs in. The FSP is saved to their account for future sessions.

  3. 7

    User grants the Perseus permission

    Not started

    We show the Registry permission text naming the EDP, us and the FSP, and log evidence of the consent.

  4. 8

    User authorises us at the EDP

    Not started

    Pushed Authorization Request over mTLS, then the SME confirms at the EDP and we exchange the code for tokens.

  5. 9

    EDP confirms the permission

    Not started

    We ask the EDP for its record of the permission, using our refresh token over mTLS.

  6. 10

    We retrieve half-hourly consumption data

    Not started

    Twelve complete months of readings for each meter from the EDP, over mTLS with the access token.

  7. 11

    We retrieve grid carbon intensity

    Not started

    Half-hourly regional intensity from NESO for each electricity meter’s postcode outcode.

  8. 12

    We calculate emissions

    Not started

    The Perseus methods: half-hourly consumption × grid intensity (electricity) or × the Defra factor (gas), by whole month.

  9. 13

    We verify and extend the provenance record

    Not started

    We verify the EDP’s signed record, then add and sign our receipt, grid intensity origin, processing and transfer-to-FSP steps.

  10. 14

    We produce the report for the FSP

    Not started

    An emissions report for the FSP the SME chose, with its data in the Perseus emissions API format and its provenance.