# `Diffo.Provider.Extension`
[🔗](https://github.com/diffo-dev/diffo/blob/v0.9.0/lib/diffo/provider/extension.ex#L5)

Unified DSL extension for all Diffo provider resource kinds.

Provides a single `provider do` section for Instance, Party, and Place kinds.
The sections within `provider do` are self-similar across kinds — each kind uses
the sections relevant to it, and verifiers enforce correct usage.

## Instance

    provider do
      specification do
        id "da9b207a-26c3-451d-8abd-0640c6349979"
        name "DSL Access Service"
        type :serviceSpecification
      end

      characteristics do
        characteristic :circuit, Diffo.Access.Circuit
      end

      features do
        feature :dynamic_line_management do
          characteristics do
            characteristic :constraints, Diffo.Access.Constraints
          end
        end
      end

      pools do
        pool :ports, :port
      end

      parties do
        party :provider, MyApp.Provider
        party_ref :owner, MyApp.InfrastructureCo
        parties :technicians, MyApp.Technician, constraints: [min: 1]
      end

      places do
        place :installation_site, MyApp.GeographicSite
        place_ref :billing_address, MyApp.GeographicAddress
      end

      behaviour do
        actions do
          create :build
        end
      end
    end

## Party

    provider do
      instances do
        role :facilitates, MyApp.AccessService
        instance_ref :manages, MyApp.InternalService
      end
      parties do
        role :employer, MyApp.Person
      end
      places do
        role :headquarters, MyApp.GeographicSite
      end
    end

## Place

    provider do
      instances do
        role :site_for, MyApp.AccessService
      end
      parties do
        role :managed_by, MyApp.Organization
      end
      places do
        role :within, MyApp.GeographicSite
      end
    end

See `Diffo.Provider.Extension.Info` for runtime introspection.
See `Diffo.Provider.BaseInstance`, `Diffo.Provider.BaseParty`, `Diffo.Provider.BasePlace`
for full usage documentation.

# `provider`
*macro* 

---

*Consult [api-reference.md](api-reference.md) for complete listing*