diff --git a/docs/spec/README.md b/docs/spec/README.md
index 1f1c33489dc..06ebb54343c 100644
--- a/docs/spec/README.md
+++ b/docs/spec/README.md
@@ -1,30 +1,23 @@
# Knative Eventing API spec
This directory contains the specification of the Knative Eventing API, which is
-implemented in [`channels.knative.dev`](/pkg/apis/channels/v1alpha1),
-[`feeds.knative.dev`](/pkg/apis/feeds/v1alpha1) and
-[`flows.knative.dev`](/pkg/apis/flows/v1alpha1) and verified via [the e2e
-test](/test/e2e).
+implemented in [`eventing.knative.dev`](/pkg/apis/eventing/v1alpha1) and
+verified via [the e2e test](/test/e2e).
**Updates to this spec should include a corresponding change to the API
-implementation for [channels](/pkg/apis/channels/v1alpha1),
-[feeds](/pkg/apis/feeds/v1alpha1) or [flows](/pkg/apis/feeds/v1alpha1) and [the
-e2e test](/test/e2e).**
+implementation for [eventing](/pkg/apis/eventing/v1alpha1) and [the e2e
+test](/test/e2e).**
Docs in this directory:
-* [Motivation and goals](motivation.md)
-* [Resource type overview](overview.md)
-
+- [Motivation and goals](motivation.md)
+- [Resource type overview](overview.md)
+- [Interface contracts](interfaces.md)
+- [Object model specification](spec.md)
+
-
\ No newline at end of file
+See the [Knative Eventing Docs
+Architecture](https://github.com/knative/docs/blob/master/eventing/README.md#architecture)
+for more high level details.
diff --git a/docs/spec/images/overview-reference.dot b/docs/spec/images/overview-reference.dot
deleted file mode 100644
index 5d049b11ee8..00000000000
--- a/docs/spec/images/overview-reference.dot
+++ /dev/null
@@ -1,33 +0,0 @@
-// This is the overview graph for object refrences in the control plane.
-//
-// To reproduce the PNG, run the following:
-// $ dot -Tpng overview-reference.dot -o overview-reference.png
-//
-digraph G {
- ordering = out;
- rankdir = LR;
-
- node [shape=rectangle; width=1.25; height=.5; fixedsize=true;]
-
- subgraph cluster_A {
- Source -> EventType [dir=back];
- color=white;
- {rank = same; Source; EventType;}
- }
-
- subgraph cluster_C {
- Feed;
- Channel
- Subscription;
- label = "Flow";
- }
- EventType -> Feed [dir=back];
- Feed -> Channel;
-
- Subscription -> Service;
- Channel -> Subscription [dir=back];
-
- Bus -> Channel [dir=back];
-
- {rank = max; Service;}
-}
diff --git a/docs/spec/images/overview-reference.png b/docs/spec/images/overview-reference.png
deleted file mode 100644
index 69d363eeeb2..00000000000
Binary files a/docs/spec/images/overview-reference.png and /dev/null differ
diff --git a/docs/spec/images/resource-types-overview.svg b/docs/spec/images/resource-types-overview.svg
new file mode 100644
index 00000000000..943ac7d96f0
--- /dev/null
+++ b/docs/spec/images/resource-types-overview.svg
@@ -0,0 +1 @@
+
\ No newline at end of file
diff --git a/docs/spec/images/resource-types-provisioner.svg b/docs/spec/images/resource-types-provisioner.svg
new file mode 100644
index 00000000000..53426f57f04
--- /dev/null
+++ b/docs/spec/images/resource-types-provisioner.svg
@@ -0,0 +1 @@
+
\ No newline at end of file
diff --git a/docs/spec/interfaces.md b/docs/spec/interfaces.md
new file mode 100644
index 00000000000..3142554fb24
--- /dev/null
+++ b/docs/spec/interfaces.md
@@ -0,0 +1,91 @@
+# Interface Contracts
+
+## Subscribable
+
+A **Subscribable** resource contains a list of subscribers and is responsible
+for delivering events to each of them. Subscriptions only allow Channels to be
+Subscribable (via `spec.from` on the Subscription) at the moment, but this may
+be revisited with future experience. _Channel_ as the target of a
+_Subscription_'s `from` field.
+
+
+### Control Plane
+
+The **Subscribable** resource stores a list of resolved _Subscriptions_ in the
+resource's `spec.subscribers` field. The Subscription Controller is responsible
+for resolving any ObjectReferences (such as _call_ and _result_) in the
+_Subscription_ to network addresses.
+
+### Data Plane
+
+**Subscribable** resources will attempt delivery to each of the _subscribers_
+at least once, and retry if the subscriber returns errors.
+
+
+
+---
+
+## Targetable
+
+A **Targetable** resource represents an endpoint that receives events and
+optionally returns events to forward downstream. One example of a _Targetable_
+is a function.
+
+### Control Plane
+
+A **Targetable** resource MUST expose a _status.targetable.domainInternal_
+field. The _domainInternal_ value is an internal domain name that is capable of
+receiving event deliveries. _Targetable_ resources may be referenced in the
+_call_ section of a _Subscription_.
+
+### Data Plane
+
+The **Targetable** resource receives one event and returns zero or more events
+in response. The returned events are not required to be related to the received
+event. The _Targetable_ should return a successful response if the event was
+processed successfully.
+
+The _Targetable_ is not responsible for ensuring successful delivery of any
+received or returned event. It may receive the same event multiple times even
+if it previously indicated success.
+
+---
+
+## Sinkable
+
+A **Sinkable** resource receives events and takes responsibility for further
+delivery. Unlike _Targetable_, a _Sinkable_ cannot return events in its
+response. One example of a _Sinkable_ is a _Channel_ as the target of a
+_Subscription_'s _result_ field.
+
+
+
+### Control Plane
+
+A **Sinkable** resource MUST expose a _status.sinkable.domainInternal_ field.
+The _domainInternal_ value is an internal domain name that is capable of
+receiving event deliveries. _Sinkable_ resources may be referenced in the
+_result_ section of a _Subscription_, and also by other custom resources acting as an event Source.
+
+### Data Plane
+
+A **Sinkable** resource will only respond to requests with success of failure.
+Any payload (including a valid CloudEvent) returned to the sender will be
+ignored. It may receive the same event multiple times even if it previously
+indicated success.
+
+---
+
+_Navigation_:
+
+- [Motivation and goals](motivation.md)
+- [Resource type overview](overview.md)
+- **Interface contracts**
+- [Object model specification](spec.md)
diff --git a/docs/spec/motivation.md b/docs/spec/motivation.md
index f1f6d4f2e58..6417f11b16c 100644
--- a/docs/spec/motivation.md
+++ b/docs/spec/motivation.md
@@ -25,11 +25,26 @@ decoupled way.
Kubernetes has no primitives related to event processing, yet this is an
essential component in serverless workloads. Eventing introduces high-level
-primitives for event production and delivery with a focus on push over HTTP. If
-a new event source or type is required of your application, the effort required
-to plumb them into the existing eventing framework will be minimal and will
-integrate with CloudEvents middleware and message consumers.
+primitives for event production and delivery with an initial focus on push over
+HTTP. If a new event source or type is required of your application, the effort
+required to plumb them into the existing eventing framework will be minimal and
+will integrate with CloudEvents middleware and message consumers.
-The Knative Eventing API is intended to operate independently, and interop
+Knative eventing implements common components of an event delivery ecosystem:
+enumeration and discovery of event sources, configuration and management of
+event transport, and declarative binding of events (generated either by storage
+services or earlier computation) to further event processing and persistence.
+
+The Knative Eventing API is intended to operate independently, and interoperate
well with the [Serving API](https://github.com/knative/serving) and [Build
API](https://github.com/knative/build).
+
+
+---
+
+_Navigation_:
+
+- **Motivation and goals**
+- [Resource type overview](overview.md)
+- [Interface contracts](interfaces.md)
+- [Object model specification](spec.md)
diff --git a/docs/spec/overview.md b/docs/spec/overview.md
index 9dd1121e912..f111164d321 100644
--- a/docs/spec/overview.md
+++ b/docs/spec/overview.md
@@ -1,70 +1,93 @@
-# Resource Groups
-
-Knative Eventing API is grouped into _Channels_, _Feeds_ and _Flows_:
+# Resource Types
-* _Channels_ define an abstraction between the eventing infrastructure and the
- consumption and production of the events.
+The API defines and provides a complete implementation for
+[Subscription](spec.md#kind-subscription), and abstract resource definitions
+for [Channels](spec.md#kind-channel) and
+[ClusterChannelProvisioners](spec.md#kind-clusterchannelprovisioner) which may
+be fulfilled by multiple backing implementations (much like the Kubernetes
+Ingress resource).
-* _Feeds_ bridge the event source into the eventing framework.
+With extendibility and compostability as a goal of Knative Eventing, the
+eventing API defines several resources that can be reduced down to a well
+understood contracts. These eventing resource interfaces may be fulfilled by
+other Kubernetes objects and then composed in the same way as the concreate
+objects. The interfaces are ([Sinkable](interfaces.md#sinkable),
+[Subscribable](interfaces.md#Subscribable),
+[Targetable](interfaces.md#targetable)). For more details, see
+[Interface Contracts](interfaces.md).
-* _Flows_ abstract the path of an event from a source takes to reach an event
- consumer.
+- A **Subscription** describes the transformation of an event and optional
+ forwarding of a returned event.
-Typically, _Feeds_ perform out-of-cluster provisioning, while _Channels_ are
-within-cluster management of event delivery. _Flows_ is a higher order wrapper
-used to connect event producers directly with event consumers leveraging
-_Feeds_ and _Channels_.
+- A **Channel** provides event persistance and fanout of events from a
+ well-known input address to multiple outputs described by _Subscriptions_.
-# Resource Types
+
-The primary resources in the Knative Eventing _Feeds_ API are EventSource,
-EventType and Feed:
+
-* **EventSource**, an archetype of an event producer.
+- **ClusterChannelProvisioners** implement strategies for realizing backing resources
+ for different implementations of _Channels_ currently active in the eventing
+ system.
-* **EventType**, the schema for an event.
+
-* **Feed**, the association between the output of an event producer to the
- input of an event consumer.
+
-An example _Feeds_ setup: GitHub would be the _EventSource_, a Pull Request
-notification would be the _EventType_ and the _Feed_ describes the _org/repo_,
-credentials, the specific _EventType_ and the consumer of the _Feed_ events.
+Sources are defined by independent CRDs that can be installed into a cluster.
+For more information see [Knative Eventing
+Sources](https://github.com/knative/eventing-sources).
+## Subscription
-The primary resources in the Knative Eventing _Channels_ API are Channel,
-Subscription and Bus:
+**Subscriptions** describe a flow of events from one _Channel_) to the next
+Channel\* through transformations (such as a Knative Service which processes
+CloudEvents over HTTP). A _Subscription_ controller resolves the addresses of
+transformations (`call`) and destination storage (`result`) through the
+_Targetable_ and _Sinkable_ interface contracts, and writes the resolved
+addresses to the _Channel_ in the `from` reference. _Subscriptions_ do not need
+to specify both a transformation and a storage destination, but at least one
+must be provided.
-* **Channel**, a named endpoint which accepts and forwards events.
+All event delivery linkage from a **Subscription** is 1:1 – only a single
+`from`, `call`, and `result` may be provided.
-* **Bus**, an implementation of an event delivery mechanism.
+For more details, see [Kind: Subscription](spec.md#kind-subscription).
-* **Subscription**, an expressed interest in events from a _Channel_ to be
- delivered to an HTTP endpoint.
+## Channel
-An example _Channels_ setup: A _Channel_ has declared it is implemented by a
-PubSubBusImpl. The PubSubBusImpl _Bus_ accepts input from an event producer
-that is pushing events to the _Channel_. The _Bus_ also watches for
-_Subscription_(s) on the _Channel_ and delivers the events accepted to the
-consumer.
+**Channel** provides an at least once event delivery mechanism which can fan
+out received events to multiple destinations via _Subscriptions_. A _Channel_
+has a single inbound _Sinkable_ interface which may accept events from multiple
+_Subscriptions_ or even direct delivery from external systems. Different
+_Channels_ may implement different degrees of persistence. Event delivery order
+is dependent on the backing implementation of the _Channel_ provided by the
+_ClusterChannelProvisioner_.
+Event selection on a _Channel_ is 1:N – a single _Channel_ may fan out to
+multiple _Subscriptions_.
-The _Flows_ API implements a single resource, Flow:
+See [Kind: Channel](spec.md#kind-channel).
-* **Flow**, is an abstraction of the connection between an event producer to
- the event consumer leveraging _Feed_s and _Channels_.
+## ClusterChannelProvisioner
+**ClusterChannelProvisioner** catalogs available implementations of _Channels_.
+_ClusterChannelProvisioners_ hold a JSON Schema that is used to validate the
+_Channel_ input arguments. _ClusterChannelProvisioners_ make it possible to
+provide cluster wide defaults for the _Channels_ they provision.
-An example _Flows_ setup: The _Flow_ describes the same properties as the _Feed_
-except the target could be a _Service.serving.knative.dev_ and the _Flow_ will
-create the _Channel_, _Feed_, and _Subscription_ for the event to flow from
-event producer (GitHub) to event consumer (MyService).
+_ClusterChannelProvisioners_ do not directly handle events. They are 1:N with
+_Channels_.
+For more details, see [Kind:
+ClusterChannelProvisioner](spec.md#kind-clusterchannelprovisioner).
-
-See the [Knative Eventing Docs
-Architecture](https://github.com/knative/docs/blob/master/eventing/README.md#architecture)
-for more details.
+---
+_Navigation_:
+- [Motivation and goals](motivation.md)
+- **Resource type overview**
+- [Interface contracts](interfaces.md)
+- [Object model specification](spec.md)
diff --git a/docs/spec/spec.md b/docs/spec/spec.md
new file mode 100644
index 00000000000..2450d41cf5a
--- /dev/null
+++ b/docs/spec/spec.md
@@ -0,0 +1,183 @@
+# Object Model
+
+Knative ships with several objects which implement useful sets of
+[interfaces](interfaces.md). It is expected that additional objects which
+implement these interfaces will be added over time. For context, see the
+[overview](overview.md) and [motivations](motivation.md) sections.
+
+These are Kubernetes resources that been introduced using Custom Resource
+Definitions. They will have the expected _ObjectMeta_, _Spec_, _Status_ fields.
+This document details our _Spec_ and _Status_ customizations.
+
+- [Channel](#kind-channel)
+- [Subscription](#kind-subscription)
+- [ClusterChannelProvisioner](#kind-clusterchannelprovisioner)
+
+## kind: Channel
+
+### group: eventing.knative.dev/v1alpha1
+
+_A Channel logically receives events on its input domain and forwards them to
+its subscribers._
+
+### Object Schema
+
+#### Spec
+
+| Field | Type | Description | Limitations |
+| ------------- | ---------------------------------- | -------------------------------------------------------------------------- | -------------------------------------- |
+| provisioner\* | ProvisionerReference | The name of the provisioner to create the resources that back the Channel. | Immutable. |
+| arguments | runtime.RawExtension (JSON object) | Arguments to be passed to the provisioner. | |
+| subscribers | ChannelSubscriberSpec[] | Information about subscriptions used to implement message forwarding. | Filled out by Subscription Controller. |
+
+\*: Required
+
+#### Metadata
+
+##### Owner References
+
+- Owned (non-controlling) by the ClusterChannelProvisioner used to provision
+ the Channel.
+
+#### Status
+
+| Field | Type | Description | Limitations |
+| ---------- | ---------- | --------------------------------------------------------------------------------------------------------------------------- | ----------- |
+| sinkable | Sinkable | Address to the endpoint as top-level domain that will distribute traffic over the provided targets from inside the cluster. | |
+| conditions | Conditions | Channel conditions. | |
+
+##### Conditions
+
+- **Ready.** True when the Channel is provisioned and ready to accept events.
+- **Provisioned.** True when the Channel has been provisioned by a controller.
+
+#### Events
+
+- Provisioned
+- Deprovisioned
+
+### Life Cycle
+
+| Action | Reactions | Limitations |
+| ------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ---------------------------------------------------------------------------------- |
+| Create | The ClusterChannelProvisioner referenced will take ownership of the Channel and begin provisioning the backing resources required for the Channel depending on implementation. | Only one ClusterChannelProvisioner is allowed to be the Owner for a given Channel. |
+| Update | The ClusterChannelProvisioner will synchronize the Channel backing resources to reflect the update. | |
+| Delete | The ClusterChannelProvisioner will deprovision the backing resources if no longer required depending on implementation. | |
+
+---
+
+## kind: Subscription
+
+### group: eventing.knative.dev/v1alpha1
+
+_Describes a linkage between a Channel and a Targetable and/or Sinkable._
+
+### Object Schema
+
+#### Spec
+
+| Field | Type | Description | Limitations |
+| ------------------ | -------------- | ---------------------------------------------------------------------------- | ------------------ |
+| from\* | ObjectRef | The originating _Subscribable_ for the link. | Must be a Channel. |
+| call1 | EndpointSpec | Optional processing on the event. The result of call will be sent to result. | |
+| result1 | ResultStrategy | The continuation for the link. | |
+
+\*: Required
+
+1: At Least One(call, result)
+
+#### Metadata
+
+##### Owner References
+
+- If a resource controller created this Subscription: Owned by the originating
+ resource.
+
+##### Conditions
+
+- **Ready.**
+- **FromReady.**
+- **Resolved.** True if `from`, `call`, and `result` all resolve into valid object references which implement the appropriate spec.
+
+#### Events
+
+- PublisherAcknowledged
+- ActionFailed
+
+### Life Cycle
+
+| Action | Reactions | Limitations |
+| ------ | ------------------------------------------------------------------------------------------------------------------------------------------- | ----------- |
+| Create | The subscription controller adds the resolved URIs of `call` and `result` to the `subscribers` field in the `from` _Subscribable_ resource. | |
+| Update | | |
+| Delete | | |
+
+---
+
+## kind: ClusterChannelProvisioner
+
+### group: eventing.knative.dev/v1alpha1
+
+_Describes an abstract configuration of a Source system which produces events
+or a Channel system that receives and delivers events._
+
+### Object Schema
+
+#### Spec
+
+| Field | Type | Description | Limitations |
+| ---------- | ---------------------------------- | ------------------------------------------------------------------------------------------------- | ---------------- |
+| parameters | runtime.RawExtension (JSON object) | Description of the arguments able to be passed by the provisioned resource (not enforced in 0.1). | JSON Schema |
+
+\*: Required
+
+#### Status
+
+| Field | Type | Description | Limitations |
+| ---------- | ---------- | ------------------------------------ | ----------- |
+| conditions | Conditions | ClusterChannelProvisioner conditions | |
+
+##### Conditions
+
+- **Ready.**
+
+#### Events
+
+- Resource Created.
+- Resource Removed.
+
+---
+
+## Shared Object Schema
+
+### ProvisionerReference
+
+| Field | Type | Description | Limitations |
+| ----- | --------------- | ----------- | ----------- |
+| ref\* | ObjectReference | | |
+
+\*: Required
+
+### EndpointSpec
+
+| Field | Type | Description | Limitations |
+| --------------------- | --------------- | ----------- | -------------------------- |
+| targetRef1 | ObjectReference | | Must adhere to Targetable. |
+| dnsName1 | String | | |
+
+1: One of (targetRef, dnsName), Required.
+
+### ChannelSubscriberSpec
+
+| Field | Type | Description | Limitations |
+| ----------- | ------ | -------------------------------------------- | -------------- |
+| callableURI | String | The URI name of the endpoint for the call. | Must be a URL. |
+| sinkableURI | String | The URI name of the endpoint for the result. | Must be a URL. |
+
+### ResultStrategy
+
+| Field | Type | Description | Limitations |
+| -------- | --------- | -------------------------------------- | ------------------ |
+| target\* | ObjectRef | The continuation Channel for the link. | Must be a Channel. |
+
+\*: Required
-An example _Feeds_ setup: GitHub would be the _EventSource_, a Pull Request
-notification would be the _EventType_ and the _Feed_ describes the _org/repo_,
-credentials, the specific _EventType_ and the consumer of the _Feed_ events.
+Sources are defined by independent CRDs that can be installed into a cluster.
+For more information see [Knative Eventing
+Sources](https://github.com/knative/eventing-sources).
+## Subscription
-The primary resources in the Knative Eventing _Channels_ API are Channel,
-Subscription and Bus:
+**Subscriptions** describe a flow of events from one _Channel_) to the next
+Channel\* through transformations (such as a Knative Service which processes
+CloudEvents over HTTP). A _Subscription_ controller resolves the addresses of
+transformations (`call`) and destination storage (`result`) through the
+_Targetable_ and _Sinkable_ interface contracts, and writes the resolved
+addresses to the _Channel_ in the `from` reference. _Subscriptions_ do not need
+to specify both a transformation and a storage destination, but at least one
+must be provided.
-* **Channel**, a named endpoint which accepts and forwards events.
+All event delivery linkage from a **Subscription** is 1:1 – only a single
+`from`, `call`, and `result` may be provided.
-* **Bus**, an implementation of an event delivery mechanism.
+For more details, see [Kind: Subscription](spec.md#kind-subscription).
-* **Subscription**, an expressed interest in events from a _Channel_ to be
- delivered to an HTTP endpoint.
+## Channel
-An example _Channels_ setup: A _Channel_ has declared it is implemented by a
-PubSubBusImpl. The PubSubBusImpl _Bus_ accepts input from an event producer
-that is pushing events to the _Channel_. The _Bus_ also watches for
-_Subscription_(s) on the _Channel_ and delivers the events accepted to the
-consumer.
+**Channel** provides an at least once event delivery mechanism which can fan
+out received events to multiple destinations via _Subscriptions_. A _Channel_
+has a single inbound _Sinkable_ interface which may accept events from multiple
+_Subscriptions_ or even direct delivery from external systems. Different
+_Channels_ may implement different degrees of persistence. Event delivery order
+is dependent on the backing implementation of the _Channel_ provided by the
+_ClusterChannelProvisioner_.
+Event selection on a _Channel_ is 1:N – a single _Channel_ may fan out to
+multiple _Subscriptions_.
-The _Flows_ API implements a single resource, Flow:
+See [Kind: Channel](spec.md#kind-channel).
-* **Flow**, is an abstraction of the connection between an event producer to
- the event consumer leveraging _Feed_s and _Channels_.
+## ClusterChannelProvisioner
+**ClusterChannelProvisioner** catalogs available implementations of _Channels_.
+_ClusterChannelProvisioners_ hold a JSON Schema that is used to validate the
+_Channel_ input arguments. _ClusterChannelProvisioners_ make it possible to
+provide cluster wide defaults for the _Channels_ they provision.
-An example _Flows_ setup: The _Flow_ describes the same properties as the _Feed_
-except the target could be a _Service.serving.knative.dev_ and the _Flow_ will
-create the _Channel_, _Feed_, and _Subscription_ for the event to flow from
-event producer (GitHub) to event consumer (MyService).
+_ClusterChannelProvisioners_ do not directly handle events. They are 1:N with
+_Channels_.
+For more details, see [Kind:
+ClusterChannelProvisioner](spec.md#kind-clusterchannelprovisioner).
-
-See the [Knative Eventing Docs
-Architecture](https://github.com/knative/docs/blob/master/eventing/README.md#architecture)
-for more details.
+---
+_Navigation_:
+- [Motivation and goals](motivation.md)
+- **Resource type overview**
+- [Interface contracts](interfaces.md)
+- [Object model specification](spec.md)
diff --git a/docs/spec/spec.md b/docs/spec/spec.md
new file mode 100644
index 00000000000..2450d41cf5a
--- /dev/null
+++ b/docs/spec/spec.md
@@ -0,0 +1,183 @@
+# Object Model
+
+Knative ships with several objects which implement useful sets of
+[interfaces](interfaces.md). It is expected that additional objects which
+implement these interfaces will be added over time. For context, see the
+[overview](overview.md) and [motivations](motivation.md) sections.
+
+These are Kubernetes resources that been introduced using Custom Resource
+Definitions. They will have the expected _ObjectMeta_, _Spec_, _Status_ fields.
+This document details our _Spec_ and _Status_ customizations.
+
+- [Channel](#kind-channel)
+- [Subscription](#kind-subscription)
+- [ClusterChannelProvisioner](#kind-clusterchannelprovisioner)
+
+## kind: Channel
+
+### group: eventing.knative.dev/v1alpha1
+
+_A Channel logically receives events on its input domain and forwards them to
+its subscribers._
+
+### Object Schema
+
+#### Spec
+
+| Field | Type | Description | Limitations |
+| ------------- | ---------------------------------- | -------------------------------------------------------------------------- | -------------------------------------- |
+| provisioner\* | ProvisionerReference | The name of the provisioner to create the resources that back the Channel. | Immutable. |
+| arguments | runtime.RawExtension (JSON object) | Arguments to be passed to the provisioner. | |
+| subscribers | ChannelSubscriberSpec[] | Information about subscriptions used to implement message forwarding. | Filled out by Subscription Controller. |
+
+\*: Required
+
+#### Metadata
+
+##### Owner References
+
+- Owned (non-controlling) by the ClusterChannelProvisioner used to provision
+ the Channel.
+
+#### Status
+
+| Field | Type | Description | Limitations |
+| ---------- | ---------- | --------------------------------------------------------------------------------------------------------------------------- | ----------- |
+| sinkable | Sinkable | Address to the endpoint as top-level domain that will distribute traffic over the provided targets from inside the cluster. | |
+| conditions | Conditions | Channel conditions. | |
+
+##### Conditions
+
+- **Ready.** True when the Channel is provisioned and ready to accept events.
+- **Provisioned.** True when the Channel has been provisioned by a controller.
+
+#### Events
+
+- Provisioned
+- Deprovisioned
+
+### Life Cycle
+
+| Action | Reactions | Limitations |
+| ------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ---------------------------------------------------------------------------------- |
+| Create | The ClusterChannelProvisioner referenced will take ownership of the Channel and begin provisioning the backing resources required for the Channel depending on implementation. | Only one ClusterChannelProvisioner is allowed to be the Owner for a given Channel. |
+| Update | The ClusterChannelProvisioner will synchronize the Channel backing resources to reflect the update. | |
+| Delete | The ClusterChannelProvisioner will deprovision the backing resources if no longer required depending on implementation. | |
+
+---
+
+## kind: Subscription
+
+### group: eventing.knative.dev/v1alpha1
+
+_Describes a linkage between a Channel and a Targetable and/or Sinkable._
+
+### Object Schema
+
+#### Spec
+
+| Field | Type | Description | Limitations |
+| ------------------ | -------------- | ---------------------------------------------------------------------------- | ------------------ |
+| from\* | ObjectRef | The originating _Subscribable_ for the link. | Must be a Channel. |
+| call1 | EndpointSpec | Optional processing on the event. The result of call will be sent to result. | |
+| result1 | ResultStrategy | The continuation for the link. | |
+
+\*: Required
+
+1: At Least One(call, result)
+
+#### Metadata
+
+##### Owner References
+
+- If a resource controller created this Subscription: Owned by the originating
+ resource.
+
+##### Conditions
+
+- **Ready.**
+- **FromReady.**
+- **Resolved.** True if `from`, `call`, and `result` all resolve into valid object references which implement the appropriate spec.
+
+#### Events
+
+- PublisherAcknowledged
+- ActionFailed
+
+### Life Cycle
+
+| Action | Reactions | Limitations |
+| ------ | ------------------------------------------------------------------------------------------------------------------------------------------- | ----------- |
+| Create | The subscription controller adds the resolved URIs of `call` and `result` to the `subscribers` field in the `from` _Subscribable_ resource. | |
+| Update | | |
+| Delete | | |
+
+---
+
+## kind: ClusterChannelProvisioner
+
+### group: eventing.knative.dev/v1alpha1
+
+_Describes an abstract configuration of a Source system which produces events
+or a Channel system that receives and delivers events._
+
+### Object Schema
+
+#### Spec
+
+| Field | Type | Description | Limitations |
+| ---------- | ---------------------------------- | ------------------------------------------------------------------------------------------------- | ---------------- |
+| parameters | runtime.RawExtension (JSON object) | Description of the arguments able to be passed by the provisioned resource (not enforced in 0.1). | JSON Schema |
+
+\*: Required
+
+#### Status
+
+| Field | Type | Description | Limitations |
+| ---------- | ---------- | ------------------------------------ | ----------- |
+| conditions | Conditions | ClusterChannelProvisioner conditions | |
+
+##### Conditions
+
+- **Ready.**
+
+#### Events
+
+- Resource Created.
+- Resource Removed.
+
+---
+
+## Shared Object Schema
+
+### ProvisionerReference
+
+| Field | Type | Description | Limitations |
+| ----- | --------------- | ----------- | ----------- |
+| ref\* | ObjectReference | | |
+
+\*: Required
+
+### EndpointSpec
+
+| Field | Type | Description | Limitations |
+| --------------------- | --------------- | ----------- | -------------------------- |
+| targetRef1 | ObjectReference | | Must adhere to Targetable. |
+| dnsName1 | String | | |
+
+1: One of (targetRef, dnsName), Required.
+
+### ChannelSubscriberSpec
+
+| Field | Type | Description | Limitations |
+| ----------- | ------ | -------------------------------------------- | -------------- |
+| callableURI | String | The URI name of the endpoint for the call. | Must be a URL. |
+| sinkableURI | String | The URI name of the endpoint for the result. | Must be a URL. |
+
+### ResultStrategy
+
+| Field | Type | Description | Limitations |
+| -------- | --------- | -------------------------------------- | ------------------ |
+| target\* | ObjectRef | The continuation Channel for the link. | Must be a Channel. |
+
+\*: Required