feat: add Cosmo Streams documentation

CLAUDE.md

@@ -42,7 +42,7 @@ mintlify install
 - **Namespaces**: Environment isolation for graphs (dev, staging, prod)
 - **Feature Flags & Feature Subgraphs**: Toggle-able subgraph replacements for incremental rollout
 - **Schema Contracts**: Filtered graph versions using @tag directives
-- **EDFS**: Event-Driven Federated Subscriptions for real-time data
+- **Cosmo Streams / EDFS**: Event-Driven Federated Subscriptions for real-time data
 
 ## Documentation Structure
 

docs/docs.json

@@ -224,20 +224,30 @@
                 ]
               },
               {
-                "group": "Event-Driven Federated Subscriptions (EDFS)",
-                "icon": "calendar-users",
+                "group": "Cosmo Streams (EDFS)",
+                "icon": "wave",
                 "pages": [
-                  "router/event-driven-federated-subscriptions-edfs",
+                  "router/cosmo-streams",
                   {
                     "group": "NATS",
                     "icon": "puzzle-piece",
                     "pages": [
-                      "router/event-driven-federated-subscriptions-edfs/nats",
-                      "router/event-driven-federated-subscriptions-edfs/nats/stream-and-consumer-configuration"
+                      "router/cosmo-streams/nats",
+                      "router/cosmo-streams/nats/stream-and-consumer-configuration"
                     ]
                   },
-                  "router/event-driven-federated-subscriptions-edfs/kafka",
-                  "router/event-driven-federated-subscriptions-edfs/redis"
+                  "router/cosmo-streams/kafka",
+                  "router/cosmo-streams/redis",
+                  {
+                    "group": "Custom Modules",
+                    "icon": "cubes",
+                    "pages": [
+                      "router/cosmo-streams/custom-modules",
+                      "router/cosmo-streams/custom-modules/subscription-on-start",
+                      "router/cosmo-streams/custom-modules/on-receive-event",
+                      "router/cosmo-streams/custom-modules/on-publish-event"
+                    ]
+                  }
                 ]
               },
               "router/compliance-and-data-management",
@@ -745,5 +755,11 @@
     "gtm": {
       "tagId": "GTM-5GPL7DQH"
     }
-  }
+  },
+  "redirects": [
+    {
+      "source": "/router/event-driven-federated-subscriptions-edfs/:path*",
+      "destination": "/router/cosmo-streams/:path*"
+    }
+  ]
 }

docs/federation/directives/openfed__subscriptionfilter.mdx

@@ -26,7 +26,7 @@ input openfed__SubscriptionFilterCondition {
 
 ## Overview
 
-The `@openfed__subscriptionFilter` directive declares that a field definition can be filtered by filter conditions. The directive can only be applied to [EDFS](/federation/event-driven-federated-subscriptions) subscriptions.
+The `@openfed__subscriptionFilter` directive declares that a field definition can be filtered by filter conditions. The directive can only be applied to [EDG](/federation/event-driven-federated-subscriptions) subscriptions.
 
 ## Arguments
 

docs/federation/event-driven-federated-subscriptions.mdx

@@ -7,6 +7,6 @@ icon: circle-info
 
 Defining an Event-Driven Graph with Event-Driven Federated Subscriptions.
 
-An Event-Driven Graph (EDG) is best thought to be an abstract subgraph that facilitates Event-Driven Federated Subscriptions (EDFS). If a subgraph uses or defines any event driven directives, it will be interpreted to be an Event-Driven Graph.
+An Event-Driven Graph (EDG) is best thought to be an abstract subgraph that facilitates [Cosmo Streams](/router/cosmo-streams). If a subgraph uses or defines any event driven directives, it will be interpreted to be an Event-Driven Graph.
 
 

docs/router/configuration.mdx

@@ -637,7 +637,7 @@ This option may change or be removed in future versions as the OpenTelemetry SDK
 | METRICS_OTLP_EXCLUDE_METRIC_LABELS | exclude_metric_labels | <Icon icon="square" />                        | The metric labels to exclude from the OTEL metrics. Accepts a list of Go regular expressions. Use https://regex101.com/ to test your regular expressions. | []            |
 | METRICS_OTLP_CONNECTION_STATS      | connection_stats      | <Icon icon="square" />                        | Enable connection metrics.                                                                                                                                | false         |
 | METRICS_OTLP_CIRCUIT_BREAKER       | circuit_breaker       | <Icon icon="square" />                        | Ensure that circuit breaker metrics are enabled for OTEL.                                                                                                 | false         |
-| METRICS_OTLP_STREAM                | streams               | <Icon icon="square" />                        | Enable EDFS stream metrics.                                                                                                                               | false         |
+| METRICS_OTLP_STREAM                | streams               | <Icon icon="square" />                        | Enable Cosmo Streams metrics.                                                                                                                             | false         |
 
 ### Attributes
 
@@ -688,7 +688,7 @@ telemetry:
 | PROMETHEUS_EXCLUDE_METRIC_LABELS | exclude_metric_labels | <Icon icon="square" />                        |                                                                           |                  |
 | PROMETHEUS_EXCLUDE_SCOPE_INFO    | exclude_scope_info    | <Icon icon="square" />                        | Exclude scope info from Prometheus metrics.                               | false            |
 | PROMETHEUS_CIRCUIT_BREAKER       | circuit_breaker       | <Icon icon="square" />                        | Enable the circuit breaker metrics for prometheus metric collection.      | false            |
-| PROMETHEUS_OTLP_STREAM           | streams               | <Icon icon="square" />                        | Enable EDFS stream metrics.                                               | false            |
+| PROMETHEUS_OTLP_STREAM           | streams               | <Icon icon="square" />                        | Enable Cosmo Streams metrics.                                             | false            |
 
 ### Example YAML config:
 
@@ -1613,7 +1613,7 @@ cdn:
 
 ## Events
 
-The Events section lets you define Event Sources for [Event-Driven Federated Subscriptions (EDFS)](/router/event-driven-federated-subscriptions-edfs).
+The Events section lets you define Event Sources for [Cosmo Streams / EDFS](/router/cosmo-streams).
 
 We support NATS, Kafka and Redis as event bus provider.
 
@@ -1688,6 +1688,15 @@ events:
 |                      | id   |          | The ID of the provider. This have to match with the ID specified in the subgraph schema. | []            |
 |                      | urls |          | A list of redis instances URLS, e.g: `redis://localhost:6379/2`                          |               |
 
+### Cosmo Streams handlers
+
+Configuration for Cosmo Streams handlers. Learn more about [Custom Modules for Cosmo Streams](/router/cosmo-streams/custom-modules).
+
+| Environment Variable | YAML                                               | Required               | Description                                                                            | Default Value |
+| :------------------- | :------------------------------------------------- | :--------------------- | :------------------------------------------------------------------------------------- | :-            |
+|                      | handlers.on_receive_events.handler_timeout         | <Icon icon="square" /> | The maximum time to wait for all OnReceiveEvents handlers to complete per event-batch. | 5s            |
+|                      | handlers.on_receive_events.max_concurrent_handlers | <Icon icon="square" /> | The maximum number of concurrent OnReceiveEvents handlers per trigger.                 | 100           |
+
 ## Router Engine Configuration
 
 Configure the GraphQL Execution Engine of the Router.

docs/router/event-driven-federated-subscriptions-edfs.mdx → docs/router/cosmo-streams.mdx

@@ -1,6 +1,6 @@
 ---
-title: "Event-Driven Federated Subscriptions (EDFS)"
-description: "EDFS combines the power of GraphQL Federation and Event-Driven Architecture (Kafka, NATS, Redis) to update a user GraphQL Subscription after an event occurs in your system."
+title: "Cosmo Streams (EDFS)"
+description: "Cosmo Streams (formally known as EDFS) combines the power of GraphQL Federation and Event-Driven Architecture to update a user GraphQL Subscription after an event occurs in your system."
 icon: "circle-info"
 sidebarTitle: "Overview"
 ---
@@ -12,7 +12,7 @@ sidebarTitle: "Overview"
   />
 </Frame>
 
-Event Driven Federated Subscriptions (EDFS) solves 3 major problems when it comes to GraphQL Federation and Subscriptions by directly connecting the Router to an event source like Kafka and NATS and making it a part of the Graph.
+Cosmo Streams solves 3 major problems when it comes to GraphQL Federation and Subscriptions by directly connecting the Router to an event source like Kafka and NATS and making it a part of the Graph.
 
 ## Intro
 
@@ -41,18 +41,18 @@ Furthermore, classic Subscriptions with Federation are quite expensive when it c
 
 ## Specification
 
-Enter Event-Driven Federated Subscriptions, a simple way to scale Federated Subscriptions in a resource-efficient manner.
+Enter Cosmo Streams, a simple way to scale Federated Subscriptions in a resource-efficient manner.
 
-EDFS supports three event providers:
+Cosmo Streams supports three event providers:
 
 <CardGroup cols={3}>
-  <Card title="Kafka" icon="sitemap" href="/router/event-driven-federated-subscriptions-edfs/kafka">
+  <Card title="Kafka" icon="sitemap" href="/router/cosmo-streams/kafka">
 
   </Card>
-  <Card title="NATS" icon="puzzle-piece" href="/router/event-driven-federated-subscriptions-edfs/nats">
+  <Card title="NATS" icon="puzzle-piece" href="/router/cosmo-streams/nats">
 
   </Card>
-  <Card title="Redis" icon="memory" href="/router/event-driven-federated-subscriptions-edfs/redis">
+  <Card title="Redis" icon="memory" href="/router/cosmo-streams/redis">
 
   </Card>
 </CardGroup>
@@ -61,7 +61,7 @@ Each provider consists of at least Publish and Subscribe capabilities. For NATS,
 
 Our goal is to integrate with various technologies rather than agree on a single unified interface. This approach allows us to leverage the strengths of each technology. This philosophy is reflected in how we structure the directives, naming parameters, exposing features as they would appear in their respective ecosystems.
 
-Here is an overview about all EDFS directives:
+Here is an overview about all Cosmo Streams directives:
 
 ```js
 # Nats and JetStream integration
@@ -117,13 +117,13 @@ The `@edfs__natsPublish`, `@edfs__kafkaPublish`, and `@edfs__redisPublish ` dire
 
 Using the `@edfs__natsSubscribe`, `@edfs__kafkaSubscribe` and `@edfs__redisSubscribe` directives, you can create a Subscription to the corresponding message bus. By default, all the provider implementations are stateless, meaning every client receives the same events in a broadcast fashion. This behavior can be adjusted. NATS allows you to create a [consumer group](https://docs.nats.io/nats-concepts/jetstream/consumers), resulting in multiple independent streams of the subject, where each client can consume events at their own pace.
 
-The `@openfed__subscriptionFilter` directive allows you to filter subscription messages based on specified conditions. For more information see [Subscription Filter](/router/event-driven-federated-subscriptions-edfs#subscription-filter).
+The `@openfed__subscriptionFilter` directive allows you to filter subscription messages based on specified conditions. For more information see [Subscription Filter](/router/cosmo-streams#subscription-filter).
 
 An Event-Driven Subgraph does not need to be implemented. It is simply a Subgraph Schema that instructs the Router on how to connect specific root fields to the Event Source. Scroll down for an example.
 
 ## Prerequisites
 
-To use EDFS, you need to have an Event Source running and connected to the Router. Currently, we support NATS, Kafka, and Redis. For simplicity, NATS is used to explain the examples.
+To use Cosmo Streams, you need to have an Event Source running and connected to the Router. Currently, we support NATS, Kafka, and Redis. For simplicity, NATS is used to explain the examples.
 
 To get started, run a NATS instance and add the following configuration to your `config.yaml` Router Configuration:
 
@@ -318,7 +318,7 @@ Here's an **invalid** message as the `__typename` field is missing:
 
 </CodeGroup>
 
-It's important to send the `__typename` field because this allows EDFS to also work for Union and Interface types.
+It's important to send the `__typename` field because this allows Cosmo Streams to also work for Union and Interface types.
 
 It's worth noting that the Router will not send any responses before you publish a message on the topic. If you need the most recent result, first make a Query, and then subscribe to the Topic. The Router will send the first response only after a message is published on the rendered topic.
 
@@ -440,11 +440,11 @@ The Cosmo Router deduplicates Subscriptions internally to save resources. If mul
 
 ### Statelessness of Subgraphs
 
-With EDFS, the Router connects directly to the Event Source but doesn't require any stateful connections, e.g. WebSocket, to the Subgraphs. This makes the Subgraphs much simpler to reason about and easier to deploy. Serverless deployment options usually have limitations on request length. With an Event Broker in the middle, Subgraphs can be stateless without having to give up on Subscriptions.
+With Cosmo Streams, the Router connects directly to the Event Source but doesn't require any stateful connections, e.g. WebSocket, to the Subgraphs. This makes the Subgraphs much simpler to reason about and easier to deploy. Serverless deployment options usually have limitations on request length. With an Event Broker in the middle, Subgraphs can be stateless without having to give up on Subscriptions.
 
 ### Efficiency, CPU & Memory Consumption (Epoll/Kqueue)
 
-EDFS is built on top of Event-Driven principles, which means that the implementation is non-blocking, as CPU efficient as possible, and has a very low memory footprint.
+Cosmo Streams is built on top of Event-Driven principles, which means that the implementation is non-blocking, as CPU efficient as possible, and has a very low memory footprint.
 
 We're using Epoll and Kqueue on Systems that support it (Linux, Darwin, etc.) to be as efficient as possible.
 
@@ -454,10 +454,10 @@ The Router supports multi-core out of the box and is capable of scaling up to a
 
 ### Publish Events from any System, not just Subgraphs
 
-It's worth noting that publishing Entity update Events is not limited to just Subgraphs. EDFS is designed to fully decouple the API Consumer from the implementation of the Event-Driven Architecture.
+It's worth noting that publishing Entity update Events is not limited to just Subgraphs. Cosmo Streams is designed to fully decouple the API Consumer from the implementation of the Event-Driven Architecture.
 
-A client can create a Job via a Mutation and Subscribe to the Job state via EDFS. Next, the Mutation can kick off a long-running process that will be handled by one or many systems in the background. At each step, e.g. when an increment of work is done, each subsystem can publish a message to indicate that the state of an Entity has changed.
+A client can create a Job via a Mutation and Subscribe to the Job state via Cosmo Streams. Next, the Mutation can kick off a long-running process that will be handled by one or many systems in the background. At each step, e.g. when an increment of work is done, each subsystem can publish a message to indicate that the state of an Entity has changed.
 
 Once the message is published by one of the sub-systems, the Router can Query all Subgraphs to resolve the current state of the Job.
 
-With EDFS, each Subgraph can add fields to an Entity that it's responsible for and publish events to the Message Broker when a long-running Operation updates the overall state of an Entity.
+With Cosmo Streams, each Subgraph can add fields to an Entity that it's responsible for and publish events to the Message Broker when a long-running Operation updates the overall state of an Entity.

docs/router/cosmo-streams/custom-modules.mdx

@@ -0,0 +1,21 @@
+---
+title: "Custom Modules"
+sidebarTitle: Overview
+description: "Customize Streams behavior with powerful handlers for subscription lifecycle, event processing, and data transformation."
+icon: "circle-info"
+---
+
+Cosmo Router provides powerful handlers to hook into the event processing of Cosmo Streams.
+These handlers allow you to implement custom logic for subscription lifecycle management, event processing and data transformation.
+
+<Info>
+Custom Modules in Cosmo Streams are available since Router version 0.266.0
+</Info>
+
+## Available Hooks
+
+The Cosmo Streams system provides three main hook interfaces that you can implement with [Custom Modules](/router/custom-modules):
+
+- [`SubscriptionOnStartHandler`](/router/cosmo-streams/custom-modules/subscription-on-start): Called when a client subscribes
+- [`OnReceiveEventHandler`](/router/cosmo-streams/custom-modules/on-receive-event): Called when events are received from a message broker
+- [`OnPublishEventHandler`](/router/cosmo-streams/custom-modules/on-publish-event): Called when events are going to be sent to a message broker