reorganize Sequencing

Author: pthmas

.vitepress/config.ts

@@ -199,6 +199,16 @@ function sidebarHome() {
           text: "Data Availability",
           link: "/learn/data-availability",
         },
+        {
+          text: "Sequencing",
+          collapsed: true,
+          items: [
+            { text: "Overview", link: "/lean/sequencing/overview" },
+            { text: "Single", link: "/lean/sequencing/single" },
+            { text: "Based", link: "/lean/sequencing/based" },
+            { text: "Forced Inclusion", link: "/lean/sequencing/forced-inclusion" },
+          ],
+        },
         {
           text: "Resources",
           collapsed: true,

guides/sequencing/single.md

@@ -22,9 +22,11 @@ It mainly consists of:
 
 ## Sequencing Implementations {#sequencing-implementations}
 
-An implementation of the sequencing interface mainly acts as a middleware that connects Rollkit rollup and the sequencing layer. It implements the sequencing interface functions described above. For example, [single-sequencer](https://github.com/rollkit/rollkit/blob/main/sequencers/single/README.md) is the refactored functionality from the Rollkit prior to `v1.0.0`. The single sequencer is the middleware run by the aggregator node of the Rollkit rollup. The aggregator node relays rollup transactions to single sequencer which then submits them to the DA network (Celestia). The header producer node then retrieves (via `GetNextBatch`) the batched transaction from the single sequencer to execute the transactions and produce the updated rollup state. Similarly, there are other sequencing middlewares which can be built for various sequencing strategies or even for connecting to different third-party sequencing networks.
+An implementation of the sequencing interface mainly acts as a middleware that connects Rollkit rollup and the sequencing layer. It implements the sequencing interface functions described above.
+There are several implementations of the sequencor:
 
-The sequencing implementations that are currently work in progress:
-<!-- * [single-sequencer](single) -->
-* [based-sequencer](/guides/sequencing/based.md)
-* [forced-inclusion-sequencer](/guides/sequencing/forced-inclusion.md)
+* [single-sequencer](/guides/sequencing/single.md) - The simplest and most widely used sequencing model, where a single node (the sequencer) is responsible for ordering transactions and producing blocks.
+
+* [based-sequencer](/guides/sequencing/based.md) - A more decentralized model where multiple sequencers work together to order transactions and produce blocks, improving censorship resistance (Not available yet).
+
+* [forced-inclusion-sequencer](/guides/sequencing/forced-inclusion.md) - A model that ensures all transactions are included in the rollup, even if they are not ordered by the sequencer, providing strong guarantees against censorship. (Not available yet).

guides/sequencing/based.md learn/sequencing/based.mdguides/sequencing/based.md renamed to learn/sequencing/based.md

@@ -0,0 +1,41 @@
+# Single Sequencer
+
+A single sequencer is the simplest sequencing architecture for a Rollkit-based rollup. In this model, one node (the sequencer) is responsible for ordering transactions, producing blocks, and submitting data to the data availability (DA) layer.
+
+## How the Single Sequencer Model Works
+
+1. **Transaction Submission:**
+   - Users submit transactions directly to the sequencer node via RPC or other interfaces.
+2. **Transaction Ordering:**
+   - The sequencer collects transactions from users and orders them into blocks according to the rollup's rules.
+3. **Block Production:**
+   - The sequencer produces new blocks at regular intervals or when enough transactions are collected.
+   - Each block contains a batch of ordered transactions and metadata.
+
+4. **Data Availability Posting:**
+   - The sequencer posts the block data to the configured DA layer (e.g., Celestia, Avail, etc.).
+   - This ensures that anyone can access the data needed to reconstruct the rollup state.
+
+5. **State Update:**
+   - The sequencer updates the rollup state based on the new block and makes the updated state available to light clients and full nodes.
+
+## Advantages
+
+- **Simplicity:** Easy to set up and operate, making it ideal for development, testing, and small-scale deployments.
+- **Low Latency:** Fast block production and transaction inclusion, since there is no consensus overhead among multiple sequencers.
+
+## Considerations
+
+- **Centralization:** The sequencer is a single point of control. However, this is often acceptable for many applications, especially in early stages or permissioned environments.
+- **No Fault Tolerance:** If the sequencer is unavailable, the rollup cannot make progress. High-availability setups and monitoring can mitigate this risk.
+
+## Use Cases
+
+- Production rollups seeking simplicity and performance
+- Prototyping and development
+- Private or permissioned rollups
+- Projects that value deterministic ordering and operational control
+
+## Future-Proofing
+
+While the single sequencer model is robust and production-ready, Rollkit is designed to support more advanced sequencing architectures in the future. Projects can seamlessly upgrade to decentralized sequencing when the technology and their needs mature.