> For the complete documentation index, see [llms.txt](https://docs.radfi.co/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.radfi.co/sequencer.md).

# Sequencer

Sequencers are nodes operated by RadFi and other stakeholders. They process raw Bitcoin transaction requests from clients, **validating sequence numbers**, **user signatures**, **data formats**, and **OPCODEs**. Once validated, the request is forwarded to other validator nodes.

Validators also **update the** **state** **on the** **EVM chain**, **sign the Bitcoin raw transaction**, and **share the signature with other validators**. When consensus is reached and all signatures are collected, one validator finalizes the BTC transaction and broadcasts it to the Bitcoin network.

<figure><img src="/files/F3yAr0Weyzro0Wgh53Ui" alt=""><figcaption><p>RadFi Validator Interaction</p></figcaption></figure>

### **Key Components**

**Client**

* Initiates the swap request.

**Sequencers**

* Handle request validation and relay information.

**EVM Node**

* Executes the swap and updates the blockchain state.

**Bitcoin Node**

* Signs and broadcasts the transaction to the Bitcoin network.

### **Flow Overview**

**1. Client Request**

* A user initiates a swap by submitting a BTC raw tx to a validator.

**2. Validation Process**

* Step 2: Sequencer 1 verifies the swap request.
* Step 2 (Rejection Case): If invalid, the request is rejected.
* Step 2 (Peer-to-Peer Validation): If necessary, the request is sent to other validators for consensus.

**3. Transaction Processing**

* The validated BTC raw transaction is parsed into an EVM-compatible swap data structure.
* A request is then sent to an EVM node to execute the swap and update the state.

**4. Bitcoin Network Broadcast**

* Once the swap is executed on the EVM node, a Bitcoin signature is collected.
* The signed Bitcoin transaction is broadcasted to the Bitcoin network via a Bitcoin node.