A proposed generic API specification to support Ethereum and Layer 2 preconfirmations. The API is compatible with the existing PBS architecture and builder-specs. This specification allows proposers to offer preconfirmations to users either directly or by delegating the privilege to a Gateway.
Ethereum’s 12 second block time may be restrictive for particular use cases and is especially inhibitive for L2s that rely on fast confirmations. One option is to reduce the block time. However, this is a very large lift and would likely require multiple hard forks. This alternative option extends the existing PBS architecture, which allows proposers or constraint delegates (Gateways) to offer transaction preconfirmations to users.
Todo
| Preconfer | A proposer who registers to offer preconfirmations is a preconfer. Any party the proposer delegates preconf authority to is also a preconfer. | | --- | --- | | Gateway | A party which has been delegated preconf authority by the proposer | | Preconf Router | The component that provides an abstracted EVM RPC API endpoint for users to submit L2 transactions and get preconfirmations |
| Namespace | Endpoint | Description |
|---|---|---|
builder |
POST /delegate |
Endpoint for proposer to delegate constraint submission rights to a Gateway. |
builder |
POST /constraints |
Endpoint for submitting a batch of signed constraints from either the proposer or gateway to the relay. |
builder |
GET /header_with_proofs |
Endpoint for requesting a builder bid with constraint proofs. |
relay |
GET /delegations |
Returns the active delegations for the proposer of this slot, if it exists. |
relay |
GET /constraints |
Returns all constraints for a given slot. |
relay |
GET /constraints_stream |
Returns an SSE stream of constraints. |
relay |
POST /blocks_with_proofs |
Endpoint for submitting blocks with inclusion proofs. |
The Builder API is the way for proposers to communicate with the gateway in the PBS pipeline. The constraints-API adds the following new responsibilities: