# Bundlers

Source: https://docs.settlemint.com/docs/architects/components/infrastructure/advanced-accounts/bundlers
How DALP exposes an authenticated bundler JSON-RPC endpoint for ERC-4337 discovery, UserOperation submission, and ERC-7677 paymaster sponsorship.



A bundler prepares valid ERC-4337 UserOperations for an EntryPoint. DALP exposes an authenticated JSON-RPC endpoint so your integration can discover the active chain and EntryPoint, submit UserOperations, track their status, and request paymaster sponsorship. Every operation scopes to the calling organization's wallets and runs inside DALP's policy and signer controls.

**Requires:** advanced accounts enabled for the deployment.

## Where the bundler fits [#where-the-bundler-fits]

Bundlers sit between a smart account and the EntryPoint contract. In a standard ERC-4337 flow, a client builds a UserOperation and sends it for relay. The relay validates the operation, then submits it to the EntryPoint.

In DALP, that protocol role is wrapped by platform controls. DALP resolves the EntryPoint for the active EVM network, applies signer and policy checks, coordinates paymaster readiness when sponsorship is used, and records the final transaction outcome.

<Mermaid
  chart="graph LR
    I[Wallet, SDK, or integration] --> D[DALP platform execution path]
    D --> P[Policy, signer, and paymaster checks]
    P --> B[Bundler service]
    B --> E[ERC-4337 EntryPoint]
    E --> S[Smart account]"
/>

The UserOperation carries the smart-account call. DALP keeps its regulated-platform controls beside that call: request permission, signer or multisig approval, gas sponsorship readiness, and final transaction recording.

## Callable JSON-RPC surface [#callable-json-rpc-surface]

Use [Bundler JSON-RPC](/docs/api-reference/wallets/bundler) when you need advanced accounts discovery data before building a flow.

| Discovery question             | JSON-RPC method            | What DALP returns                                       |
| ------------------------------ | -------------------------- | ------------------------------------------------------- |
| Which chain is active?         | `eth_chainId`              | The active network chain ID as a hexadecimal string.    |
| Which EntryPoint is supported? | `eth_supportedEntryPoints` | The EntryPoint address resolved for the active network. |

The endpoint also accepts authenticated, organization-scoped UserOperation submission, gas estimation, and ERC-7677 paymaster methods, including lookup. Operations only act on wallets the calling organization owns, so they run inside DALP's approval and tracking model rather than bypassing it. See [Bundler JSON-RPC](/docs/api-reference/wallets/bundler) for the full method list.

## Boundary for integrations [#boundary-for-integrations]

ERC-4337-aware clients use this split to discover the network shape and submit UserOperations. DALP applies its approval, sponsorship, and tracking controls to each operation. Use the bundler endpoint for ERC-4337 discovery and UserOperation flows. Use the REST smart wallet and paymaster surfaces for wallet state and sponsorship settings.

| Need                                       | Use                                          |
| ------------------------------------------ | -------------------------------------------- |
| Read active chain ID                       | Bundler JSON-RPC discovery                   |
| Read supported EntryPoint                  | Bundler JSON-RPC discovery                   |
| Submit or track a UserOperation            | Bundler JSON-RPC UserOperation methods       |
| Manage smart wallet state or signers       | REST smart wallet endpoints                  |
| Configure paymaster funding or sponsorship | REST paymaster endpoints                     |
| Track final transaction state              | DALP transaction tracking and event surfaces |

## Failure modes to expect [#failure-modes-to-expect]

EntryPoint discovery depends on network configuration and indexed Directory data. If the Directory contract is not configured, discovery returns an unavailable error. If the EntryPoint registration exists on-chain but has not been indexed yet, discovery returns a not-found error. Retry only after you complete the deployment configuration and indexing has caught up.

Unsupported methods produce JSON-RPC method-not-found responses when the request includes an `id`. Paymaster methods also respond with method-not-found when gas sponsorship is not enabled for the organization. Notifications without an `id` produce `204 No Content` under JSON-RPC notification semantics.

## Related pages [#related-pages]

* [Advanced accounts concept](/docs/architecture/concepts/account-abstraction) explains the full smart wallet execution model.
* [UserOperations](/docs/architects/components/infrastructure/advanced-accounts/user-operations) describes the request object submitted to the EntryPoint.
* [Paymasters and gas sponsorship](/docs/architects/components/infrastructure/advanced-accounts/paymasters-and-gas-sponsorship) explains sponsored gas checks.
* [Bundler JSON-RPC](/docs/api-reference/wallets/bundler) documents the callable discovery endpoint.