Bundler

DALP exposes POST /api/v2/bundler as an ERC-4337 bundler JSON-RPC endpoint with ERC-7677 paymaster support. Wallets and SDKs call it to discover the active chain and EntryPoint, submit and track UserOperations, and request gas sponsorship. The endpoint is authenticated and scopes every operation to the wallets owned by the calling organization.

Requires: account abstraction enabled for the deployment, and an authenticated API request. Paymaster methods additionally require gas sponsorship to be enabled for your organization.

For the concept model, see Bundlers, UserOperations, and Account abstraction model. For paymaster deposits, sponsorship settings, and signer-key rotation, see System paymasters and Paymasters and gas sponsorship.

Before you call

Authenticate every request with an API key for the organization whose wallets you operate. The endpoint resolves the active chain from platform configuration and the EntryPoint from the indexed Directory registration for that network.

Operations that name a sender wallet (submission, gas estimation, and paymaster sponsorship) only succeed when that wallet belongs to the authenticated organization. A wallet owned by another organization is rejected.

Send requests as JSON-RPC 2.0 objects with Content-Type: application/json. Use an id when the caller needs a response body. Requests without id are JSON-RPC notifications and return 204 No Content.

Endpoint

Supported methods

Methods not in this list return a JSON-RPC -32601 method-not-found error when the request includes an id; requests without an id are notifications and return 204 No Content. eth_getUserOperationByHash can return a mined, in-flight mempool, or pending multisig-approval result, and returns null only when the hash is unknown to every lookup source.

Quickstart

Call eth_supportedEntryPoints first when an integration needs the EntryPoint for the active network:

curl --request POST \
  "$DALP_API_URL/api/v2/bundler" \
  --header "Content-Type: application/json" \
  --header "x-api-key: $DALP_API_KEY" \
  --data '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "eth_supportedEntryPoints",
    "params": []
  }'

Example response:

{
  "jsonrpc": "2.0",
  "result": ["0x1111111111111111111111111111111111111111"],
  "id": 1
}

A successful response echoes the same id and places the EntryPoint list in result.

Discovery methods

eth_chainId

Returns the active chain ID as a hexadecimal string, matching the Ethereum JSON-RPC convention used by wallets.

curl --request POST \
  "$DALP_API_URL/api/v2/bundler" \
  --header "Content-Type: application/json" \
  --header "x-api-key: $DALP_API_KEY" \
  --data '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "eth_chainId",
    "params": []
  }'

Example response:

{
  "jsonrpc": "2.0",
  "result": "0x89",
  "id": 1
}

eth_supportedEntryPoints

Returns the EntryPoint address DALP resolves for the active network. The response is an array so ERC-4337 clients can consume it through the standard bundler method shape.

The endpoint can return an EntryPoint registered for a private or local network instead of a hardcoded canonical address, so treat the result as network-specific.

If the network Directory contract is not configured, or if the EntryPoint registration has not been indexed yet, the endpoint returns a JSON-RPC error response. Retry after the network configuration is complete and indexing has caught up.

UserOperation methods

eth_sendUserOperation, eth_estimateUserOperationGas, eth_getUserOperationByHash, and eth_getUserOperationReceipt follow the ERC-4337 v0.9 bundler shape. Submission and gas estimation take the UserOperation object and the EntryPoint address; the sender wallet must belong to the authenticated organization.

Lookup methods take the UserOperation hash. eth_getUserOperationByHash resolves a hash across mined, in-flight mempool, and pending multisig-approval states, so an in-flight operation returns its UserOperation with null block fields rather than null. It returns null only when the hash is unknown to every lookup source. Poll a pending result instead of dropping the operation.

Both lookup methods return partial, nullable read shapes rather than the full standard ERC-4337 receipt and by-hash payloads. eth_getUserOperationByHash populates only the fields the network has resolved, leaving transactionHash, blockNumber, and blockHash null while an operation is in flight. The eth_getUserOperationReceipt result carries the standard top-level receipt fields, but its nested receipt object contains only transactionHash, blockNumber, and transactionIndex. Read these fields defensively and avoid strict ERC-4337 schema validators that reject responses missing optional receipt fields.

For the data model behind these methods, see UserOperations.

Submitting for a multisig wallet

When the sender is a smart wallet with a weighted multisig validator, eth_sendUserOperation accepts one signer's signature per call and accumulates signatures against a pending approval keyed by the UserOperation hash. A single call therefore does not always enqueue the operation: it submits the calling signer's weight, and the platform enqueues the operation only once the collected weight meets the configured threshold.

Because of this, a returned hash does not by itself confirm that the operation is in the mempool. Treat the response by state:

• Below threshold. The call records the signature and returns the UserOperation hash. The operation is held, not yet enqueued. Collect the remaining signer weight before treating it as submitted.
• Threshold met. The threshold-crossing call aggregates the collected signatures, validates the operation, and enqueues it. It returns the same UserOperation hash.
• Duplicate signature. A signer that has already signed a still-pending approval can resubmit safely. The platform treats it as an idempotent retry, does not add duplicate weight, and returns the same hash.

Confirm progress and final state with eth_getUserOperationByHash, which resolves a hash across pending multisig-approval, in-flight mempool, and mined states. To inspect collected weight and per-signer signatures directly, use the multisig approvals API.

Two states return a JSON-RPC error rather than a hash, so a stalled or duplicate submission is never misread as accepted:

• A submission whose UserOperation hash is already tied to another approval flow that the calling organization cannot act on returns a -32500 validation error. Submit a UserOperation that resolves to a hash unique to your wallet.
• An approval that is no longer pending and whose operation is not in the mempool returns a -32603 internal error. Poll eth_getUserOperationByHash to check whether the operation has already settled; do not resubmit the same UserOperation.

Paymaster methods

pm_getPaymasterStubData and pm_getPaymasterData implement the ERC-7677 paymaster interface so wallets can request gas sponsorship for an owned wallet's UserOperation. Use the stub method during gas estimation and the data method to obtain signed paymaster data before submission.

These methods require gas sponsorship to be enabled for your organization. When sponsorship is not enabled, the endpoint returns a JSON-RPC -32601 method-not-found error. When no sponsorship paymaster is available for the wallet, it returns a -32501 paymaster validation error instead. For how sponsorship is funded and configured, see System paymasters.

Error responses

The endpoint returns JSON-RPC error envelopes with HTTP 200 for parse, validation, and method errors, so bundler clients can handle failures through JSON-RPC semantics.

UserOperation and paymaster methods can also return the standard ERC-4337 validation error codes. The most common are:

Validation and method-resolution errors use this shape:

{
  "jsonrpc": "2.0",
  "error": {
    "code": -32600,
    "message": "Invalid JSON-RPC request",
    "data": {
      "dapiError": {
        "id": "DALP-0085",
        "category": "client",
        "status": 400,
        "retryable": false,
        "message": "Invalid JSON-RPC request",
        "why": "The JSON-RPC request is missing required fields or uses an unsupported shape.",
        "fix": "Send a valid JSON-RPC 2.0 request with the required method, id, and params fields."
      }
    }
  },
  "id": 1
}

For invalid JSON, DALP cannot read a request id, so the response uses id: null. Unsupported method responses use the JSON-RPC error envelope without data.dapiError because the method dispatcher can return a specific method-not-found message directly.

Integration notes

• Authenticate every request with an organization API key. The sender wallet in submission, estimation, and sponsorship calls must be owned by that organization.
• Send params as an array. Discovery methods take no parameters, so [] is sufficient.
• You can include the active chainId as an optional parameter on eth_sendUserOperation and the pm_* paymaster methods. It is the third positional parameter (params[2]), after the UserOperation and EntryPoint, so an ERC-7677 context follows it. A supplied value that does not match the active chain is rejected with -32602.
• Use request IDs when the caller needs a response. Omit id only for fire-and-forget JSON-RPC notifications.
• Treat the returned EntryPoint as network-specific. Private and local networks can return an EntryPoint address registered for that environment instead of a hardcoded canonical address.
• Retry EntryPoint discovery only after the Directory contract is configured and the indexer has processed the registration. A 503 means the Directory address is not configured. A 404 means DALP could not read an indexed EntryPoint for the active network.
• Use the REST paymaster endpoints for funding and sponsorship configuration; the pm_* JSON-RPC methods request sponsorship for a specific UserOperation at submission time.