Account abstraction transaction relay

DALP exposes POST /api/v2/bundler as an ERC-4337-style JSON-RPC discovery surface. Wallets and SDKs call it to read the active chain ID or EntryPoint address before they build account abstraction flows. DALP does not expose UserOperation submission, gas estimation, lookup, or receipt retrieval through this endpoint.

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. For the broader REST API, see API reference.

Before you call

You need the DALP API base URL for the environment you are integrating with. The endpoint reads the active chain from platform configuration and resolves the EntryPoint from the indexed Directory registration for that network.

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

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" \
  --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.

Supported 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" \
  --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.

curl --request POST \
  "$DALP_API_URL/api/v2/bundler" \
  --header "Content-Type: application/json" \
  --data '{
    "jsonrpc": "2.0",
    "id": 2,
    "method": "eth_supportedEntryPoints",
    "params": []
  }'

Example response:

{
  "jsonrpc": "2.0",
  "result": ["0x1111111111111111111111111111111111111111"],
  "id": 2
}

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

The endpoint recognizes JSON-RPC method names through the standard dispatcher. UserOperation submission and lookup methods are not available from this API surface. Requests with an id return method not found. Requests without id are JSON-RPC notifications, so DALP returns 204 No Content without an error body.

Example response for a request with id:

{
  "jsonrpc": "2.0",
  "error": {
    "code": -32601,
    "message": "Method not found: eth_sendUserOperation. See ERC-4337 bundler documentation for supported methods."
  },
  "id": 3
}

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.

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

• Send params as an array. The supported methods do not require parameters, so [] is sufficient.
• 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 operations; this JSON-RPC endpoint is for bundler-compatible discovery.