---
title: "Submit signed EVM UserOperation(s)"
method: POST
path: "/exchanges/multi/{multiId}/tx"
tags: ["Exchanges"]
---

# Submit signed EVM UserOperation(s)

`POST /exchanges/multi/{multiId}/tx`

Submit signed EVM UserOperation(s) to the bundler.
Pass one signature per batch in the same order as returned by POST multi/{multiId}/tx/build.
Most multi-swaps produce a single batch, so typically only one signature is needed.

## Path parameters

- `multiId` string, required

## Request body

- SubmitEvmBatchTxRequest
  - `signatures` string[], required — One signature per batch, in the same order as the build response transactions array

## Response `200`

UserOperation(s) submitted

- SubmitEvmBatchTxResult
  - `userOpHashes` string[], required — ERC-4337 UserOperation hash(es) returned by the bundler — one per batch

## Other responses

- `400` — Bad request
- `422` — Validation Failed
- `500` — Internal Server Error

---

[API](https://skmtc.net/houdiniswap/apis/houdiniswap-backend.md) · [All operations](https://skmtc.net/houdiniswap/apis/houdiniswap-backend/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/houdiniswap/houdiniswap-backend/revisions/2063dbc88d59/schema)