> For the complete documentation index, see [llms.txt](https://www.aevo.xyz/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://www.aevo.xyz/docs/api-reference/builder-codes/become-a-builder.md).

# Become a builder

Any Aevo account can register **one** builder for itself. The registering account becomes the builder's **fee account**: builder fees are credited to it, and its API keys are the only keys that can read the builder's reports.

## Requirements

* The account's USDC balance must be at least `min_create_balance`. Read it from `GET /builder-config`; it is currently 100 USDC.
* The account must not already own a builder.
* The account must be a main account. A [subaccount](/docs/api-reference/subaccounts.md) can't register a builder.

{% hint style="info" %}
Register from a dedicated account that you use only to receive builder fees. The fee account can't be changed later.
{% endhint %}

## Register in the app

Open **Settings → Builders → Builder Dashboard** in the Aevo app, connected with your fee account. Enter a builder name and select **Register**. Your `builder_id` is shown straight away.

## Register with the API

`POST /builder/register` (authenticated with the fee account's API key)

```bash
curl -sS -X POST "https://api-testnet.aevo.xyz/builder/register" \
  -H "AEVO-KEY: $FEE_ACCOUNT_KEY" \
  -H "AEVO-SECRET: $FEE_ACCOUNT_SECRET" \
  -H "Content-Type: application/json" \
  --data '{"name":"Example Builder"}'
```

```json
{"success": true, "builder_id": "builder_0123456789abcdef"}
```

The builder is active immediately. Aevo generates the `builder_id` (`builder_` followed by 16 hex characters); you can't choose it. It is the value users sign and the value you attach to orders.

## Rename

`POST /builder/profile`

```bash
curl -sS -X POST "https://api-testnet.aevo.xyz/builder/profile" \
  -H "AEVO-KEY: $FEE_ACCOUNT_KEY" \
  -H "AEVO-SECRET: $FEE_ACCOUNT_SECRET" \
  -H "Content-Type: application/json" \
  --data '{"name":"Example Builder Pro"}'
```

Only the name can be changed. The `builder_id` and fee account are permanent.

## Public profile

`GET /builders/{builder_id}`. No authentication.

```bash
curl -sS "https://api-testnet.aevo.xyz/builders/builder_0123456789abcdef"
```

```json
{"builder_id": "builder_0123456789abcdef", "name": "Example Builder Pro", "status": "ACTIVE"}
```

## Status

| Status      | Meaning                                                                                                                    |
| ----------- | -------------------------------------------------------------------------------------------------------------------------- |
| `ACTIVE`    | New orders with this builder are accepted and fees are charged.                                                            |
| `SUSPENDED` | Set by Aevo. New builder orders are rejected, and fills of resting orders charge a builder fee of `0`. Can be reactivated. |
| `DISABLED`  | Set by Aevo. Permanent.                                                                                                    |

Historical fills keep their builder attribution and fees whatever the builder's later status.

## Errors

| Code                             | Meaning                                                      |
| -------------------------------- | ------------------------------------------------------------ |
| `BUILDER_SELF_SERVICE_DISABLED`  | Registration is not open (`min_create_balance` is `null`).   |
| `BUILDER_INSUFFICIENT_BALANCE`   | The account's USDC balance is below `min_create_balance`.    |
| `BUILDER_ALREADY_EXISTS`         | This account already owns a builder.                         |
| `SUBACCOUNT_BUILDER_NOT_ALLOWED` | The account is a subaccount. Register from the main account. |
| `BUILDER_INVALID_NAME`           | The name is empty or invalid.                                |
| `BUILDER_FORBIDDEN_UPDATE`       | Only the name can be changed.                                |
| `BUILDER_INVALID_ID`             | The `builder_id` is malformed.                               |
| `BUILDER_NOT_FOUND`              | No builder with that ID.                                     |


---

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