> ## Documentation Index
> Fetch the complete documentation index at: https://docs.opentype.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# invalid_amount

> HTTP 400 on checkout and auto-recharge: an amount out of bounds, not whole cents, a threshold too high, or a missing value. Every message and fix.

`invalid_amount` means a billing request carried an amount OpenType will not charge. Read this page when buying credits or configuring auto-recharge fails with a 400.

| HTTP  | `code`           | Retryable                 |
| ----- | ---------------- | ------------------------- |
| `400` | `invalid_amount` | No. Fix the amount first. |

## What happened

Routes:

* `POST /v1/billing/checkout`
* `PUT /v1/billing/auto-recharge`

Amounts are integers in micro-USD: 1,000,000 micros is \$1 and 10,000 micros is one cent. Nothing was charged and no setting was changed. These are every message:

| Message                                                        | Cause                                             |
| -------------------------------------------------------------- | ------------------------------------------------- |
| `amount_micros must be between 5000000 and 1000000000`         | `amount_micros` is below $5 or above $1,000       |
| `amount_micros must be a whole number of cents`                | `amount_micros` is not a multiple of 10,000       |
| `threshold_micros must not exceed 1000000000`                  | auto-recharge `threshold_micros` is above \$1,000 |
| `threshold_micros and amount_micros are required when enabled` | `"enabled": true` without both numbers            |

The bounds:

| Field              | Route                      | Accepted                                                           |
| ------------------ | -------------------------- | ------------------------------------------------------------------ |
| `amount_micros`    | checkout and auto-recharge | 5,000,000 to 1,000,000,000 ($5 to $1,000), a multiple of 10,000    |
| `threshold_micros` | auto-recharge              | at most 1,000,000,000 (\$1,000); required when `enabled` is `true` |

## How to fix

1. Convert dollars to micros by multiplying by 1,000,000, and round to whole cents first: \$25.00 is `25000000`.
2. Keep `amount_micros` between `5000000` and `1000000000`.
3. When you enable auto-recharge, send `enabled`, `threshold_micros` and `amount_micros` together.
4. Send the corrected request. The refused one changed nothing.

## Example

```json theme={"system"}
{"error":{"code":"invalid_amount","message":"amount_micros must be a whole number of cents","request_id":"req_7d3f0c1a9b2e4f6a8c0d1e2f3a4b5c6d"}}
```

Buying \$25 of credits. The call needs `billing_write` and returns a hosted Stripe checkout page; the credit arrives after payment.

<CodeGroup>
  ```bash curl theme={"system"}
  curl https://api.opentype.dev/v1/billing/checkout \
    -H "Authorization: Bearer $OPENTYPE_API_KEY" \
    -H "Content-Type: application/json" \
    -d '{"amount_micros": 25000000}'
  ```

  ```typescript TypeScript theme={"system"}
  const dollars = 25;
  // Whole cents, then micros: 1 cent = 10,000 micros.
  const amountMicros = Math.round(dollars * 100) * 10_000;

  const res = await fetch("https://api.opentype.dev/v1/billing/checkout", {
    method: "POST",
    headers: {
      Authorization: `Bearer ${process.env.OPENTYPE_API_KEY}`,
      "Content-Type": "application/json",
    },
    body: JSON.stringify({ amount_micros: amountMicros }),
  });

  const body = await res.json();
  if (!res.ok) throw new Error(`${body.error.code}: ${body.error.message}`);
  console.log(body.checkout_url); // send the buyer here
  ```

  ```python Python theme={"system"}
  import os
  import requests

  dollars = 25
  # Whole cents, then micros: 1 cent = 10,000 micros.
  amount_micros = round(dollars * 100) * 10_000

  resp = requests.post(
      "https://api.opentype.dev/v1/billing/checkout",
      headers={"Authorization": f"Bearer {os.environ['OPENTYPE_API_KEY']}", "Content-Type": "application/json"},
      json={"amount_micros": amount_micros},
      timeout=30,
  )

  body = resp.json()
  if not resp.ok:
      raise RuntimeError(f"{body['error']['code']}: {body['error']['message']}")
  print(body["checkout_url"])  # send the buyer here
  ```
</CodeGroup>

Enabling auto-recharge: top up $20 whenever the balance falls below $5.

<CodeGroup>
  ```bash curl theme={"system"}
  curl -X PUT https://api.opentype.dev/v1/billing/auto-recharge \
    -H "Authorization: Bearer $OPENTYPE_API_KEY" \
    -H "Content-Type: application/json" \
    -d '{"enabled": true, "threshold_micros": 5000000, "amount_micros": 20000000}'
  ```

  ```typescript TypeScript theme={"system"}
  const res = await fetch("https://api.opentype.dev/v1/billing/auto-recharge", {
    method: "PUT",
    headers: {
      Authorization: `Bearer ${process.env.OPENTYPE_API_KEY}`,
      "Content-Type": "application/json",
    },
    body: JSON.stringify({ enabled: true, threshold_micros: 5_000_000, amount_micros: 20_000_000 }),
  });

  const body = await res.json();
  if (!res.ok) throw new Error(`${body.error.code}: ${body.error.message}`);
  console.log(body.auto_recharge);
  ```

  ```python Python theme={"system"}
  import os
  import requests

  resp = requests.put(
      "https://api.opentype.dev/v1/billing/auto-recharge",
      headers={"Authorization": f"Bearer {os.environ['OPENTYPE_API_KEY']}", "Content-Type": "application/json"},
      json={"enabled": True, "threshold_micros": 5_000_000, "amount_micros": 20_000_000},
      timeout=30,
  )

  body = resp.json()
  if not resp.ok:
      raise RuntimeError(f"{body['error']['code']}: {body['error']['message']}")
  print(body["auto_recharge"])
  ```
</CodeGroup>

## Related

* [Credits and billing](/guides/credits-and-billing) - balance, checkout and the transaction list.
* [Auto-recharge](/guides/auto-recharge) - how the threshold and the top-up amount work.
* [Billing in the console](/console/billing) - add credit without writing code.
* [Problem codes](/problems) - every code, its status, and whether a retry can help.