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

# Update Token Balance

> Update an agent's output token balance by incrementing or setting directly.

## Authentication

Requires JWT token or Platform API key via `Authorization: Bearer <token>` header.

<ParamField path="id" type="string" required>Agent UUID</ParamField>

<ParamField body="amount" type="number" required>
  Number of output tokens to add (increment) or set as the new balance (set)
</ParamField>

<ParamField body="type" type="string" required>
  Update type: `increment` (adds to current balance) or `set` (replaces balance)
</ParamField>

## Example Request

### Increment Balance

```bash theme={null}
curl -X POST https://api.app.shinzo.ai/v1/agent/a1b2c3d4-e5f6-7890-abcd-ef1234567890/balance \
  -H "Authorization: Bearer <token>" \
  -H "Content-Type: application/json" \
  -d '{
    "amount": 500000,
    "type": "increment"
  }'
```

### Set Balance

```bash theme={null}
curl -X POST https://api.app.shinzo.ai/v1/agent/a1b2c3d4-e5f6-7890-abcd-ef1234567890/balance \
  -H "Authorization: Bearer <token>" \
  -H "Content-Type: application/json" \
  -d '{
    "amount": 1000000,
    "type": "set"
  }'
```

## Example Response

```json theme={null}
{
  "message": "Agent balance updated successfully",
  "new_balance": 1500000,
  "previous_balance": 1000000
}
```

<Note>
  Token balance controls how many output tokens the agent can generate. At Sonnet 4.5 pricing (\~$15 per million tokens), a balance of 1,000,000 tokens ≈ $15 of usage.
</Note>

## Status Codes

| Code  | Description                                      |
| ----- | ------------------------------------------------ |
| `200` | Balance updated successfully                     |
| `400` | Invalid amount or type                           |
| `401` | Unauthorized - invalid or missing authentication |
| `404` | Agent not found                                  |