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

# Budget Config

> Configure WithBudget to stop or pause a run when token or cost limits are reached

Shows [`WithBudget`](/features/budget) on a single agent: `BudgetStopRun` ends the run with `ErrBudgetExceeded`, and `BudgetWaitForApproval` pauses for the caller to continue or stop.

Source: [`examples/agent_with_budget/`](https://github.com/agenticenv/agent-sdk-go/tree/main/examples/agent_with_budget)

Limits in the example are intentionally low so they trigger on a short prompt. Raise them for real workloads.

## What it demonstrates

* Token cap via `MaxTokens`
* Optional `MaxCostUSD` with caller-supplied `PromptUSDPer1M` / `CompletionUSDPer1M`
* `BudgetStopRun` — run stops and `Get` returns `ErrBudgetExceeded`
* `BudgetWaitForApproval` — `WithApprovalHandler` decides whether to continue

## Run

From `examples/`:

```bash theme={null}
go run ./agent_with_budget
go run ./agent_with_budget "Tell me a short interesting fact about space."
```

## Expected output

Scenario 1 prints `run stopped: per-run budget exceeded (BudgetStopRun)` when the token cap is hit.

Scenario 2 prints a `[budget] limit reached` line, then prompts `continue this run? (y/n)`. Type `y` to continue or `n` to stop with `ErrBudgetExceeded`. `task examples:*` sets `EXAMPLES_AUTO_APPROVE=true` and continues without a prompt.

## Learn more

<CardGroup cols={2}>
  <Card title="Budget" icon="gauge" href="/features/budget" horizontal>
    Limits, actions, validation, nested sub-agents
  </Card>

  <Card title="Approvals" icon="hand" href="/features/approvals" horizontal>
    Run handler vs Stream CUSTOM events
  </Card>
</CardGroup>