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

# Security boundary

> Preserve argv safety, default-deny permits, secret names, spend ceilings and caller cancellation.

export const RemoteContract = () => <Warning>
    <strong>Preview surface.</strong> The root package types the intended
    workflow HTTP and SSE API. The reference engine does not ship a compatible
    workflow service today. Do not point it at the stable resident firer or
    <code>nika model serve</code>.
  </Warning>;

export const LocalContract = () => <Tip>
    <strong>Live surface.</strong> <code>@supernovae-st/nika-client/local</code>
    drives the released <code>nika</code> binary through its versioned machine
    contracts. It is the production path today.
  </Tip>;

The SDK carries types and transport. The engine remains the policy enforcer.

## Local seam

<LocalContract />

<div className="sdk-flight sdk-flight-compact">
  <span>PROCESS BOUNDARY · ONE ARGV VALUE</span>

  <pre tabIndex={0}>
    {`unsafe  shell("nika run " + path)

        safe    spawn("nika", ["run", path, "--json"])
                                    └── never shell-parsed`}
  </pre>
</div>

`LocalNika` never wraps workflow paths in a shell string.

## Admit authority before execution

```ts theme={"system"}
const report = await nika.check(file)

if (!report.clean || report.cost?.has_unbounded) {
  throw new Error('workflow is not admitted here')
}

const plan = await nika.dryRunPlan(file)
authorize(plan.permits, plan.requirements)

await nika.runToEnd(file, {
  maxCostUsd: 0.25,
  signal: request.signal,
})
```

Check these facts explicitly:

* permitted filesystem paths, network hosts, programs and tools;
* model and environment requirements;
* secret names, never values;
* the static cost floor and unbounded flag;
* caller cancellation and runtime ceiling.

## Remote seam

<RemoteContract />

Bearer tokens belong in governed environment or workload identity plumbing,
not source. Custom loggers must not record authorization headers or webhook
secrets. Verify webhooks against the raw body before parsing.

## Threat boundaries

| Boundary                            | Owner              |
| ----------------------------------- | ------------------ |
| Workflow grammar and permits        | Engine             |
| Process argv and cancellation       | Local SDK          |
| HTTP timeout, retry and concurrency | Remote SDK preview |
| Secret storage and identity         | Deployment         |
| Artifact destination and retention  | Application        |

## Continue

<CardGroup cols={2}>
  <Card title="Security concepts" icon="shield" href="/concepts/security">
    Read the default-deny engine model.
  </Card>

  <Card title="Cost honesty" icon="scale-balanced" href="/guides/cost-honesty">
    Refuse unknown spend deliberately.
  </Card>

  <Card title="Webhooks" icon="webhook" href="/sdk/remote/webhooks">
    Verify delivery before dispatch.
  </Card>

  <Card title="CI gate" icon="shield-check" href="/sdk/operations/ci">
    Put admission before secrets.
  </Card>
</CardGroup>