Bearer Auth

Bearer (JWT) authentication is used in multi-project contexts where the caller belongs to more than one project and must pass projectId per request. Bearer tokens are typically short-lived session tokens that can expire after ~60 seconds. Any SDK call that outlives the token window — a long .wait() poll or a slow uploadFile() — risks a mid-flight 403. withBearerRefresh wraps fetch to detect these rejections and retry transparently.

Not applicable to API-key auth — API keys are long-lived credentials and don’t expire mid-session.

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withBearerRefresh(refresh, options?)

Wraps fetch so that AWS API Gateway authorizer rejections (HTTP 403 with header x-amzn-errortype: AccessDeniedException) automatically trigger a JWT refresh and a transparent retry.

Signature

withBearerRefresh(
  refresh: () => Promise<string | null>,
  options?: BearerRefreshOptions,
): typeof fetch

Parameters

Name	Type	Description
refresh	() => Promise<string | null>	Async callback that returns a fresh JWT string, or null if the refresh fails (the original 403 is then propagated unchanged).
options?	BearerRefreshOptions	Optional configuration.

Returns

typeof fetch — a drop-in fetch replacement. Pass it to the fetch option of the Scenario constructor.

Example

import Scenario, { withBearerRefresh } from '@scenario-labs/sdk';

const client = new Scenario({
  bearerAuth: initialJwt,
  projectId: 'proj_...',
  fetch: withBearerRefresh(async () => {
    // Replace with your IdP or session-token API call.
    return await mintFreshJwt();
  }),
});

// Long-running poll — JWT can expire mid-flight; the wrapper handles it:
const run = await client.workflows.run('wflow_...', { body: { prompt: 'a snowy mountain pass' } });
const completed = await run.job.wait({ timeoutMs: 600_000 });

Note

withBearerRefresh only intercepts AWS API Gateway authorizer rejections. Real downstream permission denials (HTTP 403 without x-amzn-errortype: AccessDeniedException) are propagated unchanged so the caller can still read the error.

Caution

Multiple concurrent requests that all hit a gateway 403 share a single in-flight refresh (single-flight coalescing). Only one new JWT is minted per round, regardless of how many requests were waiting.

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BearerRefreshOptions

Options for withBearerRefresh().

interface BearerRefreshOptions {
  maxRefreshes?: number;  // Default: 2
  fetch?: typeof fetch;   // Default: globalThis.fetch
}

Name	Type	Default	Description
maxRefreshes?	number	2	Maximum refresh attempts per wrapper instance. After this limit, subsequent authorizer 403s are propagated unchanged.
fetch?	typeof fetch	globalThis.fetch	Underlying fetch to wrap. Useful for composing with other wrappers (logging, retries, test mocks).

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ClientOptions.projectId

The enhanced Scenario constructor accepts a projectId option, which is required for bearer auth when the user belongs to multiple projects.

const client = new Scenario({
  bearerAuth: jwt,
  projectId: 'proj_...',
});

Name	Type	Default	Description
projectId?	string | null	null	Default project scope for all requests (sent as ?projectId=...). Useful with bearerAuth when the user belongs to multiple projects — the server derives the team from the project, so teamId doesn’t need to be set separately. With apiKey auth the project is implied by the key and this option is unnecessary.

Per-call override: pass options.query.projectId to override for a single request. SDK helpers (.wait(), model.run(), workflow.run()) automatically reuse the scope of the originating call, so an action created in project A always polls in project A even if the client default changes later.