feat(api): expose protocol and host on lambda fastify requests

[mgramigna]

We have a use case where we need to re-construct a url in our lambda handler based on the event.

In a typical lambda handler, these properties are expected to be there, but cedar appears to not be mapping all required properties from the fastify request. We just need these ones, but worth considering if we should be trying to map more. This is the expected type from aws lambda:

export interface APIGatewayProxyEventBase<TAuthorizerContext> {
    body: string | null;
    headers: APIGatewayProxyEventHeaders;
    multiValueHeaders: APIGatewayProxyEventMultiValueHeaders;
    httpMethod: string;
    isBase64Encoded: boolean;
    path: string;
    pathParameters: APIGatewayProxyEventPathParameters | null;
    queryStringParameters: APIGatewayProxyEventQueryStringParameters | null;
    multiValueQueryStringParameters: APIGatewayProxyEventMultiValueQueryStringParameters | null;
    stageVariables: APIGatewayProxyEventStageVariables | null;
    requestContext: APIGatewayEventRequestContextWithAuthorizer<TAuthorizerContext>;
    resource: string;
}

export interface APIGatewayEventRequestContextWithAuthorizer<TAuthorizerContext> {
    accountId: string;
    apiId: string;
    authorizer: TAuthorizerContext;
    connectedAt?: number | undefined;
    connectionId?: string | undefined;
    domainName?: string | undefined;
    domainPrefix?: string | undefined;
    eventType?: string | undefined;
    extendedRequestId?: string | undefined;
    protocol: string;
    httpMethod: string;
    identity: APIGatewayEventIdentity;
    messageDirection?: string | undefined;
    messageId?: string | null | undefined;
    path: string;
    stage: string;
    requestId: string;
    requestTime?: string | undefined;
    requestTimeEpoch: number;
    resourceId: string;
    resourcePath: string;
    routeKey?: string | undefined;
}

[netlify]

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[nx-cloud]

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☁️ Nx Cloud last updated this comment at 2026-04-22 15:02:16 UTC

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☁️ Nx Cloud last updated this comment at 2026-04-21 21:28:31 UTC

[Tobbe]

Thanks for the PR Matt.

Since you're touching this area of the code I also wanted to make you aware of this: #1616

[mgramigna]

Thanks for the PR Matt.

Since you're touching this area of the code I also wanted to make you aware of this: #1616

Oh sweet, this might not be necessary then if you're moving to a standardized approach. We can probably work around it for now, feel free to close

[Tobbe]

We can probably work around it for now, feel free to close

It's such a small change I'll merge it as soon as CI passes. Also gives me a good reason to get a new release of Cedar out :)

[greptile-apps]

Greptile Summary

This PR updates lambdaEventForFastifyRequest to inject x-forwarded-proto from request.protocol as a default header (allowing upstream headers to override it), and adds requestContext.domainName from request.hostname. The implementation correctly addresses the previous review thread's feedback about requestContext.protocol semantic mismatch, and the new tests verify both the fallback and precedence behaviours. The project overview doc remains accurate — no architectural details are affected by this change.

Confidence Score: 5/5

Safe to merge — the change is well-scoped, properly tested, and resolves the prior review feedback.

No P0 or P1 findings. The spread order correctly lets existing upstream headers override the x-forwarded-proto default, which is verified by the new tests. The domainName mapping is a straightforward addition with no correctness concerns.

No files require special attention.

Important Files Changed

Filename	Overview
packages/api-server/src/requestHandlers/awsLambdaFastify.ts	Injects x-forwarded-proto from request.protocol as a fallback header (upstream headers take precedence), and maps request.hostname to requestContext.domainName — both addressing the prior review thread's feedback.
packages/api-server/src/tests/requestHandlers/awsLambdaFastify.test.ts	Adds a new test suite for lambdaEventForFastifyRequest covering both the absent-header case (protocol fallback) and the header-precedence case (upstream x-forwarded-proto wins), with correct assertions.

_{Reviews (3): Last reviewed commit: "fix: use x-forwarded-proto, respecting h..." | Re-trigger Greptile}

[mgramigna]

@greptileai re-review the PR