fakecloud-sdk

Rust client SDK for fakecloud, a local AWS cloud emulator.

The crate wraps fakecloud's introspection and simulation API (/_fakecloud/*) so Rust tests can inspect emulator state, reset services, and trigger time-based processors without going through raw HTTP calls.

As of v0.15.0 the Rust SDK covers all 111 introspection routes across 31 sub-clients, matching the TypeScript / Python / Go / Java / PHP SDKs.

Installation

cargo add fakecloud-sdk

Rust 1.75+. Async-only, built on reqwest + tokio.

Quick Start

use fakecloud_sdk::FakeCloud;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let fc = FakeCloud::new("http://localhost:4566");

    let health = fc.health().await?;
    println!("{}", health.version);

    fc.reset().await?;

    let emails = fc.ses().get_emails().await?;
    println!("sent {} emails", emails.emails.len());

    Ok(())
}

Top-level

Sub-clients

fc.acm()

fc.apigatewayv2()

fc.application_autoscaling()

fc.athena()

fc.bedrock()

fc.bedrock_agent()

fc.bedrock_agent_runtime()

fc.cloudfront()

fc.cognito()

fc.dynamodb()

fc.ecr()

fc.ecs()

fc.elasticache()

fc.elbv2()

fc.events()

fc.glue()

fc.kms()

fc.lambda()

fc.logs()

fc.organizations()

fc.rds()

fc.route53()

fc.s3()

fc.scheduler()

fc.secretsmanager()

fc.ses()

fc.sns()

fc.sqs()

fc.ssm()

fc.stepfunctions()

fc.wafv2()

Testing Bedrock-calling code

use fakecloud_sdk::FakeCloud;
use fakecloud_sdk::types::{BedrockFaultRule, BedrockResponseRule};

#[tokio::test]
async fn classifier_branches_on_spam_vs_ham() {
    let fc = FakeCloud::new("http://localhost:4566");
    fc.reset().await.unwrap();

    let model_id = "anthropic.claude-3-haiku-20240307-v1:0";
    fc.bedrock()
        .set_response_rules(
            model_id,
            &[
                BedrockResponseRule {
                    prompt_contains: Some("buy now".into()),
                    response: r#"{"label":"spam"}"#.into(),
                },
                BedrockResponseRule {
                    prompt_contains: None, // catch-all
                    response: r#"{"label":"ham"}"#.into(),
                },
            ],
        )
        .await
        .unwrap();

    classify("hello friend").await;         // user code calls Bedrock
    classify("buy now cheap pills").await;

    let invs = fc.bedrock().get_invocations().await.unwrap();
    assert_eq!(invs.invocations.len(), 2);
    assert!(invs.invocations[0].output.contains("ham"));
    assert!(invs.invocations[1].output.contains("spam"));
}

#[tokio::test]
async fn retries_on_throttling() {
    let fc = FakeCloud::new("http://localhost:4566");
    fc.reset().await.unwrap();

    fc.bedrock()
        .queue_fault(&BedrockFaultRule {
            error_type: "ThrottlingException".into(),
            message: Some("Rate exceeded".into()),
            http_status: Some(429),
            count: Some(1), // only the first call faults; the retry succeeds
            ..Default::default()
        })
        .await
        .unwrap();

    classify("hello").await;

    let invs = fc.bedrock().get_invocations().await.unwrap();
    assert_eq!(invs.invocations.len(), 2);
    assert!(invs.invocations[0]
        .error
        .as_deref()
        .unwrap_or("")
        .contains("ThrottlingException"));
    assert!(invs.invocations[1].error.is_none());
}

Error handling

All methods return Result<T, fakecloud_sdk::Error>. Error has two variants:

• Error::Api { status, body } — fakecloud returned a non-2xx response
• Error::Http(reqwest::Error) — transport-level failure

Repository

• Project: https://github.com/faiscadev/fakecloud
• Website: https://fakecloud.dev