What’s New in Thrubit

Track every improvement to Thrubit, the local-first platform for running and debugging AWS Step Functions with real Lambda execution. Each release brings faster workflows, deeper integrations, and better visibility into your state machines without the need for constant cloud deployments. Follow along to see how Thrubit continues to help teams run step functions local, iterate instantly, and control development costs.

Version 1.3.8

EventBridge Mock Support — Now Available for Lambda Invocations

When you invoke a Lambda function directly from the Lambda tab, Thrubit now intercepts EventBridge.putEvents calls the same way it does for state machine executions. No events are sent to AWS — instead, mock responses are returned instantly so your workflow logic continues without requiring real AWS connectivity.

What this means for you:

Toggle it off per-invocation from the Lambda invoke panel if you want to test with real EventBridge

Lambda functions that publish to EventBridge will work end-to-end during local testing without hitting AWS

Mock responses include a realistic EventId so downstream code that checks the response won’t break

The mock is on by default — no configuration needed to get started

Version 1.3.7

EventBridge Support Improvements

EventBridge states now work correctly in local executions. Previously, events:putEvents states could fail or produce unexpected results when the event `Detail` field contained objects. This is now handled automatically.
New EventBridge Mock Mode. You can now toggle EventBridge between mock and live AWS modes — just like Bedrock and SQS. In mock mode, events return instantly with a simulated response so your state machine keeps running without sending real events to AWS.
Mock toggle available per execution. The EventBridge mock toggle appears in the run modal alongside Bedrock and SQS, so you can switch modes on a per-run basis without going into Settings.

Version 1.3.6

EventBridge Support in State Machine Execution

events:putEvents state support — Fully executes arn:aws:states:::events:putEvents Task states locally
waitForTaskToken support — Recognized and handled; the state sends the event and completes immediately (no hanging), with a warning in the logs
Mock mode — Returns a valid simulated EventId response for each entry instantly, no AWS connection required. On by default.
Live AWS mode — Sends real events using your configured AWS profile and region when mock is disabled; surfaces partial failure errors per entry
Automatic Detail serialization — Object Detail values are auto-converted to JSON strings, matching real Step Functions behavior
Multi-entry support — Handles both single events and arrays of entries (Entries[])
ResultSelector support — Applies ResultSelector transformations to the EventBridge response output

Bug Fixes

Fixed Map states rendering as empty nodes when the workflow uses the Iterator key (older ASL spec). Child states — including Choice, Wait, and Task nodes — now render correctly inside the Map compound node.
Fixed Choice states inside Map iterators not displaying as the correct hexagon shape.
Fixed an issue where clicking mock service toggles in the execution or invoke modals would appear to change the app theme.

Version 1.3.5

Sample Projects Gallery
Browse a library of ready-made AWS Step Functions workflow templates directly inside Thrubit. Filter by industry, preview each project, and add it to your workspace with a single click — no manual setup required.

Mock Service Controls
The Bedrock and SQS mock toggles in the Run Execution and Invoke Lambda dialogs have been redesigned. Each service now shows a clear Real AWS / Mock selector so it’s always obvious which mode is active before you run.

Version 1.3.4

Event file picker in the execution modal
You can now select from saved JSON event files directly in the Run Execution modal — the same experience as the Lambda invoke modal. Pick an event to pre-fill the input, or leave the selector on the default to start with an empty editor.

Quick mock toggles
Bedrock and SQS mock modes are now accessible directly in the Run Execution modal as toggle switches. Flip them on or off before each run without opening Settings. Changes save instantly — no restart required.

Settings no longer restart the app unnecessarily
AWS, UI, path, and mock setting changes apply immediately.

Version 1.3.3

SQS Support in State Machine Execution

You can now run Step Functions workflows that include Amazon SQS states locally in Thrubit.

SQS sendMessage — arn:aws:states:::sqs:sendMessage states now execute locally,
returning a real or simulated MessageId depending on your mode setting
waitForTaskToken — supported; completes immediately in local execution rather than
blocking (consistent with how other task token integrations work in Thrubit)
Mock SQS mode — a new toggle in Settings → AWS lets you switch between mock and real
AWS. Mock mode is on by default so workflows run without any AWS setup
SQS icon in graph view — SQS states now display with the SQS service icon in the
visual state machine diagram
Auto region detection — Thrubit reads the region directly from the QueueUrl, so
cross-region queues work correctly regardless of your global region setting

Version 1.3.2

Bedrock Integration — Expanded Service Support

Thrubit now supports the full range of AWS Step Functions Bedrock service integrations, not just invokeModel. You can now build and run workflows locally using:

bedrock:retrieve — Query a Bedrock Knowledge Base and get back ranked document chunks, without generating an answer.
bedrock:retrieveAndGenerate — Full RAG: retrieve relevant chunks from a Knowledge Base and generate a grounded answer in a single step.
bedrock:applyGuardrail — Run content through a Bedrock Guardrail before processing. Returns the guardrail action (NONE or INTERVENED) and any policy assessments.
bedrock-agent:invokeAgent — Invoke a Bedrock Agent synchronously. The .waitForTaskToken variant is also recognised and runs synchronously in local execution.

All new integrations support Mock mode and write structured logs to execution_logs/.

Smarter Mock Responses

When Mock Bedrock AI is enabled, invokeModel now returns a response body shaped correctly for the model family in use — so ResultSelector paths in your ASL work identically in mock and real modes:

Model family	Mock response path
Amazon Nova / Claude 3+	$.Body.output.message.content[0].text
Claude 2 / Instant	$.Body.completion
Amazon Titan Text	$.Body.results[0].outputText
Meta Llama 2 / 3	$.Body.generation
Mistral / Mixtral	$.Body.outputs[0].text
Cohere Command	$.Body.generations[0].text
Image models	$.Body.artifacts[0].base64

Settings UI Improvements

The Mock Bedrock AI setting now uses a Real AWS / Mock button toggle, consistent with the Lambda Execution Mode control.

Version 1.3.1

Fixed

Cmd+Q (and quit menu) now reliably terminates the background server process. Previously the server could remain running as an orphan after the app closed, causing port conflicts on next launch. The fix ensures the server is SIGKILLed synchronously on exit under all quit paths (normal, hung flush, and timed-out graceful shutdown).

Version 1.2

Easier Ways to Get Started

You can now import an existing project folder directly — Thrubit will detect your Lambdas and generate the necessary configuration automatically.
Each project can now use its own AWS credential profile, so you can work across multiple AWS accounts without changing your global settings.
Lambda functions stored in non-standard folder layouts are now discovered and resolved correctly.

Version 1.1

Stop a Running Lambda

You can now cancel a Lambda that is actively executing, giving you more control during development and testing.

AWS Credential Management

View, add, and switch AWS credential profiles directly within the app — no need to edit config files manually.
A real-time connection status indicator shows your AWS health at a glance, with a click-through to credential settings if something needs attention.
Lambdas that don’t require AWS services can now be executed offline without needing credentials configured.

Lambda Execution Modes

Choose between strict and unrestricted execution modes when invoking Lambdas, giving you more flexibility during testing.

Bug Fixes

Fixed a race condition that caused Lambda logs to display results from a previous run on slower machines.
Eliminated duplicate log entries from appearing in the execution panel.
Resolved a state machine runtime error that affected certain execution flows.
Fixed startup crashes caused by missing configuration defaults.

Version 1.0 — First Public Release

Windows Support

Thrubit is now available on Windows alongside macOS.

Work Offline

The app now works without an internet connection. Your work is saved locally and synced to the cloud when you reconnect.

Lambda Logs in State Machine View

Lambda execution logs now appear inline within the state machine execution view, so you can see exactly what happened at each step without switching screens.

Automatic Updates

The app checks for updates on launch and notifies you when a new version is available.

Reliable Usage History

Execution history is now saved locally first, ensuring your cloud history stays accurate even if you lose connectivity mid-session.

Real-Time Team Presence

See when teammates are active in the app with live presence indicators.

Version 0.5

Save Lambda Inputs Between Runs

Input data you use to invoke a Lambda is now remembered between runs, saving you from re-entering the same values repeatedly.

Event Dropdown Updates Instantly

After saving a new Lambda event, it appears immediately in the dropdown with no refresh required.

Lambda Logs During Execution

Lambda output is now streamed to the log panel in real time as your state machine runs.

Version 0.4

Monaco Code Editor

All JSON and code editing panels now use the Monaco editor (the same editor that powers VS Code) — with syntax highlighting, auto-formatting, and keyboard shortcuts.

Premium License Support

Entering a valid license key now upgrades your account immediately without requiring an app restart.

Improved Reliability Under Heavy Workloads

Resolved memory management issues that could cause slowdowns or crashes when running large or long-running state machines.

Version 0.2

Bug Fixes & Stability

Fixed a blank screen that appeared after navigating back from a Lambda execution.
Execution history is now correctly filtered to the project you’re working in.
Execution timestamps in history now reflect the actual completion time.
Resolved a crash that occurred on the very first run of a new project.
Fixed an issue where account activation was blocked after a trial expired.
The login screen now correctly transitions to the main app after signing in.

Version 0.1 — Alpha

The Foundation

Visual AWS Step Functions state machine runner with real-time execution progress.
Sign in with Google, GitHub, or Microsoft.
Lambda function discovery from your SAM template.yaml.
7-day free trial — no credit card required.
Secure credential storage using your operating system’s built-in keychain.
Settings for paths, server configuration, AWS regions, and more.
Execution history with per-project filtering.