> ## Documentation Index
> Fetch the complete documentation index at: https://docs.argalabs.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Testing integrations locally
> Use digital twins as drop-in replacements for third-party APIs during local development
When your app integrates with services like Stripe, Slack, or Notion, testing locally means either hitting real APIs (risky, rate-limited, costs money) or maintaining hand-written mocks (fragile, always out of date). Arga's digital twins give you a third option: spin up API-compatible replicas of these services and point your local app at them.
## How it works
Each twin is a full API emulator that runs on Arga's infrastructure and is reachable via a public URL. Your app talks to the twin URL instead of `api.stripe.com` or `api.slack.com` — no code changes needed beyond swapping environment variables.
```text theme={null}
Your local app
│
├── SLACK_BOT_TOKEN → twin token
├── Slack API calls → https://...--slack.sandbox.argalabs.com
│
├── STRIPE_SECRET_KEY → sk_test_...
└── Stripe API calls → https://...--stripe.sandbox.argalabs.com
```
Twins maintain realistic state (users, channels, files, payments), support webhooks, and behave like the real service — so you can test end-to-end flows without side effects. Twins start with minimal auth infrastructure and no content; use [scenario seeding](/features/custom-scenarios) or API calls to populate the data your tests need.
## Spin up twins
From your project directory:
```bash theme={null}
npx arga-wizard
```
```bash theme={null}
arga wizard
```
The CLI version uses your saved API key from `arga login`, so you skip the key prompt.
The wizard walks you through three steps:
1. **Select twins** — pick the services your app uses (Slack, Stripe, Notion, etc.)
2. **Review `.env` changes** — the wizard detects your environment variables and rewrites them to point at twins. Your original `.env` is backed up to `.env.arga-backup`.
3. **Wait for provisioning** — twins spin up in under a minute
Once ready, start your app normally. All API calls to the selected services now route through twins.
## Example: testing a Stripe checkout flow
```bash theme={null}
# 1. Spin up a Stripe twin
npx arga-wizard
# → Select "Stripe", approve .env changes, wait for provisioning
# 2. Start your app as usual
npm run dev
# 3. Test checkout in your browser — payments go to the twin
# Use Stripe test card numbers (4242 4242 4242 4242, etc.)
# 4. When you're done, tear down or let the session expire
arga wizard teardown
```
The Stripe twin supports customers, payment intents, subscriptions, checkout sessions, webhooks, and more. Test card numbers trigger the same outcomes (declines, 3D Secure) as Stripe's own test mode.
## Example: testing Slack messaging workflows
```bash theme={null}
# 1. Spin up a Slack twin
npx arga-wizard
# → Select "Slack", approve .env changes
# 2. Start your app
npm run dev
# 3. Open the twin dashboard to send messages and inspect app behavior
# Dashboard URL is printed after provisioning
# 4. Reset state and test again
arga wizard reset
```
The Slack twin starts with a workspace and users but no channels — create them through [scenario seeding](/features/custom-scenarios) or the `conversations.create` API. It also supports OAuth flows if your app has an "Add to Slack" install step.
## Managing your session
Twin sessions last **10 minutes** by default. Use these commands from your project directory:
| Command | What it does |
| ---------------------- | ----------------------------------------------------- |
| `arga wizard status` | Check if twins are still running and when they expire |
| `arga wizard extend` | Add another 10 minutes |
| `arga wizard reset` | Reset all twins to their initial empty state |
| `arga wizard teardown` | Destroy the session immediately |
Session state is tracked in `.arga-session.json` in your project root. Add it to your `.gitignore`.
From that same project directory, `arga runs logs` can read `.arga-session.json` automatically, so you can inspect the current logs snapshot for the active run without passing a run ID. Add `--errors-only` to focus on failed worker logs and warning/error runtime logs.
## Restoring your original environment
```bash theme={null}
cp .env.arga-backup .env
```
Or just tear down the session — but remember to restore your `.env` manually since teardown doesn't revert it.
## Available twins
| Service | Type | What you can test |
| ----------------------------------------------------------- | ------- | --------------------------------------------------------------------------------------------------- |
| [Stripe](/concepts/twin-reference#stripe) | UI | Payments, subscriptions, checkout, webhooks, billing portal, billing meters, dashboard |
| [Slack](/concepts/twin-reference#slack) | UI | Messaging workflows, OAuth install flow, file uploads |
| [Discord](/concepts/twin-reference#discord) | UI | Channel workflows, file uploads |
| [GitHub](/concepts/twin-reference#github) | UI | Repos, PRs, issues, branches, commits, check runs, webhooks, OAuth |
| [GitLab](/concepts/twin-reference#gitlab) | UI | Projects, merge requests, pipelines, hooks, REST and GraphQL |
| [Gmail](/concepts/twin-reference#gmail) | UI | Mailbox flows, drafts, labels, threads, and watches |
| [Google Drive](/concepts/twin-reference#google-drive) | UI | File CRUD, sharing, permissions |
| [Google Calendar](/concepts/twin-reference#google-calendar) | UI | Event CRUD, calendar management |
| [Dropbox](/concepts/twin-reference#dropbox) | UI | File storage, uploads, downloads |
| [Notion](/concepts/twin-reference#notion) | UI | Pages, databases, workspace management |
| [Box](/concepts/twin-reference#box) | Backend | File storage, enterprise management |
| [Jira](/concepts/twin-reference#jira) | Backend | Issues, projects, JQL, Agile, comments, and webhooks |
| [Linear](/concepts/twin-reference#linear) | Backend | GraphQL teams, projects, cycles, issues, labels, comments, OAuth, and webhooks |
| [Salesforce](/concepts/twin-reference#salesforce) | Backend | sObject CRUD, SOQL/SOSL, composite, limits and actions, support-style case and email-template flows |
| [Waterfall](/concepts/twin-reference#waterfall) | Backend | Company search, people search, enrichment, verification, and account lookups |
| [Unified](/concepts/twin-reference#unified) | Backend | Aggregated API across Slack, Drive, Calendar, Notion, Dropbox |
| [Unstructured](/concepts/twin-reference#unstructured) | Backend | Document parsing and partitioning |
**UI twins** have an interactive dashboard where you can see and manipulate state in the browser. **Backend-only twins** respond to API calls but don't have a visual interface.
See the [twin reference](/concepts/twin-reference) for per-twin support, limitations, and MCP tool coverage. See the [twins quickstart](/features/twins-quickstart) for quickstart state and environment variables.
## Tips
After spinning up twins and starting your app, run an Arga validation against your local deployment (exposed via a tunnel like ngrok or Cloudflare Tunnel) to get automated browser-level testing with twins backing every integration.
```bash theme={null}
# Expose your local app
ngrok http 3000
# Validate with Arga
arga test-runner runs url --url https://your-ngrok-url.ngrok.io --prompt "complete a checkout with Stripe"
```
You can provision twins in a CI pipeline by calling the API directly or running `npx arga-wizard` non-interactively. Set `ARGA_API_KEY` as a secret and the wizard will skip the key prompt.
Add these to your `.gitignore`:
```text theme={null}
.arga-session.json
.env.arga-backup
```