Lock down async timing with deterministic mocks for bulletproof E2E tests
E2E tests for asynchronous flows fail flakily due to unpredictable timing and race conditions.
AsyncLock is a proxy server that intercepts your app's async APIs (fetch, WebSockets) and lets you control response timings precisely during tests. Configure delays, sequences, and races via a simple dashboard—no code changes needed. Integrate with Cypress/Playwright commands to make async flows 100% predictable and flake-free.
Test automation engineers and QA developers using tools like Cypress or Playwright for E2E testing in React/Node.js apps with async operations
Zero-code mock proxy tailored for E2E async control, unlike MSW which requires test rewrites
friendly
One-click proxy config for local/dev
Record real async calls and replay with custom timings
Visual drag-drop for delays, races, and throttling
Native commands to trigger mock scenarios
Preview test runs with mocks before CI
Export/import mock configs for teams
Docker image for pipeline mocks
Detect potential issues in mock setups
| Column | Type | Nullable |
|---|---|---|
| id | uuid | No |
| text | No | |
| created_at | timestamp | No |
| Column | Type | Nullable |
|---|---|---|
| id | uuid | No |
| user_id | uuid | No |
| name | text | No |
Relationships:
| Column | Type | Nullable |
|---|---|---|
| id | uuid | No |
| workspace_id | uuid | No |
| name | text | No |
| mock_config | jsonb | No |
| created_at | timestamp | No |
Relationships:
| Column | Type | Nullable |
|---|---|---|
| id | uuid | No |
| scenario_id | uuid | No |
| status | text | No |
| metrics | jsonb | Yes |
Relationships:
/api/workspacesCreate workspace
/api/scenariosSave mock scenario
/api/scenarios/:id/runSimulate test with mocks
/api/proxy-configGet proxy setup for test
No CI integration
| Month | Users | Conversion | MRR | ARR |
|---|---|---|---|---|
| Month 1 | 60 | 2% | $37 | $444 |
| Month 6 | 600 | 4% | $888 | $10,656 |
Proxy mocks make E2E tests deterministic— no rewrites, just timings you control.
Share proxy demo video on r/Playwright and Twitter #E2Etesting, offer free Pro to first 3 who integrate and share results.
Popular mocking
Unit-test focused, hard for E2E timing
E2E proxy with timing control
Robust proxy
Complex setup, no test integration
Wizard + test plugins
Network of shared mock scenarios building community library
Async-heavy frontends exploding; proxy tools underevolved for browser E2E
Proxy compatibility with all APIs
Focus on fetch/WS first, expand via feedback
Adoption barrier for proxy
Wizard + video tutorials
Success: 3 want early access
Success: Flake drop >50%
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