@lastest/mcp-server

MCP server for Claude Code, Cursor, Windsurf, Cline, and Claude Desktop. Lets AI agents run visual regression tests, review screenshot diffs, and approve baselines on a Lastest instance through the Model Context Protocol.

Quick start

npx -y @lastest/mcp-server@latest --url https://your-lastest-instance --api-key YOUR_API_KEY

Generate an API key in the Lastest UI: Settings → Runners & API Access → Create API Key (shown only once). The server speaks MCP over stdio — wire it into any compatible client below.

Compatible clients

| Client | Status | Install method |
| -------------- | -------- | ---------------------------- |
| Claude Code | Verified | claude mcp add (see below) |
| Claude Desktop | Verified | claude_desktop_config.json |
| Cursor | Verified | ~/.cursor/mcp.json |
| Windsurf | Verified | MCP config (generic JSON) |
| Cline | Verified | MCP config (generic JSON) |

Any MCP-compliant client that can launch a stdio server with arguments works.

Install — Claude Code

claude mcp add lastest -- npx -y @lastest/mcp-server@latest \
  --url https://your-lastest-instance \
  --api-key YOUR_API_KEY

Verify with claude mcp list.

Install — Claude Desktop / Cursor / Windsurf / Cline

Add to claude_desktop_config.json, ~/.cursor/mcp.json, or your client's MCP config:

{
  "mcpServers": {
    "lastest": {
      "command": "npx",
      "args": [
        "-y",
        "@lastest/mcp-server@latest",
        "--url",
        "https://your-lastest-instance",
        "--api-key",
        "YOUR_API_KEY"
      ]
    }
  }
}

Restart the client.

What an agent can do

- List repositories, tests, functional areas, builds, and active jobs
- Create AI-authored tests from a URL or natural-language prompt
- Update or delete tests and functional areas
- Self-configure test runtime: playwrightOverrides, diffOverrides, stabilizationOverrides, viewport, setup wiring
- Manage shared auth: storage states (Playwright storageState() blobs) and reusable setup scripts
- Trigger test runs (optionally forceVideoRecording) and read run results
- Inspect visual diffs and approve / reject baselines individually or in bulk
- Heal failing tests with AI based on the latest run
- Publish, list, and revoke public-share links for builds and tests
- Read and update repo-level Playwright settings (browser, viewport, timeouts, parallelism, stabilization)
- Drive the Verify phase: Change Map, step comparisons, per-layer approvals
- Pull QA summaries, build review reports, and coverage stats

Tools exposed

The server registers 20 MCP tools (all prefixed lastest_). Every tool returns a structured { status, summary, actionRequired?, details } payload.

Pure CRUD operations are consolidated into resource tools that take an action (or scope) discriminator; workflow verbs stay as standalone tools.

Resource tools (action-dispatched)

| Tool | action (or scope) values | Purpose |
| ----------------------- | -------------------------------------------------------------------- | --------------------------------------------- |
| lastest_status | health, jobs, job | Instance connectivity + background-job status |
| lastest_repo | list, get, create, update, get_settings, update_settings | Repositories + repo-level Playwright settings |
| lastest_area | list, create, update, delete, list_tests | Functional areas (test groupings) |
| lastest_test | list (filter: all\|failing), get, update, delete | Read/update/delete tests |
| lastest_storage_state | list, create, delete | Saved Playwright storageState() blobs |
| lastest_setup_script | list, get, create, update, delete | Reusable Playwright/API setup blocks |
| lastest_get_diffs | scope: single\|build | Read visual diffs (one, or all for a build) |
| lastest_decide_diff | approve, reject (via diffIds batch or buildId approve-all) | Approve/reject visual diffs & baselines |
| lastest_build | list, get, review | Builds: list, status, comprehensive QA review |
| lastest_share | list, revoke | List/revoke existing public shares |
| lastest_verify | view, change_map | Verify-phase view + build-level Change Map |
| lastest_insights | coverage, qa | Repo coverage stats + QA summary |

Workflow verbs (standalone)

| Tool | Purpose |
| --------------------------- | ----------------------------------------------------------------- |
| lastest_run_tests | Trigger a test build (repo / area / specific tests) |
| lastest_create_test | Create a test (direct/AI, browser/API modes) |
| lastest_heal_test | AI healer agent auto-fixes a failing test |
| lastest_validate_diff | Diff-scoped validation: run only affected tests, return a verdict |
| lastest_suggest_app_fix | Advisory application-code fix for a real regression |
| lastest_approve_layer | Per-layer approve/reject/snooze on a step comparison |
| lastest_publish_share | Publish a /r/<slug> public share for a build/test |
| lastest_quickstart | Spin up the productized 2-test demo (returns sessionId) |
| lastest_quickstart_status | Poll a QuickStart session |

Self-configuring tests

lastest_test (action: "update") accepts a full override surface so an agent can shape a test without touching the UI:

- Setup wiring — setupTestId (use another test as setup, takes precedence) or setupScriptId, plus setupOverrides / teardownOverrides blocks to inject/skip default steps (test | script | storage_state).
- Runtime overrides — playwrightOverrides (browser, navigation/action/selector timeouts, error modes, baseUrl, cursor speed), viewportOverride, diffOverrides, stabilizationOverrides.
- Lifecycle — quarantined, executionMode (procedural | agent).

Pass null to any override block to clear it. The API validates each referenced id is in the same repo before persisting.

Migration — tool consolidation (v0.3.x)

The tool surface was consolidated from ~56 discrete tools to ~21 by folding pure
CRUD into the resource tools above. This is a breaking change for scripts
that called the old per-operation tool names. The workflow verbs and the
QuickStart chain (lastest_quickstart → lastest_quickstart_status →
lastest_publish_share) kept their names and signatures. Map any removed names
as follows:

| Removed tool(s) | Now call |
| ----------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------- |
| lastest_health, lastest_list_jobs, lastest_get_job | lastest_status { health \| jobs \| job } |
| lastest_list_repos, lastest_get_repo, lastest_create_repo, lastest_update_repo, lastest_get_repo_settings, lastest_update_repo_settings | lastest_repo { action } |
| lastest_list_areas, lastest_create_area, lastest_update_area, lastest_delete_area, lastest_list_area_tests | lastest_area { action } |
| lastest_list_tests, lastest_get_test, lastest_update_test, lastest_delete_test, lastest_list_failing_tests | lastest_test { action } |
| lastest_list_storage_states, lastest_create_storage_state, lastest_delete_storage_state | lastest_storage_state { action } |
| lastest_list_setup_scripts, lastest_get_setup_script, lastest_create_setup_script, lastest_update_setup_script, lastest_delete_setup_script | lastest_setup_script { action } |
| lastest_get_diff, lastest_get_build_diffs | lastest_get_diffs { scope } |
| lastest_approve_diff, lastest_reject_diff, lastest_approve_build_diffs | lastest_decide_diff { approve \| reject } |
| lastest_list_builds, lastest_get_build_status, lastest_review_build, lastest_get_test_run | lastest_build { list \| get \| review } |
| lastest_list_build_shares, lastest_list_test_shares, lastest_revoke_share | lastest_share { list \| revoke } |
| lastest_get_coverage, lastest_get_qa_summary | lastest_insights { coverage \| qa } |
| lastest_verify_view, lastest_get_change_map | lastest_verify { view \| change_map } |

If you need the old names temporarily, pin a 0.2.x release of this package
while you migrate.

CLI

lastest-mcp --url <url> --api-key <key>

Both flags are required. The process communicates with the host client over stdio.

Requirements: Node.js 18+ and a reachable Lastest instance.

Authentication

The server authenticates against Lastest's REST API (/api/v1/*) with a Bearer token. Manage and revoke keys from Settings → Runners & API Access in the Lastest UI.

Troubleshooting

| Symptom | Fix |
| ----------------------------------------------- | ------------------------------------------------------------------------------ |
| Failed to connect to Lastest at … | Check the URL is reachable from this machine and that the API key is valid. |
| Lastest API error 401 | Token revoked or expired — generate a new one in Settings. |
| Tools don't appear in Claude Code | Run claude mcp list; if missing re-run claude mcp add. Restart the client. |
| Tools don't appear in Cursor / Windsurf / Cline | Confirm the JSON config is valid and the client was fully restarted. |

Local development

git clone https://github.com/las-team/lastest
cd lastest/packages/mcp-server
pnpm install
pnpm dev -- --url http://localhost:3000 --api-key <key>

Used with

- Lastest — visual regression testing platform with screenshot diffs and AI test authoring
- @lastest/runner — self-hosted runner so AI-triggered tests execute on your infra
- Model Context Protocol — open standard powering tool use in Claude, Cursor, Windsurf, and others

Links

- Homepage: https://lastest.cloud
- GitHub: https://github.com/las-team/lastest
- Wiki: https://github.com/las-team/lastest/wiki/MCP-Server
- Issues: https://github.com/las-team/lastest/issues
- npm: https://www.npmjs.com/package/@lastest/mcp-server

License

FSL-1.1-ALv2 — see LICENSE.