Drik

Vision-driven UI flow testing for localhost. Write tests in Markdown, let a local vision model click through your app like a human.

Drik (दृक्, "sight / the act of seeing").

Each test is a plain Markdown file describing a flow in natural language ("click the Sign in button", "verify the dashboard is visible"). Drik drives a real Chromium browser and, at each step, screenshots the page and asks a locally-hosted vision-language model either where to click or whether something is true on screen. It reports pass/fail per step and exits non-zero on failure, so it slots into CI like unit tests.

The bet: tests written against intent ("the Sign in button") instead of structure (#login-btn) are more readable and survive markup changes that break selector-based tests.

Install

As a tool, from PyPI:

uv tool install drik                          # or: pipx install drik
uvx --from drik playwright install chromium   # one-time browser download

Or for development, with uv:

uv sync                              # install dependencies
uv run playwright install chromium   # one-time browser download

Quick start

1. Have your app running on localhost.
2. Run a spec:

uv run drik run specs/auth.md \
  --base-url http://localhost:3000 \
  --report report.json

On Apple Silicon that's all: if no model server answers at --endpoint, drik starts one itself (see Model serving) — the first run downloads the model (~3 GB, one-time). --model is optional; drik asks the server which model it serves. On other platforms, start an external OpenAI-compatible vision server first.

Exit code is 0 if every step in every test passed, 1 otherwise.

Journey layout + dashboard

The recommended per-project layout keeps one spec per user journey and one results folder per journey:

drik/
  journeys/          # one .md spec per user journey (committed)
    login.md
    checkout.md
  results/           # written by runs (gitignore this)
    login/
      report.json
      artifacts/*.png

Run a journey into its results folder:

uv run drik run drik/journeys/login.md \
  --base-url http://localhost:3000 \
  --report drik/results/login/report.json \
  --artifacts drik/results/login/artifacts

Then browse all journeys in a localhost dashboard — index of journeys with pass/fail, per-journey pages with every step, failure detail, and screenshots:

uv run drik serve drik/results

The dashboard re-scans the results folder on every refresh, so leave it running while you iterate.

Before running real flows, validate the model + coordinate space with the bundled calibration spec:

uv run drik run specs/calibration.md --headed

How it works

read .md spec → launch browser at localhost → for each step:
    screenshot ──► model
        action step  → "where is <element>?"  → {x,y} → Playwright clicks/types
        assert step  → "is <statement> true?" → yes/no → record pass/fail
    → screenshot again → next step
→ print report, exit 0 (all pass) or 1 (any fail)

The model is used through exactly two primitives:

Primitive	Input	Output	Used for
Localization	screenshot + element description	{x, y} in [0,1000]	clicks, typing targets
Visual QA	screenshot + question	yes / no	assertions, wait conditions

Coordinates are rescaled from [0,1000] to the viewport's pixel size before clicking. The coordinate convention is model-dependent — getting it wrong is the #1 cause of clicks landing in empty space:

Model family	Emits	Use
Qwen-VL grounding (UI-Venus, Holo, Qwen2.5/3-VL)	normalized [0,1000]	--coord-space normalized_1000 (default)
UI-TARS	absolute pixels	--coord-space pixel

run.sh picks this automatically from the model name. If your clicks are consistently offset, you have the wrong space — flip it. The --report JSON records the exact pixel each step clicked, so a mismatch is easy to spot.

Spec format

A spec is a Markdown file. A ## heading starts a named test case. Each - bullet is one step: a leading verb plus arguments. Quoted strings are literal input text. Paths are resolved against --base-url.

Verb	Form	Action
goto	goto /login	Navigate to base URL + path (or a full URL)
click	click the "Sign in" button	Localize element, click it
type	type "a@b.com" into the email field	Localize field, focus, type text
type	type "hello"	Type into the currently focused element
press	press Enter	Keyboard key press
scroll	scroll down / scroll up	Scroll the viewport
wait	wait 500ms / wait for the spinner to disappear	Fixed delay, or poll a VQA condition until true/timeout
verify	verify the dashboard is visible	VQA assertion; passes if model answers yes
verify not	verify not an error message is shown	Passes if model answers no
screenshot	screenshot	Force-save a labeled screenshot

check and assert are accepted as synonyms for verify.

Example

# Auth flows

## Successful login
- goto /login
- type "test@example.com" into the email field
- type "hunter2" into the password field
- click the "Sign in" button
- wait for the dashboard to load
- verify the user dashboard is visible
- verify not an error message is shown

Agent skill (Claude Code & friends)

skills/drik/SKILL.md packages all of this as an Agent Skill so a coding agent can install drik, write journey specs into drik/journeys/, run them into drik/results/, and serve the dashboard — on its own. Install it for Claude Code, Codex, Zed, Amp, and any other SKILL.md-compatible agent:

npx skills add krishnarathore12/drik

(Or manually: copy skills/drik/SKILL.md into ~/.claude/skills/drik/ for Claude Code, or your agent's equivalent skills directory.)

Then ask the agent: "use drik to test the checkout flow" — it will scaffold the folders, author the spec, run it, and hand you the dashboard URL.

CLI

drik run <file-or-dir> [options]
drik serve [results-dir] [options]

Flag	Default	Meaning
--base-url	http://localhost:3000	Root for relative paths
--endpoint	http://localhost:1234/v1	OpenAI-compatible model server URL
--model	holo-3.1-4b	Model name as the server exposes it
--coord-space	normalized_1000	normalized_1000 or pixel
--headed / --headless	headless	Show or hide the browser window
--viewport WxH	1280x800	Browser viewport size
--report PATH.json	—	Write a machine-readable report
--artifacts DIR	./drik-artifacts	Where per-step screenshots go
--retries N	1	Retry a failed localization/action up to N times
--timeout SECONDS	30	Per-step model + browser timeout
--no-color	—	Disable colored console output

drik serve flags:

Flag	Default	Meaning
results	./drik/results	Results directory, one subfolder per journey
--host	127.0.0.1	Address to bind
--port	8123	Port to listen on
--no-open	—	Don't auto-open a browser tab

Model serving

Drik talks to any OpenAI-compatible server over HTTP; the model must support multimodal (image) input.

Managed (Apple Silicon — zero config)

On Apple Silicon, drik hosts the model itself. When drik run finds nothing at --endpoint (and the endpoint is localhost), it creates an mlx-vlm venv under ~/.drik/, downloads pipenetwork/Holo-3.1-4B-MLX-8bit into the Hugging Face cache, applies the mlx-vlm Holo patch (gotcha #1 below), and starts the server. It stays up between runs so re-runs are instant. Manage it explicitly with:

drik model start [--repo HF_REPO] [--port 1234]   # download + serve (idempotent)
drik model status                                  # up/down + loaded model
drik model stop                                    # shut it down

Pass --no-auto-model to drik run to fail instead of auto-starting, and --model-repo to auto-serve a different model. Server logs: ~/.drik/mlx-server.log.

External servers

Drik targets Apple Silicon. The Holo model card's vllm / SGLang / GPU-Docker instructions are NVIDIA/CUDA only and do not run on a Mac.

Supported setups, in priority order:

1. LM Studio — GUI, one-click model load, built-in OpenAI server. Recommended default. Point --endpoint at its local server (http://localhost:1234/v1).
2. mlx-vlm — Apple MLX vision stack (mlx-vlm, not mlx-lm); ships an OpenAI-compatible server. Most native / fastest path.
3. Ollama / llama.cpp GGUF — only if a vision-capable build (with the mmproj projector) is confirmed working for this architecture.

Footprint: Holo-3.1-4B at 4-bit ≈ 2.5–3 GB RAM (fine on a 16 GB Mac); 8-bit ≈ 5–6 GB; BF16 ≈ 8–9 GB. The 9B at 8-bit (~11 GB) OOMs the Metal GPU on a 16 GB Mac during vision prefill — stick to the 4B, or the 9B at 4-bit.

Running Holo-3.1 on mlx-vlm (two gotchas)

./run.sh defaults to pipenetwork/Holo-3.1-4B-MLX-8bit and handles both of these, but if you wire your own serving:

1. Patch the vision-type guard. Holo-3.1 reports vision_config.model_type = "qwen3_5_vision", which mlx-vlm 0.6.0's qwen3_vl/vision.py rejects. Add the types to the allow-list (line ~200):

   if self.model_type not in ["qwen3_vl", "qwen3_5", "qwen3_5_moe",
                              "qwen3_5_vision", "qwen3_5_moe_vision"]:

   Re-applying this after any mlx-vlm reinstall is required until upstream fixes it.
2. Coordinates are normalized [0,1000] for Holo (use --coord-space normalized_1000, the default), and the localize prompt must elicit Click(x, y) — Holo punts to the image center on a generic "output one point" prompt. Drik's built-in prompt already does this.

Drik sends temperature=0 and disables thinking mode for determinism.

Development

uv run pytest        # run the test suite

src/drik/
  cli.py       # arg parsing, entry point, exit code
  parser.py    # .md  -> Test/Step objects
  model.py     # vision-model client: localize() + ask()
  browser.py   # Playwright wrapper
  runner.py    # orchestration, retries, artifact capture
  report.py    # console + JSON output
  dashboard.py # `drik serve` localhost results dashboard
  serving.py   # managed mlx-vlm model server (`drik model`, run auto-start)

License

MIT