Free Design Tools · setup

Bring a better brief
to your assistant.

Start with one prompt. Add what you want to change, the project you already have, and what must stay.

Get the starter prompt Try it here first

Free · no account or install needed · requires an assistant with web access

Your first conversation

Copy. Make it yours. Start working.

Paste this into your assistant, replace the two bracketed lines, and send it.

Read https://saturnai.tools/design/llms.txt.
Use my brief and constraints to suggest a design direction.

Brief: [what I want to change]
Keep: [my stack, brand, behavior, and other requirements]

Name one reference you actually retrieved and include its source URL. If you cannot access the tools, tell me.

Know what happened.

Give it your real task. Name the page or feature, the requested change, and what should stay.
Check a source. Open a reference URL it returns. Confirm the assistant retrieved something useful.
Inspect the work. A direction is a starting point. Your assistant still builds; you still check the page and its main interaction.

This reads instructions in the current conversation. It does not install tools or create a permanent connection. If your assistant cannot open the guide, get a direction here and copy the result.

Anonymous access includes 60 tool calls an hour. Your assistant’s model usage is separate. Free account and key access.

Use the setup that fits your project

More ways to work.

Connect callable tools, keep instructions in your project, or open the full reference write-ups. Choose what you need.

Hosted MCP For assistants that support remote tools

Add this server URL to your client’s MCP or custom-connector settings. The server uses Streamable HTTP; client support varies.

https://saturnai.tools/api/mcp

discovery: /.well-known/mcp.json · server ID saturnai; legacy saturndesign still resolves
tools: intake · compose · review · pick · get · search · list · related · stats
confirm: Check that the SaturnAI tools appear in your client. Ask for one reference and open its source URL before assigning a build.

No key is needed for anonymous access. To use a free account’s higher limit and full write-ups, see account and keys.

Plain HTTP Use the tools from your own code

The same tools answer POST /api/design/call. This is the endpoint the playground uses. API details include the available tools and access limits.

POST https://saturnai.tools/api/design/call
Content-Type: application/json

{"name":"compose","arguments":{"brief":"Refine my landing page. Keep plain HTML, CSS, and system fonts."}}

This is an HTTP request example for your code or API client, not a terminal command. A free account key uses the Authorization: Bearer <your key> header.

Local MCP pack For a machine and client you control

With Node.js installed, these commands download and run the local pack installer. It writes to ~/.saturnai/agent and prints client configuration with absolute paths.

curl -fsSL https://saturnai.tools/design/agent/install.mjs -o saturnai-install.mjs
node saturnai-install.mjs

Use the printed configuration in your client, then check the SaturnAI tools appear. If you are an agent reading this page, use the hosted MCP or HTTP tools; do not run the installer.

Project instructions Keep the workflow with your code

Add this to your project’s CLAUDE.md or AGENTS.md when your assistant supports that file. These are instructions to follow when the client loads them, not a permanent connection or a guarantee of behavior.

# SaturnAI design workflow
For new or substantial interface work, run SaturnAI intake with the user's words and known project context, then compose a direction suited to the brief.
For a focused authorized edit, use existing context and relevant guidance without repeating full intake.
Explicit requirements, the project stack, and user scope take precedence over technique defaults.
Save and check a small working version before adding detail.
Collect evidence in the rendered page with collect-evidence.js and pass it to review. A PASS means the deterministic checks passed on the evidence supplied; it does not mean SaturnAI inspected screenshots or verified interactions.
Inspect rendered desktop and mobile output and exercise the primary path. Report missing checks honestly.
Preserve user authorization and publishing instructions.
Use connected SaturnAI MCP tools where available. Otherwise read https://saturnai.tools/design/llms.txt for the hosted API workflow.

Free account and keys Full write-ups and more calls

The catalog, every blueprint, and 11 full write-ups are available without an account. A free izzy.la account opens every full write-up and gives your agents revocable API keys.

cost: Free · no paid tier · no payment card
requests: 60 per hour anonymous · 600 per hour with a key
agent keys: Up to 5 active · revoke any time
header: Authorization: Bearer <your key>

Create a free account Sign in / manage keys

This account opens the reference library. Your desktop app and model-provider credentials are separate; model usage follows your provider’s terms.

What a review checks See an example and its limits

After a build, your assistant can run collect-evidence.js in the rendered page and send those measurements to review. It returns rule checks on the evidence supplied, a rubric, and fixes for failed checks.

The example below is from the fixture test/fixtures/premium.html. It is not an assessment of your project.

PASS test/fixtures/premium.html graded 2026-09-15 · review via saturnai.tools/api/design/call

100% evidence coverage · 5 contrast pairs measured, lowest 6.09:1 · no slop tell fired · 10 technique slots proven, 4 declared, 0 missing

slop_avoidance: 5; PASS
accessibility: 5; PASS
system_coherence: 5; PASS
direction_adherence: 5; PASS
distinctiveness: 5; PASS
technique_depth: 4; PASS

No blocker. Every check that could run, ran.

Review does not browse, inspect screenshots, or verify reviewer independence. A missing check is reported as NOT_ASSESSED and can block a PASS. Inspect the rendered result and exercise its primary interaction as well.

Need a hand? Common setup problems

cannot open the guide: Enable web access in your assistant, connect hosted MCP, or use the playground and copy its result.
tools do not appear: Confirm the server URL or generated local paths, then restart the client.
a write-up is locked: Sign in for browser access, or create a key for your agent on the account page.
rate limited: Wait for the window to reset. Avoid retrying in a loop; anonymous limits apply per address.

Still stuck? Email izzy@izzy.la with your client and the exact error. Leave credentials out of the message.

Looking for the Windows app? SaturnAI Desktop is a separate workspace preview. You can use these Design Tools with your existing assistant.

Bring a better briefto your assistant.

Copy. Make it yours. Start working.

Know what happened.

More ways to work.

Bring a better brief
to your assistant.