Connect your MCP client

Before you connect

This guide shows how to connect the SandboxAQ MCP Server to the client you work in. The SandboxAQ OAuth flow is the same everywhere — only the interface around it differs, so pick your client below and follow that section.

In a hurry? The Quickstart has the condensed version — a handful of steps per client and nothing else. This page adds screenshots, client-specific caveats, and troubleshooting.

Client interfaces change frequently, so treat the steps below as a general guide. For the most accurate instructions, check the documentation for the client you’re using.

Every client needs two things: your server URL, and an account to authenticate against. Both come from sign-up.

Create your account

Go to platform.aisim.sandboxaq.com/signin and sign up. You can register with an email address and password, or use Google social login.

Accept the subscription terms

Review and accept the terms on the subscription page to activate your account.

Add a payment method

A card is required at sign-up, but nothing is charged against it while your free credits last. Once the credits are exhausted, usage is billed pay-and-deduct and requests fail with a 402 error if the balance reaches zero. See Pricing for rates.

Copy your MCP URL

In the platform console, use the Copy MCP URL button in the top-right corner, or open Account → MCP. Keep it on your clipboard — every client below asks for it.

Self-serve accounts all share the same server URL — https://mcp.platform.aisim.sandboxaq.com — which is what this page uses throughout. Enterprise accounts are issued their own host; use the URL shown in your platform console instead.

Scope. The pricing, limits, and legal terms (Master Customer Agreement, Data Protection Addendum, Privacy Policy) linked from this site cover the Individual self-serve tier. Enterprise terms are negotiated separately — contact mcp-prod@sandboxaq.com to discuss enterprise contracts, SLAs, custom deployments, or volume commitments.

How authentication works

Many scientific APIs authenticate with a static key passed as a request header. The SandboxAQ MCP Server does not — no API keys are issued, stored, or accepted. Every client authenticates you over OAuth 2.0: email and password, Google social login, or enterprise SSO through your organization’s identity provider. Practically, this means there is no secret to copy into a config file. The only thing you paste anywhere is your MCP URL; the sign-in happens in a browser window that your client opens for you, and the resulting session is scoped to your user and your account.

Connecting the server and authenticating your user are two distinct steps. Adding the server wires up the transport; you still need to complete an OAuth handshake before the client can call any tools. Skipping the handshake presents as Unauthorized errors or missing tools when you prompt the model.

Client	Where you authenticate	What “connected” looks like
Claude Desktop / claude.ai	A browser tab opened by Add connector — click Allow Access, then sign in	The connector shows Connected ✓, and its toggle is blue under + → Connectors in a chat
Claude Science	Inherited from your Claude account — the app asks to Authorize access to your connectors on first launch	SandboxAQ is listed and toggled on under Connectors & skills
Claude Code	`/mcp` → select `sandboxaq-mcp` → Authenticate → browser sign-in	`/mcp` lists the server as authenticated and shows its tools
Antigravity	A browser prompt after you add the server and click Refresh	The server appears under Installed MCP Servers with its tools listed

Set up your client

The SandboxAQ OAuth flow is identical in every client; only the surrounding interface changes. Pick the client you work in.

Claude Desktop and claude.ai
Claude Science
Claude Code
Antigravity

Use this method to connect from the standard Claude chat interface. The SandboxAQ MCP Server is a remote connector, and connectors are stored on your Claude account — so the steps below are identical in the Claude Desktop app and at claude.ai, and configuring one configures both.

Open claude.ai or the Claude Desktop app and sign in with your Anthropic account.

Open the connector settings

Click your profile icon, choose Settings, then go to Customize → Connectors — or go directly to claude.ai/customize/connectors.

Add the SandboxAQ connector

Click Add → Browse connectors, search for SandboxAQ, and select it. Click Connect, paste the MCP URL you copied above, and click Continue. If your workspace administrator has already published the connector, it appears in the list directly — just click Connect.

Authenticate

A new browser tab opens. Click Allow Access, then sign in with your SandboxAQ credentials (email and password, or Google). When the handshake finishes you are returned to Claude and the connector shows Connected ✓.

Enable it in a conversation

Open a new chat, click the + button at the bottom of the composer, choose Connectors, and confirm the SandboxAQ toggle is on (blue). Claude now has access to the SandboxAQ tools in that conversation.

Tired of approving every call? The first time Claude invokes a SandboxAQ tool it asks you to confirm, and a single prompt often triggers several tool calls. To stop re-approving, go back to Settings → Connectors, select the SandboxAQ connector, and switch Needs approval to Always Allow.

Turn off “Lazy load tools.” Lazy loading defers loading the tool schemas until Claude thinks it needs them, which makes tool selection less reliable. In Settings → Connectors → SandboxAQ MCP Server, set Lazy load tools to off and restart Claude. See Improving tool-invocation reliability for the full explanation.

Verify the connection. Ask Claude:

What tools do you have available from SandboxAQ?

Claude should enumerate aqcat and the four AQPotency tools — AqpotencyPotency, AqpotencyScreen, AqpotencyScan, and AqpotencySelectivity — along with their descriptions.Try it: “Predict the binding potency of CC1=CC=C(C=C1)S(=O)(=O)N against protein P00533.” More in Run your first query.

Claude Science is a desktop research application that runs analyses, searches databases, and traces its work. It uses the connectors on your Claude account rather than defining its own, so the SandboxAQ MCP Server carries over automatically once it is connected.

Prerequisite. Complete the Claude Desktop and claude.ai tab first. Claude Science has no place to paste an MCP URL — it reads the connectors already attached to your Claude account.

Download and install

Go to https://claude.com/product/claude-science, click Download now, and install the app for your platform.

Launch Claude Science and choose Sign in with Claude.ai — use the same Claude account that holds the SandboxAQ connector. (Paste code instead is the fallback if the app cannot open a browser for you.)

Authorize the app

In the browser, Claude Science asks to connect to your Claude chat account and lists the permissions it needs — including Use and manage your connectors, which is what carries the SandboxAQ connection across. Click Authorize.

Start onboarding

On Set up Claude for your science, click Continue. On Connect to the scientific web, choose which public sources Claude may reach — papers, sequences, structures, and the databases behind them — then click Continue.

Confirm the SandboxAQ connector

On the Connectors & skills screen, find SandboxAQ in the connector list and make sure its toggle is on, then click Continue.

Finish setup

Describe your field on What do you work on? (for example, “I am a catalysis scientist working with homogeneous and heterogeneous systems”). On Where should we start?, pick a first task — Run in silico experiments with MCP server tools is the relevant one here — and click Start.

Turn off “Lazy load tools.” Claude Science inherits this setting along with the connector, so it has to be changed on your Claude account — in Settings → Connectors → SandboxAQ MCP Server at claude.ai or in Claude Desktop, not in Claude Science itself. See Improving tool-invocation reliability for the full explanation.

Verify the connection. In a Claude Science session, ask:

What tools do you have available from SandboxAQ?

Claude should list aqcat and the four AQPotency tools. If it does not, open Claude Science’s settings and re-check the connector toggle under Connectors & skills, confirm the connector still shows Connected ✓ at claude.ai/customize/connectors, and check that Lazy load tools is off.Try it: “Scan CC1=CC=C(C=C1)S(=O)(=O)N against the human_kinome.” More in Run your first query.

Claude Code connects to the SandboxAQ MCP Server over Streamable HTTP. The only prerequisite is a working Claude Code installation.Register the server (enterprise accounts: substitute your own host in the URL):

claude mcp add sandboxaq-mcp --transport http https://mcp.platform.aisim.sandboxaq.com

# Confirm it was registered
claude mcp list

Scope. Claude Code asks where to register the server — local to the current directory, shared with the project, or for your user account. Choose user scope if you want the server available everywhere. Restart Claude Code after the change so it picks up the new configuration.

If you prefer editing configuration directly, the equivalent entry is:

// .mcp.json (project-scoped) or ~/.claude.json (user-scoped)
{
  "mcpServers": {
    "sandboxaq-mcp": {
      "type": "http",
      "url": "https://mcp.platform.aisim.sandboxaq.com"
    }
  }
}

Registering the server is not the same as signing in — complete the handshake before prompting:

Start Claude Code

Start Claude Code in your project directory (or any directory that inherits the user-scoped ~/.claude.json).

Run /mcp

Run /mcp inside the session to open the MCP server menu. Select sandboxaq-mcp and choose Authenticate — Claude Code offers the option whenever a server requires auth.

Complete the handshake in the browser

Claude Code opens the SandboxAQ sign-in page. Click Allow Access and sign in with your SandboxAQ credentials (email and password, or Google). No API key is involved.

Verify

Back in the session, re-run /mcp — sandboxaq-mcp should now show as authenticated and list its tools.

Set ENABLE_TOOL_SEARCH=true before launching Claude Code. Claude Code has no “lazy load tools” UI toggle; tool discovery is controlled by this environment variable, and without it Claude Code may fail to fetch the SandboxAQ tool schemas. See Improving tool-invocation reliability for the shell export and the env block variant.

Verify the connection. As a functional check, prompt:

What tools do you have available from SandboxAQ?

Claude Code should enumerate aqcat and the four AQPotency tools — AqpotencyPotency, AqpotencyScreen, AqpotencyScan, and AqpotencySelectivity.Try it: “Use the AQCat tool to find the lowest-binding-energy configuration for N₂ on a cobalt-nickel (111) surface.” More in Run your first query.

Antigravity connects to remote MCP servers through a raw JSON config file rather than a connector UI, and it uses the serverUrl key where the Claude clients use url.

Open the raw MCP config

Open the Agent panel, click the ⋯ menu, then choose MCP Servers → Manage MCP Servers → View raw config. This opens ~/.gemini/config/mcp_config.json.

Add the SandboxAQ server

Add the entry below and save the file.

// ~/.gemini/config/mcp_config.json
{
  "mcpServers": {
    "sandboxaq-mcp": {
      "serverUrl": "https://mcp.platform.aisim.sandboxaq.com"
    }
  }
}

Refresh the server list

Back in Manage MCP Servers, click Refresh in the Installed MCP Servers list. sandboxaq-mcp should appear.

Authenticate

Complete the OAuth prompt when it appears and sign in with your SandboxAQ credentials (email and password, or Google). No API key is involved.

serverUrl, not url. Antigravity rejects the url key that the Claude clients use. This is the most common reason a server never appears in the list.

Two limitations to know before you start. File upload is not supported, so AqpotencyScreen cannot run at all — use AqpotencyScan or run the screen from a Claude client instead. Tool invocation is also inconsistent, so name the tool explicitly and supply every required parameter up front. Details: Platform Compatibility.

Verify the connection. Prompt:

What tools do you have available from SandboxAQ?

Try it: “Scan CC1=CC=C(C=C1)S(=O)(=O)N against the human_kinome.” More in Run your first query.

Run your first query

Once the tools are listed, you can run real calculations by describing what you want in natural language. The prompts below work identically in Claude Desktop, Claude Science, and Claude Code. Naming the tool explicitly — as these do — makes invocation substantially more reliable. Each prompt below shows what comes back and what it costs. Run all four and you’ll have spent under $2 in total.

AQPotency — protein–ligand potency, panels, and selectivity

Predict the potency of a single compound against a single protein target:

Predict the binding potency of CC1=CC=C(C=C1)S(=O)(=O)N against protein P00533

You get back a predicted pIC₅₀ for that pair, its uncertainty (potency_sigma), and two applicability flags — ligand_similarity and protein_in_training — that tell you how much to trust the number. Cost: $0.01. Scan one compound across a whole protein panel:

Scan CC1=CC=C(C=C1)S(=O)(=O)N against the human_kinome

You get back all 604 kinases in the panel scored and ranked by predicted potency, so you can see what else the compound is likely to hit. Cost: $0.694. Assess selectivity against a named set of off-targets:

Assess the selectivity of CC1=CC=C(C=C1)S(=O)(=O)N against target Q15078 vs. off-targets Q6J9G0, Q13546, Q15768

You get back the on-target potency, each off-target’s potency, and the fold-selectivity between them — including which off-target is the worst offender. Cost: $0.04.

AQCat — adsorption energies on catalyst surfaces

Use the AQCat tool to find the lowest-binding-energy configuration for N₂ adsorbed on a
cobalt-nickel (111) surface. Report the binding energy of the winning placement and
confirm whether the relaxation converged.

You get back the lowest-energy placement out of the five AQCat evaluates, its binding energy in eV, and a per-placement convergence flag so you can tell whether each relaxation finished within the step budget. Cost: $1.00 (one relaxation unit). For the full catalog of tool-triggering prompts and worked examples with expected output, see AQCat → Example Prompts and AQPotency → Example Use Cases.

Other MCP clients

The SandboxAQ MCP Server works with any client that speaks the Model Context Protocol over Streamable HTTP transport. Point the client at your server URL and authenticate when prompted.

Anything else — use your client’s remote-MCP or HTTP-transport configuration with the URL https://mcp.platform.aisim.sandboxaq.com, then complete the OAuth prompt when it appears.

Config key names differ between clients: the Claude clients use url, Antigravity uses serverUrl. Watch for this if you’re copy-pasting between configs.

If something doesn’t work

The connector shows “disconnected” even though the browser said it worked. A known Claude Desktop UI-refresh delay. Toggle the connector off and back on in Settings → Connectors; if that doesn’t clear it, sign out of Claude Desktop and back in. Full steps: Desktop app showing ‘Disconnected’.
Unauthorized, or no tools listed, in Claude Code. Registering the server starts the transport but does not sign you in. Re-open /mcp, select sandboxaq-mcp, and run Authenticate again.
Claude answers from its own knowledge instead of calling a tool. Turn off Lazy load tools (Claude Desktop and Claude Science) or set ENABLE_TOOL_SEARCH=true (Claude Code), name the tool explicitly in your prompt, and include the required parameters up front. See Improving tool-invocation reliability.
A call fails with 402. Your balance is exhausted. Add or update your payment method in the platform console; see Pricing.
You pasted the wrong URL. Re-copy it from Account → MCP in the platform console. It always has the form https://mcp.platform.aisim.sandboxaq.com.

Still stuck? Contact support.aisim@sandboxaq.com, or use the contact form.

Next steps

SandboxAQ MCP Server

How the server works, the full tool list, limits and quotas, security model, and support terms.

AQCat Adsorption Spin

Parameter reference, supported bulks and adsorbates, and worked adsorption examples.

AQPotency

Potency, screening, panel scan, and selectivity tools, with panel definitions and output schemas.

Pricing

Per-unit rates, tiers, and sample billing scenarios.

FAQ

Short answers on supported clients, account setup, accuracy, privacy, and billing.

Contact

Enterprise sales, technical support, and privacy inquiries.

Get Started

MCP Server

Models

Support & Legal

Before you connect

How authentication works

Set up your client

Run your first query

AQPotency — protein–ligand potency, panels, and selectivity

AQCat — adsorption energies on catalyst surfaces

Other MCP clients

If something doesn’t work

Next steps

SandboxAQ MCP Server

AQCat Adsorption Spin

AQPotency

Pricing

FAQ

Contact

​Before you connect

​Sign up and get your MCP URL

​How authentication works

​Set up your client

​Run your first query

​AQPotency — protein–ligand potency, panels, and selectivity

​AQCat — adsorption energies on catalyst surfaces

​Other MCP clients

​If something doesn’t work

​Next steps

SandboxAQ MCP Server

AQCat Adsorption Spin

AQPotency

Pricing

FAQ

Contact

Before you connect

Sign up and get your MCP URL

How authentication works

Set up your client

Run your first query

AQPotency — protein–ligand potency, panels, and selectivity

AQCat — adsorption energies on catalyst surfaces

Other MCP clients

If something doesn’t work

Next steps