MCP Agent Studio is a browser-based MCP client that runs any hosted or remote MCP server with Claude, GPT-5, Gemini, DeepSeek, Grok and 60+ other AI models — chat with your real data, compare models side by side, and run evals that prove an agent can answer using your tools. No install, no SDK, no API key.
Free credits on sign-up · No credit card · Terms
Or browse agent templates · hosted MCPs — no sign-in needed.
Discover the best, most cost-effective model for your AI agent use case
MistralWhat you can do
Auto-generate a test suite from your own tools, then prove an agent can actually answer with them.
See evalsAsk in plain English. The agent picks tools, calls them, and shows live JSON.
See itRun your server across 60+ models — Claude, GPT, Gemini, Grok — side by side.
See compare modePin a model + servers + system prompt as a reusable agent. Reopen in one click.
See agent setupCall your saved agent from your own code — POST to /api/v1/agents/<id>/chat.
See the APIConnect any MCP server — remote HTTP, SSE, or Streamable HTTP — pick a model, and start asking questions. The agent discovers your tools, decides which to call, and streams every invocation live with full JSON input and output. No glue code, no SDK install.


Send the same prompt to up to 4 models in parallel: Claude, GPT-5, Gemini, DeepSeek, Grok and more. See every tool call live, compare outputs side-by-side, and let automatic winner ribbons surface the fastest, cheapest, and most accurate model for your tools.
Paste your server URL. Agent Studio reads every tool, writes a full eval suite from your real schemas, then runs it: a driver model works your tools like a real client would, code checks the responses, and a scoring model grades the answers. You get a pass/fail report that says which tool is broken — and why — instead of a vague feeling that “the agent seems confused”.
Step 1
Connect
handshake + tool discovery
Step 2
Harvest
real values to ground tasks
Step 3
Run
the driver model works your tools
Step 4
Score
batched grading
18 evals · 24 tools discovered
14 passed/3 failed
driver: gpt-5.4-mini
scorer: claude-haiku-4.5
list_issuesPassedstate="open" never returns a closed issue
search_issuesFailed resulthonours per_page — never over-returns
get_issuePassedunknown id errors instead of returning null
Task · triageFailed to answer“Which P0 issues are unassigned?”
delete_issueUntestabledestructive — excluded from the run
Code-checked failures are confirmed defects — no model decided them.
Tools that look perfect in an inspector still fail in an agent loop — a vague description, an unbounded list, a silent null. Evals catch that before your users do, and re-run in one click every time you change a schema.
Free credits on sign-up · Suites save and replay
Pin a model, MCP servers, and a system prompt as a named agent — “GitHub Code Reviewer”, “Stripe Refund Assistant”, “Linear Standup”. Reopen any saved agent in one click from your sidebar, or start from one of dozens of pre-built templates and customize from there.
My agents
POST endpoint
https://mcpplaygroundonline.com/api/v1/agents/<AGENT_ID>/chat$ curl https://mcpplaygroundonline.com/api/v1/agents/agt_8f3d/chat \ -H "Authorization: Bearer mcpp_••••••••••" \ -H "Content-Type: application/json" \ -d '{ "message": "Top 5 open PRs?" }' # → streamed response with tool calls + final answer { "role": "assistant", "text": "Found 5 open PRs. Top: #312 Auth timeout (P0)…", "tool_calls": [{ "name": "list_pull_requests" }] }
Every saved agent gets a stable endpoint. Generate an API key in settings, then call /api/v1/agents/<id>/chat from your backend, scripts, or worker. Same model, same MCP servers, same system prompt — now driven by your code.
Who is this for?
Add one or more MCP servers, pick any AI model, and ask in plain English. Run evals to prove your tools hold up, inspect every live tool call, compare models side-by-side, and find the best quality-to-cost fit for your workflow.
For MCP server authors
Generate a suite from your own tools and get a pass/fail report proving an agent can answer with them.
For MCP developers
Run your server against Claude, GPT, Gemini & 60+ models side-by-side. See every tool call live before you ship.
For teams & power users
Start from a Stripe, GitHub, or Linear template. Save the config and use it every day — no re-setup.
Free credits on sign-up · No credit card · Terms
Or browse agent templates — no sign-in needed.
Templates
Ready-to-run templates for the tools you already use — click one, add your access token, and start chatting in under a minute. No sign-in needed to browse.
Notion Knowledge Agent
Chat with your Notion workspace — search pages, summarise docs, create new entries and keep your knowledge base tidy.
GitHub Code Review
Review PRs, inspect diffs, summarise commits and suggest improvements across any repository.
Sentry Error Triage
Triage Sentry errors in natural language — inspect stack traces, group issues and spot the commits that caused them.
Linear Project Manager
Create issues, triage backlogs, track progress and summarise sprint status directly from chat.
HubSpot CRM Assistant
Query contacts, deals and companies in HubSpot — update records, spot pipeline risks and draft personalised outreach.
Shopify Storefront
Browse a Shopify store’s catalog, search products and build a cart from chat — powered by the store’s own hosted Storefront MCP.
Amazon Ads Operator
Query Sponsored Products, Brands and Display campaigns in plain English — bid adjustments, keyword analysis and performance reports without Seller Central tab-switching.
Paid Media ROAS · Meta, Amazon & Stripe
Meta Ads, Amazon Ads and Stripe in one chat — see true blended ROAS across Facebook, Instagram and Amazon with live revenue attribution.
Zapier Automator
Trigger automations, list Zaps and manage workflows across 6,000+ connected apps.
Full-Stack Shipper · GitHub, Vercel & Sentry
GitHub PRs, Vercel deploys and Sentry errors in one chat — the complete Next.js ship-and-debug loop.
Hosted MCPs
To test a hosted MCP server, paste its URL (HTTP, SSE, or Streamable HTTP) into MCP Agent Studio — a no-install browser MCP client — or deploy your own sandboxed hosted server with a live URL in under a minute.
| Service | Official hosted MCP URL | Auth |
|---|---|---|
| GitHub | https://api.githubcopilot.com/mcp/ | PAT / OAuth |
| Notion | https://mcp.notion.com/mcp | OAuth |
| Stripe | https://mcp.stripe.com/ | API key |
| Supabase | https://mcp.supabase.com/mcp | OAuth / PAT |
| Linear | https://mcp.linear.app/sse | OAuth |
| Sentry | https://mcp.sentry.dev/mcp | OAuth |
| Figma | https://mcp.figma.com/mcp | OAuth |
| Neon | https://mcp.neon.tech/sse | OAuth |
| PostgreSQL | user-provided URL — or deploy a hosted sandbox | Bearer token |
Or deploy your own sandboxed MCP server
MongoDB
Full read/write access to a MongoDB cluster.
Postgres
Read-only SQL queries against any reachable database.
GitHub
Browse repos, read code, manage issues and pull requests.
Slack
Post messages, read channels, manage threads in a workspace.
Playwright
Drive a real Chrome browser — navigate, click, fill, screenshot.
Stripe
Read and manage customers, charges, subscriptions, invoices.
Notion
Read and write pages, databases, and blocks in a Notion workspace.
Wikipedia
Search and read Wikipedia articles — zero-config.
60+
AI Models
Auto
Generated Evals
4
MCP Servers per Chat
Free
To Get Started
Model choice
There is no single best model for MCP tool calling — it depends on your server's tools. MCP Agent Studio runs the same prompt on up to 4 models in parallel and scores accuracy, speed, and cost automatically.
Claude Sonnet 4.6 and Claude Opus 4.6 are the strongest default tool-callers in our catalog; GPT-5.4 and GPT-5.5 lead on structured-output tasks; Gemini 3.1 Pro handles long tool lists well; DeepSeek V4, GLM 5.1, and Nemotron 3 are the budget picks that still call tools reliably. Instead of guessing, paste your MCP server URL, pick 4 models, and let Compare Mode's winner ribbons (Fastest / Cheapest / Best Accuracy) decide — then lock the choice in with an eval suite that re-runs on every schema change. Works with Claude, GPT-5, Gemini, Grok, Qwen, Kimi, MiniMax, Mistral — 60+ models total.
Claude Desktop only speaks to Claude and ChatGPT only speaks to OpenAI models. MCP Agent Studio is a browser MCP client that connects the same server to any model — switch mid-conversation without reconfiguring.
Server × model
Every popular MCP server — GitHub, Notion, Postgres, Stripe, Supabase, Linear, Slack — works with every major AI model in MCP Agent Studio. Pick a server below for the recommended model, its official hosted URL, and a ready-made agent template.
| MCP server | Recommended model | Budget pick | Official hosted URL | Start from |
|---|---|---|---|---|
| GitHub MCP server | Claude Sonnet 4.6 | GPT-5.4 mini | https://api.githubcopilot.com/mcp/ | GitHub Code Review |
| Notion MCP server | GPT-5.4 | Gemini 3 Flash | https://mcp.notion.com/mcp | Notion Knowledge Agent |
| PostgreSQL MCP server | Claude Sonnet 4.6 | DeepSeek V4 Flash | user-provided URL — or hosted sandbox | Data Analyst |
| Stripe MCP server | Claude Opus 4.6 | GLM 5.1 | https://mcp.stripe.com/ | Stripe Billing Assistant |
| Supabase MCP server | Claude Sonnet 4.6 | Gemini 3 Flash | https://mcp.supabase.com/mcp | Supabase Builder |
| Linear MCP server | GPT-5.4 | GPT-5.4 nano | https://mcp.linear.app/sse | Linear Project Manager |
| Slack MCP server | Gemini 3.1 Pro | Qwen 3.7 Plus | https://mcp.slack.com/mcp | Slack Team Assistant |
| Sentry MCP server | Claude Sonnet 4.6 | DeepSeek V4 Pro | https://mcp.sentry.dev/mcp | Sentry Error Triage |
| Figma MCP server | Gemini 3.1 Pro | Gemini 3 Flash | https://mcp.figma.com/mcp | — |
| Neon MCP server | Claude Sonnet 4.6 | Nemotron 3 Super 120B | https://mcp.neon.tech/sse | Neon Data Ops |
Also works with Grok, Kimi, MiniMax, Mistral, GLM and every other model in the catalog — and with the Cloudflare, Vercel, HubSpot, Jira & Confluence, Asana, Monday.com, MongoDB, Playwright, Salesforce, Zapier, Docker MCP servers.
Related free toolsMCP server tester · online MCP inspector · MCP security scanner · MCP token counter
FAQ
Everything you might want to know about using AI agents with MCP servers.
MCP Agent Studio is a browser-based AI agent that connects to any Model Context Protocol (MCP) server and lets you query your data in plain English using 60+ AI models including Claude, GPT-5, Gemini, DeepSeek, Mistral, Grok, Qwen, NVIDIA Nemotron, and more. It also runs evals against your server — an auto-generated test suite that proves an AI agent can actually answer questions using your tools. Sign up for free — no credit card required.
An eval is a test that checks whether an AI agent can complete a real task using your MCP server. MCP Agent Studio connects to your server, reads every tool and its schema, and writes an eval suite for you. Running the suite has four phases: connect (handshake and tool discovery), harvest (pull real values from read-only tools so the tasks use genuine data), run (a driver model works your tools like a real client would), and score (grade the answers). Direct evals are decided deterministically by code — schema conformance, JSON-RPC error codes, pagination termination, result caps, idempotency — so a failure is a confirmed defect, not a model opinion. Agentic evals send a plain-English task through the driver model and a scoring model grades the final answer.
Paste your server URL into the Evals workspace and run a suite. Instead of eyeballing a tool list in an inspector, you get a pass/fail report per tool with the evidence behind each verdict: the arguments that were sent, the raw response, and which check tripped. Typical failures it catches are tool descriptions too vague for the model to pick the right tool, list endpoints that ignore their own limit parameter, missing-record cases that return null instead of an error, and agent loops that burn dozens of calls without answering.
No. Tools are classified before anything runs — read-only, idempotent, unknown, or destructive. Anything that could mutate or delete your data is excluded from the run and reported as "untestable" rather than being quietly called, and you review and approve the tool list before the suite is generated. Mutation checks are proved indirectly with a read-only witness tool instead.
Yes. Suites are saved against your organization and versioned, so you can replay one after every schema change and compare the new report against the last run. Writing a suite is charged once per version; replaying it only costs the run, which is why regression checks stay cheap. You can also add your own assertions in plain English alongside the generated ones.
No. MCP Agent Studio is a no-code interface. You paste your MCP server URL, pick an AI model, and start chatting. The agent discovers the available tools automatically and calls them for you as needed.
You can use 60+ models from every major provider, including Claude Opus 4.6, Claude Sonnet 4.6, GPT-5.4, GPT-5.5, Gemini 3.1 Pro, DeepSeek V4, Mistral Small 2603, Grok 4.6, Qwen 3, NVIDIA Nemotron Super 120B, Google Gemma 4, Z.AI GLM 4.5 Air, and more. You can switch models mid-conversation to compare responses on the same task.
An MCP server is a lightweight service that exposes tools (functions, database queries, API calls) over the Model Context Protocol so any AI agent can use them. Popular public MCP servers include GitHub, Supabase, Notion, Slack, Stripe, Postgres, Linear, and Playwright. You can also connect your own custom MCP server over HTTP, SSE, or Streamable HTTP.
MCP Agent Studio is free to sign up — no credit card required. Running AI models costs credits, which you can purchase in packs from your Settings page. New accounts may receive a small starter credit to try the product. Credit costs vary by model; check the Settings › Credits page for current pricing.
Yes. Connect the official Postgres or Supabase MCP server (or any MCP server that wraps your database) and ask questions in plain English: "Show me my top 10 customers by revenue this month." The AI generates the SQL, runs it through the MCP server, and returns the results with a natural-language summary.
Claude Desktop only works with Claude. ChatGPT only works with OpenAI models. MCP Agent Studio works with any model from any provider — swap between Claude, GPT, Gemini, DeepSeek, and Grok on the same MCP server without re-configuring anything. It also runs entirely in your browser with no local installation.
Yes. MCP Agent Studio connects any MCP server (HTTP, SSE, or Streamable HTTP) to GPT-5.4, GPT-5.5, GPT-5 mini, and the rest of the GPT-5 family. Paste your server URL, pick the model, and every tool call streams live — no OpenAI SDK or glue code required.
It depends on your server. Claude Sonnet 4.6 and Opus 4.6 are the strongest default tool-callers; GPT-5.4 leads on structured outputs; Gemini 3.1 Pro handles long tool lists; DeepSeek V4 and GLM 5.1 are the budget picks. Compare Mode in MCP Agent Studio scores all of them on your actual server.
Yes. Official hosted endpoints include Notion (https://mcp.notion.com/mcp), Stripe (https://mcp.stripe.com/), GitHub (https://api.githubcopilot.com/mcp/), Linear (https://mcp.linear.app/sse), and Sentry (https://mcp.sentry.dev/mcp). Paste any of them into MCP Agent Studio, or deploy your own sandboxed hosted MCP server with a live URL in under a minute.
Paste the server URL into MCP Agent Studio, add an auth token if the server requires one, and click connect — the agent lists the tools automatically. Remote HTTP, SSE, and Streamable HTTP transports are all supported, entirely in the browser with nothing to install.
Yes — and with GPT-5, Gemini, Grok, or any of 60+ models. MCP Agent Studio connects the official GitHub MCP server (https://api.githubcopilot.com/mcp/) to whichever model you pick, so you can review PRs or triage issues with Claude and re-run the same prompt on GPT-5 to compare.
Yes. The Model Context Protocol is model-agnostic, and MCP Agent Studio acts as a Gemini MCP client: connect any server and run it with Gemini 3.1 Pro or Gemini 3 Flash. Gemini Flash is one of the cheapest models that still calls MCP tools reliably.
Your MCP server credentials stay in your browser session and are never stored on our servers. Conversations are scoped to your Supabase-authenticated organization. We never train on your data, and you can delete your history at any time from Settings.
Yes — this is one of the core reasons people use MCP Agent Studio. Run the same prompt against Claude, GPT-5, and Gemini side by side, inspect every tool call in the live trace panel, and find the cheapest model that still gives great results. Teams routinely cut inference costs 5–10× this way.
Any MCP server that speaks HTTP, SSE, or Streamable HTTP. That includes official servers for GitHub, Supabase, Postgres, Notion, Slack, Stripe, Linear, Playwright, Filesystem, Memory, Sequential Thinking, and hundreds of community servers. You can also point it at your own custom server deployed on Cloudflare Workers, Vercel, Fly, or anywhere else.
Yes. MCP Agent Studio ships with ready-to-run templates covering Notion, GitHub, Amazon Ads, Jira, Confluence, Sentry, HubSpot, Stripe, Linear, Slack, Supabase, Vercel, Shopify, Cloudflare, Zapier, and more — including multi-server combos like GitHub + Vercel + Sentry and Amazon Ads + Stripe for blended ROAS. Pick a template, add your access token, and start chatting in seconds. Browse all templates at /templates.
Yes. Once you set up a model, one or more MCP servers, and a system prompt, you can save the whole configuration as a named agent with one click. Open it again any time from "My Agents" — your servers, tools and model selection are all restored. Agents can be private or shared with your team.
Export is coming soon. Save your agent and open Export in the studio toolbar to preview a Next.js App Router layout or a Python starter (MCP wiring, prompts, .env.example, deploy targets). Downloadable ZIP packs and one-click deploy will ship in a follow-up release; until then you can explore the preview and recreate wiring manually if you self-host.
No credit card required. Connect any MCP server, query it with Claude, GPT-5 or Gemini, and run your first eval suite in under a minute.
Free credits on sign-up · No credit card · Terms