MCP Server
MCP Server for AI Agents
Give your AI coding agent a real workbench: compile Arduino and ESP32 firmware with a real arduino-cli backend, build circuits, and convert Wokwi diagrams — from Claude Code, Cursor, or any MCP-compatible client.
Start in three steps
Create a free account
Sign up in seconds — every account gets 1 free compile a day and unlimited free circuit tools.
Paste it into your agent
Point your client at https://app.sensbench.com/mcp with the key as a Bearer header. Done.
Connect your agent
Claude Code (CLI)
claude mcp add --transport http sensbench https://app.sensbench.com/mcp \ --header "Authorization: Bearer YOUR_KEY"
Test it: ask your agent to call get_quota — if it answers with your balance, you are connected.
Cursor
Settings → MCP → add a new server with this JSON:
{
"mcpServers": {
"sensbench": {
"url": "https://app.sensbench.com/mcp",
"headers": { "Authorization": "Bearer YOUR_KEY" }
}
}
}
Test it: ask your agent to call get_quota — if it answers with your balance, you are connected.
Claude Desktop
Add the same JSON to claude_desktop_config.json. On versions that only accept local commands, bridge with npx mcp-remote.
{
"mcpServers": {
"sensbench": {
"url": "https://app.sensbench.com/mcp",
"headers": { "Authorization": "Bearer YOUR_KEY" }
}
}
}
Transport: Streamable HTTP (POST). Legacy SSE-only clients are not supported. The key expires after 30 days — a fresh one is minted on every visit to the MCP Access page.
Tools reference
| Tool | Parameters | Returns | Billing |
|---|---|---|---|
| compile_projectpaid | files — list of {name, content} source files; board — Arduino FQBN (default arduino:avr:uno) |
Intel HEX (AVR) or base64 .bin/.uf2 (RP2040), plus stdout/stderr | 1 quota on success only; cache hit free |
| run_projectpaid | Same as compile_project | Compile result + simulation_ready flag for the browser simulator |
1 quota on success only; cache hit free |
| get_quotafree | — | Plan, calls left today, credits and pricing link — let your agent check its balance first | Never |
| create_circuitfree | board_fqbn, components, connections |
Circuit object (board_fqbn, components, connections, version) | Never |
| update_circuitfree | circuit + add/remove components, connections, optional board change |
Updated circuit object | Never |
| import_wokwi_jsonfree | diagram_json — Wokwi diagram.json as string |
Circuit object with detected board FQBN | Never |
| export_wokwi_jsonfree | circuit, optional author |
Wokwi diagram.json payload | Never |
| generate_code_filesfree | circuit, sketch_name, optional extra_instructions |
Starter .ino files ready for compile_project + board FQBN |
Never |
What a compile costs
MCP calls draw from the same balance as the AI Builder — one pool, nothing extra to buy. Only successful compiles are billed; failed compiles, cached results, light tools and the protocol handshake are always free.
| Tier | Price | MCP compiles | Effective cost |
|---|---|---|---|
| Free (any account) | $0 | 1 per day | $0 |
| Credits-5 | $1.99 | 5 — never expire | ≈$0.40 each |
| Credits-20 | $6.99 | 20 — never expire | ≈$0.35 each |
| Maker | $14.99 / 30 days | 12 per day | ≈$0.04 each |
| Pro | $19.99 / 30 days | 50 per day | ≈$0.01 each |
Daily allowances reset each day and do not roll over. Credits never expire. Full details on the pricing page — including what the AI Builder’s DeepSeek-powered project generation adds on top.
Supported boards
| Core | Example FQBNs | Boards |
|---|---|---|
arduino:avr |
arduino:avr:uno · arduino:avr:mega · arduino:avr:nano |
Uno, Mega 2560, Nano & classic AVR boards |
esp32:esp32 |
esp32:esp32:esp32 · esp32:esp32:esp32c3 · esp32:esp32:esp32s3 |
ESP32, ESP32-C3, ESP32-S3, ESP32-CAM family |
rp2040:rp2040 |
rp2040:rp2040:rpipico · rp2040:rp2040:rpipicow |
Raspberry Pi Pico & Pico W |
ATTinyCore:avr |
ATTinyCore:avr:attinyx5 |
ATtiny85 & small AVRs |
STMicroelectronics:stm32 |
STMicroelectronics:stm32:GenF4 |
STM32 boards |
Any FQBN starting with one of these core prefixes is accepted — cores are preinstalled, so compiles never trigger online downloads.
Limits & fair use
- At most 20 files and 256 KB of total code per request.
- Compiles run one at a time on the shared simulator — a second request from the same account queues and waits (120 s timeout).
- Identical code + board reuses the last 24-hour compile cache — instant and free, even at zero quota.
- Keys are personal, last 30 days, and can be revoked from the MCP Access page.
Try one of these first
- “Compile this sketch for an ESP32-C3 and tell me whether it fits in flash.”
- “Create a circuit with an ESP32 dev board, a DHT22 sensor and a relay, then generate the starter firmware.”
- “Import this Wokwi diagram.json and convert it into a circuit I can run in the simulator.”
- “Check my quota, then compile this project for an Arduino Uno.”
Get your key
Free account, 1 compile a day, and the whole circuit toolkit at no cost.