carrot-mcp-nfc

Carrot MCP NFC Server — wraps nfcscript for NFC reader communication via MCP.

Tools

Supported Readers

• pn532 — PN532 HSU (default)
• clrc663 — CLRC663 UART

Use list_readers to see all registered types at runtime.

Supported Transports

• serial — Serial/UART (default)

Use list_readers to see all registered types at runtime.

Usage

uv run carrot-mcp nfc

Script Tool

script executes a sequence of NFC operations. Each step is a dict with an op field:

Expect Matching

Data ops (transceive, find, reqa, wupa, select, anticoll) support expect, expect_bits, and on_mismatch:

[
  {"op": "transceive", "data": "26", "last_tx_bits": 7, "expect": "0A", "expect_bits": 4, "on_mismatch": "stop"}
]

• expect (hex): Expected response data for matching (case-insensitive).
• expect_bits: Number of valid bits in the last byte (1-8). Only the lower N bits of the last byte are compared; upper bits are treated as 0. Useful for 4-bit ACK/NAK responses.
• on_mismatch: "stop" (default) aborts the script on mismatch; "continue" logs the mismatch but proceeds.

The script stops on the first error or on_mismatch: "stop".

Example MCP Call Sequence

list_readers()
connect(port="COM20", reader_type="pn532")
find()
transceive(data="6007", last_tx_bits=7, tx_crc=false, rx_crc=false)
reqa()
wupa()
select(cl_level=1, uid="04AABBCCDD77")
anticoll(cl_level=1)
halt()
field_off()
trace_get()
trace_clear()
disconnect()