What is mdb-esp32-cashless AGENTS.md?

A set of instructions for controlling VMflow vending devices through MQTT, a messaging system for connected devices, and Supabase REST, a web API for stored data. It describes signed commands, per-device credentials, credits, and telemetry history.

Use it to send signed device commands, handle acknowledgements, work with credits and telemetry, and access VMflow data through Supabase.

It gives an agent the message format and timing rules needed to authenticate device commands. It also separates real-time device control from data and history access.

How nodestark/mdb-esp32-cashless configures Codex and OpenCode

Reuse

Borrowing it

Nothing to install: this file belongs to nodestark/mdb-esp32-cashless. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/nodestark/mdb-esp32-cashless/main/AGENTS.md

Clone the repo

git clone --depth 1 https://github.com/nodestark/mdb-esp32-cashless

Made for: Codex, OpenCode.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/nodestark/mdb-esp32-cashless/agents-md/github.svg)](https://agentmods.dev/instructions/nodestark/mdb-esp32-cashless/agents-md)

Your own site

<a href="https://agentmods.dev/instructions/nodestark/mdb-esp32-cashless/agents-md"><img src="https://agentmods.dev/badge/instructions/nodestark/mdb-esp32-cashless/agents-md/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/nodestark/mdb-esp32-cashless/agents-md"><img src="https://agentmods.dev/badge/instructions/nodestark/mdb-esp32-cashless/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 1,608 This file is loaded in full into every session.

When invoked 1,608 The same file — it is already loaded in full.

Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.01608	$0.01608
Opus 5.5	$0.00643	$0.00643
Sonnet 5.5	$0.00322	$0.00322
Haiku 4.5	$0.00161	$0.00161

Measured 13d ago against content hash 96a806a33c95, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

mdb-esp32-cashless AGENTS.md scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 13d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

curl -X POST 'https://supabase.vmflow.xyz/auth/v1/token?grant_type=password' \

AGENTS.md · 125 lines

How it starts

The opening of the file, as written. The whole thing — 125 lines — stays where its author put it; the contents beside it link to each section on GitHub.

VMflow — Agent Context

Drop-in context for AI agents managing a VMflow vending fleet. Two control planes: MQTT RPC (real-time, signed, device-direct) and Supabase REST (data, credits, telemetry history).

Each device is identified by its <subdomain> (e.g. 51) and holds a per-device passkey used for both credit XOR encoding and RPC HMAC signing.

1. MQTT RPC — real-time device control

Signed commands sent straight to a device over MQTT. Authentication is an HMAC, not a session — every message is self-contained and expires fast.

Envelope

<cmd>:<ts>:<hmac>

cmd — one of the commands below
ts — UTC epoch seconds (date +%s)
hmac — HMAC-SHA256(passkey, "<cmd>:<ts>"), lowercase hex

Commands that take arguments (e.g. credit) extend the envelope to <cmd>:<args>:<ts>:<hmac>; the HMAC then covers everything before the last colon. Multiple arguments are comma-separated inside <args> (: delimits only the envelope).

Freshness: device accepts only if |now - ts| <= 10s. Sign at send time; do not cache signatures.

Topics

Direction	Topic
Publish (command)	`<subdomain>.vmflow.xyz/rpc`
Generic ack	`domain.vmflow.xyz/<subdomain>/rpc/confirm` (`ok`) — fired for every command
Command reply	`domain.vmflow.xyz/<subdomain>/rpc/<cmd>` — only for commands with a payload

Broker host: mqtt.vmflow.xyz. (<subdomain>.vmflow.xyz is the topic prefix, not a hostname.)

Commands

cmd	Effect	Reply topic
`info`	Publish device snapshot JSON (see schema)	`.../rpc/info`
`credit`	Grant credit. Envelope `credit:<amount>[,<seq>]:<ts>:<hmac>`, `<amount>` in 1/100 units (cents); optional `<seq>` = `sales.seq` of the pending sale, echoed back in `vend_success`/`vend_fail` (a seq not above the last accepted one is rejected)	`.../rpc/credit` (`ok`)
`echo`	Liveness / RTT probe — replies with the request `ts`	`.../rpc/echo`
`ota`	OTA update. Envelope `ota:<tag>:<ts>:<hmac>`, omit `<tag>` for latest	`.../rpc/confirm`
`dex`	Trigger EVA-DTS DEX/DDCMP telemetry pull from the VMC	`.../rpc/confirm`
`oos`	Send MDB "command out of sequence" to the VMC	`.../rpc/confirm`
`buzzer`	1s beep (physical locate)	`.../rpc/confirm`
`restart`	Reboot the device after 3s	`.../rpc/confirm`

Read the full file on GitHub · 125 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

13d ago Changed · +1 lines · +59 tokens per session 96a806a33c95
1mo ago Changed · -21 tokens per session b53e485f7a95
2mo ago First seen · 124 lines · 1,570 tokens per session scan A 78e6539f01b2

Subscribe to this mod's changes

mdb-esp32-cashless AGENTS.md is an instructions file published in the GitHub repository nodestark/mdb-esp32-cashless (190 stars, last pushed yesterday), licensed MIT. It adds 1,608 tokens to every session, about $0.0064 per session on Opus 5.5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Backend and APIs Hardware and IoT esp32 iot nuttx protocol-mdb vending-machine

mdb-esp32-cashless AGENTS.md next to 6 instructions from other repositories
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mdb-esp32-cashless: Instructions file for Codex