mdb-esp32-cashless: Instructions file for Codex

AGENTS.md

mdb-esp32-cashless AGENTS.md is an instructions file for Codex, OpenCode from nodestark/mdb-esp32-cashless. It costs 1,570 tokens per session, scanned A, original, MIT.

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.

In plain words
What is it for?
Use it to send signed device commands, handle acknowledgements, work with credits and telemetry, and access VMflow data through Supabase.
Why use it?
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.

Instructions file for CodexOpenCode

Written for Codex and OpenCode: the file is AGENTS.md.

This is nodestark/mdb-esp32-cashless's own configuration. It tells Codex and OpenCode how to work on mdb-esp32-cashless itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything mdb-esp32-cashless configures →

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.

agentmods badge for mdb-esp32-cashless AGENTS.md

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.

agentmods 80×15 button for mdb-esp32-cashless AGENTS.md

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 1,570 This file is loaded in full into every session.
When invoked 1,570 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.01570 $0.01570
Opus 5 $0.00785 $0.00785
Sonnet 5 $0.00314 $0.00314
Haiku 4.5 $0.00157 $0.00157

Measured 9d ago against content hash 78e6539f01b2, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, 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 9d 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 · 124 lines

How it starts

The opening of the file, as written. The whole thing — 124 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)
  • hmacHMAC-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.

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>:<ts>:<hmac>, <amount> in 1/100 units (cents) .../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 · 124 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.

  1. 9d 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 (168 stars, last pushed 12d ago), licensed MIT. It adds 1,570 tokens to every session, about $0.0078 per session on Opus 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.

Related

Other instructions, from other repositories

next.js AGENTS.md

AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.

vercel/next.js · 7,296 tokens

codex AGENTS.md

AGENTS.md instructions for openai/codex, covering rust/codex-rs, the codex-core crate, code review rules, crate api surface and model visible context.

openai/codex · 5,153 tokens

vscode buildNext.instructions.md

Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).

microsoft/vscode · 6,785 tokens

vscode oss-third-party-notices.instructions.md

Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, applying the notice (cutover) and fallback chain (never fail the build).

microsoft/vscode · 5,001 tokens

langchain AGENTS.md

AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.

langchain-ai/langchain · 4,469 tokens

spec-kit AGENTS.md

AGENTS.md instructions for github/spec-kit, covering agents.md, about spec kit and specify, quickstart — add a new integration in 5 steps, integration architecture and integrationmanifest — file tracking.

github/spec-kit · 7,104 tokens