midplane AGENTS.md

A repository guide for coding agents working on Midplane, a codebase with a web application and a separate query engine. It explains the project layout, design rules, imports, server actions, tests, and licensing boundaries.

In plain words
What is it for?
Use it when changing Midplane code, choosing the right package or test command, following client/server boundaries, or checking which project rules apply to a file.
Why use it?
It gives agents one source of truth for how this repository is organised and how changes should be made. This reduces mistakes such as running the wrong tests or handling user input incorrectly.

Instructions file for CodexOpenCode

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add instructions/midplaneai/midplane/agents-md
Clone the repo
git clone --depth 1 https://github.com/midplaneai/midplane

Made for: Codex, OpenCode.

Per session 2,280 This file is loaded in full into every session.
When invoked 2,280 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
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 $0.02280 $0.02280
Opus 5 $0.01140 $0.01140
Sonnet 5 $0.00456 $0.00456
Haiku 4.5 $0.00228 $0.00228

Measured 2d ago against content hash 4d32976ccb45, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

midplane AGENTS.md scanned grade A with 0 findings 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 2d 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.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

AGENTS.md · 158 lines

How it starts

The opening of the file, as written. The whole thing — 158 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Agent operating notes — midplane-cloud

This is the canonical guidance file for AI coding agents working in this repository, following the AGENTS.md convention. Tool-specific files (e.g. CLAUDE.md) point here so there is one source of truth. A nested AGENTS.md in a subdirectory, if present, takes precedence for files in its subtree.

Monorepo layout (one codebase, two deployables)

  • Control plane (repo root: apps/web, packages/{db,kms,router}, infra/telemetry-proxy) — the web app + hosted MCP proxy. Tests: vitest (./node_modules/.bin/vitest run). MIT except apps/web/src/ee/ (commercial).
  • Engine (engine/, grafted via git subtree) — the MIT query-path engine, shipped as the compiled midplane/midplane Docker image. Tests: bun test via bun run test:engine (NEVER a bare bun test from root — it would sweep in the control-plane vitest files). Engine governance lives under engine/ (LICENSE, THREAT_MODEL.md, TELEMETRY.md, CONTRIBUTING.md, SECURITY.md).

One root bun.lock covers everything (linker = "hoisted"). The engine ships two ways from one source tree: the image is a self-contained bun build --compile binary (engine/docker/Dockerfile, repo-root context, no node_modules in the runtime image), and the midplane npm package is a --target=node bundle (engine/packages/mcp-server/scripts/build-npm.ts). The engine therefore has to run on both Bun and Node: bun:sqlite and node:sqlite are reached only through engine/packages/engine/src/audit/sqlite-driver.ts, whose specifier is computed so neither bundler sees the other runtime's builtin, and no other Bun global (Bun.*, import.meta.dir, import.meta.main) may reappear in packages/*/src. bun test cannot catch a violation — the node-compat CI job builds the package and drives the real bin under Node against a real Postgres (scripts/smoke-npm-package.mjs), which is what actually pins this. CI: engine-test.yml / engine-publish.yml (tags engine-v*) are separate from the control-plane deploy-fly.yml. The engine still ships as its own image, so the version pin persists — see "OSS image version pin sites" below.

Read the full file on GitHub · 158 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. 2d ago First seen · 158 lines · 2,280 tokens per session scan A 4d32976ccb45

Subscribe to this mod's changes

midplane AGENTS.md is an instructions file published in the GitHub repository midplaneai/midplane (4 stars, last pushed 4d ago), licensed MIT. It adds 2,280 tokens to every session, about $0.0114 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

Related

Other instructions, from other repositories