constitution

A set of non-negotiable engineering and product rules for a software project. It covers privacy, security, tenant separation, webhooks, pricing measurement, and the boundary between open-source and proprietary code.

In plain words
What is it for?
Use it when designing storage, authentication and encryption, audit logs, multi-tenant databases, MCP/API/CLI parity, webhook handling, ingestion routes, licensing boundaries, or usage metering.
Why use it?
It gives development decisions a fixed set of constraints, reducing the chance that new features weaken security, privacy, compatibility, or licensing boundaries.

Cursor rule for Cursor

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 rules/webhook-co/webhook/constitution
Clone the repo
git clone --depth 1 https://github.com/webhook-co/webhook

Made for: Cursor.

Per session 452 This file is loaded in full into every session.
When invoked 452 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 $0.00452 $0.00452
Opus 5 $0.00226 $0.00226
Sonnet 5 $0.00090 $0.00090
Haiku 4.5 $0.00045 $0.00045

Measured yesterday against content hash 0ac844893a69, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

constitution 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 yesterday.

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.

.cursor/rules/constitution.mdc · 33 lines

What it actually says

Constitution — non-negotiables

Durable principles for this repository. Design for them from day one; they are not bolt-ons.

  • Compliance-by-design. Encryption in transit and at rest; secrets in a KMS; append-only, hash-chained audit log; Postgres RLS tenant isolation; region pinning; PII/PHI scrubbed from logs.
  • MCP / AI-native parity. Every capability is reachable identically from CLI / API / web / MCP.
  • Private-by-default. Nothing is public, listed, or shared unless explicitly made so.
  • Cookieless ingestion on a separate apex. Ingestion and the CLI tunnel live on wbhk.my: cookieless, no CORS, path-token routing, 404 for unknown tokens. Never serve ingestion from a primary application subdomain.
  • Standard-Webhooks-native. Signing/verification follow Standard Webhooks (send and receive). Do not hand-roll signature schemes.
  • Open-core boundary. Open core is Apache-2.0; proprietary code is fenced into ee/. Open-core code must not depend on ee/.
  • Transparent pricing (qualitative). Keep event metering accurate and single-dimension; never add hidden per-step counters. (No prices or cost figures belong in this repo.)

Engineering guardrails (non-negotiable)

  • Human-UI-testing hard stop. When a change needs human UI/visual verification you cannot do yourself (rendering, layout, design, interaction, user-facing copy), STOP and explicitly flag it for human testing. Do not mark complete, approve, or merge until a human has verified it.
  • Never bypass tests. Never use git commit/push --no-verify; never add .only/skip/disable tests or lower coverage thresholds to make CI pass. Fix the root cause. CI required checks are mandatory for everyone (including admins) — status checks have no bypass.
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. yesterday First seen · 33 lines · 452 tokens per session scan A 0ac844893a69

Subscribe to this mod's changes

constitution is a cursor rule published in the GitHub repository webhook-co/webhook (0 stars, last pushed 6d ago), licensed Apache-2.0. It adds 452 tokens to every session, about $0.0023 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.