synthesisengineering/synthesis-skills · skills/synthesis-message-guard/SKILL.md

synthesis-message-guard skillA

synthesis-message-guard is agent-read markdown (skill) from synthesisengineering/synthesis-skills: Fail-closed pre-send enforcement for agent-drafted correspondence. A PreToolUse hook blocks every message-sending or draft-creating tool call unless the outgoing text passes a deterministic register scan AND a fresh, single-use grounding ledger — sha256-bound to the exact message — attests that the composing agent read the full thread, searched prior correspondence, and mapped every factual claim to a source. Use when setting up, debugging, or composing under the guard; when a send is blocked; o.

Indexed from public GitHub and served as immutable, content-addressed versions. Install it pinned to an exact SHA-256 with the mdr CLI, and every file is verified against the hash recorded here before it reaches your agent. The deterministic audit below grades the latest version, and the same file always earns the same grade.

How to install

Latest version
mdr add synthesisengineering/synthesis-skills/synthesis-message-guard@v1.6.0
Exact content
mdr add synthesisengineering/synthesis-skills/synthesis-message-guard@sha256:d7ae8787dccb070f

Pin to a label to follow the author's releases, or to a sha256 to freeze the exact bytes forever. Either way the resolved hash is written to mdr.lock, and mdr install reproduces it on any machine.

Badge

mdr badge

[![mdr](https://markdownregistry.com/badge/art_yqtf2xd2ptfuz6k5.svg)](https://markdownregistry.com/a/art_yqtf2xd2ptfuz6k5)

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Versions

versioncommittedcommitsizeaudit
v1.6.0 latest2026-09-02 61d6d1a 12,649 BA view · diff
v1.5.02026-09-02 423aad4 12,257 BA view · diff
v1.5.02026-09-02 229c2d5 11,587 BA view · diff
v1.3.02026-09-01 5643132 10,352 BA view · diff
v1.2.02026-09-01 ec476bb 9,811 BA view

Audit of the latest version

A  17 of 17 checks passed. Deterministic, no model, same answer every run.
  • pass: Frontmatter block present
  • pass: Frontmatter declares a name
  • pass: Frontmatter declares a description
  • pass: Size between 200 bytes and 200 KB (12649 bytes)
  • pass: No zero-width or bidi control characters
  • pass: No instruction hidden inside an HTML comment
  • pass: No link to an exfiltration or paste host
  • pass: No credential-shaped string
  • pass: No instruction to send local credentials anywhere
  • pass: No text hidden with inline styles
  • pass: No prompt-injection phrasing
  • pass: No curl or wget piped into a shell
  • pass: No recursive delete of root, home or parent
  • pass: No instruction to read or print local credentials
  • pass: No base64 blob over 200 characters
  • pass: No link to a raw IP address
  • pass: No script tag

Source

GitHub

synthesisengineering/synthesis-skills · 19 stars · license Apache-2.0 · pushed 2026-09-18 · branch main

API

GET https://markdownregistry.com/api/v1/artifacts/art_yqtf2xd2ptfuz6k5
GET https://markdownregistry.com/api/v1/resolve?ref=synthesisengineering/synthesis-skills/synthesis-message-guard
GET https://markdownregistry.com/api/v1/blob/d7ae8787dccb070f946874c6eb5e90d8ca311896f801f31adaea6baff6719b47

Agents talk at modelranch.com: hand yours the instructions there and it joins the network that reads files like this one.