mirrord-header-propagation SKILL.md skillA

mirrord-header-propagation from metalbear-co/skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.

Install it, pinned
mdr add metalbear-co/skills/mirrord-header-propagation@v1.2

Pins v1.2 in mdr.lock. Pin the fingerprint instead.

Audit grade
A, 17 of 17 checks passed
Kind
SKILL.md skill
Repository
metalbear-co/skills
Path
skills/mirrord-header-propagation/SKILL.md
Versions recorded
4
Latest version
v1.2, committed Nov 3, 2026
First version recorded
Oct 5, 2026
Size
18,743 bytes
Repository stars
29
License
MIT

Makes a codebase propagate W3C baggage (the `baggage` header carrying `mirrord-session=<key>`) end to end, so mirrord HTTP filters, preview environments, and queue splitting can route a whole request chain to one developer's session. Detects existing OpenTelemetry, Datadog, or other tracing that can already propagate baggage and enables it; otherwise adds a small propagation layer. Covers inbound/outbound HTTP and gRPC, publishing to and consuming from Kafka, RabbitMQ, SQS/SNS, GCP Pub/Sub…

Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.

What the file says

# mirrord Header Propagation Skill

> mirrord routes traffic to a developer's session by matching a header. The convention is W3C `baggage` with a `mirrord-session=<key>` entry: HTTP filters use `"header_filter": "^baggage: .*mirrord-session={{ key }}.*$"`, and queue splitting filters on a message header or attribute named `baggage`. That only works past the first hop if **every service forwards `baggage` on every outgoing call and every message it publishes**, and every consumer restores it from each message it handles. This skill makes a codebase do that, preferring the observability stack it already has.

## Security Boundaries

> **IMPORTANT:** Follow these rules for all operations in this skill.

- **Code changes only, on a branch:** Edit application code, dependency manifests, and app config in the user's repo. Don't commit to `main`, push, or open PRs unless the user asks.
…

Read the whole file at its exact version.

How to install

The exact contents, by fingerprint
mdr add metalbear-co/skills/mirrord-header-propagation@sha256:57b4af3d4ef98726

The line at the top of this page pins the label v1.2, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.

Badge

mdr badge

[![mdr](https://markdownregistry.com/badge/art_dy3p3rqzhncohwcp.svg)](https://markdownregistry.com/a/art_dy3p3rqzhncohwcp)

1 badge image fetches in 30 days. What the badge shows.

Versions

The registry has recorded 4 versions of this file, between Oct 5, 2026 and Nov 3, 2026, about one every 10 days.

versioncommittedcommitsizeaudit
v1.2 latest2026-11-03 89d64a2 18,743 BA view · diff
v1.12026-10-06 63f0547 18,660 BA view · diff
v1.02026-10-05 3726598 18,350 BA view · diff
v1.02026-10-05 84fb00d 17,062 BA view

Audit of the latest version

A  17 of 17 checks passed. Fixed automatic checks with no AI involved, so the same checks give the 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 (18743 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

metalbear-co/skills · 29 stars · license MIT · pushed 2026-11-04 · branch main

API

GET https://markdownregistry.com/api/v1/artifacts/art_dy3p3rqzhncohwcp
GET https://markdownregistry.com/api/v1/resolve?ref=metalbear-co/skills/mirrord-header-propagation
GET https://markdownregistry.com/api/v1/blob/57b4af3d4ef98726b01465b641ef9e939f0841263bce5426ffb355299fa1ec0a

Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.

Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.

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Every file in metalbear-co/skills

Other files named mirrord-header-propagation

mirrord-header-propagation SKILL.md skill
metalbear-co/mirrord · mirrord/mcp/corpus/skills/mirrord-header-propagation/SKILL.md · Makes a codebase propagate W3C baggage (the `baggage` header carrying `mirrord-session=<key>`) end to end, so mirrord…
v1.1 · audit A · 5,401 stars

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