mirrord-header-propagation SKILL.md skillA
mirrord-header-propagation from metalbear-co/mirrord is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add metalbear-co/mirrord/mirrord-header-propagation@v1.1Pins v1.1 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- metalbear-co/mirrord
- Path
mirrord/mcp/corpus/skills/mirrord-header-propagation/SKILL.md- Versions recorded
- 2
- Latest version
- v1.1, committed Oct 11, 2026
- First version recorded
- Oct 7, 2026
- Size
- 18,660 bytes
- Repository stars
- 5,401
- 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
mdr add metalbear-co/mirrord/mirrord-header-propagation@sha256:059f6a3a56a2886eThe line at the top of this page pins the label v1.1, 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.
[](https://markdownregistry.com/a/art_sfuazlklfn3e26mj)
1 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 2 versions of this file, between Oct 7, 2026 and Oct 11, 2026, about one every 4 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| v1.1 latest | 2026-10-11 | 31fe829 | 18,660 B | A | view · diff |
| v1.0 | 2026-10-07 | 651261d | 18,350 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (18660 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
metalbear-co/mirrord · 5,401 stars · license MIT · pushed 2026-11-04 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_sfuazlklfn3e26mj GET https://markdownregistry.com/api/v1/resolve?ref=metalbear-co/mirrord/mirrord-header-propagation GET https://markdownregistry.com/api/v1/blob/059f6a3a56a2886e45fe5bb12c43e49c8f85de208834f14869bebb66abac3967
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.
More from metalbear-co/mirrord
Every file in metalbear-co/mirrord