thunderbird-extension SKILL.md skillA
thunderbird-extension from codeatcode/oss-ai-skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add codeatcode/oss-ai-skills/thunderbird-extension@v2.0.0Pins v2.0.0 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- codeatcode/oss-ai-skills
- Path
extend/thunderbird-extension/SKILL.md- Versions recorded
- 5
- Latest version
- v2.0.0, committed Oct 28, 2026
- First version recorded
- Mar 9, 2026
- Size
- 9,168 bytes
- Repository stars
- 28
- License
- GPL-3.0
Use when developing Thunderbird MailExtensions - Manifest V2/V3 configuration, messenger.* APIs for accounts, messages, folders and compose, UI actions, message display scripts, Experiment APIs, ATN submission, or migration from legacy extensions.
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
> **Objective:** Use this skill to reduce manifest-schema rejections, messenger-API-typed errors, and ATN-review failures by enforcing manifest-version discipline, API-boundary rules, and permission-scoping patterns below. # Thunderbird MailExtension Development ## Core Rules **Do manifest_version discipline because MV2 deprecation will break extensions at Thunderbird 137+.** Set manifest_version: 3 for new extensions; migrate existing MV2 extensions now. **Do declare messenger.* permissions explicitly because missing permissions fail silently at runtime.** Enumerate every API namespace in permissions before calling it. **Do use Experiment APIs only when messenger.* cannot reach required functionality because reviewers reject unnecessary Experiment access.** Cite the missing built-in API in submission notes. **Do validate message content before processing because untrusted email data causes XSS in display scripts.** Sanitize HTML, escape user input, verify MIME types. **Do use vCard format for contacts in MV3 because legacy contacts API is removed.** Call messenger.addressBooks.contacts.create with vCard string, not name/email fields. …
Read the whole file at its exact version.
How to install
mdr add codeatcode/oss-ai-skills/thunderbird-extension@sha256:371bd9b54c6032beThe line at the top of this page pins the label v2.0.0, 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_eahu343dzrz4xiyp)
5 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 5 versions of this file, between Mar 9, 2026 and Oct 28, 2026, about one every 58 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| v2.0.0 latest | 2026-10-28 | 83beb90 | 9,168 B | A | view · diff |
| v2.0.0 | 2026-10-01 | 268819e | 11,938 B | A | view · diff |
| v2.0.0 | 2026-09-23 | f8bf298 | 11,937 B | A | view · diff |
| v1.0.0 | 2026-04-20 | e5744c4 | 27,479 B | A | view · diff |
| v1.0.0 | 2026-03-09 | 46f73cd | 27,487 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 (9168 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
codeatcode/oss-ai-skills · 28 stars · license GPL-3.0 · pushed 2026-10-28 · branch master
API
GET https://markdownregistry.com/api/v1/artifacts/art_eahu343dzrz4xiyp GET https://markdownregistry.com/api/v1/resolve?ref=codeatcode/oss-ai-skills/thunderbird-extension GET https://markdownregistry.com/api/v1/blob/371bd9b54c6032bebbe693384ab2111585c4dd2bb6b3b8d533888d6cf083c8af
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.