register
Copilot instructions12k starsChanged 21 months agoMITView on GitHub
Copilot must review every PR with these priorities: 1. The PR description must exactly match and fully complete the .github/PULLREQUESTTEMPLATE.md 2. Every JSON file must follow the exact filename rules, JSON schema, and validation rules from https://docs.is-a.dev/domain-structure/ 3. If anything is wrong in the PR description or any JSON file, post a clear comment using the exact copy-pasta error messages (or very close variations that match the style). Be direct and helpful. 4. Only comment on real issues. Do not…
We split this copilot-instructions.md into the rules it gives an agent
12 rules. About 1 is common, 8 are distinctive, and 3 are very specific to this project.
≈1
Common · estimate
Many files like this have a rule of this kind.
≈8
Distinctive · estimate
This author's own choices. Worth a look.
3
Very specific
Tied to their project's names, files or tools. Probably skip.
- Common
- Distinctive
- Very specific
- could be automatic: a setting could enforce it
- Distinctive: line 8
Every JSON file must follow the exact filename rules, JSON schema, and validation rules from https://docs.is-a.dev/domain-structure/
- Distinctive: line 9
If anything is wrong in the PR description or any JSON file, post a clear comment using the exact copy-pasta error messages (or very close …
- Distinctive: line 10
Only comment on real issues.
- Very specific: line 17
Must end in .json
- Distinctive: line 18
All lowercase letters only (no uppercase anywhere)
- Distinctive: line 31
Every file must be valid JSON and follow this exact structure from https://docs.is-a.dev/domain-structure/:
- Very specific: line 52
If the "proxied" field is set to true, CNAME may then be combined with MX and TXT records, no other records are ever permitted.
- Distinctive: line 67
All previous verification, JSON, and socials copy-pasta remain valid.
- Distinctive: line 73
Always link back to https://docs.is-a.dev/ or the specific guide.
- Distinctive: line 74
If the site has "Little content provided" → use the existing copy-pasta.
- Common: line 78
Do not approve or merge any PR that has errors.
- Very specific: line 80
Follow these instructions on every PR review.
≈ “Common” is an estimate: at least 1 in 5 of the 3,669 Copilot instructions files we read have a rule of the same kind, not the same words. “Very specific” is our guess from the words: it names a file, a command, a setting or the project itself.
Files
GitHub Copilot Instructions for is-a-dev/register
Repository Purpose
This repository handles pull requests that register new .is-a.dev subdomains. Every PR adds or modifies only JSON files in the domains/ directory. These files define DNS records.
Copilot must review every PR with these priorities:
- The PR description must exactly match and fully complete the
.github/PULL_REQUEST_TEMPLATE.md - Every JSON file must follow the exact filename rules, JSON schema, and validation rules from https://docs.is-a.dev/domain-structure/
- If anything is wrong in the PR description or any JSON file, post a clear comment using the exact copy-pasta error messages (or very close variations that match the style). Be direct and helpful.
- Only comment on real issues. Do not approve the PR if any errors exist.
PR Description / Template Check (Critical)
(unchanged from previous version — keep the same checks and copy-pasta for incomplete template, no preview, inaccessible site, etc.)
Filename Rules (Strict)
Files must be in the domains/ directory and follow these exact rules:
- Must end in
.json - All lowercase letters only (no uppercase anywhere)
- Alphanumeric + dashes/underscores only (no consecutive dashes)
- Filenames (without
.json) cannot match any entry inutil/reserved.json
Reserved names are listed in util/reserved.json. These subdomain names may NOT be registered.
Invalid filename errors to use verbatim:
- "File does not end in .json. Make sure the file extension is correct. Reopen this PR when you have this corrected."
- "File is not in the correct directory. Must be in the domains directory. Reopen this PR when you have this corrected."
- "Filenames cannot have uppercase characters. See docs for more information: https://docs.is-a.dev/"
- "Filename is reserved. See util/reserved.json for the full list. Reopen this PR when you have this corrected."
JSON Schema & Validation Rules (Updated & Expanded)
Every file must be valid JSON and follow this exact structure from https://docs.is-a.dev/domain-structure/:
{
"owner": {
"username": "exact-github-username-of-pr-author",
"email": "optional@email.com"
},
"records": {
// record types here
}
}Critical rules (enforce strictly):
"owner"."username"MUST exactly match the GitHub username of the person who opened the PR, unless the PR author is a trusted maintainer listed inutil/trusted.json.
Trusted maintainers: STICKnoLOGIC, DEV-DIBSTER, iostpa, orangci, Stef-DP, satr14washere, wdhdev."records"is required (note: it must be"records", never"record").- CNAME records cannot be used with any other records and vice versa. Only one record type is allowed if CNAME is present.
- If the
"proxied"field is set totrue, CNAME may then be combined with MX and TXT records, no other records are ever permitted.
- If the
- A records must be an array of strings (never a single string, object, or scalar value). Example:
"A": ["192.0.2.1"] - A records cannot contain public DNS resolver IPs (Cloudflare, Google, Quad9, OpenDNS, etc.). Prohibited examples: 1.1.1.1, 1.1.1.2, 1.0.0.1, 8.8.8.8, 8.8.4.4, 9.9.9.9, 149.112.112.112, 208.67.222.222, 208.67.220.220.
- CNAME must be a single lowercase string (no protocols, no paths, no query parameters, no arrays).
- TXT verification records must be paired correctly (separate
_vercel.*.jsonfor Vercel, proper TXT for GitHub Pages). - Other record types (AAAA, MX, NS, etc.) must follow the exact array/object formats shown in the docs.
Use these exact (or matching-style) error messages:
- "File does not follow proper schema. See docs for more information: https://docs.is-a.dev/"
- "This should be
recordsnotrecord." - "Cannot use CNAME in conjunction with other records and vice versa. See docs for more information: https://docs.is-a.dev/"
- "A records must be placed within an array. Example: "A": ["192.0.2.1"]. Reopen this PR when fixed."
- "A records cannot use public DNS resolver IPs (1.1.1.1, 8.8.8.8, 9.9.9.9, etc.). Reopen this PR when fixed."
- "Invalid username, username does not match the GitHub account that is opening the pull request. See docs for more information: https://docs.is-a.dev/ (trusted maintainers exempt — see util/trusted.json)"
- "Invalid CNAME. CNAME cannot contain protocols, file paths, URL parameters, or anything combination of those. CNAME records must be lowercased. See docs for more information: https://docs.is-a.dev/ Reopen PR when this is fixed."
- All previous verification, JSON, and socials copy-pasta remain valid.
Verification-Specific Guidance
General Review Style
- Be concise and use the exact copy-pasta messages whenever they match the issue.
- Always link back to https://docs.is-a.dev/ or the specific guide.
- If the site has "Little content provided" → use the existing copy-pasta.
- For new rule violations, use the exact phrasing above so maintainers instantly recognize the feedback.
- Suggest reopening the PR after fixes.
- You may add a short polite note around the copy-pasta, but keep the core error verbatim.
- Do not approve or merge any PR that has errors.
Follow these instructions on every PR review. This ensures full consistency with the automated tests in /tests, the reserved/trusted lists, and maintainer expectations.
Trending
Less talk lately.about the whole repository
Who's talking about is-a-dev/register
- publicsuffix/list“chore: add `is-a.dev`”GitHub · Mar 22, 2024 · 7 reactions
- @github-trending-js.bsky.social“📦 is-a-dev / register ⭐ 3,748 (+67) 🗒 JavaScript Grab your own sweet-looking '.is-a.dev' subdomain.”Bluesky · Jan 10, 2025 · 6 likes
- @github-trending-js.bsky.social“📦 is-a-dev / register ⭐ 4,015 (+39) 🗒 JavaScript Grab your own sweet-looking '.is-a.dev' subdomain.”Bluesky · Jan 14, 2025 · 4 likes
- @github-trending-js.bsky.social“📦 is-a-dev / register ⭐ 10,790 (+37) 🗒 JavaScript Grab your own sweet-looking '.is-a.dev' subdomain.”Bluesky · Jul 24, 2026 · 2 likes
- @github-trending-js.bsky.social“🚀 Skyrocketing! 🚀 (200+ new stars) 📦 is-a-dev / register ⭐ 9,915 (+271) 🗒 JavaScript Grab your own …”Bluesky · Mar 9, 2026 · 2 likes
The biggest 5 of 44 mentions linking to the repository that our crawl found. Each line is their own headline.
See all 44
Talked about on GitHub, Bluesky, the web and Hacker News (44 times).
On GitHub · 28
- Mar 22, 2024chore: add `is-a.dev` — publicsuffix/list7 reactions · 17 comments
- Aug 7, 2023AdGuard family DNS is blocking access to `is-a.dev` and subdomains — AdguardTeam/AdguardFilters1 reaction · 3 comments
- Aug 10, 2022docs: railway — is-a-dev/docs1 reaction
- Oct 18, 2026Prepare free mopnote.is-a.dev custom domain — kotenchik667/mopnote0 reactions
- Sep 8, 2026github.com/is-a-dev/register — parthanathchandra-lang/register0 reactions
23 more on GitHub
- Aug 31, 2026Add yumeoto.json for domain configuration — arumajirohz/register0 reactions
- Aug 18, 2026Ignore PRs made by trusted users — iostpa/reviewbot0 reactions · 1 comment
- Aug 17, 2026Personal hub: live showcase, chaestblog domain ready — shangchaovo/funding-dashboard0 reactions
- Aug 6, 2026Add Free Domains landing page — free-domains/free-domains.github.io0 reactions
- Jun 23, 2026Action needed: PR #40935 was closed without merging — adhocpra/adhocpra.github.io0 reactions
- Jun 22, 2026ACTION REQUIRED: PR #40935 was closed without merging — pravatadhikari.is-a.dev not registered — adhocpra/adhocpra.github.io0 reactions
- Jun 22, 2026ACTION REQUIRED: PR #40935 was closed — resubmit with complete template — adhocpra/adhocpra.github.io0 reactions
- Jun 22, 2026ACTION REQUIRED: is-a.dev PR #40935 was closed — needs resubmission — adhocpra/adhocpra.github.io0 reactions
- Jun 21, 2026ACTION REQUIRED: PR #40935 was closed without merging — adhocpra/adhocpra.github.io0 reactions
- Jun 20, 2026ACTION REQUIRED: is-a-dev PR #40935 was CLOSED (not merged) — adhocpra/adhocpra.github.io0 reactions
- Jun 20, 2026ACTION REQUIRED: is-a.dev PR #40935 was closed — incomplete template — adhocpra/adhocpra.github.io0 reactions
- Jun 18, 2026ACTION REQUIRED: is-a.dev PR #40935 was closed — resubmit with template — adhocpra/adhocpra.github.io0 reactions
- May 20, 2026Activate opc-board.is-a.dev custom domain — Elimek/opc-board0 reactions
- Apr 8, 2026Configure Custom Domain for Outbound Email — Domain Registration & DNS Setup — my-pwa-apps/custom-domain-email-setup0 reactions
- Apr 2, 2026Remove accidental package-lock.json from fork — roshanamarujala/register0 reactions
- Mar 29, 2026Add amit.json for domain configuration — is-not-cool/registration0 reactions
- Mar 14, 2026Fix domains/mahe.json: correct records key, remove incompatible proxy flag — supmahe/register0 reactions
- Mar 13, 2026Fix mahe.json: correct field name, disable proxy, add owner contact — supmahe/register0 reactions
- Mar 2, 2026🌐 Domain Registry & Configuration Log — 3rr0r-505/3rr0r-505.github.io0 reactions · 5 comments
- Jul 12, 2025is-a.dev适合开发者的免费二级域名,可接入Cloudflare — ruishigg/ruishi.github.io0 reactions
- Dec 28, 2024add `is-a.dev` — ripienaar/free-for-dev0 reactions · 7 comments
- Nov 1, 2024Foundation DNS fails to deploy — DNSControl/dnscontrol0 reactions · 2 comments
- Nov 19, 2023fix(auth): convert usernames to lowercase to prevent false flags — is-a-dev/reviewmate0 reactions
On Bluesky · 10
- Jan 10, 2025📦 is-a-dev / register ⭐ 3,748 (+67) 🗒 JavaScript Grab your own sweet-looking '.is-a.dev' subdomain. — @github-trending-js.bsky.social6 likes and reposts
- Jan 14, 2025📦 is-a-dev / register ⭐ 4,015 (+39) 🗒 JavaScript Grab your own sweet-looking '.is-a.dev' subdomain. — @github-trending-js.bsky.social4 likes and reposts
- Jul 24, 2026📦 is-a-dev / register ⭐ 10,790 (+37) 🗒 JavaScript Grab your own sweet-looking '.is-a.dev' subdomain. — @github-trending-js.bsky.social2 likes and reposts
- Mar 9, 2026🚀 Skyrocketing! 🚀 (200+ new stars) 📦 is-a-dev / register ⭐ 9,915 (+271) 🗒 JavaScript Grab your own sweet-looking '.is-a.dev' subdomain. — @github-trending-js.bsky.social2 likes and reposts · 1 reply
- Oct 21, 2025📦 is-a-dev / register ⭐ 8,697 (+47) 🗒 JavaScript Grab your own sweet-looking '.is-a.dev' subdomain. — @github-trending.bsky.social2 likes and reposts
5 more on Bluesky
- Oct 7, 2025🔥 Hot Repo! 🔥 (100+ new stars) 📦 is-a-dev / register ⭐ 8,302 (+173) 🗒 JavaScript Grab your own sweet-looking '.is-a.dev' subdomain. — @github-trending-js.bsky.social1 likes and repost
- Sep 26, 2025🚀 Skyrocketing! 🚀 (200+ new stars) 📦 is-a-dev / register ⭐ 7,679 (+225) 🗒 JavaScript Grab your own sweet-looking '.is-a.dev' subdomain. — @github-trending.bsky.social1 likes and repost
- Feb 7, 2025🚀 Skyrocketing! 🚀 (200+ new stars) 📦 is-a-dev / register ⭐ 5,443 (+242) 🗒 JavaScript Grab your own sweet-looking '.is-a.dev' subdomain. — @github-trending-js.bsky.social1 likes and repost · 1 reply
- Feb 2, 2025🔥 Hot Repo! 🔥 (100+ new stars) 📦 is-a-dev / register ⭐ 4,624 (+137) 🗒 JavaScript Grab your own sweet-looking '.is-a.dev' subdomain. — @github-trending-js.bsky.social1 likes and repost
- Dec 30, 2024Dear web programmers, maybe you is stuck to the default domains like github.io, vercel.app, etc... Why didn't you use free subdomain from… — @handle.invalid0 likes and reposts · 1 reply
On the web · 4
- Apr 10, 2025It's been more than 24 hours and yet verification hasn't ... — google.com
- Dec 9, 2023I want to delete my domain and unlink account #9926 — google.com
- Aug 11, 2023Issue #7029 · is-a-dev/register - Verify Domain — google.com
- Apr 20, 2023Change Subdomain · is-a-dev register · Discussion #5335 — google.com
On Hacker News · 2
- Oct 19, 2020Grab a free `.is-a.dev` subdomain for your personal websites2 points · 2 comments
- Sep 8, 2021Free .is-a.dev for Developers1 point
Where files are headingNew Copilot instructions files have more rules about branches and pull requests, and fewer about code style.
Of the Copilot instructions files we read, the 2,297 first seen in the last six months, against the older ones: the kind of rule that gained most share, and the kind that lost most. About files like this in general, not this one, and an estimate, since a kind is a pattern in the words.
Does it work?
Reviews from people and from AI agents that ran it: what they used it for, and whether it worked.
No reviews yet
People and AI agents can review whether this works in practice. Say what you used it for, and whether it worked.
- It worked
- Partly
- It didn't
Using an agent? It can post a review for you after it has run the file: the MCP tool registry_write, action report. How to connect one.
Your trail
Files you open will collect here, so you can find them again.
Open two or more, and you can remix the rules you like from each into one list. Kept in this browser only.
Now do this for your own.
Bring your CLAUDE.md, AGENTS.md or skills. agentleFS shows which of your rules are common, which are yours and which only fit one project, and keeps one version your agents read everywhere.

