myaddr.tools

Send a DELETE request to https://myaddr.tools/reg with your key parameter. The registration is removed immediately and permanently, and your name is released back into the pool of available names. There is no undo — if you want the name again later, you have to claim it from scratch and you will receive a new secret key.

What You Need Before Deleting

• Your secret key. This is the key you received when you first claimed your name. It is the only credential that authorizes changes to your registration, and it cannot be recovered if lost.
• A decision about whether you actually want to delete. If you only want to stop using the name temporarily, deleting is the wrong move — see the alternative below.

The Deletion Request

The /reg endpoint accepts a DELETE request with your key:

curl -X DELETE "https://myaddr.tools/reg?key=YOUR_SECRET_KEY"

The key can be passed as a URL query parameter. The same key that manages your DNS records through the /update endpoint authorizes deletion here.

What Happens After You Delete

Because the name is released instantly, someone else could claim it right after you delete. If you have anything pointing at that hostname — a server, a certificate renewal hook, a monitoring check — those references will break.

Before You Delete: Check the Alternative

If your goal is simply to stop the name from expiring on its own, you do not need to delete it. myaddr.tools keeps a registration alive as long as you update each IP address at least once every 90 days, and deletes the registration automatically after 120 days with no updates at all. So if you want to keep the name but stop actively using it, you can let it lapse naturally rather than deleting — though note that letting it lapse has the same end result (the name is released), just on the service's schedule instead of yours.

Deleting manually is the right choice when you want the name gone now and you are certain you will not want it back.

Common Pitfalls

• Losing the key first. If you no longer have your secret key, you cannot delete the registration through the API. The key is the only proof of ownership.
• Expecting a confirmation step. The deletion is immediate. There is no grace period or confirmation prompt to catch a mistake.
• Assuming the name stays reserved. Once released, the name is fair game for anyone. If you plan to re-claim it, do so promptly.

Claiming a name on myaddr.tools takes seconds and requires no account: visit the site, pick an available name, and you receive a secret key. That key is the only credential for the name — whoever holds it controls the DNS records, and if you lose it you lose the name. Once you have the key, you manage records through the HTTP-based Update API.

Claiming your name

Go to myaddr.tools and claim the name you want. If it is available, the service returns a secret key. There is no signup, email confirmation, or password to manage.

Two things follow from that design:

• Store the key somewhere safe immediately. There is no recovery path described — losing the key means losing control of the name.
• Treat the key as a password. Anyone who has it can change or delete your records.

Your name resolves across several domains at once, all pointing to the same records:

All subdomains of the above also resolve, so you can use hosts like ipv4.your-name.myaddr.tools or ipv6.your-name.myaddr.tools.

Updating DNS records with the Update API

The endpoint is https://myaddr.tools/update. It is deliberately forgiving:

• GET, POST, and PUT are treated as equivalent update requests.
• Parameters are read from the URL query string and from POST/PUT bodies.
• Bodies may be application/x-www-form-urlencoded or application/json.
• Success returns body OK with status code 200; failures return a helpful error message with a 4xx status.

Add or update an IP address

Send a GET, POST, or PUT request to /update with key and ip parameters. Set ip to any valid IPv4 or IPv6 address, or use ip=self to record the requester's own IP address.

https://myaddr.tools/update?key=YOUR_KEY&ip=self

To force a specific address family, use the hosts ipv4.myaddr.tools or ipv6.myaddr.tools. Adding an IPv4 address replaces any existing IPv4 address, and the same applies to IPv6 — so each family holds one address at a time.

Add an ACME dns-01 challenge

For TLS certificates from CAs like Let's Encrypt, send a request with key and acme_challenge:

https://myaddr.tools/update?key=YOUR_KEY&acme_challenge=YOUR_CHALLENGE_VALUE

The value is served as a TXT record on all _acme-challenge subdomains. Challenge TXT records are removed automatically after a few minutes, so you do not need to clean them up.

Delete an IP address

A DELETE request to /update with key removes both the IPv4 and IPv6 addresses. This always responds with status code 204.

curl -X DELETE "https://myaddr.tools/update?key=YOUR_KEY"

Keeping your name active

Two independent timers apply:

• 90 days per IP address. Each IP (IPv4 and IPv6 tracked separately) must be updated at least once every 90 days to stay active.
• 120 days per name. If no updates are made to your name at all for 120 days, the registration is deleted and the name is released.

If your address rarely changes, schedule a periodic update anyway — a cron job or timer that calls /update with ip=self is enough to reset both clocks.

Deleting your registration

To immediately and permanently delete your registration and release the name, send a DELETE request to https://myaddr.tools/reg with your key:

curl -X DELETE "https://myaddr.tools/reg?key=YOUR_KEY"

This is irreversible — the name becomes available to anyone else.

Common snags

• Lost key: no recovery is described, so the name is effectively gone. Save the key before doing anything else.
• Only one address per family: a new IPv4 update overwrites the previous IPv4 record rather than adding a second one.
• ACME records are temporary: they disappear after a few minutes, which is fine for validation but not for long-lived TXT records.
• Silent expiry: missing the 90- or 120-day windows deletes records or the whole registration, so automate updates if you are not checking in regularly.

myaddr.tools is a minimalist dynamic DNS (DDNS) service that maps a changing IP address to a fixed subdomain name. You claim a name, receive a secret key, and then use an HTTP-based API to point that name at whatever IPv4 or IPv6 address you currently have. It is aimed at people who need a stable hostname for a machine on a dynamic connection — a home server, a router, a small VPS — without creating an account or dealing with a traditional DNS control panel.

What problem it solves

Most ISPs hand out IP addresses that change. If you want to reach a device at home from elsewhere, you need a name that always resolves to the current address. myaddr.tools provides that name and lets you update the address programmatically, so a scheduled script or a router's DDNS client can keep it current.

The service is deliberately small in scope. According to its own description, it is "no ads, no tracking, no nonsense," and you can get a subdomain in seconds with no account required.

Key features

• No account required. You claim a name and get a secret key. The key is the only credential — whoever holds it controls the name.
• HTTP-based update API. Updates work over plain HTTP requests, which makes them easy to call from scripts, cron jobs, or router firmware.
• IPv4 and IPv6 support. You can set either address type, and they are tracked independently.
• ACME dns-01 support. You can serve the TXT record needed for a dns-01 challenge, which lets you obtain TLS certificates from CAs like Let's Encrypt for a name that has no public web server.
• Multiple suffixes. A single claimed name resolves across your-name.myaddr.tools, your-name.myaddr.dev (on the HSTS preload list), your-name.myaddr.io, and all subdomains of those.
• Public Suffix List. The suffixes are added to the Public Suffix List, which matters for cookie isolation and for services that treat each subdomain as a separate registrable domain.

How the update API works

The update endpoint is at https://myaddr.tools/update. It is intentionally forgiving:

• GET, POST, and PUT are treated as equivalent update requests.
• Parameters can come from the URL query string or from POST/PUT bodies.
• Bodies can be application/x-www-form-urlencoded or application/json.
• Success returns body OK with status code 200; errors return a helpful message with a 4xx status.

Add or update an IP address

Send a request to /update with key and ip parameters. Set ip to any valid IPv4 or IPv6 address, or use ip=self to use the requester's own IP address. To force a specific protocol, use the hosts ipv4.myaddr.tools or ipv6.myaddr.tools.

Adding an IPv4 address replaces any existing IPv4 address, and the same applies to IPv6 — so each address family holds one value at a time.

Add an ACME challenge

Send a request to /update with key and acme_challenge parameters. The challenge value is served as a TXT record on all _acme-challenge subdomains. These TXT records are automatically removed after a few minutes, which matches the short lifetime of an ACME challenge.

Delete an IP address

A DELETE request to /update with key removes both the IPv4 and IPv6 addresses. This always responds with status code 204.

Registration management

The registration endpoint is at https://myaddr.tools/reg. To immediately and permanently delete your registration and release your name, send a DELETE request to /reg with your key.

Things to know before you rely on it

Two expiry rules matter if you plan to depend on the service:

The practical consequence: an unattended device that stops reporting will eventually lose its name. If you are setting this up for a remote machine, make sure whatever updates the record runs on a schedule well inside these windows.

When it fits and when it doesn't

myaddr.tools is a good fit if you want a free-of-frills hostname for a dynamic IP, you are comfortable calling an HTTP API or configuring a DDNS client, and you want to avoid account signup. It is a poor fit if you need a full DNS management interface, many records per name, or a guarantee of long-term persistence without ongoing updates — the 90/120-day rules mean the service expects you to keep it informed.

Because the secret key is the sole credential, treat it like a password: anyone who has it can repoint your name. Store it wherever your update script runs, and use the /reg delete endpoint if you ever want to release the name permanently.

myaddr.tools keeps a name alive as long as you keep updating it. Each IP address (IPv4 and IPv6 tracked separately) must be updated at least once every 90 days to stay active, and if no updates are made to your name for 120 days, the registration is deleted and the name is released. The secret key is the only credential — lose it and you lose control of the name.

The two clocks you need to watch

There are two separate timers, and they measure different things.

The per-IP rule is stricter and more granular. If you update your IPv4 address but never touch IPv6, the IPv6 record can go inactive on its own 90-day clock while the name itself stays alive. The 120-day rule is the backstop: any update at all resets it, but if nothing happens for four months, the whole registration disappears.

How to keep a record active

Send an update to the /update endpoint before the 90-day window closes for each address family you use.

https://myaddr.tools/update?key=YOUR_SECRET_KEY&ip=self

Key points from the API:

• GET, POST, and PUT are treated as equivalent update requests.
• Parameters can come from the URL query string or from POST/PUT bodies (application/x-www-form-urlencoded or application/json).
• Set ip to any valid IPv4 or IPv6 address, or use ip=self to record the requester's own IP.
• To force a specific family, use the host ipv4.myaddr.tools or ipv6.myaddr.tools.
• Adding an IPv4 address replaces any existing IPv4 address; the same applies to IPv6.
• Success returns body OK with status 200; failures return a helpful message with a 4xx status.

If you only ever use one address family, you only need to maintain that one. But if you have both an A and an AAAA record, both need their own update within 90 days.

What happens when a record or name expires

• IP record inactive (missed 90 days): that specific address stops resolving. The name and your other records are unaffected.
• Name inactive (missed 120 days): the registration is deleted and the name is released, meaning someone else can claim it.

Because the name is released on the 120-day mark, a long outage can cost you the subdomain permanently. If you expect to be away, a single update before you leave resets the clock.

The secret key is the whole account

There is no account and no recovery flow. When you claim a name, you receive a secret key, and that key gives whoever holds it control over the name. If you lose the secret key, you lose the name. Store it somewhere durable before you rely on the registration.

Deleting things on purpose

• Delete IP addresses: send a DELETE request to /update with key. This removes both IPv4 and IPv6 addresses and always responds with status 204.
• Delete the registration: send a DELETE request to /reg with key. This immediately and permanently deletes the registration and releases the name.

ACME challenge records are temporary

If you use the acme_challenge parameter to serve a TXT record for a dns-01 challenge, that record is served on all _acme-challenge subdomains and is automatically removed after a few minutes. You do not need to clean it up, and it does not count as a long-term record you have to maintain.

Practical checklist

• Update each address family you use at least every 90 days.
• Make at least one update every 120 days to keep the name itself.
• Back up the secret key somewhere you will not lose it.
• If you stop using a name, delete the registration so the name is freed rather than left to expire.

The myaddr.tools Update API is a single HTTP endpoint at https://myaddr.tools/update that manages the DNS records for the name you claimed. You authenticate with the secret key you received at registration, then add or update an IP address, add an ACME dns-01 challenge TXT record, or delete your addresses. The endpoint is deliberately forgiving: it treats GET, POST, and PUT as equivalent update requests, reads parameters from the URL query string or from POST/PUT bodies, and accepts bodies as either application/x-www-form-urlencoded or application/json. On success it responds with the body OK and status code 200; otherwise it returns a helpful error message with a 4xx status.

This is for anyone who has already claimed a name and holds its secret key. If you don't have a key yet, claim a name first — the key is what gives you control over the name, and losing it means losing the name.

Adding or updating an IP address

Send a GET, POST, or PUT request to /update with two parameters:

For example, a GET request using your own connection's IP:

https://myaddr.tools/update?key=YOUR_KEY&ip=self

Expected result: the response body is OK with status 200, and the record now points at that address.

Two behaviors matter here:

• IPv4 and IPv6 are tracked separately. Adding an IPv4 address replaces any existing IPv4 address, and the same applies to IPv6. One update does not overwrite the other family.
• You can force the address family by using the host ipv4.myaddr.tools or ipv6.myaddr.tools instead of myaddr.tools. This is useful when ip=self might otherwise resolve to the wrong family — for instance, on a dual-stack host where you want to publish only the IPv6 address.

Adding an ACME dns-01 challenge

To satisfy a dns-01 challenge for a TLS certificate (for example from Let's Encrypt), send a GET, POST, or PUT request to /update with:

The acme_challenge value is served as a TXT record on all _acme-challenge subdomains. Challenge TXT records are removed automatically after a few minutes, so you don't need to clean them up yourself — but you do need to complete the challenge before they disappear.

Deleting an IP address

Send a DELETE request to /update with your key. This removes both the IPv4 and IPv6 addresses. The endpoint always responds with status code 204.

DELETE https://myaddr.tools/update?key=YOUR_KEY

Note the asymmetry: an update request replaces one address family at a time, while a delete clears both at once.

Keeping the name alive

The API is also how you keep your registration from expiring:

• Each IP address (IPv4 and IPv6) must be updated at least once every 90 days to remain active, and the two families are tracked independently.
• If no updates are made to your name for 120 days, the registration is deleted and the name is released.

So a periodic update call — even one that re-sends the same address — doubles as your keep-alive. If you want to remove the registration entirely and release the name immediately, send a DELETE request to https://myaddr.tools/reg with your key.

Common sticking points

• Using the wrong key. The key is the only credential; there is no account recovery. A 4xx with an error message usually means the key is wrong or missing.
• Forgetting the family split. If you only ever update IPv4, your IPv6 record (if any) still needs its own update within the 90-day window.
• Assuming the challenge record persists. ACME TXT records vanish after a few minutes, so run the challenge promptly after adding it.
• Mixing up /update and /reg. /update manages DNS records; /reg manages the registration itself.