Build links and channel links

extension.dev gives you two links to share an extension. A build link opens one build. A channel link opens the newest build of a channel. Read this page when you send a build to someone and need to know which link to send, who can open it, and how long it works.

Quick start

Start the MCP server with --features=local,platform, log in, and ask the agent:

Publish my latest build and give me the link to send

The agent calls extension_publish. The answer carries link, the link to send, and tellThem, one sentence to send with it.

How it works

Public and private projects

A project is public or private. Visibility is a setting of the extension.dev project, not of its GitHub repository. A workspace owner or admin changes it under Visibility in project settings. See Public project pages.

Build links

A build link opens the page of one build:

https://<workspace>.extension.dev/<project>/builds/<sha>

It always shows that one build, even after newer builds land. On a public project the link has no token and no end date.

On a private project the link carries a signed ?share= token. The token lasts 7 days by default. You can ask for more, up to your plan's share window: 30 days on Free and 365 days on Pro. After that, the link stops working. Publish again to get a new one.

Channel links

A channel link opens a channel:

https://<workspace>.extension.dev/<project>/channels/<channel>

It always opens the newest build on that channel, and it never expires. Send it when testers should get every update without a new link. A channel link exists on a public project. It also exists on a public channel of a private project.

Channel audience

Every channel has an audience, public or private. On a public project, every channel is public. On a private project, a new channel is private unless you ask for public when you create it.

Only a workspace owner or admin, signed in, can make a channel public. They choose it when they create the channel, or later on the Releases page. A project token, which is what the agent uses, can create a private channel only. Changing the project's visibility sets every channel's audience to match.

A public channel shows its page, the build it serves now, and every build it served before. It never shows a build that no public channel served. Build logs stay private in every case. Nothing recalls a file someone already downloaded.

The live channel

The project's landing page, https://<workspace>.extension.dev/<project>, opens the live channel. Choose it under Opens on in the project's General settings. Automatic chooses the first channel the project has, in this order: production, stable, latest, release, development, preview.

Share links open only what they name

Publishing a build of a private project gives a link that opens that one build and nothing else in the project. A link that opens the whole project is for members of the workspace, not for testers.

Named tester lists are not available yet. Send a build link or a channel link.

What the agent answers

On a private project, extension_publish answers a build link:

{
  "link": {
    "kind": "build",
    "url": "https://acme.extension.dev/notes/builds/a1b2c3d4e5f6?share=…",
    "expiresAt": "2026-10-09T12:00:00.000Z",
    "pointsAt": "this build",
    "audience": "anyone with the link"
  },
  "tellThem": "Here is the build link for version 1.2.0. Anyone who has it can open it until October 9, 2026 at 12:00 UTC, and it always shows this build."
}

On a public project whose build a channel serves, it answers the channel link, with "pointsAt": "latest in stable" and the sentence "Here is the channel link. It always opens the newest stable build."

Store submission is a separate path, and these links do not change it. See Publishing.

Reference

Link	Opens	Token	Ends
Build link, public project	One build	None	Never
Build link, private project	One build	?share=	After 7 days by default, at most the plan's share window
Channel link	The channel's newest build	None	Never

link field	Meaning
kind	build or channel
url	The address to send
expiresAt	When the link stops working, as an ISO date, or null when it never does
pointsAt	this build for a build link, latest in <channel> for a channel link
audience	public, or anyone with the link for a private project's build link

Setting	Who changes it	HTTP call, signed in
Project visibility	Workspace owner or admin	PUT /api/projects/{id}/visibility
Channel audience at creation	Workspace owner or admin for public, any member or project token for private	POST /api/projects/{id}/channels with audience set to public or private. Without it, the channel takes the project's visibility
Channel audience later	Workspace owner or admin	PUT /api/projects/{id}/channels/{channel}/audience with audience set to public or private
Live channel	Workspace owner or admin	PATCH /api/projects/{id}/settings/general with liveChannel set to a channel name, or null for Automatic

Plan	Default build link life	Longest build link life
Free	7 days	30 days
Pro	7 days	365 days

When it fails

• A tester's build link stopped working: the token reached its end date. Publish again for a new link, or send a channel link, which never expires.
• The link shows an older build than you expected: a build link always shows one build. Send the channel link to follow the newest build.
• A private project has no channel link: none of its channels is public. A workspace owner or admin makes one channel public, or makes the project public.
• Changing or creating a channel answers 400 with PROJECT_IS_PUBLIC: on a public project, every channel is public. Make the project private first.
• Creating a public channel answers 403 with TOKEN_CANNOT_OPEN_CHANNEL: a project token cannot open a channel on a private project. Create it private, then a workspace owner or admin makes it public on the Releases page.
• Changing a channel's audience answers 403 with TOKEN_CANNOT_CHANGE_AUDIENCE: a project token cannot change who can download a channel. Sign in to extension.dev as a workspace owner or admin.
• The link ends sooner than you asked: the platform cut the request to your plan's share window. Read expiresAt for the date it set.
• The landing page opens the wrong channel: choose the channel under Opens on in General settings.

Next

• Share an unpublished build for review to send a build before it lands on a channel
• Public project pages for what a public project shows
• Releases for how a build reaches a channel
• Publishing for the store path