Collections
Shared reading lists with members, invitations, per-paper discussion and exports
A Collection is a reading list you can share. Its members see the same papers, discuss each one in a thread, and export the whole list. What stays private is unchanged: your Library and your reader notes are never part of a Collection. You need to be signed in for all of this.
Create a Collection
Press New collection in the Library sidebar, type a name of up to 100 characters and confirm. The same form is reachable from New collection… in a row’s + menu, and the reader’s folder button has a New collection field that creates the Collection and files the open paper in one step. You can own up to 100 Collections.
File papers
Any member can add papers, and any member can remove them.
- From the reader: the folder button, Save to a collection, lists your Collections with a check mark on each one that already holds the paper.
- From the Library table: the + menu on a row does the same.
- From inside the Collection: Add from saved papers opens a picker over your shelf with a search box and multi-select, ending in Add N papers; papers already filed are greyed out as Already in this collection. The sidebar box with Save to collection saves a new identifier to your shelf and files it at once.
- Through your own agent: a personal key you issue under Agent access lets it save and add papers for you, within the reach you gave it; see Agent access.
A Collection holds up to 2,000 papers, whoever adds them; adding beyond that is refused.
The Collection view
The header shows Collection · N members · N papers, the member avatars (the first five, then a count), Invite for the owner, and the ellipsis button Members & settings. The table has the same columns as the Library, except that Added replaces Saved and the last column is Thread: the number of notes on that paper, with a dot when there are unread ones. Sort gains a Thread option, most notes first. Clicking a row opens its discussion; the address becomes /library/c/<id>?paper=<arxiv id>, which you can send to another member.
Discuss a paper
The discussion opens over the table with the paper’s identifier and Collection name, its title, authors, venue and year, Read paper, Remove from collection, and who added it when. Notes follow, each with the author’s avatar and username and a relative time. The composer, Note for collection members, takes up to 10,000 characters; Post or ⌘↵ sends it. The line beside the button says Visible to all N members, or Only you can see this so far while you are the only one.
A paper or note that came through a personal key carries a via mark beside the username Via marks: Live: you, as the key’s owner, see the key’s label, and other members see the agent’s name. The note is under your name all the same. An agent cannot remove a paper whose thread holds a note; that stays yours to do here. See Agent access.
You can Delete your own notes; the button appears only on those. Notes cannot be edited after posting, and the app offers no way to delete another member’s note, the owner included.
A thread counts as unread for you when another member posted in it after you last opened it: a dot appears in the Thread column and the sidebar styles the Collection’s note count. Opening the thread clears the mark, posting a note counts as having read it, and your own notes never make a thread unread for you.
Members and settings
Members & settings opens a dialog with these sections. What you see depends on whether you own the Collection.
| Section | Owner | Member |
|---|---|---|
| Name | Edit and Save | Read only: only the owner can rename this collection. |
| Members | List with roles, and Remove beside every member but yourself | List with roles |
| Invite | Generate and revoke invitation links | Not shown |
| Export | BibTeX, Markdown with notes, JSON | The same |
| Footer | Delete collection | Leave collection |
Removing a member also revokes any invitation link they accepted, so the old link cannot let them back in. Leave collection takes you out while you keep your saved papers and private reader notes; the notes you posted stay. The owner cannot leave; the only way out for an owner is to delete the Collection.
Invitation links
Press Invite in the header, or open the Invite section of the dialog, and press Generate invitation link. The link appears in a field with a Copy link button. Substrate sends no email and no GitHub message: paste the link into whatever you use to talk to the person. Each link is listed as Unused link · expires on a date, with Revoke, until it is used, revoked or expires. Generate a new link makes another; each person needs their own.
| Property | Detail |
|---|---|
| Uses | One. After someone accepts, the link is spent. |
| Lifetime | Seven days from generation. |
| Secret | The part after # in the link. Browsers do not send it to servers, so it never appears in Substrate's logs. |
| Storage | Only a hash of the secret is stored; the link cannot be recovered later, only revoked. |
The link opens /collections/invite. Signed in, press Accept invitation and you land in the Library with the Collection in your sidebar. Signed out, press Sign in to accept; the secret is held in your browser for the sign-in round trip, so you come back to the same page and can accept. Opening the address without its secret shows Open the complete invitation link to continue. A used, revoked or expired link is refused with Collection or invitation unavailable.
Export a Collection
The three buttons in the Export section walk through every page of the Collection, so the file holds the whole list, and name the file after the Collection.
| Format | Contents |
|---|---|
| BibTeX | One @article entry per paper with title, authors, the venue or an arXiv preprint journal line, year, eprint and URL. |
| Markdown with notes | A heading per paper with authors, identifier, year, venue, link and who added it, followed by the discussion as a bulleted list with usernames and dates. |
| JSON | schemaVersion 1, the name, every paper with its added-by and note counts, and every note. |
Delete a Collection
Only the owner sees Delete collection. Pressing it asks you to type the Collection’s exact name before Delete permanently becomes available. No agent can do it: a personal key reaches neither deletion nor invitations nor membership.
Deleting removes the Collection, its memberships, its pending invitations and all of its shared notes, for everyone. It does not touch anyone’s Library: every member keeps the papers on their own shelf and every private reader note they wrote.