OPDS is what lets an e-reader browse a catalog of books and download one over WiFi, without a computer, a cable, or an account — type one URL into the reader's settings and the book list appears on the screen. LingoBlend publishes its free blended library this way, so a CrossPoint reader (or any other reader that supports OPDS) can pull a book straight from our servers. OPDS is one of three ways to get a blended book onto a reader — Blended Books on Your E-Reader lays out all three, plus what the companion dictionary and clipping add once the book is there.
What OPDS actually is, in plain words#
OPDS stands for Open Publication Distribution System. Strip the acronym away and it is a simple idea: a catalog is a web page written in a format readers understand, listing books with their titles and download links, and a reader with OPDS support can browse that page the way a podcast app subscribes to a feed. No app store, no login screen, no proprietary sync client in the middle — a reader just asks a URL "what books do you have?" and gets back an answer it knows how to render as a list.
That is the whole trick. Because it is an open format rather than a company's private system, the same catalog works for whichever device points at it. A reader that supports OPDS does not need to know anything about LingoBlend specifically — it already knows how to read a catalog, and ours happens to be one. It's also a much shorter path than the one described in how to read Kindle books in a foreign language: there's no store region to switch and no purchase to make, because the catalog is free and open rather than DRM-locked.
Add the LingoBlend catalog on CrossPoint#
On a CrossPoint reader, adding our catalog is one settings screen and one URL:
- Go to Settings → System → OPDS Servers → Add Server.
- Enter the address exactly:
https://www.lingoblend.app/opds/root.xml. - Save it, and the catalog appears in your list of OPDS servers. Open it to browse the library and download a book directly to the device.
That's the entire setup — no sign-in, no app to install first, and nothing else to configure before you can see the catalog.
The one typo that breaks it#
Type the address with https:// at the front. Leave it off and the reader assumes http://, and the catalog never loads. This is the usual cause when someone adds the server and sees nothing: the field looks filled in, but it never reaches the catalog. If the server shows up on your list but browsing it fails or times out, re-check the address before anything else.
Which edition to pick#
The catalog offers the same book in three editions (covered in more depth in Underlined, Glosses Above, or Linked). They differ in how a blended word is shown on the page, and only one of them is built around the companion dictionary. In short: underlined is the one the dictionary exists for, while glosses above and linked carry the meaning inside the file and need no dictionary at all.
If you want retrieval practice — meeting a word, guessing at it, then confirming — download the underlined edition and set up the dictionary alongside it, as covered in Reading a Blended Book on CrossPoint, Step by Step. If you'd rather see the answer immediately with nothing else to configure, glosses above needs no dictionary at all and is drawn by most modern EPUB renderers (support varies by reader and firmware — open it and look), which also makes it a practical choice if you're reading somewhere other than CrossPoint — see Blended EPUBs on Kobo, Kindle and Other Readers for what that looks like.
What OPDS can't carry: the dictionary#
Here's the honest limitation of this whole path. OPDS is a catalog protocol for books — it lists entries and serves file downloads, and a dictionary file isn't a book entry, so it never appears in an OPDS feed. Download the underlined edition over OPDS and you'll have a perfectly good EPUB with no way yet to look a word up, because the companion dictionary that explains what each blended word replaced has to arrive by a different route.
There are two fixes, and neither is complicated:
| Path | What you get | Needs |
|---|---|---|
| OPDS catalog | The book, downloaded over WiFi | Settings → System → OPDS Servers; any OPDS-capable firmware |
| USB transfer | Book and dictionary together, in one trip | A computer; CrossPoint 1.6.0 or newer |
| LingoBlend Dictionaries plugin | The dictionary, downloaded over WiFi, no computer | CrossPoint 1.7 or a Nightly build |
If you're on current stable firmware (1.6.5 as of this writing), the straightforward move is USB: connect the reader, choose Home → File Transfer → USB Drive, and unzip the dictionary into dictionaries, so you end up with /dictionaries/lingoblend-…/ holding three files. If you're running a Nightly build, the LingoBlend Dictionaries plugin fetches the same file over WiFi instead. Either route ends the same way — select the dictionary once per book under Settings → Reader → Dictionary; the step-by-step guide spells both out.
Other OPDS clients can use this catalog too#
Because OPDS is an open format rather than something built just for CrossPoint, any OPDS-capable e-reader or app can add the same URL and browse the same catalog. The book itself is an ordinary EPUB, so it opens and reads correctly wherever OPDS gets it. What changes elsewhere is what happens after you open it: looking up what a blended word replaced is a CrossPoint feature built on its on-device dictionary lookup, and clipping a word to sync back into the app is the same story — neither travels with a plain EPUB file. On a different OPDS client, you get the book; tap-to-look-up and the Clip / Sync clippings loop are CrossPoint features. KOReader is the likely exception for the dictionary, though we have not tested it — Blended EPUBs on Kobo, Kindle and Other Readers covers that.
The takeaway#
OPDS turns "download a book onto an e-reader" into typing one URL. On CrossPoint, that URL is https://www.lingoblend.app/opds/root.xml, added under Settings → System → OPDS Servers, and the https:// has to be there or nothing connects. It gets you the book; the dictionary still needs a short trip over USB or the Dictionaries plugin, and that's worth doing before you start reading the underlined edition rather than partway through.