Requirements and platforms

Markdown · Agent index

Sponge captures on a computer and reads anywhere with a browser. This page says what each platform can do today, and which features need a model download or a native helper.

A computer running sponge

Install with npm install -g @hraness/sponge. The command needs Node.js 24.20 or newer on macOS or Linux. Windows is not supported.

Capability	macOS	Linux	Needs
Save articles	Yes	Yes	Nothing extra
Save PDFs	Yes	Yes	Poppler (pdfinfo, pdftohtml); Tesseract for optional OCR
Read, list, keyword search	Yes	Yes	Nothing extra
Highlights, notes, export, backup, restore	Yes	Yes	Nothing extra
Sync, save queue, public pages	Yes	Yes	A Sponge account
MCP server and JSON CLI for agents	Yes	Yes	Nothing extra
Summaries	Apple Silicon, macOS 26	x64 or ARM64 with glibc	sponge setup --digest and 16 GiB of memory
Summaries with your own model server	Yes	Yes	A server on 127.0.0.1
Background worker installed as a service	Yes (sponge worker install)	Run sponge worker foreground under systemd	Nothing extra
Signed-in pages through your browser	Yes (sponge browser setup)	No	A Chromium browser and the capture extension
Media transcripts	Apple Silicon, macOS 26	No	sponge setup --capture
Local speech recognition, English	Apple Silicon, macOS 26	No	sponge setup --asr
CLI semantic search	Apple Silicon, macOS 26	No	sponge setup --embedding
Building the library map	Apple Silicon, macOS 26	No	sponge setup --embedding and the summary model

Summaries

sponge setup --digest downloads a pinned llama.cpp build and one model from their public sources and verifies their hashes.

Memory	Model	Download
16 GiB to 32 GiB	Qwen3.5 9B	About 5.6 GB
32 GiB or more	Gemma 4 26B-A4B	About 16.9 GB

On Linux the managed model server also needs bubblewrap with user and network namespaces, glibc 2.35 or newer on x64, and glibc 2.39 or newer on ARM64. Linux has the package list. With less than 16 GiB, run a smaller model yourself and pass its loopback address; Summaries shows how.

Native helpers

Media transcripts, local speech recognition, CLI semantic search and library-map building use native helpers built for Apple Silicon Macs on macOS 26. The helpers ship inside the sponge package, and sponge setup --capture, --asr and --embedding install them with no account or token. Setup downloads only public files: the speech and embedding models from Hugging Face, and the embedding library from LiteRT-LM’s release on GitHub. Every file is checked against the hashes in the package before it is used. A package from before 0.28.0, or a source checkout, has no helpers and reports runtime-missing.

Everything else on this page works without them. sponge search falls back to keyword search and says so, and the web library has its own search by meaning that needs no helper.

Where you read

Surface	Requires	Status
Web library at account.sponge.computer/library	A current browser that allows private site storage	Available
Sponge for Mac	macOS 15 or later	Available at sponge.computer/mac
Sponge for iPhone and iPad	iOS 17 or later	Available on the App Store
Sponge for Chrome	Chrome 116 or later	Available on the Chrome Web Store

The Mac and iPhone apps show the web library, so the table below applies to all three.

In the web library	Works for everyone	Notes
Reading, filing, reading progress	Yes	Offline once the browser’s copy has loaded
Keyword search	Yes	Runs in the browser
Search by meaning	Yes	A model of about 4 MB loads with the page; ranking happens in the tab
Highlights, notes, notebook export	Yes	Edits made offline are sent later
Saving a link	Yes	A computer running sponge captures it
Sharing and public pages	Yes	See Sharing and publishing
Summaries on an item	When one of your computers drafted it and you accepted it	See Summaries
Library map	When one of your computers built a map	Building needs an Apple Silicon Mac, as above; viewing does not

A browser that cannot keep its own copy of the library, such as some private windows, cannot open the library. Account settings, the save queue and device management still work there.