Every feature, honestly marked

Everything Curio does,
and what is not built yet.

Shipped means running and covered by tests. Building means specified and in progress. Coming means designed and not started. Nothing on this page is described as working when it is not.

The catalog

Seven groups, in pipeline order.

Capture, read, triage, compose, draft, publish, measure — plus the surfaces the whole thing is reachable from.

shipped running and covered by tests
building specified and in progress
coming designed, not started

42 features listed · 34 shipped and covered by tests

01 — 9 features
Capture

Eight ways in, one inbox. Every path deduplicates against everything already there.

Bookmarklet

shipped

One click from any page in any browser. Opens a small window, offers a note, closes itself.

Save from a chat message

shipped

Post a link in a designated Chirp channel and it is captured, with the sentence you wrote around it kept as the note.

Ask an assistant to save it

shipped

Claude, or any MCP client, can capture links on your behalf — with the reason attached.

Watched feeds

shipped

Follow an RSS or Atom feed and new entries arrive as suggestions, in their own lane, never entering the inbox until you say so.

A key for scripts and Shortcuts

shipped

A named, revocable key for Shortcuts, Raycast, Alfred or curl. It can only capture.

Deduplication on arrival

shipped

Tracking parameters stripped per host, shorteners followed, near-duplicates offered as a suggested merge and never merged automatically.

Share sheet on your phone

coming

Will share from Safari, X, your feed reader or Mail, and will work offline and sync when the network returns.

Forward it by email

coming

A private address of your own. Every link in what you forward will be captured, with the text above the first link kept as the note.

Browser extension

coming

A keyboard shortcut and a right-click menu, for people who would rather not use a bookmarklet.

02 — 4 features
Read

Every link arrives legible, and the save never waits on the fetch.

Automatic details

shipped

Title, author, publication, date, standfirst, hero image, language and reading time, pulled in the background.

Reader view

shipped

The article's text, stripped of navigation and subscribe-nags, so you can judge something without leaving Curio.

Posts and videos too

shipped

X, YouTube, Vimeo, Bluesky and Mastodon are read through their own metadata rather than scraped, because their pages are shells.

A paywall does not lose the link

shipped

When a page cannot be read, the item survives with its URL, your note, and a plain explanation of what happened.

03 — 6 features
Triage

A hundred items without touching the mouse.

Keyboard-complete

shipped

j and k to move, 1–9 to file into a publication, x to drop, u to undo, o to open. Shortcuts never fire while you are typing a note.

Everything is undoable

shipped

Every destructive action comes back with u, including a drop and a merge.

Your note outranks the site's blurb

shipped

One sentence on why you kept something is worth more than the article's own marketing copy, so Curio shows it first and never overwrites it.

File one link into several newsletters

shipped

The same link can go to two publications and read completely differently in each.

Search everything, including what you have sent

shipped

Titles, standfirsts, your notes, URLs and tags — sent issues included, so “have I used this before?” has an answer.

Tags, suggested

shipped

Lightweight automatic tagging on capture, editable and never binding.

04 — 5 features
Compose

Several newsletters, each with its own voice.

Publications

shipped

Each is one newsletter: its own sections, schedule, template, voice and mailing list. Pause one without touching capture.

Sections

shipped

Named buckets you define, with optional guidance the writing follows and an optional cap so one section cannot swallow an issue.

Issues assemble themselves

shipped

Everything filed since the last issue, ordered by section, with a draft blurb waiting on each. Assembling twice never produces two issues; an empty week produces none.

Review on a phone

shipped

Reorder, edit any blurb, write the intro, drop something back to the queue for next week. The Saturday morning screen works at 360 pixels.

Assembly on a schedule

coming

The draft will be waiting when you wake up, built the night before the send window.

05 — 7 features
Draft

A first pass in your voice, never the last word. This is the one place Curio spends the strongest model available.

Written from why you kept it

shipped

Your capture note carries more weight in the prompt than the article does.

Voice profiles

shipped

Describe your tone in your own words and give examples of blurbs you consider correct. Versioned, so changing it never rewrites what is already drafted.

Re-draft with a nudge

shipped

“Shorter.” “Less arch.” “Lead with the number.” A draft you have edited is never overwritten by a later one.

You can see how much is yours

shipped

Every blurb is marked drafted, drafted-then-edited, or written by you. The proportion is visible because it is the only honest measure of whether the drafting is earning its keep.

What it cost

shipped

Token spend per issue, on the issue. A newsletter that costs more to draft than it earns in attention should be legible as such.

Five voices to start from

building

Professional, conversational, dry, analytical, warm — ready to use and editable, so the first issue does not begin with an empty box.

Grounded, or honest about it

building

Drafts written only from the piece itself. When there is not enough to say anything true, Curio says so and leaves the blurb to you rather than inventing something confident.

06 — 7 features
Publish

Deliberate, and impossible to send twice.

Pick the list, do not retype it

shipped

Choose from the Herald mailing lists you own. A list you do not own cannot appear, because Herald decides that, not Curio.

The preview is the email

shipped

Rendered by the same engine the send uses, so what you approve is exactly what arrives.

Templates

shipped

Editable per publication and versioned, so an archived issue always shows what actually went out. Ships with a classic layout and a stripped-back one.

Send yourself a copy

shipped

Unlimited test sends that move none of your numbers, so proving a template renders costs nothing.

A confirmation that names the list

shipped

The dialog says where it is going, and the send is refused if the list changed while you were reading.

Send now, or schedule it

shipped

Either way it is a decision you make. Curio assembles automatically; it never sends automatically.

More layouts

building

Additional shipped templates — digest, magazine, and a link-only edition — as starting points rather than a blank file.

07 — 4 features
Measure

Which of the six things you sent did people actually open?

Full archive

shipped

Every issue kept as sent: its items, its blurbs, the template version it used. Searchable alongside everything you have ever saved.

Opens and clicks per issue

shipped

Pulled back from Herald automatically, more often just after a send and rarely once the numbers settle.

Already sent this?

shipped

Capturing something you have published before tells you so, with the issue and the date.

Clicks per link

building

Which of the six things you sent people actually opened — ranked, per issue, and carried back to the item so next week's triage knows.

Where you use it

Three surfaces, one workflow.

Web

shipped

The full product: dashboard, triage, reader, publications, issue review, archive, settings. Light and dark, down to 360 pixels.

Anywhere with a URL bar

shipped

The bookmarklet and the capture page work in any browser, on any machine, signed in or not yet.

iPhone and iPad

coming

Native, with a share extension that will make saving effortless, plus triage and full issue review — the Saturday morning pass, on a phone.

Built for assistants, up to a point

Thirty-two MCP tools.
None of them can send.

Curio exposes its whole workflow over the Model Context Protocol: capture, triage, publications, feeds, issue assembly, blurb drafting and preview. There is no tool that sends, schedules or test-sends, and a test enforces that as the surface grows.

capture_linklist_inboxtriage_itemmerge_itemslist_publicationscreate_sectionadd_feedlist_suggestionsassemble_issuereorder_issuedraft_blurbredraft_blurbset_voice_profilerender_previewsearch_everythingissue_metrics… 32 in all

Keep the good bits.
Send them Saturday.

Curio does the half of a newsletter that is not sending: capturing, triaging, drafting, assembling, reviewing. Herald owns the subscribers, the opt-in, and the send.

Curio is in active development at Renkara. Nothing here is for sale yet and there is no list to join — write to contact@renkara.com if you want to hear when it opens.

Claude and the Model Context Protocol are trademarks of Anthropic, PBC. Apple, iPhone, iPad, iOS, iPadOS, Safari, Shortcuts, and Mail are trademarks of Apple Inc. X is a trademark of X Corp. Raycast is a trademark of Raycast Technologies Inc. Alfred is a trademark of Running with Crayons Ltd. YouTube is a trademark of Google LLC. Vimeo is a trademark of Vimeo, Inc. Bluesky is a trademark of Bluesky Social, PBC. Mastodon is a trademark of Mastodon gGmbH. Curio is not affiliated with, endorsed by, or sponsored by any of them.