Rivet & Rune
PRODUCTS ABOUT NOTES SUPPORT

Capture what you did, and why.
Recall it when it matters.

The work log your AI can read.

CogniLog is a native Mac & iOS work log for anything worth remembering. It captures the story between your commits, meetings, and deliverables: the decisions, the dead ends, and the reasoning. A built-in MCP server means your AI assistant can read it, and write to it.

Download on the App Store See how it works

For Mac and iPhone. Want the newest features first? Join the beta on TestFlight.

The CogniLog composer. A Markdown entry titled Pull Request Review Jamboree, formatted live. The CogniLog composer. A Markdown entry titled Pull Request Review Jamboree, formatted live. Capture
The Almanac year view. Twelve months of days, colored by channel. The Almanac year view. Twelve months of days, colored by channel. The Almanac month view. Each day shows its entries, colored by channel. The Almanac month view. Each day shows its entries, colored by channel. The Almanac week view. A week of entries laid out day by day, one expanded. The Almanac week view. A week of entries laid out day by day, one expanded. Scan and recall
Hovering a day in the year view. A rollup lists that day's entries by channel. Hovering a day in the year view. A rollup lists that day's entries by channel. Hovering an entry in the week view. A popover previews the entry. Hovering an entry in the week view. A popover previews the entry. Drill in for summaries
CAPTURE

Write the way you already write

Entries are plain Markdown, and they format live while you type: headings become headings, code fences become code. Drop a #tag inline and CogniLog files it for you, and channels keep each context separate.

The CogniLog composer formatting an entry live as it is typed: a channel picker and formatting bar up top, then a heading, bold text, and bullets. The CogniLog composer formatting an entry live as it is typed: a channel picker and formatting bar up top, then a heading, bold text, and bullets.

One feed of everything you’ve logged

Every entry lands in the Stream, grouped by day, with channels and tags in the sidebar. A timeline along the edge shows your whole history in miniature. Scrub it to move across months, or hover a cluster to preview that day.

The CogniLog Stream. Entries grouped by day, channels and tags in the sidebar, and a timeline scrubber along the right edge. The CogniLog Stream. Entries grouped by day, channels and tags in the sidebar, and a timeline scrubber along the right edge.
RECALL · THE ALMANAC

A map of everything you’ve logged, from the over-all view to the play by play

The Almanac turns your log into a map. Scan whole months, hover a day for a rollup of what happened, and drill from the year down to a single entry. The week view lays the days out side by side, which helps for standup or catching up after time away.

The Almanac month view. Each day shows its entries colored by channel, and a hover rollup expands one day. The Almanac month view. Each day shows its entries colored by channel, and a hover rollup expands one day. The Almanac week view. A week of entries laid out day by day, one expanded to its full text. The Almanac week view. A week of entries laid out day by day, one expanded to its full text.
A BUILT-IN MCP SERVER · BRING YOUR OWN AI

Your AI assistant reads and writes to the same log

When your AI session ends, the context goes with it, and the thread is easy to lose. CogniLog ships with a built-in MCP server, so the assistant you already use can both read your history and write to it. Ask it what happened last week, and it answers from your log. Set it to work, and it records what it did, in the same place you record what you did. Capture by hand or by prompt: it all lands in one timeline your assistant can search, cite, and reason across.

CAPTURE · BY HAND OR BY PROMPT
The CogniLog composer with an entry titled Orders table: partition cutover done, formatting tags and a Python code block live while it is typed. MANUAL
An AI agent in a terminal checking the last ETL run, then logging the results to CogniLog on its own. WITH AI
Write it, or ask AI to log it.
READ OVER
MCP →
RECALL · BROWSE OR ASK
The CogniLog Stream showing both entries in one timeline, grouped by day with channel and tags. STREAM
An AI agent in a terminal answering catch me up on the meridian db work with a summary built from CogniLog entries. ASK
Scroll the timeline, or just ask.

AI prompts shown run in your own agent, here a terminal, over CogniLog’s built-in MCP server, not inside the app.

The gap between reasoning and recollection

Finished work gets archived to make room for the next thing. What comes back later is an index of what happened, not the why. Most tools are good at capture or good at recall, rarely both in one place. CogniLog exists to close that gap.

Read the whole story

Built for desktop and mobile

Log from your desktop while you and your agents work, or capture a thought on the go from your phone. Entries sync between your devices through your own iCloud, whoever wrote them. Capture from the menu bar, the share sheet, Shortcuts, Siri or your lock screen.

Menu bar Share sheet Siri & Shortcuts Widgets iCloud sync
CogniLog on iPhone. The Stream with entries grouped by day. CogniLog on iPhone. The Stream with entries grouped by day.
The Almanac on iPhone. Months as a grid of days, colored by channel. The Almanac on iPhone. Months as a grid of days, colored by channel.

The same composer on your phone

The iPhone composer formats as you type, the same as on the desktop, with a formatting bar above the keyboard. An entry you tap out on your phone reads like one you wrote at your desk.

The iPhone composer. A formatted entry about planting a tomato bed, tags at the top, formatting bar above the keyboard. The iPhone composer. A formatted entry about planting a tomato bed, tags at the top, formatting bar above the keyboard.

Markdown in, Markdown out

Bring your notes in from the apps you already use, and take everything back out as plain Markdown.

IMPORT
Start with your history

Notes from Apple Notes, Day One, Obsidian and Bear import directly, and a CogniLog backup restores the same way.

EXPORT
Take it anywhere

Your entries export as plain Markdown, so anything that reads Markdown can pick up where CogniLog leaves off. The whole log also exports as a portable backup that imports right back in.

Your log lives on your devices and in your iCloud

There’s no account to create, and no servers of mine hold your log. The MCP server runs on your Mac, and only when your AI tool starts it.

In the works

NEXT
GitHub import
Pull commits, PRs, and review comments straight into the log.
NEXT
Calendar ingestion
Your meetings and events, alongside what you actually did.
EXPLORING
On-device AI
Auto-titles and roll-ups with Apple’s on-device models. Nothing leaves your Mac.
PLANNED
Apple Watch
Log a quick note from your wrist, and it shows up in your log on iPhone and Mac.
LATER
iPad support
The full CogniLog experience, sized for the iPad. Bigger than it first looked, so there is no date on it.

CogniLog is currently free

Everything in the app is free right now. If that ever changes, it won’t change for the people already here.

Get CogniLog

It’s on the App Store now, for Mac and iPhone.

Download on the App Store

Want occasional updates? Leave your email and I’ll write when there’s a new release.

Also from Rivet & Rune: Dice Builder, a dice roller made to sit on the table with you.