FeisouDocument searchShippedGood knowledge deserves to be found.
A search tool for public Feishu documents. Built independently, from the first interface to launch.
Open Feisou ↗FeisouDocument searchShippedAn independent product studio · One person, a crew of agents.
Infra for people who use AI.
01 / Selected work
Small tools. Real work.
Built from everyday friction. Shipped into the hands of real people.
FeisouDocument searchShipped
SwobmacOS · Open sourceShippedPick up the thread.
Your conversations with agents are part of your work. Find them, keep their context, and carry on where you left off.
Open Swob ↗
KeyKeepermacOS · CLI · Open sourceShippedYour keys. Your control.
Keep API keys in the macOS Keychain. Give agents credential names, with values injected into the process that needs them.
🔑You manage the keysmacOS Keychain
Named credential · Process injection
>_Your agent uses the toolWithout putting keys into the chat
Adoption is a historical, founder-reported figure for Feisou’s April 2026 web relaunch, not current active users. Product status follows the studio’s public catalogue.
02 / The product map
Around a day of real work.
14 products. Four connected moments. One person at the center.
01
Find the context
Capture, search, collect.
Long2Text
Long screenshots become text an agent can actually read.
Feisou
Search public Feishu docs, so good writing is easier to find.
OpenTrends
Trend signals collected for you, so watching the world stops being a chore.
Wristory
Speak a thought to your Apple Watch and it becomes a note card. If it hears a to-do, it asks whether to act on it.
ManuFold
Snap your manuals once and toss the paper. When you are stuck, ask: the AI has read them and walks you through.
02
Stay in control
Keys, sessions, shared surfaces.
KeyKeeper
Keys stay in Keychain and get injected into the process that needs them. Nothing pasted into a chat.
Swob
Find your agent sessions in one place and pick up where you left off, in the tools that support it.
Halo
A desktop ring that shows what your agent is doing, with an optional Moonside lamp.
NaviBoard
Lay out pages, apps and notes on a canvas. Bookmarks and layout stay in your own files.
03
Make it yours
Review, refine, publish.
Agent Comments
Underline a sentence in your notes, @ an agent to reply.
soon
DraftBox
Review what your agents drafted and shape it into versions for each platform.
04
Close the loop
Remember, reflect, switch off.
soon
AI Diary
What your agents did today, written up as a timeline.
soon
Highlighter Timeline
Where the hours went, drawn as colour blocks in your notes.
soon
Mindful Guard
Ends the day with you, instead of pulling the plug.
03 / The constant
We don’t build agents.We don’t build for agents.We build for the people who use them.
Models, protocols and tools will come and go. The person making decisions, holding the context, and needing sleep is still there.
$model = variable $price = variable $protocol = variable $context_window = variable $tool_of_the_week = variable $you = constant
- 01
Start with lived friction.
We use these tools ourselves. A lost conversation, a key pasted into the wrong place, a day that never ends: that is where a product begins.
- 02
Two ways in. Human control.
Interfaces for people, programmable access for agents. KeyKeeper already pairs a macOS workflow with a CLI. That is the pattern we want to take further.
- 03
Let the work lead the thesis.
Ship something small, learn from actual use, and keep improving it. An independent studio can change direction without losing its center.
Agents change everything. The only constant is you.
Dark, like the unseen things that hold everything together. Constant, like the person at the center of it.
04 / The person behind it
Hi, I’m yytyyf.
Founder, designer, developer.
“Turn every assignment into something worth sharing.”
I learned to design, then to code, by building things I wanted to use. After working on AI products at Kimi and Feishu, I now build independently, with a crew of agents.
The longer story on my personal site ↗Experience that informs the work
2026 —
Independent builder
Dark Constant · Design → build → ship2025–26
Feishu
AI product management · Cloud documents2025
Moonshot AI / Kimi
AI innovation & growth2023–26
Peking University
Master’s · Software & Microelectronics05 / Build what comes next
Same direction? Let’s talk.
Interested in the human side of working with agents? I’d love to meet people building toward the same future.