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Justn
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INDEPENDENT SOFTWARE STUDIO

Justn

We build brgr, which runs coding agents in parallel, agent-progress, a progress pane for agents, and Rapi, a personal agent.

We are a one-person software studio. We develop tools that enable people to monitor and stop agent work, and verify its results.

See brgr
Start a conversation
brgr · real recording of three workers reporting back
Real TUI recording · Taken as-is from the repository README. 2x speed.
Available now

01 / PRODUCTS

Products

We develop and operate four products directly. We co-develop two products as part of a two-person team, responsible for planning, design and frontend development.

Built by Justn

FlagshipOn crates.io

brgr

An orchestrator that runs coding agents in parallel

When Codex or Claude Code hands work to other coding agents, brgr opens the workers and returns each result as a sealed report.

Each worker opens in its own Herdr pane, and brgr clicks through the trust and continue prompts for it. Results come back to the owner agent as sealed reports, and a diff is applied only after an explicit accept. Failures are repeated until acknowledged. Twelve harnesses can be workers: Claude Code, Codex CLI, Gemini CLI, GitHub Copilot CLI, Pi, OpenCode, Cursor CLI, Devin CLI, Cline, GJC, OMP and Command Code.

Form · stack
Rust CLI · macOS Apple Silicon · Herdr 0.9+ · MIT
RustHerdrMIT
Since
13 Sept 2026
Latest release
v2.13.4 · 2026-10-06
Real TUI recordingTaken as-is from the repository docs.
On Homebrew

agent-progress

A terminal progress pane for agent plans

When a coding agent writes its plan with the ap command, a progress pane opens right under it. The user registers nothing.

Reads the plan recorded with ap goal, ap add, ap start and ap done, and shows the goal, progress, what is happening now, what is blocked and why, and what comes next. Install with Homebrew, then run ap skill install once so agents use it on their own.

Form · stack
Rust CLI · macOS Apple Silicon · open source
RustHomebrewHerdr / tmux
Since
28 Sept 2026
Latest release
v3.4.0 · 2026-10-08
Real TUI recordingTaken as-is from the repository docs.
Private operation

라피rapi-agent

A personal agent that collects, summarises and delivers

Gathers changes from RSS, GitHub and webhooks, classifies and summarises them, and sends Discord DMs and an email newsletter.

Receives changes from many sources in one place, removes duplicates, and summarises them on the schedule and categories you choose. Approved development tasks are handed to a coding agent with their permissions and execution state recorded. A separate crawler (rapi-crawler, Go + Playwright) collects newsletter sources.

Form · stack
Discord bot + server · open source
Node.jsPostgreSQLDiscord botGo crawler
Since
6 Sept 2026
Latest release
v0.1.2 · 2026-09-28
Private testing · external access restrictedRepository
  1. collect
  2. normalise
  3. classify · summarise
  4. deliver
Discord DMemailblog
Interactive demoIllustrative demo. Not real data or live state.
Running · justn.me

justn.me

A resume and portfolio editor you edit and share on the web

Edit resumes and portfolios field by field, export to PDF and web, and share per-company copies.

Keeps a resume, a portfolio deck and a cover letter as base documents and creates per-company copies to share. An MCP server lets agents read and edit the same documents, and exports are print-ready PDFs.

Form · stack
Web app · private repository
Next.jsMCP serverPDF export
Since
24 Aug 2026
resume/feversion 68fd…
  • sections.0.title=Intro
  • sections.1.title=Team projects
  • sections.2.title=Skills
Interactive demoIllustrative demo. Not real data or live state.

Built with a team

Two-person team · Justn: planning, design, frontend

Public prototype, running

사주리움Sajurium

Saju reports, read as data

Computes a birth chart from date and time of birth, then runs free reports, relationships, consultations and passes in one web flow.

Start from an anonymous session and read and write chart calculation, free reports, relationship analysis, consultation answers, the product catalogue, a pass ledger and an archive against a real API. Payments, social login and push are fully built on staging behind production flags that stay off until each one is switched on separately.

Form · stack
Web app · two-person team (backend sasaju by a teammate)
Next.js 16React 19FastAPI
Since
25 Aug 2026
Chart
Free report · day 丙寅 · free
Interactive demoIllustrative demo. Not real data or live state.
Private testing

벙개Bungae

Small meetups that happen within 24 hours

A mobile web app for adults aged 18 to 39 to meet safely in public places within 24 hours.

Built the participant flow: three tabs for browsing, my meetups and notifications, meetup creation, join and waitlist, the under-capacity decision, chat, check-in, feedback, reporting and blocking. Session tokens live only in memory, and the UI never guesses values the server has not sent.

Form · stack
Mobile web · two-person team (backend by a teammate)
Next.jsMobile web 320–430px/v1 API
Since
31 Aug 2026
Private testing · external access restrictedRepository
closes in05:12:40

Today 20:00 · public place

3 / 4
Interactive demoIllustrative demo. Not real data or live state.

02 / APPROACH

Agents doing the work does not mean people have to lose track of it.

We build tools where you can see what is happening, step in when you need to, and check the result. So every product asks the same questions. What is going on right now. Can it be stopped or undone. How is the result proven. What the screen shows has to be the real state, and automation must never do the same thing twice.

  1. 01visible
  2. 02interruptible
  3. 03verifiable

03 / MILESTONES

Milestones

Dates come from GitHub releases and dated records in the repositories. Repository creation dates are not listed.

  1. Evidence ↗ github.com/justn-hyeok/agent-progress/releases/tag/v3.3.0
  2. Evidence ↗ github.com/justn-hyeok/brgr/releases/tag/v2.13.4
  3. Evidence ↗ github.com/bread-dispenser/sajurium-client
  4. Evidence ↗ github.com/justn-hyeok/rapi-agent/releases/tag/v0.1.0
  5. Evidence ↗ justn.me

04 / FOUNDER

Founder

Junhyeok Hwang

Representative · Founder · Frontend & Product Engineer

A one-person indie startup. I find and fix the places where user flows and system state drift apart, and design complex UI state, input, validation, submission, autosave and failure recovery as one product flow. Code and results suggested by AI are checked with tests and real screens before they ship.

Mostly working in
ReactNext.jsTypeScriptRust (CLI)
GitHub · justn-hyeokPortfolio · justn.me

05 / COMPANY

Company overview

We are a one-person software studio based in South Korea, developing coding-agent tools, personal agents and web products.

Legal entity
Justn
Entity type
One-person software studio
Established
Representative
Junhyeok Hwang (황준혁)
Business areas
Coding-agent tools brgr and agent-progress, Rapi personal agent, web products
Business model
Developer tools are published as open source; consumer products will offer paid features after general release.
Contact
ceo@justn.me
Registered in
South Korea
Address
Gimhae-si, Gyeongsangnam-do, Republic of Korea
Public repositories
github.com/justn-hyeok

06 / CONTACT

If you are building something, let's talk.

Product collaboration, adopting a tool, or a small question are all welcome. Email is read and answered directly.

Inquiries we take

  • Collaboration proposals
  • Tool adoption · technical questions
  • Co-development
  • Hiring · interview requests

We reply within two business days.

Send email
GitHub · justn-hyeok ↗

Open source · security

Developer tools are published under the licence stated in each repository (brgr: MIT), and issues and pull requests are welcome. Please report security vulnerabilities privately to the address below rather than in a public issue.

Security reports · ceo@justn.me