A shared understanding for you, your team and your agents.

_line (you say it “underline”) is where your agents map how things work, people correct them, and what nobody knows yet stays in yellow until someone answers it.

Try _line, it's free – no card needed

Explore the map from the film

Sarah's refunds map. Click the yellow question, or any part to see what is known about it and how; “3 steps ›” goes inside.

looks up pays through Where it starts Customer asks A check Check it's eligible 3 steps › A decision Approve What it does Pay back Where it ends Tell the customer What it tracks Orders Outside system Card provider Open question Can refunds over $500 skip approval? A rule · seen in the code Over $500 always needs a manager Step 1 Bought in the last 30 days Step 2 Not used Step 3 Has the receipt Where it starts Customer asks A check Check it's eligible 3 steps › A decision Approve What it does Pay back Where it ends Tell the customer What it tracks Orders Open question Can refunds over $500 skip approval? A rule Over $500 always needs a manager Outside system Card provider Step 1 Bought in the last 30 days Step 2 Not used Step 3 Has the receipt
Every part says what is known about it, and how. What nobody knows yet stays in yellow: not knowing is allowed, pretending to know is not.

How it works

Your agents do the drawing and the reading. People bring what only people know.

  1. Connect your agent, then ask

    Once (see below), then “_line this”.

  2. It draws the map

    In plain language, saying how each thing is known.

  3. You read and correct it

    Add what you know, ask, confirm or dispute.

  4. It does its homework

    Say “read my comments”: it answers what it can and updates the map.

Honest about what is known

Every statement on a map says how it is known, so nobody mistakes a guess for a fact (agents included), and what nobody knows yet stays visible until someone answers it.

Bring the agents you already have

Connect an agent once, with _line's address. It signs in through _line in your browser, where you choose whether it may only read or also change maps. No keys to copy; disconnect it at any time. After you sign in, the welcome project shows how to connect each one, step by step.

ClaudeClaude CodeChatGPTCodexCursorGeminiVS Code with CopilotGrokZedPerplexityLe Chat

Shared, on your terms

Invite the people you work with

Each at a level you choose: viewers read, commenters also add what they know and ask questions, editors also change maps. Their agents never get more than they have. On the free plan they read; commenting and editing are coming with paid plans. Want them sooner? Ask us from your Account page for early access, free while we're early.

Or open one map with a link

Anyone with the link can read it, without signing in. Switch the link off at any time.

Every change is kept

See how a map got where it is, who changed what, and what changed since you last looked. Even the ideas that did not make it.

The free plan

Everything you need to try _line properly, on your own or with the people you show it to.

Free, no card needed

  • Up to 20 living maps (archive any to make room)
  • Connect as many agents as you like: Claude, ChatGPT, Cursor and more
  • As many changes as you like, by you and your agents
  • The last 30 days of each map's history
  • Share maps for others to read, by invitation or a public link

Coming in paid plans

  • People you share with (and their agents) commenting on, answering and editing your maps
  • Each map's full history
  • More maps

Want your team commenting and editing now? Ask from your Account page for early access, free while we're early. If the free plan ever changes, we'll tell you first, and you can always keep a copy of what you made.

Get everyone on the same _line.

Try _line, it's free