Redline

Turn precise webpage feedback into changes a coding agent can make.

Redline combines a Chrome extension, a local helper, and an open agent skill. Select text on a page, leave the requested change in context, and ask your agent to pull it. Built by ArchAstro.

[ Chrome extension ]  --local-->  [ Helper @ 127.0.0.1:7878 ]  --local-->  [ Coding agent ]
  select + comment                   private local state                    pull + act

See the loop

Leave the change where you see it:

Then pull the structured feedback into your coding workflow:

Quickstart

Prerequisites: macOS or Linux, Node.js 18 or newer, Bash, curl, and jq, plus Chrome or another Chromium-based browser. Windows and Safari are not currently supported.

1. Install Redline from the Chrome Web Store.

2. Install the CLI and portable agent skill:

   npm install -g @archastro/redline
   npx skills add ArchAstro/redline

3. Start the local helper and pair the extension:

   redline setup

The standard skills CLI owns skill installation and updates. Redline's CLI never installs, updates, removes, or inspects agent skills or legacy plugin state.

redline setup starts the local helper and opens a short-lived consent page. Approve it to pair the extension with the local helper. Install the Chrome extension first or run setup first — both orders finish on that same consent page. No ArchAstro account or hosted service is required.

Verify the loop

1. Open a webpage where Redline is enabled.

2. Select text, click Redline, add a concrete change, and submit it.

3. Ask your agent "Pull my redlines." or preview from the terminal:

   redline pull --no-ack

4. Confirm the pending item appears, let the agent make and verify the change, then pull with acknowledgement or delete the item. Resolved highlights are removed from the page.

Run redline status if the extension or local helper appears unavailable. The CLI can verify the Store extension and helper, but the extension popup is the source of truth for whether the active Chrome profile is paired. Use redline logs -f for helper diagnostics.

Agent invocation

| Surface | Invocation | | ------- | ---------- | | Portable prompt | "Pull my redlines." | | Agent skill | redline | | Terminal | redline pull |

The skill inspects each item, finds the corresponding source, applies focused changes, runs relevant checks, and only then acknowledges completed feedback. Ambiguous or risky requests still require clarification.

Commands

| Command | Purpose | | ------- | ------- | | redline setup | Configure or pair the Chrome extension | | redline status | Diagnose extension and helper state | | redline version | Print CLI, helper, and Chrome extension versions | | redline start | Start the local helper | | redline stop | Stop the local helper | | redline restart | Restart the local helper | | redline logs -f | Follow helper logs | | redline pull | Fetch and acknowledge pending feedback | | redline pull --no-ack | Preview without consuming feedback | | redline watch | Poll for new feedback | | redline clear | Delete helper-side redlines/screenshots and revoke every paired browser |

Filter pulls by origin or project:

redline pull http://localhost:5173
redline pull --project my-app

redline clear does not delete browser-local retry drafts. Use Clear all data in the extension popup when you also need to remove that profile's local browser data.

For a one-off setup without a global install:

npx --yes --package @archastro/redline redline setup

Local-first data model

Redline listens only on 127.0.0.1 and stores its state under ~/.redline by default. Redlines can contain selected text, comments, page URLs, page titles, DOM context, element geometry, and optional screenshots.

The Store flow gives each paired Chrome profile its own revocable browser credential. CLI requests use a separate owner-only credential. The current unpacked development flow uses an owner-only local browser credential.

ArchAstro does not receive this data. It leaves your machine only when you explicitly provide it to a coding agent or model provider. See the Redline privacy policy and security policy.

Permissions and limitations

• Screenshots and non-local pages require broader Chrome site access.
• Chrome internal pages, the Chrome Web Store, and other protected pages cannot run content-script extensions.
• Text matching can be ambiguous when the same phrase appears multiple times; Redline also records selectors and surrounding context to improve location.
• Content-heavy single-page apps may replace selected DOM nodes. Redline re-renders pending markers when it can and keeps the item in local state.
• Chrome/Chromium is supported today. Safari and Firefox are not.

Architecture

The extension sends authenticated requests to the loopback-only helper. The helper persists state atomically and exposes it to authenticated CLI commands. Public endpoints are limited to health, compatibility, and the short-lived pairing handshake.

Default data layout:

~/.redline/
|-- state.json          # redlines, paired clients, and pairing state
|-- cli-credential      # owner-only CLI credential
|-- screenshots/        # optional captured images
|-- sidecar.pid
`-- sidecar.log

Set REDLINE_DIR to move local data. Set REDLINE_PORT only for explicit development mode; the Store extension pairs on port 7878.

Development

See CONTRIBUTING.md for the isolated unpacked-extension workflow and pull request checklist. The core verification commands are:

npm install
npm test
npm run check:syntax
npm run check:versions
npm pack --dry-run

Releases

Changesets drive package versions and GitHub Actions publishes npm releases with provenance. Add a changeset for user-visible changes:

npx changeset

To publish manually, first run npm run version, commit the synchronized version files, run the full verification suite, and then run npm run release.

Community

• Discussions for questions, workflows, and ideas
• Issues for reproducible bugs and scoped feature requests
• Contributing guide
• Security policy
• Code of conduct

Redline is licensed under Apache-2.0.