Nowline

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What is Nowline?

Nowline is a text-first DSL for describing product and engineering roadmaps — human readable and machine readable. You write plain .nowline text files — indented, keyword-driven, diff-friendly — and tooling renders them as timelines, validates them, and composes them.

examples/minimal.nowline:

nowline v1

roadmap minimal "Starter" start:2026-01-05 scale:2w author:"Jane Doe"

swimlane engineering "Engineering"
  item research "Research"  duration:3w status:done
  item design   "Design"    duration:2w status:in-progress remaining:5d
  item build    "Build"     duration:3w status:planned

Renders to:

Why Nowline?

• Text, not a Gantt chart. Version-controlled, diffable, reviewable in a PR.
• Indentation, not XML. Roadmaps read like outlines, because that's how people think about them.
• Strict enough to catch mistakes. 30+ validation rules, clear error messages with line and column numbers.
• Composable. include other files with explicit merge / ignore / isolate semantics.

Quick start

Install the CLI from your package manager:

brew trust lolay/tap                                 # macOS / Linux / WSL (one-time)
brew install lolay/tap/nowline

Debian/Ubuntu and Windows users can grab the latest .deb or .exe from GitHub Releases. See packages/cli/README.md for the full install matrix (including man nowline setup).

Toolchain

Two-tier Node policy: Node ≥ 22 to consume @nowline/* packages (engines.node on every published package), Node 26 (.nvmrc) to develop. CI tests both versions on every PR. See Toolchain & Supported Versions for the full policy and bump procedure.

Render your first roadmap:

nowline examples/minimal.nowline                     # writes ./minimal.svg
nowline --version

Or scaffold a brand-new file from a template:

nowline --init my-project                            # ./my-project.nowline
nowline --init my-project -t teams                   # ./my-project.nowline (teams template)

To give an AI agent Nowline tools, install the plugin from this repo's marketplace. In Claude Code:

/plugin install nowline --marketplace lolay/nowline

GitHub Copilot CLI and Codex read the same marketplace; see plugins/nowline/README.md for those and the other ways to add the MCP server.

For the VS Code / Cursor / VSCodium extension, search Nowline on the VS Code Marketplace or Open VSX.

0.x versioning. nowline is on 0.x.y while we settle the embed surface and IDE expansion. Public APIs may change between minor versions; full SemVer guarantees apply once we ship 1.0. See specs/releasing.md for the version contract.

To run from a checkout for local development (pnpm install && pnpm build), see CONTRIBUTING.md.

Use the CLI

nowline is verbless: rendering is the default. Other operations are flags on the same command.

Render (default)

nowline roadmap.nowline                          # writes ./roadmap.svg
nowline roadmap.nowline -f png                   # writes ./roadmap.png
nowline roadmap.nowline -f pdf                   # writes ./roadmap.pdf
nowline roadmap.nowline -f html                  # writes ./roadmap.html
nowline roadmap.nowline -f mermaid               # writes ./roadmap.md
nowline roadmap.nowline -f xlsx                  # writes ./roadmap.xlsx
nowline roadmap.nowline -f msproj                # writes ./roadmap.xml
nowline roadmap.nowline -o roadmap.pdf           # format inferred from extension
nowline roadmap.nowline -o -                     # SVG to stdout
nowline roadmap.nowline --theme dark --now 2026-03-15
nowline roadmap.nowline --now - --asset-root ./brand --no-links --strict
nowline roadmap.nowline -f pdf --page-size a4 --orientation landscape --margin 0.5in
cat roadmap.nowline | nowline -                  # stdin → ./roadmap.svg

The render pipeline is @nowline/core parse → @nowline/layout layout → @nowline/renderer SVG → format-specific exporter. Output is byte-for-byte deterministic for the same input, theme, and --now. A single nowline binary ships every format — see packages/cli/README.md for install details.

Validate (--dry-run)

Run the full pipeline (parse + validate + layout + format) without writing. Exits 0 on success, 1 if any errors are emitted.

nowline roadmap.nowline --dry-run
nowline roadmap.nowline -n                          # short alias
cat roadmap.nowline | nowline - --dry-run           # read stdin
nowline roadmap.nowline -n --diagnostic-format json # machine-readable output
nowline - -n --format=json < roadmap.nowline        # same, json is the default here

--diagnostic-format text|json picks the stderr format; with --dry-run --format=json it defaults to json, otherwise text. JSON mode writes one { "$nowlineDiagnostics": "1", "diagnostics": [...] } document to stderr whenever any diagnostic exists, warnings included, so a warnings-only source exits 0 with the document. Clean sources print nothing.

Convert text ↔ JSON

Convert is just -f json (or -f nowline to go the other way). Input format is inferred from the extension; --input-format overrides for unusual filenames.

nowline roadmap.nowline -f json -o roadmap.json    # text → JSON
nowline roadmap.json -f nowline -o roadmap.nowline # JSON → text (canonical)
nowline roadmap.nowline -f json -o - | jq '.ast.roadmapDecl.name'

The emitted JSON carries a top-level "$nowlineSchema": "1" so downstream tools can detect schema changes. Comments are not preserved across round-trips — see packages/cli/README.md for the canonical printer rules.

Serve (--serve)

Run a live-reload preview in the browser. Great while authoring.

nowline roadmap.nowline --serve                    # http://127.0.0.1:4318
nowline roadmap.nowline --serve -p 4400 -t dark --open
nowline roadmap.nowline --serve -o latest.svg      # rewrite latest.svg on each rebuild

The server re-parses, re-validates, re-lays-out, and re-renders on every file change; connected clients refresh automatically via Server-Sent Events. Validation errors are displayed as an overlay on top of the most recent successful render.

Init (--init)

Scaffold a new .nowline file in cwd. The positional argument is the project name, not a file path. .nowline is auto-appended.

nowline --init                              # ./roadmap.nowline (default name)
nowline --init my-project                   # ./my-project.nowline
nowline --init my-plan.nowline              # ./my-plan.nowline (literal)
nowline --init my-project --template=teams  # use the teams template

minimal, teams, and product correspond to the files under examples/. Existing files are silently overwritten.

Exit codes

Code	Meaning
0	Success
1	Validation error (parse failure, invalid reference, any include error such as a missing include, a wave rule across included files)
2	Usage error (missing input, bad flags, unsupported format, file not found, empty stdin, invalid --diagnostic-format, binary→TTY refusal)
3	Output error (cannot write to destination)

Manual

After any package-manager install (brew install lolay/tap/nowline, npm install -g @nowline/cli, or the .deb from GitHub Releases), man nowline shows the CLI manual and man 5 nowline shows the full DSL reference. Both man pages also ship as standalone assets on every GitHub Release — see packages/cli/man/ for the mdoc sources.

Language at a glance

File structure

nowline v1                        // 1. version directive (optional, must be first)

include "shared/teams.nowline"    // 2. includes
include "brand.nowline" config:isolate

config                            // 3. config section (optional)
scale
  name: weeks
style enterprise
  bg: blue
  fg: navy

roadmap r "My Roadmap"            // 4. roadmap section

swimlane platform
  item x "Work item" duration:1w status:done

Entities

Keyword	Purpose
roadmap	The top-level roadmap declaration. At most one per file.
swimlane	A horizontal lane of work.
item	A unit of work inside a swimlane.
parallel	A block whose children run concurrently.
group	A logical grouping of items, rendered together.
anchor	A named date on the timeline.
milestone	A point-in-time marker that depends on work.
wave	A barrier across every swimlane: no work in the next wave starts until this one ends.
footnote	A callout anchored to one or more entities.
person, team	Ownership references.
non-working, working	Days that consume no work (weekends, holidays, closures) and the exceptions that give them back. Config entries with date:, start: / end: or every:; a declaration named weekend replaces the business weekend. A dated closure with a title is labelled on the chart (Thanksgiving · 2d) and carried into the MS Project and Mermaid exports; a titled working day is labelled with the days it adds (Crunch Saturday · +1d).
style, symbol, label, size, status, scale, calendar, default	Config and declaration entries.

Properties

item auth "Auth refactor"
  duration: 2w              // duration literal: d, w, m, q, y
  status: in-progress       // builtin or custom from config
  owner: sam                // id reference (person or team)
  wave: build               // barrier the item belongs to (a declared wave)
  after: kickoff            // dependency (single)
  after: [kickoff, approvals] // dependency (list)
  remaining: 30%             // percentage
  labels: [security, p0]     // list of label ids
  link: https://…            // URL (bare, no quotes)

Roadmap start date

A roadmap may carry an optional start:YYYY-MM-DD that anchors the timeline baseline:

roadmap platform-2026 "Platform 2026" start:2026-01-06

• If the roadmap contains any anchor, or any milestone with a date: property, start: is required.
• Every such date must be on or after start:.
• A pure-relative roadmap (built from duration: and after: only) does not need start:.
• Across includes that don't use roadmap:ignore, the parent and any included roadmap must agree on start: — both absent, or both present with the same value. Mismatches are errors, not silent overrides.

Includes

include "teams.nowline"                     // merge everything (default)
include "snippet.nowline"  config:ignore    // skip child config
include "partner.nowline"  roadmap:isolate  // render child as a separate region

• merge — default: child content is merged; parent definitions win on collision.
• ignore — child content of that kind is discarded.
• isolate — child roadmap is preserved as a self-contained region (requires a roadmap in the child).

Waves never merge. Under roadmap:merge or roadmap:isolate, an included file that declares a roadmap, swimlanes, or waves must declare the same waves as its parent, in the same order with the same start floors (NL.E0202).

For the full grammar reference, see specs/dsl.md.

Examples

Progressively-richer examples are included. Every build of main renders them, and the renderer fixtures in tests/, at review.nowline.dev.

• examples/minimal.nowline — smallest complete file.
• examples/capacity.nowline — lane and item capacity: with on-call support taking a quarter of team bandwidth; lane utilization underline.
• examples/sizing.nowline — T-shirt size: entries plus shortening calendar span with capacity: (parallel work).
• examples/teams.nowline — persons, teams, anchors, milestones, footnotes.
• examples/product.nowline — full config, styles, labels, parallels, groups, descriptions.
• examples/long.nowline — stress test: eight swimlanes, ~160 items, parallels, groups, anchors, milestones, footnotes, cross-cutting labels. Used for layout/render perf.
• examples/nested.nowline + examples/nested/ — parent Security swimlane plus five isolated per-team roadmap includes (iOS, Android, Web, Platform, Data). Demonstrates roadmap:isolate.
• examples/waves.nowline — wave barriers: three waves (Foundations, Build, Launch) across three lanes, a group wave: that assigns its children, unwaved background work, and milestones after: a wave.
• + — multi-team waves: web and API team files re-declare the same waves (with a start floor), so each renders alone and the program file merges them behind one barrier.

Editor support

A TextMate grammar lives at grammars/nowline.tmLanguage.json. It works in any editor that supports TextMate grammars (VS Code, Sublime Text, Zed, IntelliJ via third-party plugins, etc.). A first-class LSP server and VS Code extension are tracked in packages/lsp/ and packages/vscode-extension/.

Use as a library

@nowline/core is a pure-TypeScript parser, typed AST, and validator built on Langium. Everything the CLI does on top of parsing is itself built against this library. See packages/core/README.md for the API and a usage example.

Status

Nowline is on v0.x — published to Homebrew, npm, the VS Code Marketplace, Open VSX, and GitHub Releases. The parser, validator, layout, renderer, every export format (SVG, PNG, PDF, HTML, Markdown+Mermaid, XLSX, MS Project XML), and the verbless CLI (--dry-run, --init, --serve) are usable today. Breaking changes may land between 0.x minor versions while the embed surface and IDE expansion settle; full SemVer guarantees kick in at 1.0. The release-by-release roadmap lives in specs/milestones.md.

Contributing

Bug reports, feature requests, and pull requests are welcome. Start with CONTRIBUTING.md for setup, build/test commands, and the expected workflow. Before opening an issue, please check the templates under .github/ISSUE_TEMPLATE/. Security issues should follow SECURITY.md. All participation is governed by our CODE_OF_CONDUCT.md.

Design specs for the DSL, renderer, CLI, IDE integrations, and OSS milestones live under specs/ — start there to understand how Nowline is shaped before touching code.

License

Apache 2.0 — see LICENSE.