Draughtsman

[Draughtsman by Overpass]

Draughtsman

Agent-native, self-hosted diagramming. A Draughtsman diagram is a typed graph, not a picture: nodes and edges with kinds, ports and properties, stored in a database you run. The graph has a lossless text form (the DSL) that people and AI agents can read, diff and write, and a built-in MCP server so an agent can create, amend, critique and render diagrams directly. The canvas editor, the exports and the renders are all drawn from that one model. It runs on your own server, and nothing leaves your network unless you switch on an optional feature that says so.

• Typed graph model: four document types (flowchart, architecture, freeform, sequence) with kind vocabularies an agent can ask for with get_schema.
• Lossless text DSL: print a diagram, edit the text, parse it back with nothing lost. Diffs read in sentences, so diagrams belong in git.
• MCP server: eight tools over HTTP (/mcp) or stdio (draughtsman mcp --stdio).
• Self-hosted: one executable (or one container), SQLite by default, Postgres if you prefer. No account with us, no phone-home.

Quick start

You need a machine that can run Docker, or one of the release archives. About five minutes.

Docker

No sign-up, no account with us, nothing to request. No image is published to a registry yet, so build it from this repository. The quickest way is docker-compose.yml:

git clone https://github.com/overpassapps/draughtsman.git && cd draughtsmandocker compose up -d --builddocker compose logs draughtsman | grep "setup code"

Or by hand, with a folder on the host for the data:

docker build -t draughtsman:local .
mkdir -p draughtsman-data && sudo chown -R 10001:10001 draughtsman-data && sudo chmod 700 draughtsman-data   # Linux; Docker Desktop needs no chowndocker run -d --name draughtsman --restart unless-stopped \  -p 127.0.0.1:5180:5180 \  -v "$(pwd)/draughtsman-data:/data" \  draughtsman:local
curl -s http://127.0.0.1:5180/api/health      # {"status":"ok"}docker logs draughtsman 2>&1 | grep "setup code"

Open http://localhost:5180, enter the one-time setup code from the log, and create the first administrator. The port is published to loopback only; put a reverse proxy in front for anyone else (docs/deployment.md). Full Docker guide: docs/install-docker.md.

To publish a multi-platform image (linux/amd64 and linux/arm64, built from one Dockerfile on any machine, Apple silicon included), use a docker-container builder; the default builder cannot push a multi-platform image. The build stages run natively on your machine and only the final runtime stage differs per platform:

docker buildx create --name multi --driver docker-container --use    # oncedocker buildx build --platform linux/amd64,linux/arm64 -t docker.io/wroolie/draughtsman:<ver> --push .

Release archive

Archives for macOS (Apple silicon and Intel), Linux (x64, arm64) and Windows (x64, arm64) are one folder with nothing else to install: no .NET, no Node. No release has been cut yet, so there is no download to link to; scripts/publish.sh <platform> builds an archive from source, and docs/install.md covers unpacking, running as a service and checksums.

tar -xzf draughtsman-0.1.0-linux-x64.tar.gz && cd draughtsman-0.1.0-linux-x64./draughtsman                      # http://localhost:5180

From source

.NET SDK 10.0.x (pinned in global.json) and Node 22.12 or later:

dotnet run --project src/Draughtsman.Server        # http://localhost:5180

The web app is served from web/dist when it exists (cd web && npm ci && npm run build). CONTRIBUTING.md has the whole developer loop.

Connect an AI agent over MCP

Sign in, open Tokens in the top bar, create a token (the secret, dst_…, is shown once), then:

# a running server, over HTTP (Claude Code shown; any MCP client that speaks streamable HTTP works)claude mcp add --transport http draughtsman http://127.0.0.1:5180/mcp --header "Authorization: Bearer dst_…"
# the same machine and data folder, over stdio: no token, no portclaude mcp add draughtsman -e DRAUGHTSMAN_DATA=/path/to/data -- /path/to/draughtsman mcp --stdio

The tools are list_documents, read_document, create_document, patch_document, render_document, diff_documents, critique_document and get_schema. A token can be read-only. SKILL.md is a ready-made agent skill that teaches the DSL and the tools; the HTTP contract is in docs/api.md.

What is built

• Editor: a canvas with pan, zoom, marquee select, snapping, undo and redo, connectors that route around shapes (orthogonal, straight, curved), ports, containers and grouping, a styling panel, a text pane (DSL or Mermaid beside the canvas), pen and touch, and live merging of an agent's edits into the open diagram.
• Diagram types and shapes: flowchart (ISO 5807 symbols, BPMN, swimlanes), architecture (generic tech icons, org chart, UML class and interface), sequence (edited by message order, with fragments and notes), freeform, UML state shapes, database tables with column-to-column connectors, and basic shapes.
• Import: Mermaid (flowchart and sequence, plus erDiagram), SQL DDL (T-SQL, PostgreSQL, MySQL, SQLite), draw.io, and Visio .vsdx (which also covers Lucidchart via its Visio export).
• Export: PNG and SVG in the browser, PDF from the browser's print dialog (or server-side through an optional Chromium component), DSL, JSON, Mermaid, SQL, and a fly-through exported as one self-contained HTML file.
• Fly-through: a camera path over a diagram, saved in the document and played full screen with captions.
• For teams: local accounts (Administrator and Editor), API tokens, a recycle bin, named versions with compare and restore, a critique panel, thumbnails, admin pages for branding, themes, AI and email settings, and backup and restore from the command line.
• Optional AI: bring your own model (Ollama, any OpenAI-compatible endpoint, Anthropic, Azure OpenAI) for Generate from text and Diagram to document. Off unless an administrator configures it; with a local Ollama nothing leaves your network.
• Operations: SQLite or Postgres, a Docker image, service installers for systemd, launchd and Windows, draughtsman doctor and config check, upgrade safety checks with automatic rollback of a failed SQLite migration, and an air-gapped install path (docs/air-gapped.md, docs/data-flow.md).

The long-form version, with configuration, is docs/status.md.

Not built yet

We would rather you heard it here first:

• Single sign-on (OIDC, SAML) and workspaces beyond default. Sign-in is local only.
• A Viewer role or per-document permissions. Every signed-in user can read every diagram, and an Editor can change any of them.
• Real-time multi-user editing. The open editor polls and merges newer versions, and a stale save is refused rather than overwritten.
• A published container image and published release archives. You build both from source for now, and archives are not yet code-signed or notarised.
• SQL Server storage (SQLite and Postgres are supported).
• A PDF renderer that needs no extra install on the server: server-side PDF needs the optional Chromium component, and render_document cannot return PNG.
• Per-kind theme colours for BPMN shapes, and server-side styling of edge kinds (the server render draws a BPMN message flow as a plain arrow).
• Fly-through video or GIF export; BPMN compensation, loop and multi-instance markers and choreography diagrams.
• Automatic clean-up of orphaned uploaded images, and pruning of the security event log.
• Windows is a release target with its own CI leg, but the Windows archive and service install are less proven than the Linux and macOS ones.

The full list of known limitations is in CHANGELOG.md.

Documentation

Full documentation: https://draughtsman.overpass.co.uk/docs/. The same pages are in docs/ in this repository, alongside the build specification, the architecture decisions, the document schema and the DSL grammar.

Licence

Draughtsman is free software, released under the GNU Affero General Public Licence v3.0 only (LICENSE). Copyright © Overpass Limited. You can use it, change it and fork it; if you run a modified version as a network service you must offer its source to the people using it.

If the AGPL does not suit you, Overpass also offers Draughtsman under a commercial licence (COMMERCIAL-LICENSE.md). It lets your organisation change Draughtsman and connect it to your own systems for internal use, and keep those changes private, without the AGPL's duty to offer source to network users. It costs £1,500 one-off for a team of up to 50 people, or £3,000 one-off with no limit on people. Each includes 12 months of updates and email support, and renewing updates costs 25% of list a year. It covers running Draughtsman inside your own organisation; to embed it in a product or service for others, ask about a separate agreement. To buy or ask, write to [email protected].

Buying a commercial licence. Commercial licences are bought by email: write to [email protected] with your organisation's name and the tier you want, and we reply with an order to confirm and an invoice. The licence text is COMMERCIAL-LICENSE.md; the version in force when you buy is the one you accept.

Third-party components keep their own licences: see THIRD-PARTY-NOTICES.txt.

Contributing

Bug reports, ideas and pull requests are welcome. Read CONTRIBUTING.md first. Outside contributions need a signed-off Contributor Licence Agreement so that Overpass Limited can keep offering commercial licences. Everyone taking part is expected to follow the Code of Conduct. For questions, use GitHub Discussions rather than issues.

Support the project

Draughtsman is built and maintained by Overpass. If it saves you time, you can sponsor the work at https://github.com/sponsors/overpassapps.

Security

Please report vulnerabilities privately to [email protected], not in a public issue. See SECURITY.md for scope, timescales and the security model.

Made by Overpass.