LaTeX Coder

A self-hosted LaTeX workspace where people, coding agents, and Git work on the same paper.

Website · Documentation

LaTeX Coder combines real-time collaborative editing, a built-in PDF and Log workflow, project Git repositories, and agent-safe editing APIs. The source tree remains ordinary files on disk. Yjs keeps browser sessions synchronized, SQLite stores application state, and every project is a real Git repository on main.

Working with BibTeX? See Biblock, an auditable bibliography workflow for humans and agents.

Why LaTeX Coder

Write together

• Edit simultaneously with live cursors and presence.
• Share a project with a View or Edit capability link. Guests do not need an account; signed-in recipients confirm before joining persistently as viewers or collaborators.
• Comment, reply, and suggest changes inline. Review data is encoded as LaTeX macros, so an agent can read and edit it instead of interacting with an opaque UI-only review layer.
• Inspect character-level authorship in Blame mode, including the first Git checkpoint containing each range.

Navigate the paper, not just its files

• Browse an indented file tree with folders, drag-and-drop moves, downloads, recoverable deletion, image/PDF previews, and open-file tabs.
• Edit Markdown beside LaTeX and switch to a sanitized GFM preview with project-relative images, tables, task lists, code blocks, and links to other project files.
• Use Tree for the section outline and TreeWriter for a paper-level view of section titles, \tldr, and \sectiontldr summaries. Leaf source can be edited in place with the same CodeMirror interactions as the main editor.
• Command-click on macOS, or Ctrl-click elsewhere, to follow \cite, \citep, \citet, \ref, \autoref, \cref, \include, \includegraphics, and \url targets. Citation completion includes titles and authors.
• Search the entire project, optionally with sandboxed ripgrep-compatible regular expressions, and preview multi-file replacements before applying them.

Compile and debug without leaving the editor

• Compile with Tectonic or an explicitly configured latexmk installation.
• Switch between PDF and Log beside the editor. Log groups errors and warnings, surfaces the first fatal error, and links diagnostics back to their source file and line.
• Navigate both ways with SyncTeX: source to PDF and PDF to centered source.
• Fit the PDF to page width or a whole page, zoom it, download it, or switch between Source and PDF on smaller screens.
• Keep the last successful preview while editing; the UI marks it only when it becomes stale.

Give agents a first-class editing path

Every collaborator can copy a project-specific Agent editing command from the Collaborate menu. It opens a plain-text manual containing the project's files and capability-bearing API URLs.

The default edit workflow is deliberately simple:

1. Download a complete UTF-8 file and retain its X-Content-SHA256 header.
2. Edit it with ordinary local tools.
3. Upload the complete replacement with that hash as X-Base-SHA256.

The server calculates and applies the Yjs changes in one transaction. If a collaborator changed the file in the meantime, the upload is rejected with HTTP 409 rather than overwriting newer work. Agent access can apply changes directly or force every edit into reviewable suggestions. The same manual also documents project search, PDF and Log diagnostics, blame, reviews, and Git. It tells agents to use Git only when the user explicitly asks for it.

LaTeX Coder vs. Overleaf

LaTeX Coder is not intended to match Overleaf's hosting scale, template ecosystem, publisher integrations, or support organization. It takes a different approach for trusted teams that want to own their infrastructure and make coding agents part of the writing workflow.

	LaTeX Coder	Overleaf
Hosting	Self-hosted Node service; persistent data stays on your volume.	Hosted service, with separate on-premises products.
Guest collaboration	View/Edit capability links; an account is optional for project access.	Account-based collaboration with plan-dependent collaborator limits.
Review data	Comments, replies, and suggestions are LaTeX macros visible to humans, agents, and Git.	Comments and Track Changes are platform-managed; Track Changes is a premium feature.
Git model	Every project is a Git repository. Yjs represents main; incoming changes are merged before import.	Git Bridge translates Overleaf history into one linear branch named master; cloud Git integration is premium.
Git and reviews	Macro-backed review state travels with source and is validated on import.	Overleaf advises against mixing active Git use with comments or Track Changes because pushes can displace or lose review metadata.
Agent editing	Project-scoped plain-text manual, checked full-file edits, search, build/Log diagnostics, blame, review, and Git APIs.	General editor and integration workflows rather than this checked file-edit protocol.
Export	ZIP of the live working tree, including uncommitted source changes.	Source ZIP; the compiled PDF and most generated files are downloaded separately.

Comparison details are based on Overleaf's official documentation for plans, Track Changes, advanced Git behavior, and project downloads.

Quick Start

Requirements: Node.js 22+, pnpm 10+, and Git.

pnpm install
pnpm check
LATEXCODER_ADMIN_PASSWORD='use-a-long-random-password' pnpm start

Open http://127.0.0.1:8090. On an empty data directory, sign in as admin with LATEXCODER_ADMIN_PASSWORD. The password must contain at least 10 characters and is used only to create the first account. Internal users can then issue registration links that expire after seven days, choosing whether the new account is Internal or External. Links are single-use by default and can optionally remain reusable until they expire. External users keep a full project dashboard and can create projects, but cannot invite more users.

For local development:

LATEXCODER_ADMIN_PASSWORD='1234567890' pnpm dev

Vite serves the client at http://127.0.0.1:5173 and proxies application, WebSocket, share, and Git traffic to the TypeScript server on port 8090.

Projects and access

Only registered users have a project dashboard and can create projects. A project may have multiple registered collaborators; each collaborator sees it in their own dashboard and receives distinct Browser, Agent, and Git secrets. Projects support shared tags, title/tag search, tag filters, and per-user archiving. Project URLs use short generated IDs and do not change when a project is renamed.

The bootstrap administrator has a paginated administration panel for all users and projects. It supports account search, password resets with session revocation, soft user deletion that preserves projects and attribution, and project deletion. Administrators can also switch active non-admin accounts between Internal and External. Regular members cannot access the panel or its APIs. Existing accounts are migrated as Internal users.

Guests enter through /share/<project-id>/<secret>. The secret is exchanged for a 24-hour, project-scoped HttpOnly session before redirecting to the clean project URL. Signed-in users see a confirmation page before adding a project or upgrading View access to Edit access. Rotating a collaborator's secret invalidates that person's old Browser, Agent, and Git links without affecting other members.

New projects can be created from ZIP archives. ZIP upload inside an existing project adds files without overwriting existing paths. Imports reject path traversal, Git metadata, and oversized archives.

Git and live collaboration

Every project starts on main, and the collaborative Yjs documents always represent that branch. Browser edits are checkpointed after 30 seconds of inactivity, or at most every five minutes during continuous editing. Unchanged content does not create an empty commit.

Clone, fetch, and pull first checkpoint the latest collaborative content, so a browser user does not need to push before a local Git client can see their work. Add a public key under Account Settings → SSH keys, then copy the default SSH command from Collaborate → Git access. Clone and push require the matching private key and project membership. Viewers can clone but cannot push. Removing a key revokes its SSH access.

git clone ssh://git@your-host:2222/<project-id>.git
cd <project-id>
# edit and commit normally
git push origin main

The Access link option retains the existing HTTPS remote at https://your-host/git/<project-id>/<personal-secret>, which works without an SSH key. SSH keys are managed separately from project access-link secrets. The server's SSH host key is generated on first startup and persisted in the state directory; its fingerprint is shown in the Git dialog.

On push, LaTeX Coder checkpoints current Yjs state, merges the incoming commit in a temporary worktree, validates the result, and imports a clean merge into the live documents. If it cannot merge safely, the incoming work is retained on conflict/<UTC timestamp> while main and Yjs remain unchanged.

The History view provides paginated checkpoints, per-file diffs, an Agent edits filter, and whole-project or single-file restore. A restore creates a new commit instead of rewriting history.

Compilation and Log

Project settings select the main TeX file, compiler, and optional automatic compilation. In auto mode the server uses LATEXCODER_LATEX_BIN, Tectonic, or latexmk. If neither compiler is present, it installs a local verified Tectonic binary on first use. Selecting latexmk explicitly requires latexmk to be installed already.

The Log view separates parsed diagnostics from the full compiler output. Errors and warnings are grouped into scannable items; source-aware items jump directly to the relevant file and line. The first fatal error is promoted so it can be found without searching the raw transcript.

PDF navigation requires the synctex executable. The Docker image includes it. Compile an older project once after deployment to generate its synchronization data.

The Agent PDF endpoint always represents current source. It compiles when needed and reuses the cached artifact otherwise. A failed current build returns HTTP 422 JSON with the compiler log, structured diagnostics, and the first fatal error; it never silently gives an agent a stale PDF as evidence of success.

Docker and Railway

The image includes Tectonic, SyncTeX, Git, ripgrep, and bubblewrap. It stores all persistent state beneath /data but deliberately declares no Docker VOLUME.

docker build -t latexcoder .
docker volume create latexcoder-data
docker run --rm \
  --name latexcoder \
  --publish 8090:8090 \
  --publish 2222:2222 \
  --security-opt seccomp=unconfined \
  --env LATEXCODER_ADMIN_PASSWORD='use-a-long-random-password' \
  --volume latexcoder-data:/data \
  latexcoder

The seccomp override permits bubblewrap to create the namespaces used by regex search. It is unnecessary when sandboxed ripgrep search is not used.

For Railway, use the deploy button above, attach a persistent volume at /data, and set LATEXCODER_ADMIN_PASSWORD. Railway's injected PORT is accepted automatically; no custom start command is required.

For SSH Git, add a Settings → Networking → TCP Proxy targeting port 2222. Keep the existing HTTPS domain for the web app. If Railway assigns shuttle.proxy.rlwy.net:15140, for example, configure:

PORT=8080
LATEXCODER_PORT=8080
LATEXCODER_SSH_PORT=2222
LATEXCODER_SSH_PUBLIC_HOST=shuttle.proxy.rlwy.net
LATEXCODER_SSH_PUBLIC_PORT=15140

SSH key management and SSH clone options appear only when both public endpoint variables are valid and the SSH listener starts successfully. Otherwise, the Git menu provides the existing access link.

Keep the HTTPS domain target port at 8080; HTTP and SSH must use different internal ports. Replace the example hostname and public port with your assigned TCP proxy address, then redeploy. The Git menu uses these values for SSH clone commands; the existing HTTPS access links remain available under Access link.

Configuration

Variable	Default	Purpose
LATEXCODER_ADMIN_PASSWORD	none	Creates the initial admin account on an empty database.
LATEXCODER_STATE_DIR	.latexcoder	SQLite database, projects, Git repositories, Yjs snapshots, build cache, and PDFs.
LATEXCODER_HOST	0.0.0.0	Listener address.
LATEXCODER_PORT	PORT or 8090	HTTP listener port.
LATEXCODER_SSH_PORT	2222	SSH Git listener port; enabled only with a valid public host and port.
LATEXCODER_SSH_HOST	0.0.0.0	SSH listener address.
LATEXCODER_SSH_PUBLIC_HOST	none	Required public hostname for SSH Git.
LATEXCODER_SSH_PUBLIC_PORT	none	Required external SSH port.
LATEXCODER_LATEX_BIN	auto-detected	Explicit Tectonic or latexmk executable.
LATEXCODER_TECTONIC_BUNDLE_URL	Tectonic default	Tectonic bundle mirror URL, useful when the default package bundle is slow or unavailable.
LATEXCODER_COMPILE_CONCURRENCY	2	Process-wide concurrent build limit.
LATEXCODER_RG_BIN	rg	ripgrep executable used by regex search.
LATEXCODER_BWRAP_BIN	bwrap	bubblewrap executable used to sandbox ripgrep.
LATEXCODER_SYNCTEX_BIN	synctex	SyncTeX executable used for source/PDF navigation.

GET /health/live is the liveness probe. GET /health/ready reports the SQLite schema version, compile queue, and detected external tools. Missing optional tools are reported without making the editor itself unready.

Data model

<state-dir>/
  state.sqlite
  projects/<project-id>/
    project/        source files and the project's .git directory
    build/          current compilation artifacts

SQLite is authoritative for users, invitations, sessions, membership, sharing, project settings, build state, trash, and Yjs snapshots. Source files and each project's Git repository remain directly accessible on disk.

The codebase is TypeScript throughout:

• src/client contains the React/Vite interface and browser controllers.
• src/server contains HTTP routes, Git/Yjs coordination, persistence, compilation, and bounded external processes.
• src/shared contains schemas, parsers, review macros, diagnostics, and source mapping used across environments.

Run the complete validation suite with:

pnpm check
pnpm test

Security model

LaTeX Coder is designed for trusted teams, not hostile multi-tenant workloads. Passwords are scrypt-hashed; invitations and capability URLs use high-entropy tokens; sessions and access records persist in SQLite. Anyone holding an Edit, Agent, or Git capability can modify that project within the capability's scope.

Regex search runs through ripgrep in a read-only bubblewrap sandbox with no network, a 15-second timeout, and a 4 MiB output limit. Literal search also works on macOS without bubblewrap. LaTeX compilation itself is not a security sandbox. Do not compile untrusted projects or store unrelated secrets inside project directories.

License

MIT