Show HN: Cerea – yet another self-hosted LLM chat front end

A self-hosted chat for any OpenAI-compatible endpoint, with knowledge bases, artifacts, Python in the browser, and coding agents on your own machines. The name. Cerea is a Turinese modo di dire: a historic, affectionate greeting that means both buongiorno and arrivederci. Cerea and Pystino Cerea is one half of a pair. Each half solves a different problem, and each runs on its own: Cerea (this repository) serves the people using models: the chat, its knowledge, artifacts and tools, and galopin, which pairs coding agents on a person's own machine. Pystino serves the organisation paying for them: an OpenAI-compatible gateway with per-user and per-group accounting, quotas, PII redaction, model access and an admin console. Cerea alone runs against any OpenAI-compatible endpoint with one shared key. Pystino alone serves any OpenAI or Anthropic client. Together they are the intended setup: the chat calls Pystino's /v1 with each person's own sign-in token, so spend, quotas and model access follow the person, and the gateway adds web search, a local document reader and metered coding agents. Below, the gateway means Pystino. The deploy kit in this repository (kit/) runs both together, or the chat alone. Features Unmarked features work against any endpoint; those marked (Pystino) need the gateway. Chat over any model your endpoint serves, signed in with OIDC. With Pystino each call carries the person's own token, so quotas and billing are theirs; without it, every call uses the one key you configure. The stack currently signs the chat and the console in against one provider; to combine several sources of users, federate them in your own IdP (Keycloak, Authentik and the like). Web search (Pystino), run by the deployment's search backends through the gateway, with the backend chosen in Administration → Web search (the gateway can also meter provider-side search where a model offers it). File upload and extraction: PDFs, Office documents (old .doc too), images and text, read once at upload. With Pystino, extraction goes through the gateway and can stay inside your deployment; without it, PDFs and images go to an OCR endpoint you name (CHAT_OCR_BASE_URL). Scanned PDFs reach a model that sees images as page images. Artifacts: HTML, React and Mermaid previews in sandboxed frames with no network access, and generated files (see the next item). Word, Excel, PowerPoint and PDF files: the assistant creates and edits them through the bundled document service, saving each edit as a new version and leaving the original alone. Styling by asking, or from a template you upload; designed slides with backgrounds and shapes; native charts (docs/office.md). Skills and connectors: built-in skills for office files and data analysis (docs/skills.md), and remote MCP servers as connectors (docs/connectors.md). Knowledge bases and projects, shareable with people or groups, with an optional project memory (docs/knowledge.md). Python in your browser, in a WebAssembly sandbox with the scientific and office libraries (docs/pyodide.md). Your own models and look: a global system prompt and private custom models (a base model plus a prompt) under Workspace → Customize models, a searchable list of every chat at /chats, and accent and background palettes (docs/chat.md). The /code agents panel: coding agents on your own machines through galopin, with a file explorer, scheduled actions (a prompt sent to a session on a timetable) and, off by default, a browser terminal. With Pystino the agents' model calls are metered like the chat's; without it they use opencode's own providers. Quick start The deploy kit, the kit/ directory of this repository, runs the full stack by default: the chat, Pystino and its console, a bundled identity provider, a TLS proxy and the add-ons. It is one compose.yaml, a documented .env.example, and a ./configure script. Its installer fetches only that directory: curl -fsSL https://raw.githubusercontent.com/paoloviviani/Cerea/stable/kit/get-kit.sh | sh cd cerea/kit ./configure docker compose up -d It also covers a chat-only install, against a central Pystino (--preset satellite) or any OpenAI-compatible endpoint without Pystino (--preset generic). What each shape gives and lacks is in docs/deploy.md; the chat also runs without the kit. Configuration Cerea reads its settings from the environment. The ones that matter most: The deployment's full, commented list is the kit's .env.example; .env here lists every variable the app understands. galopin runs next to the coding agent (opencode) on a person's machine, dials out to Cerea with its own OIDC credential, and is confirmed by its owner in /code. What a machine allows (the permission ceiling, workspace roots, files, the terminal) is fixed on the machine at enroll time; the terminal also needs CODE_TERMINAL_ENABLED=true on the deployment. See docs/code-panel.md (operators), docs/agent-machines.md (users; the reference has the depth) and agent/PROTOCOL.md (the wire protocol). Development npm ci # also installs the git hooks (husky) cp .env .env.local # then set OPENAI_BASE_URL, OPENAI_API_KEY and friends npm run dev # http://localhost:5173 npm run check && npm run lint Tests: npm run test (server and ssr Vitest projects; on a CPU without AVX point them at a real MongoDB with TEST_MONGODB_URL and add --no-file-parallelism), npm run test:client (the component tests, in a real browser), npx playwright test (end to end; E2E_SKIP_BUILD=1 reuses build/) and cd agent && go test ./... (galopin, which needs Go 1.24+). Toolchains, git hooks, every test layer, CI, releasing and the repository's conventions are in CONTRIBUTING.md, which is also the Development page of the documentation. The image fixes SvelteKit's base path at build time, and builds galopin too: docker build --build-arg APP_BASE=/chat -t cerea . Cerea began as a fork of huggingface/chat-ui, with its history intact, and is now a hard fork: it does not merge upstream and carries nothing for upstream's sake. The attribution stays in NOTICE. Documentation The documentation is a mkdocs site built from docs/: chat · artifacts · pyodide · skills · knowledge · connectors · agent-machines · agent-machines-reference · browser · deploy · deploy-kit · configuration · chat-admin · code-panel · reference · development · PRIVACY. Build it with uv run --with-requirements docs/requirements.txt mkdocs build --strict (there is no Python project in this repository; the pins are in docs/requirements.txt). Pystino's documentation lives in its own repository. docs/source is upstream chat-ui's documentation, kept as upstream wrote it, excluded from the site; parts of it do not apply to Cerea. Contributing, security, licence See CONTRIBUTING.md and, for vulnerabilities, SECURITY.md. Cerea is Copyright 2026 Paolo Viviani and licensed under the Apache License 2.0; NOTICE records that it is based on huggingface/chat-ui, © Hugging Face, and carries the third-party notices. How this code was written is disclosed in AI-DISCLOSURE.md. Acknowledgments This work is supported by LINKS Foundation.