Free Coding Agent With Unlimited frontier models

Free Coding Agent has launched as an open-source, provider-neutral MCP execution layer that gives any MCP-capable frontier model controlled access to files, terminals, Git, language servers, browsers, Windows UI, jobs, checkpoints, tests and diagnostics, with no relay, domain, account, API key, tunnel or backend operated by the project. The tool ships a provider-neutral task kernel for autonomous and multi-agent coding whose durable loop runs task_submit, task_next/task_claim, worker edits, task_ready and task_verify, backed by an append-only fsync'd task journal, idempotency keys, explicit task DAGs, exclusive leaseKey ownership, cross-process journal locking, lease expiry that fails to interrupted rather than faking success, and configurable maximum repair rounds. Installation is a ZIP download, extraction and double-clicking install.cmd, after which the user chooses the folder the agent may access and optionally configures a personal HTTPS endpoint.

Give frontier AI models real hands on a real developer workstation. Free Coding Agent is an open-source, provider-neutral MCP execution layer that turns a capable model from a chat box into a hands-on software engineer. The model supplies the intelligence; Free Coding Agent supplies controlled access to files, terminals, Git, language servers, browsers, Windows UI, jobs, checkpoints, tests, and diagnostics. LM Arena describes Code Arena as a place to build and compare with frontier AI models. Free Coding Agent is designed to be a compatible execution layer for any host that supports MCP or equivalent remote tools. It is independent software and is not an LM Arena product. Free Coding Agent does not require a relay, domain, account, API key, tunnel, or backend operated by this project. Every installation is independent: - its own local configuration; - its own workspace allowlist; - its own MCP bearer token; - its own HTTP server; - its own HTTPS hostname/tunnel when remote access is enabled; - its own third-party account, if the user chooses a tunneling provider. There is no common Free Coding Agent relay and no common remote credential. - transactional filesystem reads/writes; - atomic multi-file patches and rollback checkpoints; - optimistic SHA-256 concurrency protection; - shell commands and long-running processes; - real PTY / ConPTY for REPLs, debuggers, SSH and TUIs; - Git status, diff, history and repository operations; - headless LSP diagnostics, definitions, references, hover and symbols; - project inspection and project-local memory; - Playwright browser automation; - optional real-Chrome companion extension; - optional VS Code companion extension; - Windows UI automation; - FFmpeg/media workflows; - resource admission to avoid CPU/RAM stampedes; - MCP batching and capability discovery; - local stdio MCP; - authenticated local HTTP MCP; - optional personal public HTTPS MCP. Free Coding Agent includes a provider-neutral task kernel for autonomous and multi-agent coding. It does not call or hardcode a model vendor: any MCP-capable model can act as a worker. The durable loop is: task submit ↓ task next / task claim ↓ worker edits + targeted checks ↓ task ready ↓ task verify ↙ ↘ repairing succeeded ↓ task claim → repair → task ready → task verify Important guarantees: - append-only task journal with fsync; - idempotency keys prevent duplicate submissions; - dependencies form explicit task DAGs; - exclusive leaseKey ownership prevents two workers from editing the same worktree at once; - cross-process journal locking prevents two MCP processes from racing the same task; - lease expiry and dead-owner recovery fail to interrupted , never fake success; - task next atomically assigns the highest-priority runnable work; - verification commands are executed as real processes in the task workspace; - tasks can require an independent logical verifier identity distinct from every implementation worker; - failed gates create an evidence-backed repair loop; - configurable maximum repair rounds prevent infinite retry loops; - only task verify can transition verified work to succeeded ; - task events provide a durable audit trail. Core tools: task submit task next task claim task heartbeat task ready task verify task update task reconcile task contract task status task list task events task stats task cancel This is the portable agent-control layer: the model may come from OpenCode, an MCP desktop host, an IDE, a self-hosted model, or another compatible client. The task kernel only coordinates ownership, state, evidence and verification. Worker/verifier IDs are logical identities supplied by the MCP host for coordination and audit; they are not authentication credentials. The normal installation flow is: Download ZIP → extract → double-click install.cmd → choose the folder the agent may access → optionally configure YOUR personal HTTPS endpoint → Ready The installer: 1. verifies Node.js 20+; 2. can install Node.js LTS when Windows Package Manager is available; 3. installs free-coding-agent globally; 4. configures the user's own workspace; 5. runs free-coding-agent doctor ; 6. optionally guides the user through personal HTTPS setup. The extracted installer folder can be deleted afterwards. For an MCP client running on the same machine, nothing public is needed: { "mcpServers": { "free-coding-agent": { "command": "free-coding-agent", "args": "stdio" } } } No domain. No TLS. No exposed port. No external service. For HTTP clients, Free Coding Agent uses the current MCP Streamable HTTP transport at POST /mcp . Deprecated legacy HTTP+SSE endpoints are intentionally not exposed in v3. When the model host is remote/cloud-based, it needs a public HTTPS URL that reaches the user's machine. Free Coding Agent's official remote model is personal self-configuration , not a shared relay. Run: free-coding-agent remote setup The setup uses the current user's own Tailscale account. Tailscale Funnel gives that machine its own stable HTTPS hostname under the user's tailnet: https://<device .<tailnet .ts.net/mcp Free Coding Agent then: - generates a strong MCP bearer token locally; - keeps the HTTP origin bound to 127.0.0.1 ; - exposes it only through that user's Funnel; - stores the URL/token only in that user's application-data directory; - adds a current-user startup entry for the local HTTP server; - prints the exact MCP configuration. Example output shape: { "mcpServers": { "free-coding-agent": { "url": "https://YOUR-PERSONAL-HOST.ts.net/mcp", "headers": { "Authorization": "Bearer YOUR LOCAL TOKEN" } } } } Tailscale documents Funnel hostnames as predictable/stable, automatically TLS-protected, and publicly reachable while the user's machine is online. Users who own a domain on Cloudflare can use a locally managed named Cloudflare Tunnel instead. The ownership model remains the same: their Cloudflare account + their domain + their tunnel + their DNS record + their local MCP token Cloudflare's documented flow is: cloudflared tunnel login cloudflared tunnel create <name cloudflared tunnel route dns <name-or-id <hostname cloudflared tunnel run <name-or-id A named tunnel can also be installed as an OS service. Free Coding Agent does not own or operate it. Because the open-source project should keep working independently of its author. With personal endpoints: - no project-operated server can go offline and break everybody; - no project operator sees MCP traffic; - no shared credential exists; - no shared customer/device database exists; - no central billing requirement exists; - users can replace Tailscale/Cloudflare with another provider; - users can self-host everything indefinitely. free-coding-agent free-coding-agent stdio free-coding-agent setup free-coding-agent remote setup free-coding-agent remote start free-coding-agent remote status free-coding-agent remote off free-coding-agent doctor free-coding-agent print-config The package is structured for public npm installation: npm install -g free-coding-agent free-coding-agent setup The npm package must exist in the registry before those commands can be used from npm directly. The agent can modify files and execute code, so remote exposure must fail closed. The personal HTTPS setup enforces: - a random local MCP API KEY ; - bearer authentication for every remote MCP request; - loopback-only local HTTP binding; - filesystem allowlisting via FCA ALLOWED ROOTS ; - no anonymous proxy access; - no secret committed to Git; - no project-wide tunnel or account; - no remote credentials shared between users. A remote URL without the user's bearer token cannot use the agent. Normal users should use the CLI instead of editing config manually. Important variables: | Variable | Purpose | |---|---| | FCA WORKSPACES | User's known workspaces | | FCA DEFAULT WORKSPACE | Default workspace | | FCA ALLOWED ROOTS | Filesystem sandbox | | FCA REMOTE PROVIDER | Personal remote provider | | FCA REMOTE URL | User's personal public MCP URL | | FCA TAILSCALE DNS NAME | User's personal Tailscale DNS name | | MCP API KEY | User's own HTTP bearer token | | MCP HOST | Local HTTP bind address | | PORT | Local HTTP port | | TASKS DIR | Durable task journal directory | | TASK LEASE TTL MS | Worker lease lifetime | | TASK MAX ACTIVE | Maximum simultaneously running task workers | | TASK MAX REPAIR ROUNDS | Maximum evidence-backed repair rounds | | TASK VERIFY TIMEOUT MS | Per verification-command timeout | | FCA CHROME BRIDGE ENABLED | Enable real-Chrome integration | | CHROME BRIDGE TOKEN | Local Chrome pairing secret | | CHROME EXTENSION ID | Optional extension identity pin | | VSCODE BRIDGE URL | Local VS Code companion endpoint | Configuration and runtime state live in standard per-user application-data directories, outside the repository. OpenCode supports both local and remote MCP servers. A personal Free Coding Agent HTTPS endpoint can be configured as a remote MCP server with bearer authentication. Conceptually: { "type": "remote", "url": "https://YOUR-PERSONAL-HOST/mcp", "oauth": false, "headers": { "Authorization": "Bearer YOUR LOCAL TOKEN" } } Use OpenCode's current configuration schema/documentation for the surrounding config structure. Arena's public documentation describes Agent Mode and Code Arena as environments for agentic coding and frontier-model comparison. Free Coding Agent does not scrape or automate Arena's private UI/API. If Arena exposes a supported MCP or compatible remote-tool integration, the user's personal HTTPS MCP endpoint is ready for it. This distinction is intentional: the open-source agent remains standards-based and does not depend on undocumented consumer-site behavior. References: The optional extension gives the local MCP server controlled access to the user's real Chrome. 1. Load chrome-extension as an unpacked extension. 2. Configure a local CHROME BRIDGE TOKEN . 3. Enter the same token in the extension popup. 4. Optionally pin the assigned extension ID. No fixed extension identity key is stored in this repository. The optional extension exposes loopback-only editor state: - diagnostics; - references; - definitions; - open files; - debugger state. Configuration key: freeCodingAgent.port Default port: 3005 . npm install npm run check npm run privacy npm run preflight npm test The public source tree intentionally excludes: - local .env files; - API keys; - tunnel credentials; - machine-specific paths; - user names and email addresses; - conversation archives; - browser profiles; - screenshots and clips; - logs, checkpoints and job state; - local memory; - fixed Chrome extension identity keys; - provider-account-specific orchestration. npm run privacy fails if common secrets, email addresses, absolute Windows paths, or user-home paths appear in publishable source. ISC. See LICENSE .