{"slug": "show-hn-reachpad-mcp-share-fullstack-applications-using-mcp-cli-in-minutes", "title": "Show HN: Reachpad MCP – Share fullstack applications using MCP/CLI in minutes", "summary": "Reachpad launched Reachpad MCP, an MCP server that lets coding agents like Claude, ChatGPT, Cursor, and OpenCode create, fork, and persist cloud development environments via a REST API, CLI, or SDK. The tool supports persistent snapshots, forking, and brokered credentials, and is available via npx with configuration through environment variables.", "body_md": "**Development infrastructure for coding agents.** A reachpad environment is a\ncloud development computer an agent operates itself: a repo, a filesystem,\ninstalled dependencies and build state that all survive between calls — not an\nephemeral sandbox that forgets. Processes are the exception; see below.\n\nThis is the MCP server. It lets Claude, ChatGPT, Cursor, OpenCode or your own agent create an environment, run commands in it, fork it, and come back to it later, without a developer keeping a laptop open for them.\n\n**It persists.** Pause it and the disk is sealed; the next call boots from that seal with the files, installs and git state intact, rather than rebuilding. Processes are the exception: a start is always a cold boot.**It forks.** Twenty attempts from one prepared state cost a delta each, not twenty rebuilds — because the environment is a snapshot chain, not a machine.**It can keep secrets out of the box.** A brokered credential is called at the boundary on your behalf and its value never enters the environment, the log or the store. A credential written into the environment instead is readable there, by design.**It is agent-agnostic.** The REST API is canonical; this server, the SDK and the CLI are translations of it. Bring your own agent.\n\nThe API is the product boundary, not a web UI: [reachpad.dev](https://reachpad.dev).\n\n```\nnpx -y @reachpad/mcp          # stdio, for a local client\n```\n\nIn Claude Code:\n\n```\nclaude mcp add reachpad -e REACHPAD_IDENTITY_CREDENTIAL=… -- npx -y @reachpad/mcp\nnpx @reachpad/mcp                                  # stdio\nREACHPAD_MCP_HTTP_PORT=8722 npx @reachpad/mcp      # streamable http\n```\n\nstdio is what a local client talks to; Streamable HTTP is what a remote connector talks to. Same tools, same behaviour — added rather than forked, because two implementations of one surface is how they drift.\n\nThe HTTP side answers **405 to GET**: every tool here is request/response, and\nthe spec permits declining the server-initiated stream rather than holding a\nconnection open for traffic that never comes. There are\n\n**no sessions**— nothing is held across calls that a restart could not rebuild. And it carries\n\n**no credential of its own**: whatever authorizes the HTTP request is what authorizes reachpad.\n\n| variable | meaning |\n|---|---|\n`REACHPAD_ENDPOINT` |\nyour reachpad host. Plaintext `http://` to anything but loopback is refused before a socket opens. |\n`REACHPAD_IDENTITY_CREDENTIAL` |\nyour per-user credential. It names one account and can act for no other — the server takes the identity from the credential's own record, never from the request. |\n`REACHPAD_API_KEY` |\noptional, per-environment scoped and revocable. When set, `run_command` uses it and needs no identity exchange. |\n`REACHPAD_MCP_HTTP_PORT` |\nserve HTTP instead of stdio. |\n`REACHPAD_MCP_HTTP_HOST` |\ndefault `127.0.0.1` . This process bridges to a control plane with your credentials, so binding it to the world is a decision made on purpose, behind a proxy that terminates TLS. |\n`REACHPAD_MCP_HTTP_TOKEN` |\nbearer token, compared in constant time. Absent, every caller that can reach the port is authorized, and the server says so on stderr. |\n`REACHPAD_MCP_ALLOWED_ORIGINS` |\ncomma-separated. A request carrying an unlisted `Origin` is refused — a browser cannot forge it, which closes DNS rebinding. No `Origin` at all is a non-browser client and is allowed. |\n\nIf several credentials are set, the narrowest wins, and **a refused credential\nis never retried under a broader one** — falling back would be privilege\nescalation nobody chose to perform.\n\n| tool | what it does |\n|---|---|\n`get_credit_balance()` |\nremaining compute credits. One credit runs one standard environment for one minute. |\n`create_environment(repo?, ref?, name?)` |\na new environment, optionally with a repository cloned into `/work` . Reachpad generates its display name when omitted. |\n`list_environments()` |\nyour environments and how many forks each has |\n`get_environment(environment)` |\nwhat it boots from: its head snapshot, its log position and its fork tree |\n`run_command(environment, argv, cwd?, env?, timeout_ms?)` |\none command, its exit code and its output. A paused environment resumes to serve it. |\n`checkpoint_environment(environment, name?)` |\nfork from the last sealed snapshot; the original is untouched |\n`delete_environment(environment)` |\narchive it and free the plan slot. Nothing is deleted — snapshots and history survive. |\n\n**Not here, deliberately:** exposing a port and starting an agent inside the\nenvironment. Both are in reachpad's roadmap and neither is in the fleet yet — a\ntool that always fails costs a model a turn and teaches it to distrust the rest,\nso this server advertises nothing it cannot serve.\n\nThese are the ways a naive client of a streaming exec API misleads a model, and what this one does instead.\n\n**An unterminated stream is UNKNOWN, never success.** If the response ends without a terminal event, the tool says so in those words. It is not a zero exit, and an agent must not retry a non-idempotent command on the strength of it.**Its deadline is looser than the server's**, so a server-side answer always wins the race. A client that gives up first turns \"your build finished\" into \"unknown\", and the numbers are mirrored from the server rather than guessed.**Refusals carry remedies, not codes.** At your plan limit you get the limit, your current count, and what to do — the numbers come from the server, because a limit hardcoded in a client is a lie the moment your plan changes.**Results are handles, not payloads.** Output is tailed with the dropped byte count named. Build logs can be megabytes, and an MCP result that size destroys the caller's context window.**A refusal is a result, not a transport error**, so the model can read it and act. Only an unknown*tool*is a protocol error.\n\n```\nnode --test 'test/*.test.mjs'\n```\n\nNo network and no credentials. The protocol suite spawns the shipped server as a child process and speaks real JSON-RPC over its stdio against a stub control plane on a real socket, so nothing under test is an internal import. One test runs the same arc against a real reachpad and skips when no endpoint is configured.\n\nThis repository is the source. It is deliberately **separate from the reachpad\nbackend**: this code is public, it is published to npm, and its release\nworkflow holds publishing rights — none of which belong in the same repository\nas the control plane. Nothing here can read the backend's source, and no job in\nthe backend copies files out to here.\n\nTwo server constants are mirrored in `src/client.js`\n\n— the exec grace period\nand the default exec timeout. A mirrored constant normally rots; this one does\nnot, because the backend's own CI fetches this published package and fails if\nthey disagree. The check lives where the number would change.", "url": "https://wpnews.pro/news/show-hn-reachpad-mcp-share-fullstack-applications-using-mcp-cli-in-minutes", "canonical_source": "https://github.com/Reachpad/reachpad-mcp", "published_at": "2026-08-22 07:02:07+00:00", "updated_at": "2026-08-22 07:13:34.172375+00:00", "lang": "en", "topics": ["developer-tools", "ai-agents", "ai-infrastructure"], "entities": ["Reachpad", "Claude", "ChatGPT", "Cursor", "OpenCode"], "alternates": {"html": "https://wpnews.pro/news/show-hn-reachpad-mcp-share-fullstack-applications-using-mcp-cli-in-minutes", "markdown": "https://wpnews.pro/news/show-hn-reachpad-mcp-share-fullstack-applications-using-mcp-cli-in-minutes.md", "text": "https://wpnews.pro/news/show-hn-reachpad-mcp-share-fullstack-applications-using-mcp-cli-in-minutes.txt", "jsonld": "https://wpnews.pro/news/show-hn-reachpad-mcp-share-fullstack-applications-using-mcp-cli-in-minutes.jsonld"}}