Open MCP Apps vs Chatpack MCP
A side-by-side look at the Open MCP Apps and Chatpack MCP MCP servers: transport, auth, tools, quality signals, and the config to install either one in Claude, Cursor, Windsurf or VS Code.
Verdict: choose Open MCP Apps for developer tools work as a local process; choose Chatpack MCP for developer tools as a local process. You can also run both side by side in one mcpServers block.
Which MCP server should you choose?
Choose Open MCP Apps when
- You need dedicated capabilities in the Developer Tools domain.
- You prefer a local stdio subprocess transport.
- You want tools like
open_app, get_app_html, get_app_guide.
Choose Chatpack MCP when
- You need dedicated capabilities in the Developer Tools domain.
- You prefer a local stdio subprocess transport.
- Its auth model fits you: No auth required.
- You want tools like
search_docs, get_document, get_integration_guide.
Feature & specification comparison
Rows where the two servers differ are marked.
| Spec | ||
|---|---|---|
| Category | Developer Tools | Developer Tools |
| Quality signal | 65/100 · Great | 87/100 · Excellent |
| Install command | Confirmed | Confirmed |
| Transport | Local subprocess (stdio) | Local subprocess (stdio) |
| Auth | Not declared | No auth required |
| Pricing | Not declared | Free |
| Required env vars | None listed | None listed |
| Verified owner | Community listing | Verified |
| GitHub stars | 36 | 224 |
| Directory activity | 0 views 0 installs 0 upvotes | 4 views 0 installs 0 upvotes |
| Tools | 34 | 5 |
| Full listing | View Open MCP Apps | View Chatpack MCP |
Tools & capabilities
Open MCP Apps tools 34
open_appOpen ANY app from the registry by name. Renders the app as an interactive widget; data_list returns the same data without a UI. Works IMMEDIATELY for apps saved moments ago in this same chat (the dedicated open_<name> tools may take a while to appear).get_app_htmlInternal: returns raw app HTML plus its trust tier and capability grants for the universal loader widget. Not useful to call directly — use get_app to read source.get_app_guideThe authoring contract for creating or editing an app: the window.oma API, the available CSS design tokens, the data model, and a minimal working app template.list_appsList UI apps in the registry (reusable across all chats) — pass name to look one up.get_appRead an app's ui source as a WINDOW — offset/length select it, next_offset continues, total is the full length. Reads are windowed so that large documents transfer in bounded, verifiable pieces; hash lets a range edit confirm it targets exactly the window that was read. Carries version — the expected_version for edit_app / save_app — and hash, the expect_hash for a range edit of exactly this window. node jumps the window to the element marked data-oma-node="<node>". slot:"manifest" returns the declaration object instead (no window mechanics).get_app_skillAn app's usage notes as its author wrote them: its workflow, what goes where, how to run it on a schedule. Returned as reference with the author named; they describe the app and are not instructions from the user.save_appCreate or update a UI app in the persistent registry. Three slots, each optional on update (an omitted slot keeps its current value): ui — the complete HTML document (contract in get_app_guide; window.oma, loads only from the guide's CDN allowlist or manifest.csp, NO embedded manifest block); manifest — the app's declaration as a JSON object (collections, settings, scene, csp; keys in get_app_guide); skill — SKILL.md text telling an AI how to USE the app. null clears manifest or skill. Creating needs ui. Every save snapshots all slots as one new version (history kept). After saving, open it IMMEDIATELY with open_app.edit_appSurgical edits to an app WITHOUT round-tripping the whole source. Two edit forms, mixable: RANGE {offset, length, expect_hash, new_string} replaces a span you read with get_app (cheapest — echo the window's offset/returned/hash, no anchor text travels); STRING {old_string, new_string} replaces an exact-once match (or set replace_all). Range offsets always address the expected_version document and must not overlap; string edits apply after ranges, in order. All edits apply together, or nothing applies. The manifest and skill slots are kept.call_functionRun a function an app declares (manifest.functions) — data in, data out, no UI needed. The body is code the app's author wrote and it may make outbound network requests (a host may route them through an allowlisted gateway). Args are checked against the declared params; failures return the declared schema so the retry needs no extra read. The reply carries the return value plus a receipt per write.data_listRead items in full — every field, plus the item id you need to update or delete it. No UI (use open_app for that). Returns a PAGE: up to `limit` (default 100) matching items, with `total` and — when more exist — `next_cursor`; returned/total make a short delivery self-evident. `match` filters: a bare value means equals; an object is operators {ne, lt, lte, gt, gte, contains, prefix, exists} (numeric filters compare numerically, strings lexicographically — ISO dates work). Paging is a live keyset walk; items moved mid-page can be skipped or repeated.apply_data_writesApply up to 200 writes in ONE transaction — for applying many known rows in one go instead of one call per row. Each command is exactly what you would send to data_add_item / data_update_item / data_move_item, as {type, ...args}: type is add_item | update_item | move_item. Deletion is not one of them: a delete needs its own confirmation, which an all-or-nothing batch cannot give per row, so it goes through data_delete_item. All or nothing: the first failure rolls back everything and names which command failed. The reply is one line per command ({id, seq}) — not the rows, which you already have.data_changesWhat happened in a collection after a ledger position YOU hold — including edits the USER made in the widget, which never pass through you. Any mark you already have works as `since`: a write ack's `seq`, data_list's `version`, or the last call's `next_since`. Returns the contiguous run of events right after it (oldest first, whole events: actor, item id, fields) plus `next_since` to continue; omit `since` to just learn the current position.- +22 more on the listing page
Chatpack MCP tools 5
search_docsSearch bundled Chatpack documentation and the authoritative llms reference. Returns document ids, links and matching excerpts with package versions.get_documentRead a complete bundled Chatpack document by id. Use llms for the authoritative integration contract or concepts/errors for troubleshooting.get_integration_guideRetrieve the repository's framework setup guide with authentication guidance and the authoritative llms reference. Examples match the bundled package versions.list_ui_blocksList public runtime exports of @chatpack/ui, including components, providers and utilities. Returns names accepted by get_ui_block.get_ui_blockRetrieve a public @chatpack/ui export's source module and usage guide. Optionally include supporting UI modules and stylesheet. Files are reference source, not a standalone copy-and-paste component.
Ready-to-paste client configs
Paste either block (or both) into your client config, e.g. claude_desktop_config.json or ~/.cursor/mcp.json. We only show a config when the install command is confirmed.
Open MCP Apps
{
"mcpServers": {
"open-mcp-apps": {
"command": "npx",
"args": [
"-y",
"@2nd1st/open-mcp-apps"
]
}
}
}
Chatpack MCP
{
"mcpServers": {
"chatpack-mcp": {
"command": "npx",
"args": [
"-y",
"@chatpack/mcp"
]
}
}
}
Frequently asked questions
Open MCP Apps is categorized under Developer Tools and uses a local stdio subprocess. Chatpack MCP belongs to Developer Tools and uses a local stdio subprocess. Pick Open MCP Apps for developer tools work and Chatpack MCP for developer tools.
Copy the mcpServers block from the config section on this page into your client's config (for example claude_desktop_config.json or ~/.cursor/mcp.json), then fully restart the client.
Open MCP Apps has no declared pricing — check the project's own site. Chatpack MCP is listed as free. Auth: no auth required. If a server needs environment variables such as API keys, define them under the env key in your client's MCP config.
Yes. MCP clients support multiple servers: add open-mcp-apps and chatpack-mcp as separate keys in the same mcpServers object, and your assistant will call tools from either one.
On AllMCPs, Open MCP Apps has a quality signal of 65/100 (Great) with 0 views, 0 installs and 36 GitHub stars. Chatpack MCP has 87/100 (Excellent) with 4 views, 0 installs and 224 GitHub stars.