Lousa vs Semiotic
A side-by-side look at the Lousa and Semiotic MCP servers: transport, auth, tools, quality signals, and the config to install either one in Claude, Cursor, Windsurf or VS Code.
Verdict: choose Lousa for data visualization work as a local process; choose Semiotic for data visualization as a local process. You can also run both side by side in one mcpServers block.
Which MCP server should you choose?
Choose Lousa when
- You need dedicated capabilities in the Data Visualization domain.
- You prefer a local stdio subprocess transport.
- You have the keys it needs:
PORT, HOST, LOUSA_DATA_DIR, LOUSA_BUCKET, LOUSA_TOKEN, LOUSA_URL, LOUSA_DEFAULT_TTL_HOURS. - You want tools like
create_board, update_board, get_board.
Choose Semiotic when
- You need dedicated capabilities in the Data Visualization domain.
- You prefer a local stdio subprocess transport.
- Its auth model fits you: No auth required.
- You want tools like
renderChart, renderInteractiveChart, getSchema.
Feature & specification comparison
Rows where the two servers differ are marked.
| Spec | ||
|---|---|---|
| Category | Data Visualization | Data Visualization |
| Quality signal | 51/100 · Good | 71/100 · Great |
| Install command | Confirmed | Confirmed |
| Transport | Local subprocess (stdio) | Local subprocess (stdio) |
| Auth | Not declared | No auth required |
| Pricing | Not declared | Free |
| Required env vars | PORTHOSTLOUSA_DATA_DIRLOUSA_BUCKETLOUSA_TOKENLOUSA_URLLOUSA_DEFAULT_TTL_HOURS | None listed |
| Verified owner | Community listing | Community listing |
| GitHub stars | 0 | 2,716 |
| Directory activity | 0 views 0 installs 0 upvotes | 6 views 0 installs 0 upvotes |
| Tools | 5 | 18 |
| Full listing | View Lousa | View Semiotic |
Tools & capabilities
Lousa tools 5
create_boardCreates a board from a scene, returns `{id, url}update_boardReplaces the scene; unchanged elements stay byte-identical so only changes animateget_boardRead boardsget_selectionWhat the user selected in the viewer (ids + full elements)delete_boardDeletes a board
Semiotic tools 18
renderChartRender a Semiotic chart to static SVG. Supports the components returned by `getSchema` that are marked `[renderable]`. Pass `{ component: "LineChart", props: { data: [...], xAccessor: "x", yAccessor: "y" } }`. Returns SVG string plus a "Render evidence" JSON block (mark counts by scene type, resolv…renderInteractiveChartRender a static-data chart as a ChatGPT Apps widget. Uses the same Semiotic server render path as `renderChart`, then hydrates an iframe UI with fit, zoom, data, hover, and render-evidence controls.getSchemaReturn the prop schema for a specific component. Pass `{ component: "LineChart" }` to get its props, or omit `component` to list the complete schema-backed catalog. Components marked `[renderable]` are available through `renderChart`; realtime charts require a browser/live environment.suggestChartSample-row recommender. Pass `{ data: [{...}, ...] }` with 1–5 sample objects plus optional broad intent/capability filters.suggestChartsCapability-based recommender for bounded row data. Returns ranked chart suggestions with scores, reasons, caveats, import paths, and ready-to-use props.suggestStreamChartsRecommend streaming charts from a schema (shape, key, throughput). Returns `{ suggestions, excluded, stretchSuggestions }`.suggestStreamDashboardCompose a multi-panel dashboard from stream schemas and an audience layout policy.suggestDashboardBuild a multi-panel dashboard suggestion that covers distinct analytical intents.suggestStretchChartsRecommend audience-literacy stretch picks from an `AudienceProfile`.repairChartConfigCheck whether a requested chart fits a dataset and return ranked alternatives when it does not.interrogateChartReturn a statistical summary and chart-aware context for answering natural-language questions with optional annotations.diagnoseConfigCheck a chart configuration for common problems — empty data, bad dimensions, missing accessors, wrong data shape, and more. Returns a human-readable diagnostic report with actionable fixes.- +6 more on the listing page
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.
Lousa
{
"mcpServers": {
"lousa": {
"command": "npx",
"args": [
"-y",
"lousa"
],
"env": {
"PORT": "YOUR_PORT_HERE",
"HOST": "YOUR_HOST_HERE",
"LOUSA_DATA_DIR": "YOUR_LOUSA_DATA_DIR_HERE",
"LOUSA_BUCKET": "YOUR_LOUSA_BUCKET_HERE",
"LOUSA_TOKEN": "YOUR_LOUSA_TOKEN_HERE",
"LOUSA_URL": "YOUR_LOUSA_URL_HERE",
"LOUSA_DEFAULT_TTL_HOURS": "YOUR_LOUSA_DEFAULT_TTL_HOURS_HERE"
}
}
}
}
Semiotic
{
"mcpServers": {
"nteract-semiotic": {
"command": "npx",
"args": [
"-y",
"-p",
"semiotic",
"semiotic-mcp"
]
}
}
}
Frequently asked questions
Lousa is categorized under Data Visualization and uses a local stdio subprocess. Semiotic belongs to Data Visualization and uses a local stdio subprocess. Pick Lousa for data visualization work and Semiotic for data visualization.
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.
Lousa has no declared pricing — check the project's own site. Semiotic 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 lousa and nteract-semiotic as separate keys in the same mcpServers object, and your assistant will call tools from either one.
On AllMCPs, Lousa has a quality signal of 51/100 (Good) with 0 views, 0 installs and 0 GitHub stars. Semiotic has 71/100 (Great) with 6 views, 0 installs and 2,716 GitHub stars.