Infino MCP server
An MCP server for Infino — it lets an AI agent run keyword, semantic, hybrid, and SQL retrieval over your data on object storage, from any MCP-compatible client (Claude Code, Claude Desktop, Cursor, VS Code, and others). Published on npm as @infino-ai/mcp-server and listed on the official MCP Registry as io.github.infino-ai/mcp-server (which propagates to catalogs like Smithery, Glama, and PulseMCP).
- Local embeddings, no key. Semantic search embeds queries with a local model — nothing leaves the machine for embedding.
- The agent owns the data. Every tool, writes included, is always available. On Infino Cloud the API key's capabilities decide what a connection may do; every tool carries MCP annotations so your client can ask before a destructive call.
- Local or hosted. Point it at a local path, your own bucket (S3, Azure, or any S3-compatible store), or a hosted Infino Cloud endpoint with an API key.
Contents
- Requirements
- Quick start
- Claude Code plugin (one-step install)
- Client setup
- Configuration
- Tools
- Security & data handling
- How retrieval works
- Troubleshooting
- Local development
- License
Requirements
- Node.js ≥ 18 (the server runs as a Node process over stdio).
- An MCP-compatible client (Claude Code, Claude Desktop, Cursor, VS Code, …).
- Data reachable by Infino — a local directory, a bucket with credentials available in the environment, or a hosted Infino Cloud endpoint with an API key (see Storage backends).
- On first run the server downloads the local embedding model (~90 MB) once and caches it; subsequent runs are offline for embedding.
Quick start
The server is launched by your MCP client over stdio — you don't run it directly in normal use. Every client config follows the same shape: command npx -y @infino-ai/mcp-server, with configuration supplied via environment variables. Set INFINO_MCP_URI to the data you want to serve — a local path or a bucket URI. If it's omitted, the server uses a durable per-user directory (~/.infino/mcp) so data persists across restarts; point INFINO_MCP_URI at your own path or bucket to serve existing data.
{
"command": "npx",
"args": ["-y", "@infino-ai/mcp-server"],
"env": {
"INFINO_MCP_URI": "/Users/me/.infino/memory"
}
}
To serve a hosted Infino Cloud database instead, point INFINO_MCP_URI at
the https://<host>/<database> endpoint and supply your API key. Everything
else is identical:
{
"command": "npx",
"args": ["-y", "@infino-ai/mcp-server"],
"env": {
"INFINO_MCP_URI": "https://api.platform.infino.ws/my-database",
"INFINO_API_KEY": "inf_…"
}
}
The sections below show the exact place each client expects this block.
Claude Code plugin (one-step install)
For Claude Code, this repo is also a plugin marketplace. Installing the plugin wires up the MCP server plus a how-to-use skill and an /infino-search command in one step — no JSON to edit. Inside Claude Code:
/plugin marketplace add infino-ai/infino-mcp
/plugin install infino@infino-ai
On enable you'll be prompted for your Infino data URI (INFINO_MCP_URI) and, for Infino Cloud, your API key. That's it: the infino_* tools, the using-infino skill, and /infino-search <query> are then available. (Other clients: use the Client setup configs below.)
Client setup
Claude Code
Add the server with the CLI. Use --scope user to make it available in every project, or --scope project to commit it to the repo (writes a shared .mcp.json); the default scope is local (this project only).
claude mcp add infino \
--scope user \
-e INFINO_MCP_URI=/Users/me/.infino/memory \
-- npx -y @infino-ai/mcp-server
Add more knobs with repeated -e flags, e.g. -e INFINO_MCP_VALIDATE=true. Verify with:
claude mcp list
claude mcp get infino
Claude Desktop
Edit the configuration file (create it if it doesn't exist), then fully restart Claude Desktop.
| OS | Path |
|---|---|
| macOS | ~/Library/Application Support/Claude/claude_desktop_config.json |
| Windows | %APPDATA%\Claude\claude_desktop_config.json |
| Linux | ~/.config/Claude/claude_desktop_config.json |
{
"mcpServers": {
"infino": {
"command": "npx",
"args": ["-y", "@infino-ai/mcp-server"],
"env": {
"INFINO_MCP_URI": "/Users/me/.infino/memory"
}
}
}
}
Cursor
Add the server to ~/.cursor/mcp.json (available in all projects) or <project>/.cursor/mcp.json (this project only), then reload. The format matches Claude Desktop:
{
"mcpServers": {
"infino": {
"command": "npx",
"args": ["-y", "@infino-ai/mcp-server"],
"env": {
"INFINO_MCP_URI": "/Users/me/.infino/memory"
}
}
}
}
VS Code
VS Code (1.102+) reads MCP servers from .vscode/mcp.json in the workspace (or your user mcp.json via the command palette → MCP: Open User Configuration). Note the top-level key is servers and each entry declares "type": "stdio":
{
"servers": {
"infino": {
"type": "stdio",
"command": "npx",
"args": ["-y", "@infino-ai/mcp-server"],
"env": {
"INFINO_MCP_URI": "/Users/me/.infino/memory"
}
}
}
}
Other MCP clients
Any client that speaks MCP over stdio works. Configure it to launch:
command: npx
args: -y @infino-ai/mcp-server
env: INFINO_MCP_URI=<path-or-bucket-uri> (plus any options below)
Logs are written to stderr so they never corrupt the JSON-RPC stream on stdout — point your client's log capture there when debugging.
Configuration
All configuration is via environment variables — there are no config files and no command-line flags to manage.
Environment variables
| Variable | Required | Default | Description |
|---|---|---|---|
INFINO_MCP_URI | No | ~/.infino/mcp (persistent) | Data to serve: a local path (/Users/me/.infino/memory), a bucket URI (s3://…, az://…), or a hosted endpoint (https://<host>/<database>, Infino Cloud). If unset, a durable per-user directory (~/.infino/mcp) is used so data persists across restarts; it falls back to an ephemeral in-process catalog (memory://) only if that directory can't be created. |
INFINO_API_KEY | With a hosted URI | — | API key (inf_…) for a hosted https:// endpoint. Required when INFINO_MCP_URI is an https:// URI; ignored for local and object-storage connections. |
INFINO_MCP_EMBED_PROVIDER | No | local | Embedding provider: local (Hugging Face transformers.js, no key, nothing leaves the machine) or openai (any OpenAI-compatible /embeddings endpoint — OpenAI, Azure OpenAI's /openai/v1 surface, or a compatible server). Inferred as openai when INFINO_MCP_EMBED_BASE_URL is set. |
INFINO_MCP_EMBED_BASE_URL | With openai | — | Base URL of the OpenAI-compatible embeddings API, e.g. https://api.openai.com/v1 or https://<resource>.openai.azure.com/openai/v1. The server POSTs to <base>/embeddings. |
INFINO_MCP_EMBED_API_KEY | No | — | API key for the openai provider. Sent as both Authorization: Bearer and api-key, so one value works for OpenAI and Azure OpenAI. Omit to call an unauthenticated or ambient-identity endpoint. |
INFINO_MCP_EMBED_MODEL | No | Xenova/all-MiniLM-L6-v2 (local) · text-embedding-3-small (openai) | The embedding model. For local, a Hugging Face feature-extraction model; for openai, the model/deployment name. Must match the model that produced the table's stored vectors — and therefore its vector-index dimension (e.g. text-embedding-3-small is 1536-dim; the default local model is 384-dim). |
INFINO_MCP_VALIDATE | No | off | When set (1/true/yes), probes the object store at startup so bad credentials or an unreachable bucket fail then instead of on the first search. |
Cloud credentials are read from the standard provider environment variables — the server maps them to the store's config and introduces no credential vars of its own. Omit them entirely to use ambient cloud identity (an IAM instance role or Azure managed identity).
Serving a catalog embedded with OpenAI / Azure OpenAI. If your tables were vectorized with a hosted embedding model rather than the local default, point the server at that same model so query and document vectors align:
"env": {
"INFINO_MCP_URI": "s3://my-bucket/infino",
"INFINO_MCP_EMBED_PROVIDER": "openai",
"INFINO_MCP_EMBED_BASE_URL": "https://my-resource.openai.azure.com/openai/v1",
"INFINO_MCP_EMBED_API_KEY": "…",
"INFINO_MCP_EMBED_MODEL": "text-embedding-3-small"
}
The model must match what produced the stored vectors — a mismatch yields meaningless similarity or a dimension error. Keyword and SQL search are unaffected by the embedder.
| Backend | Credentials |
|---|---|
| AWS S3 | AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY (+ AWS_SESSION_TOKEN, AWS_REGION if used) |
| S3-compatible (R2/MinIO/B2) | AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY and AWS_ENDPOINT_URL |
| Azure Blob | AZURE_STORAGE_ACCOUNT, AZURE_STORAGE_KEY |
| Infino Cloud (hosted) | INFINO_API_KEY — no object-storage credentials needed (the platform owns the storage) |
Storage backends
// Local directory
"env": { "INFINO_MCP_URI": "/Users/me/.infino/memory" }
// AWS S3 — ambient AWS_* credentials, default endpoint
"env": {
"INFINO_MCP_URI": "s3://my-bucket/infino",
"AWS_ACCESS_KEY_ID": "…",
"AWS_SECRET_ACCESS_KEY": "…"
}
// S3-compatible (Cloudflare R2 / MinIO / Backblaze B2) — custom endpoint
"env": {
"INFINO_MCP_URI": "s3://my-bucket/infino",
"AWS_ENDPOINT_URL": "https://<account>.r2.cloudflarestorage.com",
"AWS_ACCESS_KEY_ID": "…",
"AWS_SECRET_ACCESS_KEY": "…"
}
// Azure Blob
"env": {
"INFINO_MCP_URI": "az://my-container/infino",
"AZURE_STORAGE_ACCOUNT": "…",
"AZURE_STORAGE_KEY": "…"
}
// Infino Cloud (hosted) — the database is the last path segment
"env": {
"INFINO_MCP_URI": "https://api.platform.infino.ws/my-database",
"INFINO_API_KEY": "inf_…"
}
On a hosted connection the search, SQL, and write tools all
behave exactly as they do locally — the only difference is where the data
lives. Compaction and garbage collection are handled server-side, so they are
not exposed as client operations. Note that semantic and hybrid search still
embed queries locally in this server, so INFINO_MCP_EMBED_MODEL must match
the model that produced the hosted table's stored vectors (see the OpenAI /
Azure OpenAI note above) — this matters especially when someone else ingested
the data.
Tools
| Tool | Arguments | What it does |
|---|---|---|
infino_semantic_search | table, query, k, column?, vectorColumn?, columns?, filter? | Find passages by meaning — embeds the query with a local model (no key) and ranks by vector similarity. Handles paraphrase and synonyms. score is a distance (lower is closer). Optional filter ({column, query, mode?}) restricts the ranking to rows whose keyword column matches first (a pushdown pre-filter). Optional columns chooses which fields each hit returns (e.g. a path + line range to cite); defaults to the text column, with _id and score always included. |
infino_keyword_search | table, query, k, column?, mode?, stats?, columns? | BM25 full-text search — for exact terms, identifiers, error codes, product names. score is a relevance (higher is better). mode is or (default) or and; stats is per_superfile (default) or global for one table-wide idf. |
infino_hybrid_search | table, query, k, column?, vectorColumn?, mode?, columns? | Fused keyword + semantic search in one ranking pass — BM25 over the text column combined with vector similarity, so rows matching the literal terms and the meaning rank highest. score is the fused rank (higher is better). |
infino_token_match | table, query, column?, mode?, limit? | Unranked keyword filter — the set of rows whose text column contains the token(s). Use when you need the matches, not a relevance order. |
infino_exact_match | table, value, column?, limit? | Unranked exact-equality filter over an indexed column (tag, status, id string). |
infino_count | table, query, column?, mode? | Count how many rows match a keyword query, without fetching them — a fast tally over the text column. For the matching rows use infino_keyword_search or infino_token_match. |
infino_sql | query, embed? | SQL for counts, filters, joins, aggregates. The engine's search table functions are callable inside it; a {{name}} placeholder is filled with the vector of embed[name]. Any single statement, DDL/DML included. |
infino_list_tables | — | List the tables in the connected catalog. |
infino_describe_table | table | Column names and types for a table. |
infino_create_database | — | Provision the database the connection names (Infino Cloud); a no-op success locally. Idempotent. |
infino_create_table | table, columns, fts?, vector? | Create a table from a {column: type} descriptor. Full-text indexes on fts (default: every large_utf8 column). vector: true adds an embedding column sized to the server's embedder, with a cosine index. |
infino_drop_table | table, purge? | Drop a table and, by default, delete its storage objects; purge: false only unregisters the name. |
infino_add_documents | table, documents | Append rows (one call = one commit). Rows without a vector are embedded from the text column, all in one batch; the result reports appended and embedded. A key that is not a column is an error. |
infino_update_documents | table, predicate, documents | Replace the rows matching a SQL predicate with new documents, 1:1 (missing vectors are embedded). Durable storage only. |
infino_delete_documents | table, predicate | Delete the rows matching a SQL predicate. Durable storage only. |
Search hits return full column values — the columns argument is a projection passed straight to the engine (embedded or hosted), so any column in the table can come back with each hit: ["id"] for compact hits at a large k, ["id", "text"] for the full text alongside an id to cite, metadata columns for filtering. It defaults to the text column, with _id and score always included, and nothing is ever truncated; to keep results small, project fewer columns or ask for a smaller k. Every search response also carries score_kind, stating whether its score is a distance (semantic: lower is closer) or a relevance (keyword and hybrid: higher is better).
For plain retrieval prefer the dedicated search tools, which embed and project for you. infino_sql is for filters, joins, and aggregates, including over a search table function's results, so one query can rank and aggregate at once.
Writing data
The write path an agent follows, each step one tool call and one commit:
infino_create_databaseif a hosted database answers 404.infino_create_tablewith autf8key column,large_utf8text columns, andvector: truefor semantic search. The server sizes the vector column to its embedder; the agent never types a dimension. Keep the result: itsindexesfield is the only record of which columns are indexed.infino_add_documents, tens of rows per call, always including the key. Missing vectors are embedded in one batch.- To replace rows,
infino_delete_documentsby key predicate, then add again. To remove rows, check the predicate withinfino_countfirst.
A tool call carries tens of documents. For a whole corpus, use the infino CLI (infino ingest takes Parquet or NDJSON against the same URI) or an SDK. The CLI is bring-your-own-vectors like the engine, so include the embedding column in the rows or load text and search by keyword.
There is no server-side write gate, and the retired INFINO_MCP_ENABLE_WRITES variable is ignored (the server says so on stderr if it is set). On Infino Cloud the API key's capabilities bound what the connection may do: a read-scoped key is refused every write, and the tool result says to mint one with write capability. Locally, point the server only at data the agent may change.
Security & data handling
This server runs locally, beside the client, and keeps data and credentials on the user's machine.
- Local execution, no inbound listener. It runs as a subprocess of your MCP client over stdio and opens no network listener. In the default local/bucket mode it contacts no remote service. When
INFINO_MCP_URIis a hostedhttps://endpoint, it makes outbound TLS calls to that endpoint to serve searches, SQL, and (if enabled) writes — so the data in those requests reaches the hosted service you configured, and nothing else. - No data sent for embedding, by default. With the default provider, query and document embedding uses a local model, so text is never sent to a third-party embedding API and there is no embedding API key to provision or leak. In hosted mode only the resulting vector, not the text, reaches the Infino Cloud endpoint. If you configure the OpenAI-compatible provider, the text being embedded is sent to the endpoint you name.
- Credentials stay in the environment. Storage credentials (
AWS_*/AZURE_*) and the hosted API key (INFINO_API_KEY) are read from environment variables and used only to reach the store or endpoint you configured. They are never logged or returned in tool output. - Who can write is decided outside the server. The full toolset, writes included, is always available to the agent. On Infino Cloud the API key's capabilities bound what the connection may do (a read-scoped key is refused every write). Locally, point the server only at data the agent may change. Every tool carries MCP annotations (
readOnlyHint,destructiveHint) so your client can ask for confirmation on its own terms. - Least privilege. Point
INFINO_MCP_URIat the narrowest dataset the task needs, and supply storage credentials scoped to that bucket/prefix.
How retrieval works
Semantic search embeds locally with Hugging Face transformers.js (all-MiniLM-L6-v2, 384-dim by default; override with INFINO_MCP_EMBED_MODEL). The server embeds both the documents it ingests (via infino_add_documents) and your queries with the same model, so they align in the same vector space.
If you change INFINO_MCP_EMBED_MODEL, the table's vector index must match the new model's dimension — embeddings produced by different models are not comparable, and a dimension mismatch will fail at search time.
Troubleshooting
| Symptom | Likely cause / fix |
|---|---|
| Client shows no Infino tools | Server didn't start — check the client's MCP logs (stderr). Confirm npx is on PATH and INFINO_MCP_URI is set. Fully restart the client after editing config. |
INFINO_MCP_URI is required | The env var isn't reaching the subprocess. In GUI clients, env must be inside the server's env block (the process won't inherit your shell). |
| A write says the key "was rejected or lacks write capability" | On Infino Cloud the API key is read-scoped (HTTP 403) or wrong. Mint a key with write capability and restart the server with it. |
| A write says "another writer won the commit race" | Two writers hit the same table at once and this call did not land. Reissue it. |
| Slow first query | One-time embedding-model download (~90 MB). Subsequent runs use the cache. |
Auth error against a hosted https:// URI | INFINO_API_KEY is missing, wrong, or lacks access to that database. Confirm the key (inf_…) and that the URI's last path segment is a database you can reach. |
| Dimension / vector errors on semantic search | The table's vector index doesn't match the embedding model's dimension. Re-ingest, or set INFINO_MCP_EMBED_MODEL to the model the index was built with. |
Local development
The server depends on the published @infino-ai/infino Node binding, which resolves from public npm like any other dependency.
npm install
npm run build
INFINO_MCP_URI=/path/to/data node dist/index.js # runs on stdio
Point a client at node /absolute/path/dist/index.js over stdio to dogfood a local build, or use the MCP Inspector:
npx @modelcontextprotocol/inspector node dist/index.js