--- title: "onemcp · MCP gateway: one endpoint for every data source" description: "One MCP server instead of dozens: FX rates, company registries, on-chain data and more. Your agent sees 4 tools and you pay from one balance, with audit." url: "https://onemcp.org/en/" lang: "en" --- MCP gateway · source catalog · one balance # One endpoint. Every data source for your agent. onemcp is **OpenRouter for data**. Your agent says what it needs. We find the right API, MCP server or registry, call it safely, charge it to one balance and return only the fields it asked for. [Get an API key](https://onemcp.org/app/login) [Browse the catalog →](https://onemcp.org/en/#catalog) Works with MCP clients Claude Code Cursor Claude Desktop DeepSeek Harness MCP Inspector **4** meta-tools instead of hundreds **75** capabilities in the catalog **26** no-code connectors **≈7 ms** gateway overhead, p95 **1.0** search recall@5, PL/EN Internal MVP measurements: gateway benchmark and a set of 65 test queries. Why onemcp ## An agent with twenty MCP servers pays in tokens before it does anything. 1. **Context explosion.** Every server loads all its tools with full schemas into the model. Cost and latency go up, accuracy goes down. 2. **Most sources have no MCP.** APIs without a server or docs, websites without an API. Every team writes the same integrations. 3. **Eight sources, eight invoices.** Separate accounts, keys, limits and billing with every paid data provider. 4. **Compliance says no.** A bank won't let an agent reach any server on the internet without controls, isolation and audit. How it works ## Four tools instead of hundreds. The agent doesn't get the whole catalog. It gets four meta-tools whose descriptions fit in under 600 tokens, and pulls in only what it needs at the moment. ### onemcp\_search Finds capabilities that match the need, in any language. Returns short cards instead of schemas. `"EUR to PLN rate" → nbp.rates.current · free` ### onemcp\_describe The full input schema, only when the arguments on the card are not enough. `ids: ["etherscan.gas.oracle"]` ### onemcp\_call Calls the source through the gateway and trims the response to the fields and token limit you asked for. `fields: ["ethereum.usd"] · max_tokens: 800` ### onemcp\_balance Balance, today's spend and limits: the agent knows what it can afford before it pays. `→ balance "$12.40" · today "$0.31"` ### The path of one `onemcp_call` gateway overhead p95 ≈ 7 ms per paid call 1. **Authentication** API key (HMAC) or OAuth 2.1 2. **Policies** allow/deny, scopes, RPS limits 3. **Reservation** amount held in Redis before the call 4. **Upstream** SSRF guard, DNS pinning, cache 5. **Shaping** field projection, max\_tokens, cursor 6. **Settlement** double-entry ledger, append-only 7. **Response** untrusted envelope: data, not instructions → the agent calls `onemcp_call` ``` { "id": "coingecko.price.simple", "args": { "ids": "ethereum", "vs_currencies": "usd" }, "fields": ["ethereum.usd"], "max_tokens": 800 } ``` ← the agent gets only what it asked for `143 ms` ``` { "data": { "ethereum": { "usd": 4123.51 } }, "meta": { "cost": "$0.0002", "cached": false, "source": "coingecko" }, "untrusted": true } ``` OpenRouter for data ## What OpenRouter is for models, onemcp is for data. One connection, one balance, one set of policies, and underneath as many APIs, MCP servers, registries and websites as you need. Tools in the agent's context 26 separate MCP servers `75 tools · full schemas` onemcp `4 tools · < 600 tokens` | Feature | OpenRouter · AI models | onemcp · data and tools | | --------------- | -------------------------------------- | --------------------------------------------------------------------------- | | One interface | one API for many models | one MCP endpoint for APIs, MCP servers, registries and sites without an API | | Provider choice | routing and fallback between providers | capability search picks the source for the agent's question | | Payments | credits for any model | one balance for any source: prepaid or a monthly invoice | | Your own keys | BYOK for model providers | BYOK with envelope encryption for your contracts with data providers | | Control | data policies for prompts | per-organization source allowlists, spend limits, audit log | ## Everything an agent working with data needs. ### Capability search Hybrid full-text and vector search in Polish and English. Cards of 40–80 tokens instead of full schemas. ### No-code connectors A declarative manifest instead of an integration. Connector Studio drafts it from OpenAPI, a HAR recording, an MCP server or a website, and a human approves it. ### One balance Prepaid through Stripe or a monthly invoice. Source cost and margin per call, visible in the response. Bring your own keys (BYOK) welcome. ### Control and audit Per-organization source allowlists, spend and request limits, a hash-chained audit log. Every external response is marked untrusted. ## Source catalog 26 connectors · 75 capabilities · a new source in minutes, not days [See the full catalog →](https://onemcp.org/app/catalog) - **CoinGecko**: Crypto and on-chain · prices, markets · 6 capabilities · `price.simple` · free - **Etherscan**: Crypto and on-chain · accounts, gas · 5 capabilities · `gas.oracle` · BYOK - **Ethereum RPC**: Crypto and on-chain · blocks, tx · 5 capabilities · `block.latest` · free - **DefiLlama**: Crypto and on-chain · TVL · 4 capabilities · `protocol.tvl` · free - **NBP**: Finance · Polish FX rates, gold · 5 capabilities · `rates.current` · free - **Frankfurter (ECB)**: Finance · reference rates · 4 capabilities · `fx.latest` · free - **KRS**: Registries · Polish companies · 2 capabilities · `company.summary` · free - **GLEIF**: Registries · LEI identifiers · 3 capabilities · `lei.search` · free - **Open-Meteo**: Weather · forecasts and history · 4 capabilities · `weather.forecast` · free - **Wikipedia**: Knowledge · articles and summaries · 3 capabilities · `page.summary` · free ## Who it is for ### → Agent developers Give an agent access to many sources quickly, without writing integrations. - ↳ one MCP endpoint - ↳ free tier and prepaid - ↳ ready-made connectors ### → Fintech and data teams On-chain and market data from many paid APIs, with low latency. - ↳ one balance instead of eight invoices - ↳ cache and SLOs - ↳ BYOK for your own contracts ### → Banks and regulated institutions Control, audit, isolation and data in the EU before an agent touches production. - ↳ per-organization source allowlists - ↳ audit log, SSO, invoicing - ↳ on-prem install (planned) ## Start in three steps 1. **Create an organization** Account, team and roles from day one. Test mode without a card. 2. **Top up your balance** Stripe Checkout or a monthly invoice. The balance works with every source. 3. **Connect your agent** One command in Claude Code, Cursor or Claude Desktop. You will find the URL and key in the console. ``` claude mcp add --transport http onemcp \ "$ONEMCP_URL/mcp" \ --header "Authorization: Bearer $KEY" ``` Security and compliance ## Security that passes a bank's audit. - **Tenant isolation**: Postgres RLS on every organization query. - **Controlled egress**: SSRF guard with DNS pinning, no private addresses. - **Keys and secrets**: API keys stored as HMAC + pepper, BYOK with envelope encryption. - **A tamper-evident audit log**: Append-only with a hash chain. A correction is a new entry. - **Standard authorization**: OAuth 2.1 with PKCE and DCR for MCP clients. - **External content is data**: Every response comes in an untrusted envelope, never as instructions. ## Pay for calls, not subscriptions. A cached result? You pay only the platform fee. 01 · PREPAID ### Top up and go Stripe Checkout. Each paid call deducts the source cost plus margin from your balance. 02 · POSTPAID ### Monthly invoice For organizations: a contractual credit limit, one invoice for all sources. 03 · BYOK ### Your key, our infrastructure No upstream cost, only a platform fee per call. 04 · ENTERPRISE ### On-prem and SLA Annual license, support, SSO and installation in your infrastructure. Connect your agent to every → source [Get an API key](https://onemcp.org/app/login) [See how it works](https://onemcp.org/en/#how)