Best of

The MCP ecosystem grows by hundreds of servers a month and most lists go stale within weeks. This one is generated from the live registry, so it reflects what is actually published today — ranked by how completely the record is documented, not by paid placement.

Which free APIs are actually worth integrating depends on how well they are documented and whether they need a key before you can make a single request. This shortlist is drawn from the live catalogue and ordered by documentation completeness.

Source control, continuous integration, code execution and package tooling — the servers that put an agent inside a real build pipeline rather than beside it.

Database connectors, data platforms, filesystem bridges and the knowledge stores an agent reads from. These are the servers that decide whether your agent can see your actual data.

Web search, crawling and scraping servers for retrieval pipelines. If your agent needs current information rather than training data, this is the layer that provides it.

Browser drivers, desktop control, smart-home bridges and embedded devices — servers that let an agent act on a machine instead of only reading from it.

Market data, currency exchange, accounting and payment endpoints you can call without a commercial contract. Bank and brokerage APIs are almost always gated; what is listed here is what is genuinely open.

Address lookup, reverse geocoding, routing and place data. Every major provider meters geocoding tightly, so the free options here are worth knowing before you commit to a paid plan.

Public-sector datasets, statistics, patents and civic feeds. These are usually licence-free and key-free, which makes them the cheapest way to add real data to a prototype.