Data
The whole point is that you can check our work. Code is Apache-2.0, data is CC-BY-4.0, and a stranger should be able to reproduce the headline number.
Reproducing it
The population is derived from the official MCP Registry's own public API. Unlike anything built on a ranked domain list, the frozen universe can be republished in full and you do not need to source a licensed input to repeat the work.
git clone https://github.com/radixia/mcp-census pnpm install && pnpm test
What is published
Per-domain rows with every check result, the frozen input universes with their provenance and download dates, and the methodology version that produced each row. Releases are immutable snapshots; corrections appear in the next release rather than rewriting a citable one.
Download the 2026-09-13 release
7,422 domains, 7,421 assessed. Methodology 0.5.0, candidate set 2026-08-07. Immutable: a correction ships as a new dated release rather than rewriting this one.
| File | What it is | Size |
|---|---|---|
summary.json |
The headline numbers and per-check pass rates | 1.8 KB |
census.csv |
One row per domain: score, band, every check | 835 KB |
census.jsonl.gz |
Per-domain rows with full evidence, one JSON object per line | 1.9 MB |
universe.csv |
The frozen population, with provenance | 437 KB |
to-parquet.sql |
DuckDB script: any of the above to Parquet | 621 B |
README.md |
What is in the release and how to cite it | 1.7 KB |
zenodo.json |
Deposition metadata for archiving | 1.1 KB |
The per-domain rows are gzipped JSONL rather than JSON: same data, one object per
line, and 38 MB becomes 2 MB. to-parquet.sql turns any of it into Parquet
with DuckDB, so nobody has to trust a query service of ours to re-derive a statistic.
How to cite
The release is deposited at Zenodo, so it has a DOI and outlives this site.
D'Angelo, M. (2026). MCP Census: can an agent find your MCP server? (Version 2026-09-13) [Data set]. Zenodo. https://doi.org/10.5281/zenodo.22830292
That DOI names this release and never moves, which is what you
want beside a number you quote. 10.5281/zenodo.22830291 is the concept DOI and always resolves to the newest release instead.
Earlier releases
Kept exactly as issued. A citable artifact that changes is not one, so a correction ships as a new dated release and this list only grows.
| Release | Methodology | What it is |
|---|---|---|
2026-08-09 |
0.4.0 | Eleven checks, unchanged from 2026-08-07, and the first to carry a timestamp per domain. The last cut from the local runner. |
2026-08-07 |
0.4.0 | Eleven checks. The first with D7, C1 and cacheability, and the last with one shared timestamp for every row. |
2026-08-05 |
0.2.0 | The first full census. Nine checks; no D7, no C1, no cacheability. |