I’ve been using Endole for years. I like to do my due diligence on new clients and collaborators.
Having a top-level report on a company is not only really useful, but it’s also, in my opinion, really interesting. As I’ve written before, I like to see the numbers because a website is just a marketing brochure; the information supplied for a Companies House return tells you a lot about a company.
Hopping back to Endole: it’s great, but it does not show everything. It’s geared more toward corporate risk and financing. I’m more interested in company structure, filings, and how the companies are connected by the people who run them.
Having used Claude for some time, I was curious what I could do with it and wanted to test it on a project for myself. Given my interest in company research and my existing skillset building and maintaining websites, I set about creating what is now called The Muster. As I mentioned in an earlier post about the AI opportunity, Yazaroo will be building tools, and this is the first one to go live.
It’s built using public APIs from Companies House and the Charity Commission. This means every time a company is searched, the API displays live data on its filings and directors. As a result, there are somewhere around 13 million pages covering every company, every director and every charity in the UK.
Frankly, it sounds more impressive than it is: simply a virtual page which pulls the data based on the search. Pretty simple. It looks cool, and the people that use it tell me it’s genuinely useful. They’ve started using it a lot to do due diligence on their clients.
It’s not all rosy though. There are some issues with it.
For one, I am completely reliant on the third-party APIs. I don’t think they will be removed any time soon, but they do have some pretty limiting restrictions. They only allow 600 API calls in any five-minute period. This meant that when Google started crawling the site, 30,000 pages in just 20 days, it kept displaying errors due to the API limits. So I have now blocked the site from robots, which is a short-term solution. It has made site visits drop off a cliff. Once I work out a resolution, this will be reversed.
The other, more serious thing it has exposed is that the way people submit returns is wildly inconsistent, especially around the numbers. Reporting of liabilities is by far the hardest to track through the API (which is mad, because it’s arguably one of the most important) as everyone reports it in a different format.
This makes writing an algorithm or rule-based way of displaying this number almost impossible: however you code it, it will be wrong for someone. The solution I found was to just display net assets, cash in the bank, and headcount. These are the most consistent numbers retrieved, and they give you a nice snapshot of company size and liquid assets, and from the net assets you can spot any significant debt that can’t be attributed to an asset.
One thing it does very well is linking companies to and between people, and I used a knowledge graph to visualise this. This is the element people have liked using the most.
What I particularly like is that, as a tool, it’s not something that is overly labour intensive. There is nothing beyond the standard hosting and WordPress updates that needs to be done regularly. So unlike Yazaroo and Comus, it’s very hands-off. Once I find a resolution to the API limitation, there’s a strong case for monetising it in some way. It would be an excellent candidate for my favourite revenue model: tiny amounts from lots of people, generated passively.
That’s the how. But what is The Muster?
Well, to paraphrase the website: The Muster is the bridge between Companies House and the Charity Commission. You can search over 5 million UK companies and all their directors, and 160,000 registered charities to uncover hidden leadership links and corporate networks. It’s built for journalists, investigators and business leaders who need to see the full picture.
You can search by name for companies, charities and officers, or search by area on the map for keywords, names and SIC codes. You can log in and create workspaces: save profiles to folders, organise them, track status changes and map the connections between them. Cross-sector tracing finds where charity trustees hold private corporate directorships, and the network visualisation maps the hidden connections between parent companies and subsidiaries. Financial analysis shows income against expenditure at a glance. People use it for KYC and compliance (instant background checks on UK officers and verifying charity credentials), for investigative journalism (tracing the flow of leadership across the non-profit and private sectors) and for market research (analysing industry trends using SIC codes and geographic footprints).
Go and try it for yourself.