Developers and AI agents

All 759 companies are free to use in your code, your spreadsheets and your AI tools. There is a JSON API, a remote MCP server and an llms.txt file. No key, no sign up. CORS is open. Data last updated 9 Oct 2026.

REST API

Find the fastest growing AI companies, biggest raisers first:

curl "https://londonmempool.co.uk/api/v1/companies?sector=AI&tier=fast_growing&sort=funding&limit=10"

Search by keyword, founded after 2019:

curl "https://londonmempool.co.uk/api/v1/companies?q=payments&founded_after=2019"

Get one company with all its sources:

curl https://londonmempool.co.uk/api/v1/companies/9fin

Search returns data, total, limit and offset, plus updated, license and source. A bad parameter returns a 400 that says what to fix.

Search parameters

sector: One or more of AI, Fintech, Quantum, Crypto, Defence, Deeptech, Health, Climate, Other. Use commas for several. Matches the main sector or sector_secondary.
primary_only: true to match the main sector only, so results line up with the counts in /api/v1/meta.
tier: One or more of well_known, fast_growing, up_and_coming.
borough: A London borough, like Camden. Not case sensitive.
area: A tech neighbourhood slug, like kings-cross or shoreditch-old-street. Comma-separated for several.
q: Text search over name, subsector and description. Every word must match.
min_funding_usd: Raised at least this much, in US dollars.
min_staff: At least this many average employees in the latest Companies House accounts (ch_employees).
raised_since: A month as YYYY-MM. Last round on record in or after that month, and equity or mixed (last_round_month, last_round_kind).
founded_after: Founded after this year. 2019 means 2020 onwards.
hiring: true for companies with open roles in London on their public job board.
visa_sponsor: true for companies on the Home Office register of licensed visa sponsors.
open_source: true for companies whose own website links a GitHub organisation (github_org).
presence: hq, office or people: London HQ, London office with HQ elsewhere, or London staff with no office. Comma-separated for several.
work_model: onsite, hybrid or remote, read from the workplace type on the company's current London job posts. Comma-separated for several.
investor: An investor slug, like index-ventures (see /investors.json). Comma-separated for several.
accelerator: An accelerator programme: y-combinator, antler, founders-factory, conception-x. Comma-separated for several.
cohort: A recognition list, any edition year: sifted-100-uk-ireland, tech-nation-future-fifty, tech-nation-upscale, deloitte-uk-fast-50, linkedin-top-startups-uk, forbes-ai-50. Comma-separated for several.
ecosystem: A blockchain a crypto company builds on, as its own site names it: ethereum, bitcoin, solana, polygon, base, arbitrum, optimism, avalanche, cosmos, polkadot, stellar, xrp-ledger, tezos, cardano, ton, sui, aptos, near, bnb-chain, starknet, zksync, plasma. Comma-separated for several.
sort: name, funding or founded.
order: asc or desc. Defaults: name A to Z, most funded first, newest first.
limit: Results per page. Default 20, max 500.
offset: Results to skip, for paging.

Endpoints

GET/api/v1/companies

Search, filter, sort and page.

GET/api/v1/companies/{id}

One company, every field and source.

GET/api/v1/meta

Counts by sector, tier, borough and area. What each field means.

GET/companies.json

The full dataset in one file.

GET/changes.json

Every company added, removed or updated, by day.

GET/feed.xml

The same changelog as an RSS feed.

GET/investors.json

Every investor named in a source, with company counts, leads and company ids.

GET/places.json

Context places: VCs, big tech, universities, accelerators, coworking. Not ranked.

GET/openapi.json

OpenAPI 3.1 spec for the API.

POST/mcp

Remote MCP server.

The full spec is at /openapi.json. Load it into any OpenAPI tool or give it to an agent.

MCP server

Connect any MCP client to https://londonmempool.co.uk/mcp. It uses Streamable HTTP, needs no login and is read only. In Claude Code:

claude mcp add --transport http london-mempool https://londonmempool.co.uk/mcp

For other clients that take a JSON config:

{
  "mcpServers": {
    "london-mempool": {
      "type": "http",
      "url": "https://londonmempool.co.uk/mcp"
    }
  }
}

Clients that only speak stdio can use a bridge like npx mcp-remote https://londonmempool.co.uk/mcp.

Tools:

search_companies takes the same filters as the REST search.
get_company returns one full record by id.
list_sectors gives counts by sector, tier, borough and area.
list_changes lists what was added, removed or updated. Pass since (YYYY-MM-DD) to get only recent changes.
list_places lists context places (VCs, big tech, universities, accelerators, coworking). Pass type to pick some. They are landmarks, not ranked companies.
list_investors lists investors named in sources, most companies first. Pass min_companies or q to narrow it, then use a slug with the investor filter.
get_dataset_info explains the fields, license and how we verify.

llms.txt

/llms.txt tells a language model what this site is and how to query it. /llms-full.txt adds every company as one line, so a model can read the whole list in one go.

Downloads

Get everything at once as JSON or as a CSV.

Changes

Every change to the data is logged by day: companies added and removed, and new values for tier, sector, funding, last round, employees and address. Read it on the changelog, as JSON or in an RSS feed.

curl https://londonmempool.co.uk/changes.json

License and attribution

The data is free to use, including for commercial work. Please credit London Mempool and link to londonmempool.co.uk. For example:

Data from London Mempool (londonmempool.co.uk)

How the data is checked

Every company is matched to its Companies House number where one exists. The address, funding and growth facts each link to a source. Read more in how we verify. Spotted a mistake? Tell us through the corrections page.