Find your competitors' customers

A company that already buys from a competitor knows the problem you solve. It has a budget for it, and it has a person who owns it. This makes it a strong account to contact.

The hard part is the list. A competitor’s customers are named across hundreds of public pages. This guide gets that list from the API in four calls you can run from a terminal. Each account comes with the public page that shows it, so your team can check it before they write.

What you need

• An API key. Get one free; the trial credits are enough for a first list.
• curl and jq in a terminal.
• Your own company domain, or a list of the competitors you already know.

Set the key once:

export INNERFETCH_API_KEY="<your API key>"

Step 1: list your competitors

Ask for the competitors of your own domain. Keep the rows with the basis evidenced: these are the companies that a public page compares with you.

you=helpscout.com

curl -sG https://api.innerfetch.com/api/v1/company/competitors \
  -d domain="$you" -d limit=10 \
  -H "X-API-Key: $INNERFETCH_API_KEY" |
  jq -r '.competitors[] | select(.basis == "evidenced") | .domain' >competitors.txt

You know your market. Open competitors.txt, remove a name you do not compete with, and add one that is missing. One domain on each line.

Step 2: get the customers of each competitor

Ask for the customers of each competitor. Each row has the customer’s name and domain, and the URL of the page that names it.

while read -r rival; do
  curl -sG https://api.innerfetch.com/api/v1/company/customers \
    -d domain="$rival" -d max_results=100 \
    -H "X-API-Key: $INNERFETCH_API_KEY" |
    jq -c --arg rival "$rival" '.customers[]? | {domain, name, rival: $rival, proof: .evidence.url}'
done <competitors.txt >rows.jsonl

You pay for each row that comes back, so max_results is also your cost limit. Start low, then get the next page with cursor when a list is good.

Step 3: merge and rank

One company can buy from two of your competitors, or it can change tools. Merge the rows by domain. Put the accounts that use more than one competitor first.

jq -s 'group_by(.domain)
  | map({domain: .[0].domain, name: .[0].name, rivals: map(.rival), proof: map(.proof)})
  | sort_by(-(.rivals | length))' rows.jsonl >targets.json

Step 4: add a profile and filter

Add industry and country to each account, then keep the ones that fit your ideal customer. The batch call takes up to 50 domains at a time.

jq -c '[.[].domain] | range(0; length; 50) as $i | {domains: .[$i:$i + 50]}' targets.json |
  while read -r body; do
    curl -s https://api.innerfetch.com/api/v1/company/batch \
      -H "Content-Type: application/json" \
      -H "X-API-Key: $INNERFETCH_API_KEY" \
      -d "$body"
  done |
  jq -c '.results[] | select(.status == "found") | .data
    | {domain, name, industry, country: .headquarters.country}' >profiles.jsonl

A company we have not seen before comes back as queued and costs nothing. Run this step again later to add it. Some fields, such as headcount, are not known for every company, so filter on the fields that are filled for your list.

Step 5: use the proof in your first message

Each account has a proof URL: the competitor’s own page about that customer. Read it before you write. It tells you which team uses the product and what they wanted from it. A first line that names that story is more useful than a general opener, and it is true.

A test run

We ran these steps for helpscout.com on 26 October 2026. Step 1 returned 10 competitors that a public page compares with Help Scout. Step 2 returned 126 different accounts from their customer pages, each with its proof URL. Your numbers will change: the competitors you keep change them, and we add companies every day.

Next steps

• Look for the same profile in your own market: give the best accounts to the company search API or ask for their competitors too.
• Find the right person at each account with the work e-mail API.
• Run the same job from an AI agent: see company data for AI agents.