Build your own product on the API

You run a product of your own and want AI agents inside it: each of your customers gets agents that answer their chats and calls, and you build the screens. You never send your customers to our console. The pattern is three calls: make a customer, work inside it with a header, and hear about all of them on one webhook.

1. Make a customer

When one of your customers signs up with you, create a workspace for them. Use your own id as externalId so you can find it again, and send an Idempotency-Key so a retry never makes two.

curl https://YOUR_APP/api/v1/customers \
  -H "Authorization: Bearer $KEY" \
  -H "Idempotency-Key: signup-4812" \
  -H "Content-Type: application/json" \
  -d '{ "name": "Acme Dental", "externalId": "acct_4812" }'

Keep the id it returns (org_…) next to your own record of the account.

2. Build their agent

Add Thinnest-Workspace with that id. Every endpoint now works inside that customer — agents, knowledge, phone numbers, contacts, campaigns, conversations.

curl https://YOUR_APP/api/v1/agents \
  -H "Authorization: Bearer $KEY" \
  -H "Thinnest-Workspace: org_1f2e…" \
  -H "Content-Type: application/json" \
  -d '{ "name": "Front desk" }'

Then give it something to answer from:

curl https://YOUR_APP/api/v1/agents/ag_…/knowledge \
  -H "Authorization: Bearer $KEY" \
  -H "Thinnest-Workspace: org_1f2e…" \
  -H "Content-Type: application/json" \
  -d '{ "url": "https://acme-dental.example/faq" }'

3. Hear about every customer on one webhook

curl https://YOUR_APP/api/v1/webhooks \
  -H "Authorization: Bearer $KEY" \
  -H "Content-Type: application/json" \
  -d '{ "includeCustomers": true, "url": "https://you.example/hooks/agents" }'

Each delivery says which customer it is about in data.workspaceId, inside the signed body — so you can route it to the right account.

4. Show them what they used

GET /api/v1/customers/{id} returns spendThisMonthMicro — what that customer’s usage has cost you this month — so you can show usage, or charge for it, in your own billing. Everything your customers use is charged to your balance. Keep it topped up: when it runs out, your customers’ agents stop with you.

Let your AI coding assistant do it

Connect the MCP server with the header and your assistant builds inside that customer:

claude mcp add --transport http acme https://YOUR_APP/api/v1/mcp \
  --header "Authorization: Bearer $KEY" \
  --header "Thinnest-Workspace: org_1f2e…"

When a customer leaves you

Release their phone numbers and disconnect WhatsApp, then delete the customer. You have 30 days to restore it; after that everything is erased.

Customers reference

Every field, status code and limit.

Guides

Set up

Answer the phone

Connect your systems

Reach out

Build on the API

Build your own product on the API

1. Make a customer

2. Build their agent

3. Hear about every customer on one webhook

4. Show them what they used

Let your AI coding assistant do it

When a customer leaves you

Customers reference

​1. Make a customer

​2. Build their agent

​3. Hear about every customer on one webhook

​4. Show them what they used

​Let your AI coding assistant do it

​When a customer leaves you

Customers reference

1. Make a customer

2. Build their agent

3. Hear about every customer on one webhook

4. Show them what they used

Let your AI coding assistant do it

When a customer leaves you