Which API should I use?

Choose the API for the product and workspace you use. Use the host and path
shown on each operation when making a request.

API	Host and paths	When to use it
True Platform API (v2)	Your Gen 3 tenant host, `https://<tenant>.katalon.io`, with `/v2/...` paths	New Gen 3 integrations for scheduling, test assets, reports, ALM, manual execution, and stored metadata. Authenticate with a Katalon API key using HTTP Basic with an empty username and the key as the password.
Shared-host v1 API	`https://testops.katalon.io` with `/api/v1/...` paths	Existing integrations using the shared-host TestOps API. Follow that reference's authentication and request contract; do not replace its host or IDs with v2 values.

For new Gen 3 execution integrations, start with
Run tests from CI.
If you already use the shared-host schedule trigger, read
Migrate from the v1 API.
The IDs and response bodies differ; changing the URL alone is not a migration.

Operations that keep v1 paths

Some operations on the Gen 3 tenant host keep their v1 paths. TestCloud
session-output reads use /v1/tc/ees/.... The tenant-host Files and Visual
Checkpoints API uses /api/v1/... paths. For these operations, use your tenant
host and the v1 path shown in the reference.

See v2 authentication
for the API-key helper and required project context.