Test a connection's credentials

POST

/v1/integrations/{type}/connections/{id}/test

Checks whether a connection's stored credentials still work — a live, read-only probe against the ESP that writes nothing. Returns 200 with { credential_valid, tested_at }: true if the ESP accepted the key just now, or false (plus a reason) if it rejected them — a rejected key is still a successful test, not an error. Only an ESP we couldn't reach surfaces as 503 (the result is genuinely unknown). A connection id that does not exist or belongs to another org → 404; a type that can't be managed via the API → 422 unsupported_integration. Ideal for an "is my integration healthy?" check before relying on it. Do NOT send an Idempotency-Key with this endpoint — it is a live probe, and a replayed cached result would defeat the point (poll it fresh each time).

Request

Authorization

Bearer Token

Provide your bearer token in the

Authorization

header when making requests to protected resources.

Example:

Authorization: Bearer ********************

Path Params

Responses

🟢200

application/json

Credential test result

Bodyapplication/json

🟠401

🟠403

🟠404

🟠422

🟠429

🔴500

🔴503

Request Example

Shell

JavaScript

Java

Swift

curl --location --request POST 'https://api.mailfloss.com/v1/integrations//connections//test' \
--header 'Authorization: Bearer <token>'

Response Example

200 - Success

{
    "id": "conn_5d4c3b2a1e0f9z",
    "type": "klaviyo",
    "credential_valid": true,
    "tested_at": "2026-06-20T14:30:00Z"
}

Modified at 2026-10-20 13:54:45

Re-sync a connection's audiences

List a connection's keyword rules