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Documentation Index

Fetch the complete documentation index at: https://developer.fexpayments.com/llms.txt

Use this file to discover all available pages before exploring further.

All API calls require a Bearer token obtained via the OAuth 2.0 client credentials flow. Tokens expire after 5 minutes — implement automatic refresh in your backend.

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Request

curl -X POST https://auth-sandbox.fexpayments.com/realms/payment-platform/protocol/openid-connect/token \
  -H "Content-Type: application/x-www-form-urlencoded" \
  -d "grant_type=client_credentials" \
  -d "client_id=merchant-a1b2c3d4-..." \
  -d "client_secret=xxxxxxxxxxxxxxxx"

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Response

{
  "access_token": "eyJhbGciOiJSUzI1NiIs...",
  "expires_in": 300,
  "token_type": "Bearer"
}
Request a new token before each API call, or cache and refresh proactively using the pattern below: 
if token is None or token_expires_at < now() + 30s:
    token = fetch_new_token(client_id, client_secret)
    token_expires_at = now() + token.expires_in
Important: Always refresh at least 30 seconds before expiry to avoid race conditions near the 5-minute boundary.

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