Check Username Availability

Check whether Polymarket will accept a username.

GET /v3/polymarket/profiles/username-available

Use this endpoint before creating a challenge. It calls Polymarket’s username availability check and returns the upstream result.

Query parameters

Parameter	Type	Required	Description
username	string	Yes	Desired username. Local validation is ^[A-Za-z0-9_]{3,32}$. Polymarket is still the final authority.

Example

curl "https://api.polynode.dev/v3/polymarket/profiles/username-available?username=alice123" \
  -H "x-api-key: pn_live_..."

{
  "username": "alice123",
  "available": true,
  "source": "polymarket"
}

Unavailable usernames return 200 with available: false:

{
  "username": "alice_123",
  "available": false,
  "source": "polymarket"
}

Errors

Status	Code	Meaning
400	invalid_username	Missing username or invalid local format
401	varies	Missing or invalid PolyNode API key
402	varies	Paid plan required
429	rate_limited	Profile-specific rate limit exceeded
502	upstream_unavailable	Polymarket availability check failed