Check Username Availability

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.

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"
}

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