Midpoint Price

Returns the midpoint price for a token, calculated as the average of the best bid and best ask.

If the book is one-sided (only bids or only asks), the missing side is treated as 0. Response is enriched with PolyNode market metadata.

GET /v1/midpoint/{token_id}

Midpoint price

cURL

curl --request GET \
  --url https://api.polynode.dev/v1/midpoint/{token_id} \
  --header 'x-api-key: <api-key>'

200

{
  "mid": "0.465",
  "token_id": "114694726451307654528948558967898493662917070661203465131156925998487819889437",
  "question": "Netanyahu out by end of 2026?",
  "slug": "netanyahu-out-before-2027-684-719-226"
}

Returns the midpoint price for a token or market, calculated as the average of the best bid and best ask.

Identifier types

The {token_id} parameter accepts three types:

Identifier	Format	Returns
Token ID	All digits, 70+ chars	Single midpoint (Polymarket-compatible)
Condition ID	Starts with 0x	Midpoints for both outcomes
Slug	Human-readable string	Midpoints for all outcomes in the event

By token ID

curl "https://api.polynode.dev/v1/midpoint/114694726451307654528948558967898493662917070661203465131156925998487819889437" \
  -H "x-api-key: YOUR_KEY"

{
  "mid": "0.465",
  "token_id": "114694726451307654528948558967898493662917070661203465131156925998487819889437",
  "question": "Netanyahu out by end of 2026?",
  "slug": "netanyahu-out-before-2027-684-719-226"
}

By condition ID

curl "https://api.polynode.dev/v1/midpoint/0xd1796c09d0d6f876f8580086ae9808ec991784e3a74b25a1830a25de71a78c96" \
  -H "x-api-key: YOUR_KEY"

{
  "condition_id": "0xd1796c09d0d6f876f8580086ae9808ec991784e3a74b25a1830a25de71a78c96",
  "question": "Netanyahu out by end of 2026?",
  "event_title": "Netanyahu out by...?",
  "outcomes": [
    {"outcome": "Yes", "token_id": "11469472645...", "mid": "0.465"},
    {"outcome": "No", "token_id": "66255671088...", "mid": "0.535"}
  ]
}

Calculation

midpoint = (best_bid + best_ask) / 2

If the book is one-sided (only bids or only asks), the missing side is treated as 0. This matches Polymarket’s behavior.

Notes

• The mid value is a decimal string (e.g. "0.465").
• Returns a 404 if no book exists for the identifier.

Authorizations

x-api-key · string · header · required

Path Parameters

token_id · string · required

Token ID (all digits), condition ID (starts with 0x), or event slug. Token ID returns a single book; condition ID and slug return all outcomes.

Response

200

application/json

Midpoint price

Midpoint price. The mid field matches Polymarket's CLOB /midpoint response. Additional fields are PolyNode enrichment.

mid · string · required

Midpoint price as decimal string, calculated as (best_bid + best_ask) / 2

token_id · string

Token ID (PolyNode enrichment)

question · string

Market question (PolyNode enrichment)

slug · string

Event slug (PolyNode enrichment)