Get Balance

Returns the balance for an authorized account.

GET/portfolio/{account_id}/balance

Authorization

UDX-Access-KeyAPI key · headerrequired

Opaque API key ID.

UDX-Access-TimestampAPI key · headerrequired

Unix time in milliseconds, within 30 seconds of server time.

UDX-Access-SignatureAPI key · headerrequired

Standard-base64 RSA-PSS/SHA-256 signature with a 32-byte salt.

AuthorizationBearer token (JWT) · headerrequired

Bearer token for an active signed-in UDX user.

Header parameters

UDX-Versionstring

Dated API version (YYYY-MM-DD).

min length 10 · max length 10

Path parameters

account_idEntityIdrequired

Account whose balance to return.

min length 1

Query parameters

tickerTicker

Scopes buying power to this market.

min length 1 · max length 128

Responses

200The account balance.

account_idstringrequired

The account this balance is for.

min length 1

balancestringrequired

Total account cash balance, in dollars.

max length 24 · matches ^[0-9]+(\.[0-9]{1,6})?$

available_balancestring

Funds available to open new positions in dollars. Scoped to one market when the ticker parameter is supplied.

max length 24 · matches ^[0-9]+(\.[0-9]{1,6})?$

open_ordersstring

Funds held by open orders, in dollars.

max length 24 · matches ^[0-9]+(\.[0-9]{1,6})?$

margin_heldstring

Funds held as margin against open positions and orders, in dollars.

max length 24 · matches ^[0-9]+(\.[0-9]{1,6})?$

updated_atstring<date-time>

When the balance last changed.

max length 40

400The request doesn't conform to this spec.

typestring<uri-reference>required

A stable URN identifying the kind of problem, for example urn:udx:problem:insufficient-permissions. Branch on it rather than on the localized detail. It is an identifier, not a URL to dereference.

max length 2048

titlestringrequired

A localized, human-readable summary of the error category. Stable for a given status code and resolved language — clients must not use it as a machine-readable discriminator.

max length 40

statusintegerrequired

The HTTP status code, repeated from the response itself.

detailstring

A localized, human-readable explanation specific to this occurrence. Clients must not parse it for machine-readable information.

max length 500

instancestring<uri-reference>

An identifier for this specific occurrence, so it can be correlated with server-side logs if you need to report it.

max length 100

401No valid credential was provided.

typestring<uri-reference>required

A stable URN identifying the kind of problem, for example urn:udx:problem:insufficient-permissions. Branch on it rather than on the localized detail. It is an identifier, not a URL to dereference.

max length 2048

titlestringrequired

A localized, human-readable summary of the error category. Stable for a given status code and resolved language — clients must not use it as a machine-readable discriminator.

max length 40

statusintegerrequired

The HTTP status code, repeated from the response itself.

detailstring

A localized, human-readable explanation specific to this occurrence. Clients must not parse it for machine-readable information.

max length 500

instancestring<uri-reference>

An identifier for this specific occurrence, so it can be correlated with server-side logs if you need to report it.

max length 100

403The credential lacks the read scope.

typestring<uri-reference>required

A stable URN identifying the kind of problem, for example urn:udx:problem:insufficient-permissions. Branch on it rather than on the localized detail. It is an identifier, not a URL to dereference.

max length 2048

titlestringrequired

A localized, human-readable summary of the error category. Stable for a given status code and resolved language — clients must not use it as a machine-readable discriminator.

max length 40

statusintegerrequired

The HTTP status code, repeated from the response itself.

detailstring

A localized, human-readable explanation specific to this occurrence. Clients must not parse it for machine-readable information.

max length 500

instancestring<uri-reference>

An identifier for this specific occurrence, so it can be correlated with server-side logs if you need to report it.

max length 100

404The account doesn't exist or the caller holds no grant on it.

typestring<uri-reference>required

A stable URN identifying the kind of problem, for example urn:udx:problem:insufficient-permissions. Branch on it rather than on the localized detail. It is an identifier, not a URL to dereference.

max length 2048

titlestringrequired

A localized, human-readable summary of the error category. Stable for a given status code and resolved language — clients must not use it as a machine-readable discriminator.

max length 40

statusintegerrequired

The HTTP status code, repeated from the response itself.

detailstring

A localized, human-readable explanation specific to this occurrence. Clients must not parse it for machine-readable information.

max length 500

instancestring<uri-reference>

An identifier for this specific occurrence, so it can be correlated with server-side logs if you need to report it.

max length 100

429The member rate limit was exceeded.

typestring<uri-reference>required

A stable URN identifying the kind of problem, for example urn:udx:problem:insufficient-permissions. Branch on it rather than on the localized detail. It is an identifier, not a URL to dereference.

max length 2048

titlestringrequired

A localized, human-readable summary of the error category. Stable for a given status code and resolved language — clients must not use it as a machine-readable discriminator.

max length 40

statusintegerrequired

The HTTP status code, repeated from the response itself.

detailstring

A localized, human-readable explanation specific to this occurrence. Clients must not parse it for machine-readable information.

max length 500

instancestring<uri-reference>

An identifier for this specific occurrence, so it can be correlated with server-side logs if you need to report it.

max length 100

500Something went wrong on UDX's side.

typestring<uri-reference>required

A stable URN identifying the kind of problem, for example urn:udx:problem:insufficient-permissions. Branch on it rather than on the localized detail. It is an identifier, not a URL to dereference.

max length 2048

titlestringrequired

A localized, human-readable summary of the error category. Stable for a given status code and resolved language — clients must not use it as a machine-readable discriminator.

max length 40

statusintegerrequired

The HTTP status code, repeated from the response itself.

detailstring

A localized, human-readable explanation specific to this occurrence. Clients must not parse it for machine-readable information.

max length 500

instancestring<uri-reference>

An identifier for this specific occurrence, so it can be correlated with server-side logs if you need to report it.

max length 100

503Request admission or account setup is unavailable, or the read could not be completed in time; retry.

typestring<uri-reference>required

A stable URN identifying the kind of problem, for example urn:udx:problem:insufficient-permissions. Branch on it rather than on the localized detail. It is an identifier, not a URL to dereference.

max length 2048

titlestringrequired

A localized, human-readable summary of the error category. Stable for a given status code and resolved language — clients must not use it as a machine-readable discriminator.

max length 40

statusintegerrequired

The HTTP status code, repeated from the response itself.

detailstring

A localized, human-readable explanation specific to this occurrence. Clients must not parse it for machine-readable information.

max length 500

instancestring<uri-reference>

An identifier for this specific occurrence, so it can be correlated with server-side logs if you need to report it.

max length 100

Request

curl -X GET "https://api.underdogexchange.com/portfolio/6820943174116859281/balance" \
  -H "UDX-Access-Key: API_KEY_ID" \
  -H "UDX-Access-Timestamp: UNIX_MILLISECONDS" \
  -H "UDX-Access-Signature: BASE64_SIGNATURE"

Response

{
  "account_id": "6820943174116859281",
  "balance": "1000",
  "available_balance": "820",
  "open_orders": "80",
  "margin_held": "100",
  "updated_at": "2026-01-01T00:00:00.000000Z"
}

{
  "type": "urn:udx:problem:invalid-request-parameters",
  "title": "Bad Request",
  "status": 400,
  "detail": "invalid request parameters",
  "instance": "urn:request-id:8f14e45f-ceea-4abc-a743-e89a34d3f6ef"
}

{
  "type": "urn:udx:problem:unknown-version",
  "title": "Bad Request",
  "status": 400,
  "detail": "unknown UDX-Version \"1999-01-01\"; supported versions: 2026-07-15",
  "instance": "urn:request-id:8f14e45f-ceea-4abc-a743-e89a34d3f6ef"
}

{
  "type": "urn:udx:problem:invalid-authentication-credentials",
  "title": "Unauthorized",
  "status": 401,
  "detail": "invalid authentication credentials",
  "instance": "urn:request-id:8f14e45f-ceea-4abc-a743-e89a34d3f6ef"
}

{
  "type": "urn:udx:problem:insufficient-permissions",
  "title": "Forbidden",
  "status": 403,
  "detail": "insufficient permissions",
  "instance": "urn:request-id:8f14e45f-ceea-4abc-a743-e89a34d3f6ef"
}

{
  "type": "urn:udx:problem:member-rate-limit-exceeded",
  "title": "Too Many Requests",
  "status": 429,
  "detail": "this member has temporarily exceeded its request rate",
  "instance": "urn:request-id:8f14e45f-ceea-4abc-a743-e89a34d3f6ef"
}

{
  "type": "urn:udx:problem:projection-unavailable",
  "title": "Service Unavailable",
  "status": 503,
  "detail": "account setup is still being completed; retry later",
  "instance": "urn:request-id:8f14e45f-ceea-4abc-a743-e89a34d3f6ef"
}

{
  "type": "urn:udx:problem:request-admission-unavailable",
  "title": "Service Unavailable",
  "status": 503,
  "detail": "request admission is temporarily unavailable",
  "instance": "urn:request-id:8f14e45f-ceea-4abc-a743-e89a34d3f6ef"
}

{
  "type": "urn:udx:problem:could-not-process-retry",
  "title": "Service Unavailable",
  "status": 503,
  "detail": "could not process request, please retry",
  "instance": "urn:request-id:8f14e45f-ceea-4abc-a743-e89a34d3f6ef"
}