Data API (v1)
Pull MarkQuality's peer-mark data programmatically. Every endpoint is read-only and returns the same quality-gated data as the app, scoped to your organization's entitlement.
Authentication
Create an API key under Account → API keys (owners and admins). The key is shown once — store it securely. Send it as a bearer token:
curl "https://www.markquality.io/api/v1/instruments?quarter=2026Q1&coverage=peer&limit=5" \ -H "Authorization: Bearer mq_live_…"
Endpoints
Base URL https://www.markquality.io/api/v1
GET/instrumentsFull quarterly instrument screener across all covered funds.
GET/instruments/{instrument_id}All holder positions, marks, and source evidence for one instrument.
GET/scorecardsMark discipline scorecards for a quarter.
GET/borrowersBorrower lens — cross-BDC marks per credit.
GET/mark-changesQuarter-over-quarter mark changes.
GET/outliersPeer-mark outliers (holders disagree).
Query parameters
quarterrequiredReporting quarter, e.g. 2026Q1.queryoptionalFree-text filter on names.coverageoptionalinstruments only — all, peer, single, comparable, outlier, identity_review, thin, or unmarked.fundoptionalinstruments only — restrict to a fund code such as BCRED.lienoptionalinstruments only — first, second, unsecured, other, or unknown.maturityoptionalinstruments only — through_2027, 2028_2030, 2031_plus, or unknown.sortoptionalEndpoint-specific sort key (see each endpoint's defaults).minMoveoptionalmark-changes only — minimum absolute move in pp.offsetoptionalPagination offset (default 0).limitoptionalPage size. Most endpoints allow 1–200; instruments allows 1–250.Rate limits & errors
- • 600 requests/hour per key. Over the limit returns
429RATE_LIMITED. - • Missing or invalid key →
401(API_KEY_REQUIRED/API_KEY_INVALID). - • Organization not entitled, or release not allowed →
403. - • The Data API is an Enterprise plan feature — other plans get
403PLAN_REQUIRED_ENTERPRISE. - • Responses are JSON; errors are
{ "error": "CODE" }.
Independent cross-check built on public SEC filings. Not investment advice. Questions: contact@markquality.io.