generated: '2026-07-22'
method: derived
source: bmll Python SDK 1.24.7 source (bmll/_rest.py, bmll/data.py, bmll/exceptions.py)
authentication:
  style: key-pair signed-JWT handshake -> Bearer token (+ x-api-key for Data Lab)
  see: authentication/bmll-technologies-authentication.yml
idempotency:
  supported: false
  note: No idempotency-key header or replay-safety contract is documented
    anywhere public. Most data-plane calls are reads/queries.
pagination:
  style: none-documented
  note: Query surfaces are request/response or async job based rather than
    cursor/offset paginated; the APIv2 query API returns complete result sets
    as downloadable JSONL/Arrow files.
async_pattern:
  style: initiate-poll-download
  description: APIv2 dataset queries POST /query (or /data/{dataset}) to
    initiate, GET /query?id={query_id} to poll, then download results as
    JSONL or Arrow into pandas/polars. The Market Data API uses the same
    poll-for-result pattern per instrument/date.
request_limits:
  max_body_bytes: 512000
  behavior: A 403 response to a request whose content-length is >= 512000
    raises RequestTooLarge ("The size of your query is too large.").
rate_limiting:
  signal: HTTP 429
  quota: A 429 whose JSON message is "Limit Exceeded" means the per-account
    service quota is exhausted (QuotaReachedError); usage is inspected at
    https://data.bmlltech.com/#app/permissions. Other 429s are retried.
retries:
  strategy: exponential backoff (base 2, factor 1, capped at 30s; max total 30s)
  retried_statuses: [429, 502, 503, 504]
  auth_retry: one re-login on 401, then AuthenticationError
tracing:
  request_id: none documented
  version_header: x-bmll-version sent on every request (SDK version)
content:
  request: application/json (numpy/datetime values JSON-encoded by the SDK)
  response: application/json, or application/gzip (transparently decompressed)
error_envelope:
  shape: 'JSON object with a "message" field, e.g. {"message": "Unauthorized"}'
  see: errors/bmll-technologies-problem-types.yml
versioning:
  see: lifecycle/bmll-technologies-lifecycle.yml