generated: '2026-07-18'
method: searched
source: https://arch.co/client-api/api-docs/
note: >-
  Cross-cutting request/response semantics for the Arch Client API, captured from the
  published API documentation and derived from the OpenAPI. Cross-links authentication/,
  rate-limits/, errors/, and lifecycle/.
authentication:
  style: bearer-jwt
  token_endpoint: POST https://arch.co/client-api/v0/auth/token
  flow: client-credentials
  request_fields: [clientId, clientSecret]
  header: 'authorization: Bearer <access_token>'
  token_format: JWT
  token_reuse: Store and reuse the token until it expires; decode the JWT `exp` (Unix seconds) to find expiry.
  credential_provisioning: Request a Client ID and Client Secret from api-support@arch.co.
  ref: authentication/arch-authentication.yml
pagination:
  style: offset-limit
  name: Pages
  params:
  - {name: offset, in: query, description: Zero-based item offset into the list.}
  - {name: limit, in: query, default: 25, max: 1000, description: Page size; default 25, up to 1000 on endpoints that allow it.}
  response_container: Objects returned inside a list ("Page"); list bodies carry a `contents` array.
idempotency:
  supported: false
  note: No idempotency-key header/parameter is documented or present in the OpenAPI.
versioning:
  style: uri-path
  current: v0
  base_path: /client-api/v0
  note: API version is embedded in the path (v0); the spec info.version is 0.1.0.
filtering:
  style: query-parameters
  patterns:
  - before*/after* date-range filters (e.g. afterCreatedAt, beforeDueDate, afterStatementDate)
  - id set filters (ids, holdingIds, investingEntityIds, issuingEntityIds, accountIds)
  - include* expansion flags to hydrate related data (e.g. includeCashFlow, includeFiles, includeInsights, includeTax, includeMetrics, includeWireInstructions)
field_expansion:
  style: include-flags
  note: Related data is opt-in via include* boolean query parameters rather than a generic expand param.
error_envelope:
  format: http-status + JSON body
  problem_json: false
  fields: [message]
  ref: errors/arch-problem-types.yml
rate_limit_signaling:
  style: response-headers
  headers: [RateLimit-Policy, RateLimit-Limit, RateLimit-Remaining, RateLimit-Reset]
  exceeded_status: 429
  ref: rate-limits/arch-rate-limits.yml
media_type: application/json