Versioning & Changelog

Versioning

The API is versioned in the path — the current version is /v1. We follow a simple contract:

• Additive changes are non-breaking and ship within v1 without notice: new endpoints, new optional parameters, and new response fields. In particular, new trailing-return periods appear under extra_returns (see Field reference) so your client never breaks when a period is added upstream.
• Breaking changes — removing or renaming a field, changing a type, or altering existing behavior — would ship under a new version path (/v2), with the prior version supported during a deprecation window.

Build defensively: read known fields by name, ignore unknown fields you don't use, and don't assume the return-period list is fixed.

Changelog

v1.0.0 — Initial release

• GET /v1/funds — search and list the fund universe (cursor pagination).
• GET /v1/funds/{code} — fund metadata.
• GET /v1/funds/{code}/trailing-returns — trailing returns (latest or as_of).
• POST /v1/trailing-returns/batch — trailing returns for up to 100 funds.
• GET /v1/funds/{code}/calendar-returns — calendar-year return (latest or year).
• POST /v1/calendar-returns/batch — calendar-year returns for up to 100 funds.
• Hosted MCP server at /mcp exposing all six operations as tools.
• 16 trailing-return periods (1d–20y, ytd, since-inception) and calendar-year returns for ~32,000 US mutual funds and ETFs.

New entries are added here as the API evolves.