Changelog and Versioning

How the API is versioned, what counts as a breaking change, and every change to the public contract, dated.

Versioning

The major version is in the path: every public endpoint is under /v1. The contract's own version is 1.0.0, published at /openapi.json.
Within v1, changes are additive. The API's release process compares every change with the published contract and treats these as breaking: removing an operation, a channel, a response status, a schema or a field; adding a required input or field; changing a type; and narrowing an enum.
Adding an optional field, a new endpoint or a new enum value is not breaking. Write clients that ignore fields they do not know and that handle enum values they have not seen.
The entries marked breaking date from September 2026, when the development interface was replaced by the public contract and refined, and from 16 October 2026, when the issuer X feed preview was withdrawn.

Generating a Client

Generate clients from /openapi.json: every operation has a stable operationId, which is what generators name methods after.

Added GET /v1/assets/market-pairs/latest: orientation=requested returns a pair whose quote is one of ids, and whose base is not, inverted: base and quote swapped, the price the reciprocal, base and quote volumes and bid and ask depth swapped. USD volume, liquidity, spread, score and activity_24h stay the market's. The default, market, is unchanged.
Added Market pairs: orientation (market or inverted) and ticker.price_usd, the USD price of one unit of the base as returned, through the quote's reference price; null when the quote has none.

Added Venue statistics: trade_count_24h_metadata, the trade count's own as_of and whether it was retained from an earlier refresh. last_updated_at is the latest statistics refresh.

Added GET /v1/fear-and-greed/latest: the latest published Canton Ecosystem Fear & Greed Index, a score from 0 to 100 with its classification and daily UTC update_time; data is null before the first publication.
Added GET /v1/fear-and-greed/historical: the published index history, newest first, paged by a 1-based start offset and limit rather than a cursor.
Added Global metrics volume and asset quote volume (VolumeMetrics): selection_method, methodology_version, interpretation and coverage_detail. Venue statistics: volume_24h_usd_metadata, with the same fields and its own as_of.
Added Activity measurements: market_coverage, the eligible, included, missing, unvalued, partial and incomplete-time market counts behind a selected USD volume.
Added Market pairs: activity_24h, the market's current 24-hour activity, selected as in GET /v1/activity/{entity_kind}/{entity_id}.

Added Global metrics volume and asset quote volume: as_of, when the volume was measured, independent of the price's update time.

Breaking

Added Assets and listings: liquidity_score, liquidity_score_methodology (asset-top-three-liquidity-v1) and liquidity_score_updated_at. The score is the equal average of the asset's highest market liquidity scores, up to three, rounded to two decimals, and null when no market is scored.
Removed GET /v1/issuers/{issuer_id}/x-feed and the IssuerX* schemas. Issuer profile links remain.

Added GET /v1/activity/markets/latest: the current activity snapshot for up to 100 markets in one request, in request order.
Added GET /v1/issuers/{issuer_id}/x-feed: an issuer's cached X posts, with as_of and visible_until. The preview is disabled by default and answers 503 source_unavailable while it is.
Added Asset social_links; asset candle volume_usd and volume_coverage.
Added Market fees: pool-level rates with their own evidence and coverage, separately scoped charges with amounts, and unpriced_pools for eligible pools without a valid fee.

Added GET /v1/assets/{asset_id}/supply/historical: the reported total supply of one asset over time.
Added Listings: rank, liquidity_to_fdv_ratio and volume_24h_to_fdv_ratio, each ratio with its coverage object.
Added Markets: fees, a sourced fee schedule with status, applicability, payment method and evidence, published beside the free-form fee_model.
Added Liquidity: synthetic_depth, ±2% depth modelled from stored pool state, with depth_origin and the reason when it is unavailable. Activity measurements: as_of.

Breaking

Added GET /v1/activity/{entity_kind}/{entity_id}: stored 24h, 7d and 30d volume and execution counts for a market, asset, venue or the whole network.
Added Asset documentation_url and categories; issuer official_links and last_updated_at; venue documentation_url, social_links and fee_documentation_url.
Removed POST /v1/markets/{market_id}/quote and POST /v1/pools/{pool_id}/quote. Every public operation is now a GET.

Breaking

Added category filter on market pairs, markets and venue markets; market_category on markets, pools and tickers.
Added liquidity_score, liquidity_score_methodology and liquidity_score_updated_at on tickers and liquidity snapshots.
Changed tvl_usd renamed to liquidity_usd on listing liquidity, pools, liquidity snapshots and venue statistics.

Breaking

Changed The development interface was replaced in place by the public v1 contract: consumer models for assets, listings, quotes, candles, market pairs and venues, exact decimal strings throughout, and direct last_updated_at timestamps instead of freshness wrappers.
Added GET /v1/assets/{asset_id}/registry-configurations, GET /v1/issuers/{issuer_id}/evidence and GET /v1/issuers/{issuer_id}/relationships.
Removed Administrative and internal operations moved to a separate contract, and per-figure provenance (constituents, exclusion reasons, calculation run IDs, confidence) left the public surface.