---
title: "Port-call throughput deviation with a weather risk overlay - IMF PortWatch"
method: GET
path: "/api/v2/transport/ports/congestion"
tags: ["Transportation"]
---

# Port-call throughput deviation with a weather risk overlay - IMF PortWatch

`GET /api/v2/transport/ports/congestion`

For a set of the world's ports, how far the latest port-call count sits from each port's own recent baseline (a throughput DEVIATION, not a congestion, dwell or wait measurement - IMF PortWatch publishes none of those), reported ALONGSIDE a Weather-Disruption-Risk overlay and never blended into it. Pick the busiest ports (default), one country, or specific port ids. Directionally ambiguous and several days stale by construction; not for navigation or operational routing.

## Query parameters

- `country` string, nullable — ISO3 country code, e.g. CHN, USA, NLD.
- `ports` string, nullable — Comma-separated PortWatch port ids, e.g. port1201,port1114.
- `top` integer — Number of ports to return (busiest first when no country/ports filter).
- `min_abs_z` number, nullable — Keep only ports whose absolute throughput z-score reaches this.
- `sort` 'anomaly' | 'activity' — anomaly = by absolute throughput deviation; activity = by call count.

## Response `200`

Successful Response

- EnvelopePortCongestionFeed
  - `data` PortCongestionFeed, required
    - `query` PortCongestionQuery, required
      - `country` string, nullable
      - `ports` string, nullable
      - `top` integer, required
      - `min_abs_z` number, nullable
      - `sort` string, required
    - `port_set` PortSetInfo, required
      - `requested` string, required — top | country | ports.
      - `scorable_universe` integer, required — Ports that clear the baseline gate before the page cap.
      - `resolved` integer, required
      - `capped` boolean, required — True when the request asked for more than the hard cap.
    - `total_matched` integer, required
    - `count` integer, required
    - `ports` PortCongestionEntry[]
      - `port_id` string, required
      - `name` string, nullable
      - `country` string, nullable
      - `iso3` string, nullable
      - `lat` number, nullable
      - `lon` number, nullable
      - `throughput` PortThroughput, required
        - `activity` number, nullable — Port calls on the snapshot day.
        - `baseline_mean` number, nullable
        - `baseline_stddev` number, nullable — Denominator actually used: max(observed_sd, sqrt(mean), 1.0).
        - `baseline_days` integer, nullable
        - `z_score` number, nullable
        - `pct_deviation` number, nullable
        - `direction` string, nullable — below | normal | above.
        - `band` string, nullable — normal | elevated | high | extreme (|z| bands).
        - `available` boolean, required
        - `reason` string, nullable — Why the deviation could not be scored: an offshore terminal, no snapshot count, or a baseline too small to be meaningful.
      - `risk_overlay` PortRiskOverlay, required
        - `index` number, nullable — Weather-Disruption-Risk index at the port.
        - `band` string, nullable
        - `dominant_driver` string, nullable
        - `components_count` integer, nullable
        - `sub_scores` object
        - `wave_available` boolean — Sea state is frequently unavailable at a port: the coordinate sits on a land or quay grid node. This is stated, never silently scored as calm.
        - `unavailable_factors` string[]
        - `available` boolean, required
        - `reason` string, nullable — Why no index could be formed (coverage or too few factors).
    - `methodology` object
    - `data_quality` PortCongestionDataQuality, required
      - `as_of` string, nullable, required — Snapshot date; the panel lags the calendar.
      - `staleness_days` integer, nullable, required — Days between as_of and today.
      - `directional_ambiguity` string, required — A deviation does not carry its own sign of causation: a fall can be congestion, a holiday, a strike or an AIS blackout.
      - `ais_confounds` string, required — Known AIS artefacts that a naive anomaly would misread: blackout days, transponder-off zones, GPS jamming, and Lunar New Year seasonality.
    - `attribution` object — Two halves: the IMF PortWatch throughput citation (naming the Kpler and UN Global Platform provenance and the material Sugra transformation) and the sovereign weather sources behind the risk overlay.
    - `disclaimer` string, required
  - `meta` SugraMeta, required — Metadata attached to every /api/v1/* response envelope.
    - `endpoint` string, required — Requested endpoint path.
    - `data_time` string, required — ISO 8601 UTC timestamp of the source data, not of the request.
    - `response_time` string, required — ISO 8601 UTC timestamp when this response was produced.
    - `provider` string, required — API name and version.
    - `source` string, nullable — Identifier of the primary upstream source used for this response.
    - `attribution` string, nullable — Human-readable attribution mandated by an upstream source (e.g. a securities regulator or self-regulatory organization). Present only on responses whose source requires the owner and source to be clearly identified. Do not remove or alter it when using the response.
    - `fallback_used` boolean, nullable — True when the primary source failed and a fallback produced the data.
    - `fallback_chain` string[], nullable — Ordered list of sources attempted, in the order they were tried.
    - `cached` boolean, nullable — True when this response was served from the internal cache.
    - `stale` boolean, nullable — True when the cached response was returned after the upstream rate-limited or errored. Clients can use this to detect degraded data.

## Other responses

- `401` — Missing or invalid `x-api-key` header.
- `422` — Validation Error
- `429` — Daily rate limit exceeded. Check `X-RateLimit-Reset` for the next window.
- `503` — Upstream source is temporarily unavailable. Retry after a short delay.

---

[API](https://skmtc.net/sugra/apis/sugra-api.md) · [All operations](https://skmtc.net/sugra/apis/sugra-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/sugra/sugra-api/versions/4e2740743eb4/schema)