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You need a reliable way to pull current congestion signals for Shanghai (CNSHA) into your stack and ship a working PHP lookup that your team can call in production. By the end of this guide, you will query FreightPulse for CNSHA congestion via cURL, parse the JSON in PHP, and expose a simple interface that returns the signal your UI or downstream jobs can use—plus a small Python example for teams that prototype outside PHP.

What you will build for Shanghai (CNSHA)

This post focuses on the Shanghai container port (LOCODE: CNSHA). You will:

Illustration: Shanghai (CNSHA) Congestion

All examples are platform-agnostic at the HTTP layer and use the exact endpoint, auth header, and fields provided by FreightPulse. This post does not quote freight rates and does not treat congestion as live AIS wait time.

Data source and how to interpret the lag

FreightPulse congestion signals are derived from IMF PortWatch (portwatch.imf.org) using UN Global Platform AIS data. The activity (and the deprecated alias congestion) is based on the recent 7-day average port-call volume compared to a 90-day baseline, by port. It measures activity, not vessel wait or anchorage time.

The dataset is lagged because PortWatch republishes the daily series only once a week. Expect a lag window of several days between today and the latest as_of date in the API. Always display or log the as_of date and avoid marketing it as live AIS data.

Authentication and request envelope

Use an API key via the X-API-Key header:

FreightPulse wraps responses in an envelope that looks like this:

In other words, check success first, then descend into data to read result fields. For CNSHA, you will read congestion (alias of activity), metrics.ratio_vs_baseline, and as_of.

Quick test with cURL

Run this from any shell to confirm access and validate the shape of the payload. Replace the header value with your key when you have one; you can test as a guest as well.

Live FreightPulse congestion for CNSHA.
Source: live

cURL:

curl -H "X-API-Key: YOUR_API_KEY" "https://freightpulsehq.com/api/v1/port-congestion?port=CNSHA"

Understand the JSON you will parse

Below is the official JSON sample for the CNSHA query. Do not assume that the value of any field is live beyond what is shown here—always key your logic to the fields and allow values to change.

JSON:

{
    "success": true,
    "data": {
        "results": [
            {
                "port": "Shanghai",
                "locode": "CN SGH",
                "country": "China",
                "activity": "moderate",
                "congestion": "moderate",
                "as_of": "2026-11-06",
                "metrics": {
                    "recent_avg_portcalls_per_day": 77.9,
                    "baseline_avg_portcalls_per_day": 82.8,
                    "ratio_vs_baseline": 0.94
                }
            }
        ],
        "global_summary": {
            "ports_high_activity": 0,
            "ports_moderate_activity": 1,
            "ports_low_activity": 0,
            "ports_high_congestion": 0,
            "ports_moderate": 1,
            "ports_low": 0
        },
        "meta": {
            "source": "IMF PortWatch (portwatch.imf.org) - UN Global Platform AIS data",
            "data_lag_days": "4-11 (PortWatch republishes the daily series once a week; check as_of)",
            "methodology": "activity is port-call volume, not congestion: last 7 days' avg calls vs a 90-day baseline for the same port. low means fewer calls than usual, which can be a closure or ships waiting offshore. It does not measure vessel wait or anchorage time. congestion is a deprecated alias of activity."
        }
    },
    "meta": {
        "request_id": "7b4ffe91-8133-466a-adb7-7bf7acb7459e"
    }
}

Fields you will actually use for Shanghai (CNSHA):

You may also display port (Shanghai), country (China), and the optional global_summary for context, but your integration should not depend on those values being present in any specific order.

PHP implementation: fetch and parse CNSHA congestion

The snippet below uses PHP’s cURL extension and native JSON decoding. It returns a simple associative array with the three fields you need for Shanghai: congestion, ratio_vs_baseline, and as_of.

<?php

function fetchCnshaCongestion(): array
{
$url = 'https://freightpulsehq.com/api/v1/port-congestion?port=CNSHA';

$ch = curl_init($url);
curl_setopt_array($ch, [
CURLOPT_RETURNTRANSFER => true,
CURLOPT_HTTPHEADER => [
'X-API-Key: YOUR_API_KEY',
'Accept: application/json'
],
CURLOPT_TIMEOUT => 20,
]);

$body = curl_exec($ch);
$errNo = curl_errno($ch);
$status = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);

if ($errNo !== 0) {
throw new RuntimeException('Network error calling FreightPulse: cURL errno ' . $errNo);
}
if ($status < 200 || $status >= 300) {
throw new RuntimeException('FreightPulse returned HTTP ' . $status);
}

$json = json_decode($body, true);
if (!is_array($json) || empty($json['success']) || empty($json['data']['results'][0])) {
throw new RuntimeException('Unexpected FreightPulse payload or unsuccessful response');
}

$row = $json['data']['results'][0];

// Defensive checks: ensure fields exist before accessing
$congestion = $row['congestion'] ?? ($row['activity'] ?? null);
$asOf = $row['as_of'] ?? null;
$ratio = $row['metrics']['ratio_vs_baseline'] ?? null;

if ($congestion === null || $asOf === null || $ratio === null) {
throw new RuntimeException('Missing required fields in FreightPulse response');
}

return [
'port' => $row['port'] ?? 'Shanghai',
'locode' => $row['locode'] ?? 'CNSHA',
'country' => $row['country'] ?? 'China',
'congestion' => $congestion,
'ratio_vs_baseline' => $ratio,
'as_of' => $asOf,
];
}

// Example usage:
try {
$cnsha = fetchCnshaCongestion();
// Render or log the signal
echo 'Port: ' . $cnsha['port'] . PHP_EOL;
echo 'As of: ' . $cnsha['as_of'] . ' (UTC date)' . PHP_EOL;
echo 'Congestion: ' . $cnsha['congestion'] . PHP_EOL;
echo 'Ratio vs baseline: ' . $cnsha['ratio_vs_baseline'] . PHP_EOL;
} catch (Throwable $e) {
// Integrate with your logging/alerting here
error_log($e->getMessage());
http_response_code(502);
echo 'Temporarily unable to retrieve port congestion';
}

Notes on productionizing the PHP call

Python example (same endpoint, same fields)

If your team prototypes in Python, the following requests snippet hits the same endpoint and extracts the same fields.

import requests

URL = "https://freightpulsehq.com/api/v1/port-congestion?port=CNSHA"
HEADERS = {
"X-API-Key": "YOUR_API_KEY",
"Accept": "application/json",
}

def fetch_cnsha():
r = requests.get(URL, headers=HEADERS, timeout=20)
r.raise_for_status()
payload = r.json()

if not payload.get("success"):
raise RuntimeError("Unsuccessful FreightPulse response")

results = payload.get("data", {}).get("results", [])
if not results:
raise RuntimeError("No results for CNSHA")

row = results[0]
congestion = row.get("congestion", row.get("activity"))
as_of = row.get("as_of")
ratio = (row.get("metrics") or {}).get("ratio_vs_baseline")

if congestion is None or as_of is None or ratio is None:
raise RuntimeError("Missing required fields in response")

return {
"port": row.get("port", "Shanghai"),
"locode": row.get("locode", "CNSHA"),
"country": row.get("country", "China"),
"congestion": congestion,
"ratio_vs_baseline": ratio,
"as_of": as_of,
}

if __name__ == "__main__":
data = fetch_cnsha()
print(f"Port: {data['port']}")
print(f"As of: {data['as_of']} (UTC date)")
print(f"Congestion: {data['congestion']}")
print(f"Ratio vs baseline: {data['ratio_vs_baseline']}")

How to display and store the CNSHA signal safely

Consider the following guardrails when integrating CNSHA congestion into a dashboard or feed:

What the congestion label means for Shanghai

In this dataset, congestion is a categorical alias of activity based on port-call volumes. For Shanghai, read it as a signal of relative activity versus the recent 90-day baseline. It can be informative during holidays, weather events, or operational disruptions when port calls deviate from typical patterns.

Do not interpret the label as live vessel dwell or anchorage wait. If you need operational wait time, you would need a different source designed for live AIS or queue estimates. This API’s strength is in recent activity vs. baseline.

Do not quote freight rates as today’s price

Port activity is informative for planning, but it is not a freight rate. Do not display USD fares or imply that the congestion value reflects a current rate for Shanghai. If you maintain a freight-pricing module, keep it decoupled from this signal and clearly labeled with its own source and timestamp.

Error handling and edge cases

End-to-end example: small PHP presenter

This snippet wraps the fetcher with a minimal presenter that returns an HTTP 200 JSON page for your monitoring UI. Keep it behind your own authentication if needed.

<?php

header('Content-Type: application/json');

try {
$data = fetchCnshaCongestion(); // Reuse the function from earlier

// A thin view-model for frontends
$out = [
'port' => $data['port'],
'locode' => $data['locode'],
'country' => $data['country'],
'signal' => [
'congestion' => $data['congestion'],
'ratio_vs_baseline' => $data['ratio_vs_baseline'],
'as_of' => $data['as_of'], // YYYY-MM-DD, UTC date
],
'source' => 'FreightPulse / IMF PortWatch',
'fetched_at' => gmdate('c'), // ISO 8601 UTC
];

echo json_encode($out, JSON_PRETTY_PRINT);
} catch (Throwable $e) {
http_response_code(502);
echo json_encode([
'error' => 'upstream_unavailable',
'message' => $e->getMessage(),
]);
}

Testing checklist before you ship

Troubleshooting and observability

Developer FAQ

Ready to wire up CNSHA and move from manual checks to an automated pipeline? Create an account to get an API key and read the schema notes in the docs: Register and review the Documentation.