OpenBB-finance/OpenBB · error · OpenBBError

An error occurred while fetching constraints {dataflow_id}:

Error message

An error occurred while fetching constraints {dataflow_id}: {e} -> {url}

What it means

Thrown by IMFSDMXMetadata when the HTTP request to the IMF SDMX 'constraints' endpoint for a dataflow raises a requests RequestException (connection failure, DNS error, timeout, or raise_for_status() 4xx/5xx). The message wraps the original exception text plus the offending URL so the failing call can be reproduced manually. It surfaces as an OpenBBError from the IMF provider's metadata layer.

Source

Thrown at openbb_platform/providers/imf/openbb_imf/utils/metadata.py:751

            if query_params
            else base_url
        )
        json_response: dict = {}
        try:
            headers = {
                "Accept": "application/json",
                "User-Agent": "Open Data Platform - IMF Metadata Utility",
            }
            response = make_request(url, headers=headers)
            response.raise_for_status()
            json_response = response.json()
        except json.JSONDecodeError as e:
            raise OpenBBError(
                f"Unexpected response format when fetching constraints {dataflow_id}: {e}"
                + f" -> {url}"
            ) from None
        except RequestException as e:
            raise OpenBBError(
                f"An error occurred while fetching constraints {dataflow_id}: {e} -> {url}"
            ) from None

        extracted_values: dict = {}
        json_data = json_response.get("data", {})
        data_constraints = json_data.get("dataConstraints", [])

        for constraint in data_constraints:
            for region in constraint.get("cubeRegions", []):
                for kv in region.get("keyValues", []):
                    dim_id = kv.get("id")
                    if dim_id:
                        if dim_id not in extracted_values:
                            extracted_values[dim_id] = []
                        for val in kv.get("values", []):
                            if isinstance(val, dict):
                                extracted_values[dim_id].append(val.get("value"))
                            else:

View on GitHub (pinned to 3e071fcc2c)

Solutions

Retry after a short delay — IMF SDMX endpoints intermittently fail with 5xx; a single retry usually succeeds.
Verify network reachability of the exact URL printed in the message (curl it) to distinguish proxy/firewall blocks from IMF-side errors.
If HTTP 429, slow down or add caching/backoff before re-crawling many dataflows.
Confirm dataflow_id is a valid IMF dataflow (it appears in the URL) — an invalid ID yields a 404 RequestException.

Example fix

// before
params = metadata.get_dataflow_parameters('FSIBSIS')  # raises OpenBBError on RequestException

// after
from time import sleep
for attempt in range(3):
    try:
        params = metadata.get_dataflow_parameters('FSIBSIS')
        break
    except OpenBBError as e:
        if attempt == 2 or '429' not in str(e):
            raise
        sleep(2 ** attempt)

Defensive patterns

Strategy: retry

Validate before calling

import requests
url = constraints_url_for(dataflow_id)  # the URL printed in the error
try:
    r = requests.head(url, timeout=10)
    ok = r.status_code == 200
except requests.RequestException:
    ok = False
if not ok:
    print('IMF constraints endpoint unreachable; deferring fetch')

Try / catch

try:
    params = meta.get_dataflow_parameters(dataflow_id)
except OpenBBError as e:
    if 'fetching constraints' in str(e):
        # transient network/HTTP failure: safe to retry with backoff
        raise RetryableError(str(e)) from e
    raise

Prevention

Cache constraints per dataflow_id (the class already does via _constraints_cache) so retries are rare.
Rate-limit bulk metadata crawls to avoid IMF 429s.
Log the full URL from the message to reproduce failures deterministically.

When it happens

Trigger: Calling any IMF SDMX-based fetcher (e.g. get_dataflow_parameters / indicator discovery for dataflows like 'FSIBSIS' or 'BOP_AGG') while the IMF API is unreachable, rate-limiting (HTTP 429), returning 5xx, or when a proxy/firewall blocks the request to the IMF JSON REST endpoint shown in {url}.

Common situations: Transient IMF server outages or maintenance windows, corporate proxies intercepting requests, rate limits after bulk metadata crawling, typos in dataflow_id that lead to a 404 from the constraints endpoint.

Related errors

AI-assisted analysis of OpenBB-finance/OpenBB@3e071fcc2c (2026-08-14). Data as JSON: /api/errors/7210285861f01a49. Report an issue: GitHub.