400 Bad Request - There Was An Error Returned Querying The Prometheus Api Jun 2026

level=error component=web msg="Error serving request" err="bad_data: ..."

/api/v1/query_range?query=up&start=1700000000&end=1699999999&step=1m (start after end)

curl -G http://prometheus:9090/api/v1/query \ --data-urlencode 'query=http_requests_totalstatus!~"5.."' \ --data-urlencode 'time=1600000000' This often happens when a template variable selects

Keywords: 400 bad request, Prometheus API error, query prometheus api failed, invalid PromQL, URL encoding Prometheus.

curl -G 'http://prometheus:9090/api/v1/query' --data-urlencode 'query=upjob="node"' especially when querying managed services like

The most common encounter with this error occurs within Grafana. You have built a beautiful dashboard, perhaps with templating variables, and suddenly, one panel displays a red triangle with the "400 Bad Request" message. This often happens when a template variable selects a value that creates an invalid query string.

query = 'http_requests_totalstatus="200"' encoded_query = quote(query, safe='') response = requests.get( 'http://prometheus:9090/api/v1/query', params='query': query # requests handles encoding automatically ) Prometheus API error

: Issues with API keys or account permissions, especially when querying managed services like , often manifest as a 400 error. Improper HTTP Method : Some configurations may require instead of