gofiber/fiber · error

Route ' ' has parameters, which exceeds the maximum of

Error message

Route '%s' has %d parameters, which exceeds the maximum of %d

What it means

parseRoute caps the number of path parameters per route pattern at maxParams (30). Each :param, {param}, or *wildcard segment counts as one parameter. Exceeding 30 panics with the pattern, the actual count, and the limit. The cap exists because the router stores parameters in a fixed-size stack array ([maxParams]string) on the context for zero-allocation matching, so the route parser enforces the same bound the matcher assumes.

Solutions

1. Reduce the number of path parameters to 30 or fewer by collapsing redundant segments (e.g. move some identifiers into query parameters or a nested resource under a single prefix).
2. If the long path is unavoidable, split the route across multiple handlers or use a catch-all (* wildcard counts as one) to absorb a variable tail.
3. Audit generated routes for parameter count before registering them.

Example fix

// before — 31 params, panics
app.Get("/:a/:b/:c/:d/:e/:f/:g/:h/:i/:j/:k/:l/:m/:n/:o/:p/:q/:r/:s/:t/:u/:v/:w/:x/:y/:z/:aa/:ab/:ac/:ad/:ae", h)

// after — collapse the tail into a catch-all wildcard
app.Get("/:a/:b/:c/.../:z/*rest", h)

const maxRouteParams = 30

func countRouteParams(pattern string) int {
    n := 0
    for i := 0; i < len(pattern); i++ {
        switch pattern[i] {
        case ':', '*':
            n++
        case '{':
            if strings.ContainsRune(pattern[i:], '}') { n++ }
        }
    }
    return n
}
// if countRouteParams(pattern) > maxRouteParams { refactor before registering }

func routeWithinParamLimit(pattern string) bool { return countRouteParams(pattern) <= 30 }

When it happens

Trigger: Registering a route like app.Get("/:a/:b/:c/.../:ae", ...) with more than 30 parameter segments; a generated route (e.g. from a deeply nested resource path) that accumulates parameters past the limit.

Common situations: A programmatically-generated route with many nested resource IDs; a route built by joining many path fragments each carrying a parameter; exceeding the limit after adding a new parameterized segment to an already-long route.

Related errors

• add: invalid http method
• missing handler/middleware in route
• nil handler in route
• ErrUpstreamHostBlocked
• ErrUpstreamHostInvalid

AI-assisted analysis of gofiber/fiber@a105acad6c (2026-08-11). Data as JSON: /api/errors/f2c514efdecb7104. Report an issue: GitHub.

Appendix: source

Thrown at path.go:364

	parser.minSlashes = int32(minSlashes)
	if bounded {
		parser.maxSlashes = int32(maxSlashes)
		parser.maxBounded = true
	}
}

// parseRoute analyzes the route and divides it into segments for constant areas and parameters,
// this information is needed later when assigning the requests to the declared routes
func parseRoute(pattern string, regexHandler any, customConstraints ...CustomConstraint) routeParser {
	parser := routeParser{}
	parser.parseRoute(pattern, regexHandler, customConstraints...)
	// The slash bounds only speed up the router's candidate scan; computing them
	// here keeps them off RoutePatternMatch's per-call path, which never reads them.
	parser.computeSlashBounds()

	// Check if the route has too many parameters
	if len(parser.params) > maxParams {
		panic(fmt.Sprintf("Route '%s' has %d parameters, which exceeds the maximum of %d",
			pattern, len(parser.params), maxParams))
	}

	return parser
}

// addParameterMetaInfo add important meta information to the parameter segments
// to simplify the search for the end of the parameter
func addParameterMetaInfo(segs []*routeSegment) []*routeSegment {
	var comparePart string
	segLen := len(segs)
	// loop from end to begin
	for i := segLen - 1; i >= 0; i-- {
		// set the compare part for the parameter
		if segs[i].IsParam {
			// important for finding the end of the parameter
			segs[i].ComparePart = RemoveEscapeChar(comparePart)
		} else {

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