Note
This repository has been transferred from github.com/tigerwill90/fox to github.com/fox-toolkit/fox.
Existing users should update their imports and go.mod accordingly.
Fox is a lightweight and high performance HTTP request router for Go, designed for building reverse proxies, API gateways, or other applications that require managing routes at runtime based on configuration changes or external events. It is also well-suited for general use cases such as microservices and REST APIs, though it focuses on routing and does not include convenience helpers found in full-featured frameworks, such as automatic binding, content negotiation, file uploads, cookies, etc.
Fox supports mutation on its routing tree while handling requests concurrently. Internally, it uses a Radix Tree that supports lock-free reads while allowing a concurrent writer, and is optimized for high-concurrency reads and low-concurrency writes. The router supports complex routing patterns, enforces clear priority rules, and performs strict validation to prevent misconfigurations.
The current API is not yet stabilized. Breaking changes may occur before v1.0.0 and will be noted on the release note.
Runtime updates: Register, update and delete route handler safely at any time without impact on performance.
Flexible routing: Fox strikes a balance between routing flexibility, performance and clarity by enforcing clear priority rules, ensuring that there are no unintended matches and maintaining high performance even for complex routing patterns. Supported features include named parameters, suffix and infix catch-all, regexp constraints, hostname matching, method and method-less routes, route matchers, and sub-routers.
Trailing slash handling: Automatically handle trailing slash inconsistencies by either ignoring them, redirecting to the canonical path, or enforcing strict matching based on your needs.
Path correction: Automatically handle malformed paths with extra slashes or dots by either serving the cleaned path directly or redirecting to the canonical form.
Automatic OPTIONS replies: Fox has built-in native support for OPTIONS requests.
Client IP Derivation: Accurately determine the "real" client IP address using best practices tailored to your network topology.
Growing middleware ecosystem: Fox's middleware ecosystem is still limited, but standard http.Handler middleware are fully compatible. Contributions are welcome!
- Getting started
- Concurrency
- Middleware
- Working with http.Handler
- Handling OPTIONS Requests and CORS Automatically
- Resolving Client IP
- Benchmark
- Road to v1
- Contributions
- License
With a correctly configured Go toolchain:
go get -u github.com/fox-toolkit/foxThis library requires Go 1.26.0 or above. Per the Go release policy, it only supports the two most recent major releases of Go, i.e. 1.26 and 1.25.
package main
import (
"errors"
"fmt"
"log"
"net/http"
"github.com/fox-toolkit/fox"
)
func HelloServer(c *fox.Context) {
_ = c.String(http.StatusOK, fmt.Sprintf("Hello %s\n", c.Param("name")))
}
func main() {
f := fox.MustRouter(fox.DefaultOptions())
f.MustAdd([]string{http.MethodHead, http.MethodGet}, "/hello/{name}", HelloServer)
if err := http.ListenAndServe(":8080", f); err != nil && !errors.Is(err, http.ErrServerClosed) {
log.Fatalln(err)
}
}Routes can include named parameters using curly braces {name} to match exactly one non-empty route segment. The matching
segments are recorded as Param and accessible via the
Context. Named parameters are supported anywhere in
the route, but only one parameter is allowed per segment (or hostname label) and must appear at the end of the segment.
Pattern /avengers/{name}
/avengers/ironman matches
/avengers/thor matches
/avengers/hulk/angry no matches
/avengers/ no matches
Pattern /users/uuid:{id}
/users/uuid:123 matches
/users/uuid: no matches
Pattern /users/uuid:{id}/config
/users/uuid:123/config matches
/users/uuid:/config no matches
Pattern {sub}.example.com/avengers
first.example.com/avengers matches
example.com/avengers no matches
Named parameters can include regular expression using the syntax {name:regexp}. Regular expressions cannot
contain capturing groups, but can use non-capturing groups (?:pattern) instead. Regexp support is opt-in via
fox.AllowRegexpParam(true) option.
Pattern /products/{name:[A-Za-z]+}
/products/laptop matches
/products/123 no matches
Named wildcard start with a plus sign + followed by a name {param} and match any sequence of characters
including slashes, but cannot match an empty string. The matching segments are also accessible via
Context. Catch-all parameters are supported anywhere in the route,
but only one parameter is allowed per segment (or hostname label) and must appear at the end of the segment.
Consecutive catch-all parameter are not allowed.
Pattern /src/+{filepath}
/src/conf.txt matches
/src/dir/config.txt matches
/src/ no matches
Pattern /src/file=+{path}
/src/file=config.txt matches
/src/file=/dir/config.txt matches
/src/file= no matches
Pattern: /assets/+{path}/thumbnail
/assets/images/thumbnail matches
/assets/photos/2021/thumbnail matches
/assets//thumbnail no matches
Pattern +{sub}.example.com/avengers
first.example.com/avengers matches
first.second.example.com/avengers matches
example.com/avengers no matches
Optional named wildcard start with an asterisk * followed by a name {param} and match any sequence of characters
including empty strings. Unlike +{param}, optional wildcards can only be used as a suffix.
Pattern /src/*{filepath}
/src/conf.txt matches
/src/dir/config.txt matches
/src/ matches
Pattern /src/file=*{path}
/src/file=config.txt matches
/src/file=/dir/config.txt matches
/src/file= matches
Named wildcards can include a regular expression constraint using the syntax +{name:regexp}. Regular expressions cannot
contain capturing groups, but can use non-capturing groups (?:pattern) instead. Optional wildcards (*{param}) do not
support regular expressions. Regexp support is opt-in via fox.AllowRegexpParam(true) option.
Pattern /src/+{filepath:[A-Za-z/]+\.json}
/src/dir/config.json matches
/src/dir/config.txt no matches
Route matchers enable routing decisions based on request properties beyond methods, hostname and path. Multiple routes can share the same pattern and methods and be differentiated by query parameters, headers, client IP, or custom criteria.
f.MustAdd(fox.MethodGet, "/api/users", V1Handler, fox.WithHeaderMatcher("X-API-Version", "v1"))
f.MustAdd(fox.MethodGet, "/api/users", V2Handler, fox.WithHeaderMatcher("X-API-Version", "v2"))
f.MustAdd(fox.MethodGet, "/api/users", V1Handler) // Fallback routeBuilt-in matchers include fox.WithQueryMatcher, fox.WithQueryRegexpMatcher, fox.WithHeaderMatcher, fox.WithHeaderRegexpMatcher,
fox.WithSchemeMatcher and fox.WithClientIPMatcher. Multiple matchers on a route use AND logic. Routes without matchers serve as fallbacks.
For custom matching logic, implement the fox.Matcher interface and use fox.WithMatcher. See Priority rules for matcher
evaluation order.
Routes can be registered without specifying an HTTP method to match any method. The constant fox.MethodAny is
a convenience placeholder equivalent to an empty method set (nil or empty slice).
// Handle any method on /health
f.MustAdd(fox.MethodAny, "/health", HealthHandler)
// Forward all requests to a backend service
f.MustAdd(fox.MethodAny, "/api/*{any}", ProxyHandler)Routes registered with a specific HTTP method always take precedence over method-less routes. This allows defining method-specific behavior while falling back to a generic handler for other methods.
// Specific handler for GET requests
f.MustAdd(fox.MethodGet, "/resource", GetHandler)
// All other methods handled here
f.MustAdd(fox.MethodAny, "/resource", FallbackHandler)Fox provides a composable routing API where routers can be mounted as regular routes, each with its own middleware and configuration.
api := fox.MustRouter(fox.WithMiddleware(AuthMiddleware()))
api.MustAdd([]string{http.MethodHead, http.MethodGet}, "/", HelloHandler)
api.MustAdd([]string{http.MethodHead, http.MethodGet}, "/users", ListUser)
api.MustAdd([]string{http.MethodHead, http.MethodGet}, "/users/{id}", GetUser)
api.MustAdd(fox.MethodPost, "/users", CreateUser)
f := fox.MustRouter(fox.DefaultOptions())
f.MustAdd([]string{http.MethodHead, http.MethodGet}, "/*{filepath}", fox.WrapH(http.FileServer(http.Dir("./public/"))))
f.MustAdd(fox.MethodAny, "/api*{mount}", fox.Sub(api))Requests matching the prefix are delegated to the mounted router with the remaining path.
Use cases include:
- Applying middleware, matchers or other configuration to a route prefix
- Managing entire route subtree at runtime (e.g. insert, update, or delete via the parent router)
- Organizing routes into groups with shared configuration
Hostnames are validated to conform to the LDH (letters, digits, hyphens) rule
(lowercase only) and SRV-like "underscore labels". Wildcard segments within hostnames, such as {sub}.example.com/, are exempt from LDH validation
since they act as placeholders rather than actual domain labels. As such, they do not count toward the hard limit of 63 characters per label,
nor the 253-character limit for the full hostname. Internationalized domain names (IDNs) should be specified using an ASCII
(Punycode) representation.
Fox matches requests against the canonical encoded path, equivalent to url.URL.EscapedPath() with percent-encoded hex
sequences normalized to uppercase (e.g. %2f becomes %2F). Encoded and decoded forms are not interchangeable so a request
for /foo%2Fbar will not match a pattern registered as /foo/bar. Patterns containing literal characters that require
encoding must be registered in their encoded form (e.g. /foo%20bar, not /foo bar).
The router is designed to balance routing flexibility, performance, and predictability. Internally, it uses a radix tree to store routes efficiently. When a request arrives, Fox evaluates routes in the following order:
-
Hostname matching
- Routes with hostnames are evaluated before path-only routes
-
Pattern matching (longest match, most specific first)
- Static segments
- Named parameters with regex constraints
- Named parameters without constraints
- Catch-all parameters with regex constraints
- Catch-all parameters without constraints
- Infix catch-all are evaluated before suffix catch-all (e.g.,
/bucket/+{path}/metabefore/bucket/+{path}) - At the same level, multiple regex-constrained parameters are evaluated in registration order
-
Method matching
- Routes with specific methods are evaluated before method-less routes
-
Matcher evaluation (for routes sharing the same pattern and overlapping methods)
- Routes with matchers are evaluated before routes without
- Among routes with matchers, higher priority is evaluated first (configurable via
fox.WithMatcherPriority, or defaults to the number of matchers) - Routes with equal matchers priority may be evaluated in any order
If a match candidate fails to complete the full route, including matchers, Fox returns to the last decision point and tries the next available alternative following the same priority order.
The router can transition instantly and transparently from path-only mode to hostname-prioritized mode without any additional configuration or action. If any route with a hostname is registered, the router automatically switches to prioritize hostname matching. Conversely, if no hostname-specific routes are registered, the router reverts to path-priority mode.
- If the router has no routes registered with hostnames, the router will perform a path-based lookup only.
- If the router includes at least one route with a hostname, the router will prioritize lookup based on the request host and path. If no match is found, the router will then fall back to a path-only lookup.
Hostname matching is case-insensitive, so requests to Example.COM, example.com, and EXAMPLE.COM will all match a route registered for example.com.
The fox.Context instance is freed once the request handler function returns to optimize resource allocation.
If you need to retain fox.Context beyond the scope of the handler, use the fox.Context.Clone methods.
func Hello(c *fox.Context) {
cc := c.Clone()
go func() {
time.Sleep(2 * time.Second)
log.Println(cc.Param("name")) // Safe
}()
_ = c.String(http.StatusOK, "Hello %s\n", c.Param("name"))
}Fox implements an immutable radix tree with copy-on-write semantics, which support lock-free reads while allowing a single concurrent writer. Mutations follow a three-phase pattern: first, descend recursively through the tree to locate the insertion point; then as the call stack unwinds, copy each node along the modified path back to the root and finally, update the root in a single atomic operation. The result is a shallow copy of the tree, where unmodified branches are shared between the old and new tree. Multiple mutations can be applied in a single transaction, where each cloned node is cached to avoid copying it more than once.
- Routing requests is lock-free (reading thread never block, even while writes are ongoing)
- The router always sees a consistent version of the tree while routing request
- Reading threads do not block writing threads (adding, updating or removing a handler can be done concurrently)
- Writing threads block each other but never block reading threads
As such threads that route requests should never encounter latency due to ongoing writes or other concurrent readers.
In this example, the handler for routes/{action} allows to dynamically register, update and delete handler for the
given route and method. Thanks to Fox's design, those actions are perfectly safe and may be executed concurrently.
package main
import (
"encoding/json"
"errors"
"fmt"
"log"
"net/http"
"strings"
"github.com/fox-toolkit/fox"
)
type Data struct {
Pattern string `json:"pattern"`
Methods []string `json:"methods"`
Text string `json:"text"`
}
func Action(c *fox.Context) {
data := new(Data)
if err := json.NewDecoder(c.Request().Body).Decode(data); err != nil {
http.Error(c.Writer(), err.Error(), http.StatusBadRequest)
return
}
var err error
action := c.Param("action")
switch action {
case "add":
_, err = c.Router().Add(data.Methods, data.Pattern, func(c *fox.Context) {
_ = c.String(http.StatusOK, data.Text)
})
case "update":
_, err = c.Router().Update(data.Methods, data.Pattern, func(c *fox.Context) {
_ = c.String(http.StatusOK, data.Text)
})
case "delete":
_, err = c.Router().Delete(data.Methods, data.Pattern)
default:
http.Error(c.Writer(), fmt.Sprintf("action %q is not allowed", action), http.StatusBadRequest)
return
}
if err != nil {
http.Error(c.Writer(), err.Error(), http.StatusConflict)
return
}
_ = c.String(http.StatusOK, fmt.Sprintf("%s route [%s] %s: success\n", action, strings.Join(data.Methods, ","), data.Pattern))
}
func main() {
f := fox.MustRouter(fox.DefaultOptions())
f.MustAdd(fox.MethodPost, "/routes/{action}", Action)
if err := http.ListenAndServe(":8080", f); err != nil && !errors.Is(err, http.ErrServerClosed) {
log.Fatalln(err)
}
}Fox supports read-write and read-only transactions (with Atomicity, Consistency, and Isolation; Durability is not supported as transactions are in memory). Thread that route requests always see a consistent version of the routing tree and are fully isolated from an ongoing transaction until committed. Read-only transactions capture a point-in-time snapshot of the tree, ensuring they do not observe any ongoing or committed changes made after their creation.
// Updates executes a function within the context of a read-write managed transaction. If no error is returned
// from the function then the transaction is committed. If an error is returned then the entire transaction is
// aborted.
if err := f.Updates(func(txn *fox.Txn) error {
if _, err := txn.Add(fox.MethodGet, "example.com/hello/{name}", Handler); err != nil {
return err
}
// Iter returns a collection of range iterators for traversing registered routes.
it := txn.Iter()
// When Iter() is called on a write transaction, it creates a point-in-time snapshot of the transaction state.
// It means that writing on the current transaction while iterating is allowed, but the mutation will not be
// observed in the result returned by PatternPrefix (or any other iterator).
for route := range it.PatternPrefix("tmp.example.com/") {
if _, err := txn.Delete(slices.Collect(route.Methods()), route.Pattern()); err != nil {
return err
}
}
return nil
}); err != nil {
log.Printf("transaction aborted: %s", err)
}_ = f.View(func(txn *fox.Txn) error {
if txn.Has(fox.MethodGet, "/foo") {
if txn.Has(fox.MethodGet, "/bar") {
// do something
}
}
return nil
})// Txn create an unmanaged read-write or read-only transaction.
txn := f.Txn(true)
defer txn.Abort()
if _, err := txn.Add(fox.MethodGet, "example.com/hello/{name}", Handler); err != nil {
log.Printf("error inserting route: %s", err)
return
}
// Iter returns a collection of range iterators for traversing registered routes.
it := txn.Iter()
// When Iter() is called on a write transaction, it creates a point-in-time snapshot of the transaction state.
// It means that writing on the current transaction while iterating is allowed, but the mutation will not be
// observed in the result returned by PatternPrefix (or any other iterator).
for route := range it.PatternPrefix("tmp.example.com/") {
if _, err := txn.Delete(slices.Collect(route.Methods()), route.Pattern()); err != nil {
log.Printf("error deleting route: %s", err)
return
}
}
// Finalize the transaction
txn.Commit()Middlewares can be registered globally using the fox.WithMiddleware option. The example below demonstrates how
to create and apply automatically a simple logging middleware to all routes (including 404, 405, etc...).
package main
import (
"log"
"net/http"
"time"
"github.com/fox-toolkit/fox"
)
func Logger(next fox.HandlerFunc) fox.HandlerFunc {
return func(c *fox.Context) {
start := time.Now()
next(c)
log.Printf("route: %s, latency: %s, status: %d, size: %d",
c.Pattern(),
time.Since(start),
c.Writer().Status(),
c.Writer().Size(),
)
}
}
func main() {
f := fox.MustRouter(fox.WithMiddleware(Logger))
f.MustAdd(fox.MethodGet, "/", func(c *fox.Context) {
_ = c.String(http.StatusOK, "Hello World")
})
log.Fatalln(http.ListenAndServe(":8080", f))
}Additionally, fox.WithMiddlewareFor option provide a more fine-grained control over where a middleware is applied, such as
only for 404 or 405 handlers. Possible scopes include fox.RouteHandler (regular routes), fox.NoRouteHandler, fox.NoMethodHandler,
fox.RedirectSlashHandler, fox.RedirectPathHandler, fox.OptionsHandler and any combination of these.
f := fox.MustRouter(
fox.WithMiddlewareFor(fox.RouteHandler, Logger),
fox.WithMiddlewareFor(fox.NoRouteHandler|fox.NoMethodHandler, SpecialLogger),
)Finally, it's also possible to attaches middleware on a per-route basis. Note that route-specific middleware must be explicitly reapplied when updating a route. If not, any middleware will be removed, and the route will fall back to using only global middleware (if any).
f := fox.MustRouter(
fox.WithMiddleware(fox.Logger(slog.NewTextHandler(os.Stdout, nil))),
)
f.MustAdd(fox.MethodGet, "/", SomeHandler, fox.WithMiddleware(foxtimeout.Middleware(2*time.Second)))
f.MustAdd(fox.MethodGet, "/foo", SomeOtherHandler)- fox-toolkit/oteltracing: Distributed tracing with OpenTelemetry
- fox-toolkit/timeout: Better
http.TimeoutHandlermiddleware. - fox-toolkit/waf: Coraza WAF middleware (experimental).
Fox itself implements the http.Handler interface which make easy to chain any compatible middleware before the router. Moreover, the router
provides convenient fox.WrapF, fox.WrapH and fox.WrapM adapter to be use with http.Handler.
The route parameters can be accessed by the wrapped handler through the request context.Context when the adapters are used.
Wrapping an http.Handler
articles := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
params := fox.ParamsFromContext(r.Context())
// Article id: 80
// Matched route: /articles/{id}
_, _ = fmt.Fprintf(w, "Article id: %s\nMatched route: %s\n", params.Get("id"), r.Pattern)
})
f := fox.MustRouter()
f.MustAdd(fox.MethodGet, "/articles/{id}", fox.WrapH(articles))Wrapping any standard http.Handler middleware
corsMw, _ := cors.NewMiddleware(cors.Config{
Origins: []string{"https://example.com"},
Methods: []string{http.MethodGet, http.MethodPost, http.MethodPut},
RequestHeaders: []string{"Authorization"},
})
f := fox.MustRouter(
fox.WithMiddlewareFor(fox.RouteHandler|fox.OptionsHandler, fox.WrapM(corsMw.Wrap)),
)The WithAutoOptions setting or the WithOptionsHandler registration enable automatic responses to OPTIONS requests.
This feature is particularly useful for handling Cross-Origin Resource Sharing (CORS) preflight requests.
When automatic OPTIONS responses is enabled, Fox distinguishes between regular OPTIONS requests and CORS preflight requests:
- Regular OPTIONS requests: The router responds with the
Allowheader populated with all HTTP methods registered for the matched resource. If no route matches, theNoRoutehandler is called. - CORS preflight requests: The router responds to every preflight request by calling the OPTIONS handler, regardless of whether the resource exists.
To customize how OPTIONS requests are handled (e.g. adding CORS headers), you may register a middleware for the fox.OptionsHandler scope
or provide a custom handler via WithOptionsHandler. Note that registered routes with the OPTIONS method always take precedence over automatic replies.
package main
import (
"errors"
"log"
"net/http"
"github.com/jub0bs/cors"
"github.com/fox-toolkit/fox"
)
func main() {
corsMw, err := cors.NewMiddleware(cors.Config{
Origins: []string{"https://example.com"},
Methods: []string{http.MethodGet, http.MethodPost},
RequestHeaders: []string{"Authorization"},
})
if err != nil {
log.Fatal(err)
}
corsMw.SetDebug(true) // turn debug mode on (optional)
f := fox.MustRouter(
fox.WithAutoOptions(true), // let Fox automatically handle OPTIONS requests
fox.WithMiddlewareFor(fox.RouteHandler|fox.OptionsHandler, fox.WrapM(corsMw.Wrap)),
)
f.MustAdd(fox.MethodGet, "/api/users", ListUsers)
f.MustAdd(fox.MethodPost, "/api/users", CreateUsers)
if err := http.ListenAndServe(":8080", f); !errors.Is(err, http.ErrServerClosed) {
log.Fatal(err)
}
}Alternatively, you can use a sub-router to apply CORS only to a specific section of your API.
package main
import (
"log"
"net/http"
"github.com/jub0bs/cors"
"github.com/fox-toolkit/fox"
)
func main() {
corsMw, err := cors.NewMiddleware(cors.Config{
Origins: []string{"https://example.com"},
Methods: []string{http.MethodHead, http.MethodGet, http.MethodPost},
RequestHeaders: []string{"Authorization"},
})
if err != nil {
log.Fatal(err)
}
corsMw.SetDebug(true) // turn debug mode on (optional)
f := fox.MustRouter()
f.MustAdd([]string{http.MethodHead, http.MethodGet}, "/*{filepath}", fox.WrapH(http.FileServer(http.Dir("./public/"))))
api := fox.MustRouter(
fox.WithAutoOptions(true), // let Fox automatically handle OPTIONS requests
fox.WithMiddlewareFor(fox.RouteHandler|fox.OptionsHandler, fox.WrapM(corsMw.Wrap)),
)
api.MustAdd([]string{http.MethodHead, http.MethodGet}, "/users", ListUsers)
api.MustAdd(fox.MethodPost, "/users", CreateUser)
f.MustAdd(fox.MethodAny, "/api*{any}", fox.Sub(api)) // note: Method-less route
}The CORS protocol is complex and security-sensitive. We do NOT recommend implementing CORS handling manually. Instead, consider using jub0bs/cors, which performs extensive validation before allowing middleware creation, helping you avoid common pitfalls.
The WithClientIPResolver option allows you to set up strategies to resolve the client IP address based on your
use case and network topology. Accurately determining the client IP is hard, particularly in environments with proxies or
load balancers. For example, the leftmost IP in the X-Forwarded-For header is commonly used and is often regarded as the
"closest to the client" and "most real," but it can be easily spoofed. Therefore, you should absolutely avoid using it
for any security-related purposes, such as request throttling.
The resolver used must be chosen and tuned for your network configuration. This should result in a resolver never returning an error and if it does, it should be treated as an application issue or a misconfiguration, rather than defaulting to an untrustworthy IP.
The sub-package github.com/fox-toolkit/fox/clientip provides a set of best practices resolvers that should cover most use cases.
package main
import (
"fmt"
"github.com/fox-toolkit/fox"
"github.com/fox-toolkit/fox/clientip"
)
func main() {
resolver, err := clientip.NewRightmostNonPrivate(clientip.XForwardedForKey)
if err != nil {
panic(err)
}
f := fox.MustRouter(
fox.DefaultOptions(),
fox.WithClientIPResolver(
resolver,
),
)
f.MustAdd(fox.MethodGet, "/foo/bar", func(c *fox.Context) {
ipAddr, err := c.ClientIP()
if err != nil {
// If the current resolver is not able to derive the client IP, an error
// will be returned rather than falling back on an untrustworthy IP. It
// should be treated as an application issue or a misconfiguration.
panic(err)
}
fmt.Println(ipAddr.String())
})
}It is also possible to create a chain with multiple resolvers that attempt to derive the client IP, stopping when the first one succeeds.
resolver, _ := clientip.NewLeftmostNonPrivate(clientip.ForwardedKey, 10)
f := fox.MustRouter(
fox.DefaultOptions(),
fox.WithClientIPResolver(
// A common use for this is if a server is both directly connected to the
// internet and expecting a header to check.
clientip.NewChain(
resolver,
clientip.NewRemoteAddr(),
),
),
)Note that there is no "sane" default strategy, so calling Context.ClientIP without a resolver configured will return
an ErrNoClientIPResolver.
See this blog post for general guidance on choosing a strategy that fit your needs.
The primary goal of Fox is to be a lightweight, high performance router which allow routes modification at runtime. The following benchmarks attempt to compare Fox to various popular alternatives, including both fully-featured web frameworks and lightweight request routers. These benchmarks are based on the julienschmidt/go-http-routing-benchmark repository.
Please note that these benchmarks should not be taken too seriously, as the comparison may not be entirely fair due to the differences in feature sets offered by each framework. Performance should be evaluated in the context of your specific use case and requirements. While Fox aims to excel in performance, it's important to consider the trade-offs and functionality provided by different web frameworks and routers when making your selection.
GOOS: Darwin
GOARCH: arm64
GO: 1.26
CPU: Apple M4 Max
It is just a collection of random static paths inspired by the structure of the Go directory. It might not be a realistic URL-structure.
GOMAXPROCS: 1
BenchmarkHttpRouter_StaticAll 600622 3855 ns/op 0 B/op 0 allocs/op
BenchmarkHttpTreeMux_StaticAll 460645 5186 ns/op 0 B/op 0 allocs/op
BenchmarkGin_StaticAll 437052 5522 ns/op 0 B/op 0 allocs/op
BenchmarkFox_StaticAll 322261 7463 ns/op 0 B/op 0 allocs/op
BenchmarkEcho_StaticAll 290506 7883 ns/op 0 B/op 0 allocs/op
BenchmarkStdMux_StaticAll 185131 12493 ns/op 0 B/op 0 allocs/op
BenchmarkChi_StaticAll 63568 37919 ns/op 57776 B/op 314 allocs/op
BenchmarkBeego_StaticAll 41713 57695 ns/op 55264 B/op 471 allocs/op
BenchmarkGorillaMux_StaticAll 8433 293721 ns/op 133137 B/op 1099 allocs/op
BenchmarkPat_StaticAll 5715 411287 ns/op 602832 B/op 12559 allocs/op
BenchmarkMartini_StaticAll 4327 562994 ns/op 129210 B/op 2031 allocs/op
BenchmarkTraffic_StaticAll 3784 643735 ns/op 749842 B/op 14444 allocs/op
In this benchmark, Fox performs as well as Gin and Echo which are both Radix Tree based routers. An interesting fact is
that HttpTreeMux also support adding route while serving request concurrently.
However, it takes a slightly different approach, by using an optional RWMutex that may not scale as well as Fox under heavy load. The next
test compare HttpTreeMux with and without the *SafeAddRouteFlag (concurrent reads and writes) and Fox in parallel benchmark.
GOMAXPROCS: 16
BenchmarkFox_StaticAllParallel-16 3309738 739.3 ns/op 0 B/op 0 allocs/op
BenchmarkHttpTreeMux_StaticAllParallel-16 100099 23991 ns/op 0 B/op 0 allocs/op
The following benchmarks measure the cost of some very basic operations.
In the first benchmark, only a single route, containing a parameter, is loaded into the routers. Then a request for a URL matching this pattern is made and the router has to call the respective registered handler function. End.
GOMAXPROCS: 1
BenchmarkEcho_Param 100000000 22.49 ns/op 0 B/op 0 allocs/op
BenchmarkGin_Param 99813538 23.75 ns/op 0 B/op 0 allocs/op
BenchmarkFox_Param 89412807 27.07 ns/op 0 B/op 0 allocs/op
BenchmarkHttpRouter_Param 77283691 30.87 ns/op 32 B/op 1 allocs/op
BenchmarkHttpTreeMux_Param 15785535 148.3 ns/op 352 B/op 3 allocs/op
BenchmarkPat_Param 7759366 309.3 ns/op 472 B/op 8 allocs/op
BenchmarkChi_Param 7498572 319.4 ns/op 704 B/op 4 allocs/op
BenchmarkBeego_Param 7642452 320.6 ns/op 352 B/op 3 allocs/op
BenchmarkGorillaMux_Param 4160580 579.6 ns/op 1152 B/op 8 allocs/op
BenchmarkTraffic_Param 2533519 951.1 ns/op 1808 B/op 19 allocs/op
BenchmarkMartini_Param 1968855 1218 ns/op 1096 B/op 12 allocs/op
Same as before, but now with multiple parameters, all in the same single route. The intention is to see how the routers scale with the number of parameters.
GOMAXPROCS: 1
BenchmarkGin_Param5 59644988 40.35 ns/op 0 B/op 0 allocs/op
BenchmarkEcho_Param5 48861675 47.70 ns/op 0 B/op 0 allocs/op
BenchmarkFox_Param5 40538828 58.79 ns/op 0 B/op 0 allocs/op
BenchmarkHttpRouter_Param5 29083740 81.10 ns/op 160 B/op 1 allocs/op
BenchmarkHttpTreeMux_Param5 7146506 338.1 ns/op 576 B/op 6 allocs/op
BenchmarkBeego_Param5 5716908 421.8 ns/op 352 B/op 3 allocs/op
BenchmarkChi_Param5 5187115 455.1 ns/op 704 B/op 4 allocs/op
BenchmarkPat_Param5 3462309 705.5 ns/op 776 B/op 23 allocs/op
BenchmarkGorillaMux_Param5 2532480 947.2 ns/op 1216 B/op 8 allocs/op
BenchmarkTraffic_Param5 1658610 1426 ns/op 2176 B/op 26 allocs/op
BenchmarkMartini_Param5 1672132 1436 ns/op 1256 B/op 13 allocs/op
BenchmarkGin_Param20 19447232 123.8 ns/op 0 B/op 0 allocs/op
BenchmarkEcho_Param20 18642206 128.0 ns/op 0 B/op 0 allocs/op
BenchmarkFox_Param20 12932709 185.6 ns/op 0 B/op 0 allocs/op
BenchmarkHttpRouter_Param20 9025162 266.7 ns/op 704 B/op 1 allocs/op
BenchmarkBeego_Param20 2373394 1004 ns/op 352 B/op 3 allocs/op
BenchmarkChi_Param20 1399316 1734 ns/op 2504 B/op 9 allocs/op
BenchmarkHttpTreeMux_Param20 1311330 1836 ns/op 3144 B/op 13 allocs/op
BenchmarkGorillaMux_Param20 1000000 2067 ns/op 3272 B/op 13 allocs/op
BenchmarkMartini_Param20 878756 2723 ns/op 3568 B/op 18 allocs/op
BenchmarkPat_Param20 703573 3460 ns/op 3992 B/op 75 allocs/op
BenchmarkTraffic_Param20 458248 5142 ns/op 7664 B/op 52 allocs/op
Now let's see how expensive it is to access a parameter. The handler function reads the value (by the name of the parameter, e.g. with a map
lookup; depends on the router) and writes it to /dev/null
GOMAXPROCS: 1
BenchmarkGin_ParamWrite 82057476 26.87 ns/op 0 B/op 0 allocs/op
BenchmarkFox_ParamWrite 72516771 32.68 ns/op 0 B/op 0 allocs/op
BenchmarkHttpRouter_ParamWrite 71118048 33.78 ns/op 32 B/op 1 allocs/op
BenchmarkEcho_ParamWrite 45928765 50.17 ns/op 8 B/op 1 allocs/op
BenchmarkHttpTreeMux_ParamWrite 15136818 159.6 ns/op 352 B/op 3 allocs/op
BenchmarkChi_ParamWrite 7253366 325.9 ns/op 704 B/op 4 allocs/op
BenchmarkBeego_ParamWrite 7241011 330.4 ns/op 360 B/op 4 allocs/op
BenchmarkPat_ParamWrite 4791008 502.9 ns/op 896 B/op 12 allocs/op
BenchmarkGorillaMux_ParamWrite 4056636 594.9 ns/op 1152 B/op 8 allocs/op
BenchmarkTraffic_ParamWrite 2107534 1149 ns/op 2232 B/op 23 allocs/op
BenchmarkMartini_ParamWrite 1764926 1352 ns/op 1144 B/op 15 allocs/op
Finally, this benchmark executes a request for each GitHub API route (203 routes).
GOMAXPROCS: 1
BenchmarkGin_GithubAll 275486 8594 ns/op 0 B/op 0 allocs/op
BenchmarkEcho_GithubAll 191268 11927 ns/op 0 B/op 0 allocs/op
BenchmarkFox_GithubAll 180686 13396 ns/op 0 B/op 0 allocs/op
BenchmarkHttpRouter_GithubAll 177955 13499 ns/op 14240 B/op 171 allocs/op
BenchmarkHttpTreeMux_GithubAll 56208 42220 ns/op 67648 B/op 691 allocs/op
BenchmarkBeego_GithubAll 29916 79898 ns/op 73121 B/op 629 allocs/op
BenchmarkChi_GithubAll 30638 80428 ns/op 130817 B/op 740 allocs/op
BenchmarkTraffic_GithubAll 2254 1078505 ns/op 837296 B/op 14315 allocs/op
BenchmarkPat_GithubAll 2174 1120138 ns/op 1834945 B/op 28773 allocs/op
BenchmarkGorillaMux_GithubAll 1879 1289439 ns/op 230339 B/op 1620 allocs/op
BenchmarkMartini_GithubAll 1678 1406444 ns/op 236944 B/op 2805 allocs/op
- Update route syntax @v0.6.0
- Route overlapping @v0.7.0
- Route overlapping (catch-all and params) @v0.10.0
- Ignore trailing slash, Builtin Logger Middleware, Client IP Derivation @v0.14.0
- Support infix wildcard, Support hostname routing, Support ACID transaction @v0.18.0
- Support regexp params @v0.25.0
- Support route matchers, Support SubRouter, Method-less tree @v0.26.0
- Programmatic error handling
- Improving performance and stabilizing API
This project aims to provide a lightweight, high-performance router that is easy to use and hard to misuse, designed for building API gateways and reverse proxies. Features are chosen carefully with an emphasis on composability, and each addition is evaluated against this core mission. The router exposes a relatively low-level API, allowing it to serve as a building block for implementing your own "batteries included" frameworks. Feature requests along these lines are welcome.
Fox is licensed under the Apache License 2.0. See LICENSE.txt for details.
The Fox logo is licensed separately under CC BY-NC-ND 4.0.
See LICENSE-fox-logo.txt for details.
- hashicorp/go-immutable-radix: Fox Tree design is inspired by Hashicorp's Immutable Radix Tree.
- realclientip/realclientip-go: Fox uses a derivative version of Adam Pritchard's
realclientip-golibrary. See his insightful blog post on the topic for more details. - The router API is influenced by popular routers such as Gin and Echo.
- Thanks to pawndev for development help and the many thoughtful PR reviews.