CodeVetter · Repo Unpack · Behavior traces

labstack/echo

Scanned commit 99c395d846 dated 2026-10-01 — last upstream commit. Generated by codevetter codevetter 1.15.0 on 2026-10-02. Deep analysis by cli:codex via the codex CLI on 2026-10-02 (480s). Source inspection; upstream code and tests were not executed.

The following traces follow source execution order through concrete framework flows. Startup proceeds from construction and registration into listener creation and shutdown coordination. A bound API request proceeds through dispatch, input conversion, and output serialization. Static-file delivery, proxy requests, and rate-limit decisions expose additional filesystem, network, and state boundaries.

Startup configuration: New → NewRouter → contextPool.New installation → buildRouterChains; GET → Add → Echo.add → optional OnAddRoute → Router.Add. Registration also raises contextPathParamAllocSize when a route needs more parameters.
echo.go#L400-L443 echo.go#L541-L545 echo.go#L739-L773
Server startup and stop: Echo.Start → signal.NotifyContext → StartConfig.Start → start → Listen → optional tls.NewListener → BeforeServeFunc → server.Serve. Context cancellation triggers gracefulShutdown → server.Shutdown with a default ten-second timeout; http.ErrServerClosed is suppressed.
echo.go#L870-L874 server.go#L63-L65 server.go#L119-L167 server.go#L181-L200
Request dispatch: ServeHTTP → serveHTTP → Context.Reset → preChain when registered → Router.Route → global chain → dispatch → route handler. applyMiddleware wraps in reverse registration order so the first registered middleware enters first; returned errors reach HTTPErrorHandler.
echo.go#L430-L443 echo.go#L828-L846 echo.go#L911-L915
Bound API input: handler calls Context.Bind → DefaultBinder.Bind → BindPathValues → method-conditional BindQueryParams → BindBody. JSON bodies call JSONSerializer.Deserialize; unsupported nonempty body media types return 415. Validation occurs only if the handler separately calls Context.Validate.
context.go#L459-L469 bind.go#L68-L105 bind.go#L127-L140 json.go#L47-L65
API output/error: Context.JSON → json → DefaultJSONSerializer.Serialize → delayedStatusWriter.Write → Response.WriteHeader/Write. On a returned error, DefaultHTTPErrorHandler checks commitment, extracts HTTPStatusCoder, chooses JSON payload shape, and sends NoContent instead of JSON for HEAD.
context.go#L568-L592 json.go#L28-L33 response.go#L149-L157 echo.go#L465-L517
Static file delivery: Echo.Static → MustSubFS → GET wildcard registration → StaticDirectoryHandler. At request time the handler rejects unclean paths, optionally unescapes and rechecks them, runs fs.Stat, redirects directories when needed, then fsFile opens the file/index and calls http.ServeContent.
echo.go#L629-L637 echo.go#L665-L702 echo.go#L976-L981 context.go#L704-L729
Proxy action: ProxyConfig.ToMiddleware → rewriteURL → overwrite IP/scheme headers → Balancer.Next → store selected target → proxyHTTP or proxyRaw. HTTP errors are stored under _error; retries require remaining RetryCount and RetryFilter approval, while missing targets immediately return 502.
middleware/proxy.go#L337-L411 middleware/proxy.go#L424-L450
Rate-limit state: RateLimiter middleware → IdentifierExtractor → RateLimiterMemoryStore.AllowContext → allow → lookup/create Visitor → update lastSeen → optional cleanupStaleVisitors → AllowN → setRateLimitHeaders. Denial invokes DenyHandler, which defaults to a wrapped 429; the visitor map is process-local memory.
middleware/rate_limiter.go#L60-L72 middleware/rate_limiter.go#L149-L164 middleware/rate_limiter.go#L263-L314