feat: add local monitoring dashboard

CHANGELOG.md

@@ -2,6 +2,13 @@
 
 All notable changes to HTTPing are documented in this file.
 
+## [Unreleased]
+
+### Added
+
+- A loopback-only live dashboard with summary cards, a latency chart, and recent probe results.
+- Configurable dashboard ports, browser opening, and bounded in-memory history.
+
 ## [0.1.0] - 2026-07-28
 
 ### Added

Cargo.toml

@@ -17,11 +17,16 @@ publish = false
 dist = true
 
 [dependencies]
+axum = { version = "0.8.9", default-features = false, features = ["http1", "json", "tokio"] }
 chrono = { version = "0.4.45", default-features = false, features = ["clock"] }
 clap = "4.6.4"
 humantime = "2.4.0"
+open = "5.4.0"
 reqwest = { version = "0.13.4", default-features = false, features = ["rustls"] }
-tokio = { version = "1.53.1", features = ["macros", "net", "rt-multi-thread", "signal", "time"] }
+serde = { version = "1.0.229", features = ["derive"] }
+serde_json = "1.0.151"
+tokio = { version = "1.53.1", features = ["macros", "net", "rt-multi-thread", "signal", "sync", "time"], default-features = false }
+tokio-stream = { version = "0.1.19", default-features = false, features = ["sync"] }
 
 [dev-dependencies]
 tokio = { version = "1.53.1", features = ["io-util"] }

README.md

@@ -71,6 +71,31 @@ Options:
 
 Durations accept values such as `250ms`, `1s`, and `2m`.
 
+### Local dashboard
+
+Start the local dashboard for a target:
+
+```console
+$ httping serve https://example.com
+HTTPing https://example.com/
+resolved: 93.184.216.34:443
+dashboard: http://127.0.0.1:52143/
+```
+
+HTTPing selects a free local port and opens the dashboard in the default
+browser. The dashboard shows live summary cards, a latency chart, and recent
+probe results. It binds only to `127.0.0.1`.
+
+Use `--no-open` to keep the browser closed, `--port` to select a fixed port,
+and `--history` to set the number of recent results kept in memory:
+
+```sh
+httping serve --no-open --port 8080 --history 500 https://example.com
+```
+
+The server stays in the foreground until Ctrl-C. Run it through a shell job,
+systemd, or a container when it must continue in the background.
+
 ```console
 $ httping --count 2 https://example.com
 HTTPing https://example.com/

deny.toml

@@ -18,7 +18,12 @@ ignore = []
 multiple-versions = "deny"
 wildcards = "deny"
 deny = []
-skip = []
+# Serde 1 uses syn 3 while Tokio and URL's ICU dependencies still use syn 2.
+# Keep this exact exception until the dependency graph converges.
+skip = [
+  { crate = "syn@2" },
+  { crate = "syn@3" },
+]
 skip-tree = []
 
 [licenses]