feat(egress): change the noise profile at runtime

The egress governor is now a current governor that SetProfile swaps: new requests use the new one, requests in flight finish on the old one, and one package-level ticker logs the counters of the current governor. WebFetch, the http custom tools and the enrich probe resolve it per request, and the agent prompt block reads the current profile. The noise_profile setting (off, quiet, balanced, aggressive) is applied at startup and wins over ARTEX_NOISE_PROFILE, which stays the fallback; PUT /api/settings validates, stores and applies it without rebuilding agents, and GET /api/settings/noise returns the per-host counters without resetting them. System settings gets a Target noise card.

CHANGELOG.md

@@ -4,6 +4,10 @@ All notable changes to this project are documented in this file. The format is b
 
 ## [Unreleased]
 
+### Added
+
+- **Noise profile at runtime**: System settings has a **Target noise** card. It sets the profile (`off`, `quiet`, `balanced`, `aggressive`) through the `noise_profile` setting, which takes precedence over `ARTEX_NOISE_PROFILE`. The change applies to the next WebFetch, http custom tool and enrich request, and to the next agent prompt, without a restart. The card also shows the per-host counters, which `GET /api/settings/noise` returns.
+
 ### Changed
 
 - **Untrusted-output boundary is now on by default**: Norma frames tool results for the worker, planner, chat and main agent unless `ARTEX_UNTRUSTED_BOUNDARY` is set to `0`, `false`, `off` or `no`. It was opt-in via `ARTEX_UNTRUSTED_BOUNDARY=1` in 0.6.0 (#166).

README.md

@@ -407,6 +407,8 @@ in-flight GETs and caches them briefly (60/30/10 s; never POST/PUT/PATCH/DELETE)
 per-host noise line each minute. `ARTEX_TARGET_USER_AGENT` sets a User-Agent on target requests
 that carry none. Bash-launched tools are not paced yet; the low-and-slow prompt block supplies
 their rate flags.
+The **Target noise** card in System settings sets the profile at runtime (no restart) and shows the
+per-host counters; once saved, that setting takes precedence over `ARTEX_NOISE_PROFILE`.
 
 **Low-and-slow agent guidance (off by default)**: when a noise profile is set, the planner, worker,
 main agent and chat agents receive a code-owned prompt block with the profile's per-host limits and

agent/noise_profile.go

@@ -14,10 +14,11 @@ import (
 // prompts stay byte-for-byte unchanged by default.
 const noiseProfileHeader = "[Noise profile: "
 
-// noiseProfileBlock returns the low-and-slow guidance for the active noise
-// profile (ARTEX_NOISE_PROFILE), or "" when the profile is off. The text is
-// code-owned and carries no target data.
-func noiseProfileBlock() string { return renderNoiseProfile(egress.ProfileFromEnv()) }
+// noiseProfileBlock returns the low-and-slow guidance for the current noise
+// profile (the noise_profile setting, else ARTEX_NOISE_PROFILE), or "" when the
+// profile is off. It is read at each prompt build, so a changed setting shows in
+// the next prompt. The text is code-owned and carries no target data.
+func noiseProfileBlock() string { return renderNoiseProfile(egress.CurrentProfile()) }
 
 // renderNoiseProfile renders the block for one profile. It is pure: tests cover
 // every profile without touching the environment.

agent/noise_profile_test.go

@@ -59,18 +59,23 @@ func TestPromptBuildersNoiseBlock(t *testing.T) {
 		"mainagent": func() string { return mainAgentSystem("goal", "/data", "/work") },
 		"chat":      func() string { return chatSystem("auto", "/data", "/work") },
 	}
-	for _, env := range []string{"", "off"} {
-		t.Setenv("ARTEX_NOISE_PROFILE", env)
+	prev := egress.CurrentProfile()
+	t.Cleanup(func() { egress.SetProfile(prev) })
+	// The block follows the current profile, not the environment.
+	t.Setenv("ARTEX_NOISE_PROFILE", "aggressive")
+	egress.SetProfile(egress.Profile{Name: "off"})
+	for name, build := range builders {
+		if got := build(); strings.Contains(got, noiseProfileHeader) {
+			t.Errorf("%s with profile off contains the noise block", name)
+		}
+	}
+	for _, profile := range []string{"quiet", "balanced"} {
+		egress.SetProfile(egress.Profiles[profile])
 		for name, build := range builders {
-			if got := build(); strings.Contains(got, noiseProfileHeader) {
-				t.Errorf("%s with profile %q contains the noise block", name, env)
+			got := build()
+			if !strings.Contains(got, noiseProfileHeader+profile) || strings.Contains(got, noiseProfileHeader+"aggressive") {
+				t.Errorf("%s after SetProfile(%s) is missing its block or shows the env profile", name, profile)
 			}
 		}
 	}
-	t.Setenv("ARTEX_NOISE_PROFILE", "quiet")
-	for name, build := range builders {
-		if got := build(); !strings.Contains(got, noiseProfileHeader+"quiet") {
-			t.Errorf("%s with quiet is missing the noise block", name)
-		}
-	}
 }

agent/webfetch.go

@@ -27,11 +27,12 @@ func withWebFetch(ctx context.Context, tools []actool.CoreTool, proxy, caCert st
 	gated := scoped && scope.Enabled != nil && scope.Enabled()
 	webFetch := actool.NewWebFetch(actool.WebFetchConfig{Proxy: proxy, CACert: caCert, CheckRedirect: intercept.RedirectCheck("WebFetch"),
 		DialContext: intercept.PinnedDialer("WebFetch", scoped), DisableDirectRetry: gated})
-	return append(tools[:len(tools):len(tools)], governedFetch{webFetch, egressGovernor()})
+	return append(tools[:len(tools):len(tools)], governedFetch{webFetch})
 }
 
-// egressGovernor is the governor of WebFetch; a test may pin it.
-var egressGovernor = egress.Shared
+// egressGovernor resolves the governor of a WebFetch call, once per call so a
+// changed noise profile applies to the next call; a test may pin it.
+var egressGovernor = egress.Current
 
 // governedFetch runs each WebFetch call as one send under the egress governor
 // (off by default; then the call runs unchanged). Under a noise profile it
@@ -42,7 +43,6 @@ var egressGovernor = egress.Shared
 // 429/503 is not retried.
 type governedFetch struct {
 	actool.CoreTool
-	g *egress.Governor
 }
 
 func (f governedFetch) Call(ctx context.Context, input json.RawMessage, tc *actool.ToolContext) (actool.Result, error) {
@@ -56,7 +56,7 @@ func (f governedFetch) Call(ctx context.Context, input json.RawMessage, tc *acto
 	if err != nil || u.Host == "" {
 		return f.CoreTool.Call(ctx, input, tc) // the tool reports the bad URL
 	}
-	return egress.Do(f.g, ctx, u, func() (actool.Result, error) {
+	return egress.Do(egressGovernor(), ctx, u, func() (actool.Result, error) {
 		return f.CoreTool.Call(ctx, input, tc)
 	})
 }

agent/webfetch_egress_test.go

@@ -27,7 +27,11 @@ func TestWebFetchProfileDoesNotCache(t *testing.T) {
 		checks.Add(1)
 		return nil
 	}})
-	tool := governedFetch{inner, egress.New(egress.Profiles["balanced"])}
+	balanced := egress.New(egress.Profiles["balanced"])
+	old := egressGovernor
+	egressGovernor = func() *egress.Governor { return balanced }
+	t.Cleanup(func() { egressGovernor = old })
+	tool := governedFetch{inner}
 	ctx := intercept.WithTargetScope(t.Context(), intercept.TargetScope{TaskID: "7"})
 	for range 2 {
 		res, err := tool.Call(ctx, json.RawMessage(fetchInputJSON(pair.start)), &actool.ToolContext{})

egress/current_test.go

@@ -0,0 +1,179 @@
+package egress
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"runtime"
+	"sync"
+	"testing"
+)
+
+// keepProfile restores the process profile after a test that changes it.
+func keepProfile(t *testing.T) {
+	prev := CurrentProfile()
+	t.Cleanup(func() { SetProfile(prev) })
+}
+
+func TestSetProfileConcurrentAndConsistent(t *testing.T) {
+	keepProfile(t)
+	names := []string{"off", "quiet", "balanced", "aggressive"}
+	var wg sync.WaitGroup
+	for i := range 8 {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			for j := range 200 {
+				p, _ := ProfileByName(names[(i+j)%len(names)])
+				SetProfile(p)
+				if g := Current(); g == nil || g.Profile().Name == "" {
+					t.Errorf("Current() = %v during swaps", g)
+					return
+				}
+				_ = CurrentProfile()
+			}
+		}()
+	}
+	wg.Wait()
+	for _, name := range names {
+		p, _ := ProfileByName(name)
+		g := SetProfile(p)
+		if Current() != g || CurrentProfile().Name != name || Current().Profile() != CurrentProfile() {
+			t.Fatalf("after SetProfile(%s): Current=%p want %p, CurrentProfile=%q", name, Current(), g, CurrentProfile().Name)
+		}
+	}
+}
+
+// A request in flight keeps the governor it started on: its release frees the
+// old governor's slots, and the new governor starts with no counter.
+func TestSetProfileInFlightFinishesOnOldGovernor(t *testing.T) {
+	keepProfile(t)
+	old := SetProfile(open)
+	release, err := old.acquire(t.Context(), "a.example")
+	if err != nil {
+		t.Fatal(err)
+	}
+	fresh := SetProfile(Profiles["balanced"])
+	if Current() != fresh || len(fresh.Snapshot()) != 0 {
+		t.Fatalf("new governor: current=%p fresh=%p snapshot=%v", Current(), fresh, fresh.Snapshot())
+	}
+	if s := old.Snapshot(); len(s) != 1 || s[0].Inflight != 1 {
+		t.Fatalf("old governor before release: %+v", s)
+	}
+	release()
+	if s := old.Snapshot(); len(s) != 1 || s[0].Inflight != 0 || s[0].RPM != 1 || s[0].PeakInflight != 1 {
+		t.Fatalf("old governor after release: %+v", s)
+	}
+}
+
+type recordRT struct{ got *http.Request }
+
+func (r *recordRT) RoundTrip(req *http.Request) (*http.Response, error) {
+	r.got = req
+	return &http.Response{StatusCode: 204, Body: http.NoBody, Request: req}, nil
+}
+
+// Off stays a strict passthrough, through Transport and Dynamic alike.
+func TestOffIsPassthroughAfterSetProfile(t *testing.T) {
+	keepProfile(t)
+	t.Setenv("ARTEX_TARGET_USER_AGENT", "artex-test/1")
+	off, ok := ProfileByName("OFF")
+	if !ok || off.Name != "off" || off.UserAgent != "" {
+		t.Fatalf("ProfileByName(OFF) = %+v %v", off, ok)
+	}
+	SetProfile(off)
+	base := &recordRT{}
+	if tr := Current().Transport("x", base); tr != http.RoundTripper(base) {
+		t.Fatalf("off Transport = %T, want the base itself", tr)
+	}
+	req := httptest.NewRequest(http.MethodGet, "http://a.example/", nil)
+	if _, err := Dynamic("x", base).RoundTrip(req); err != nil || base.got != req || req.Header.Get("User-Agent") != "" {
+		t.Fatalf("off Dynamic: err=%v same request=%v UA=%q", err, base.got == req, req.Header.Get("User-Agent"))
+	}
+	if len(Current().Snapshot()) != 0 {
+		t.Fatalf("off counted a request: %v", Current().Snapshot())
+	}
+	// Any other profile carries the user agent.
+	if p, _ := ProfileByName("balanced"); p.UserAgent != "artex-test/1" {
+		t.Fatalf("balanced UserAgent = %q", p.UserAgent)
+	}
+	if _, ok := ProfileByName(""); ok {
+		t.Fatal(`ProfileByName("") accepted`)
+	}
+	if _, ok := ProfileByName("loud"); ok {
+		t.Fatal(`ProfileByName("loud") accepted`)
+	}
+}
+
+// Dynamic resolves the governor per request: a client built before
+// SetProfile is paced by the new profile.
+func TestDynamicFollowsSetProfile(t *testing.T) {
+	keepProfile(t)
+	srv := newServer(t, 0, nil)
+	SetProfile(Profile{Name: "off"})
+	client := &http.Client{Transport: Dynamic("ns", nil)}
+	get := func() {
+		t.Helper()
+		resp, err := client.Get(srv.URL)
+		if err != nil {
+			t.Fatal(err)
+		}
+		resp.Body.Close()
+	}
+	get()
+	g := SetProfile(open)
+	get()
+	get()
+	if s := g.Snapshot(); len(s) != 1 || s[0].RPM != 2 {
+		t.Fatalf("snapshot after switch: %+v", s)
+	}
+}
+
+// Snapshot reads the counters without starting a new minute; report does.
+func TestSnapshotDoesNotReset(t *testing.T) {
+	g := New(open)
+	srv := newServer(t, 0, nil)
+	tr := g.Transport("ns", nil)
+	for range 3 {
+		req, _ := http.NewRequest(http.MethodGet, srv.URL, nil)
+		resp, err := tr.RoundTrip(req)
+		if err != nil {
+			t.Fatal(err)
+		}
+		resp.Body.Close()
+	}
+	want := HostNoise{Host: HostKey(srvURL(t, srv.URL)), RPM: 3, PeakRPM: 3, PeakInflight: 1}
+	for range 2 {
+		if s := g.Snapshot(); len(s) != 1 || s[0] != want {
+			t.Fatalf("snapshot = %+v, want [%+v]", s, want)
+		}
+	}
+	g.report()
+	if s := g.Snapshot(); len(s) != 1 || s[0].RPM != 0 || s[0].PeakRPM != 3 {
+		t.Fatalf("snapshot after report = %+v, want rpm 0 and peak 3", s)
+	}
+}
+
+// SetProfile never starts a goroutine of its own: one ticker serves every
+// governor.
+func TestSetProfileStartsNoGoroutine(t *testing.T) {
+	keepProfile(t)
+	SetProfile(Profiles["quiet"]) // the reporter is running from here on
+	before := runtime.NumGoroutine()
+	for range 50 {
+		SetProfile(Profiles["balanced"])
+		SetProfile(Profile{Name: "off"})
+	}
+	if after := runtime.NumGoroutine(); after > before {
+		t.Fatalf("goroutines %d -> %d after 100 SetProfile calls", before, after)
+	}
+}
+
+func srvURL(t *testing.T, raw string) *url.URL {
+	t.Helper()
+	u, err := url.Parse(raw)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return u
+}

egress/egress.go

@@ -1,6 +1,7 @@
 // Package egress is the governor the platform-owned HTTP requests to a target
 // pass through (WebFetch, the http custom tools, the enrich probe). A noise
-// profile (ARTEX_NOISE_PROFILE) sets every lever: a token bucket, a jitter and a
+// profile (the noise_profile setting, else ARTEX_NOISE_PROFILE; SetProfile
+// changes it at runtime) sets every lever: a token bucket, a jitter and a
 // concurrency cap per host, a global concurrency cap, backoff on 429/503, and,
 // for the GET requests of one task, coalescing and a short cache. The default
 // profile, off, is a strict passthrough: requests and timing are unchanged.
@@ -22,6 +23,7 @@ import (
 	"strconv"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"time"
 	"unicode"
 
@@ -54,42 +56,91 @@ var Profiles = map[string]Profile{
 	"aggressive": {Name: "aggressive", RPS: 20, Burst: 40, MaxPerHost: 4, MaxGlobal: 32, Jitter: 0.1, CacheTTL: 10 * time.Second, MaxRetries: 2, BaseDelay: 500 * time.Millisecond, MaxDelay: 10 * time.Second},
 }
 
-// ProfileFromEnv returns the profile ARTEX_NOISE_PROFILE names; unset, "off" or
-// unknown is off.
-func ProfileFromEnv() Profile {
-	name := strings.ToLower(strings.TrimSpace(os.Getenv("ARTEX_NOISE_PROFILE")))
-	p, ok := Profiles[name]
-	if !ok {
-		if name != "" && name != "off" {
-			log.Printf("[egress] ARTEX_NOISE_PROFILE=%q is not off, quiet, balanced or aggressive; using off", name)
-		}
-		return Profile{Name: "off"}
+// ProfileByName returns the profile name names (off, quiet, balanced or
+// aggressive, any case); ok is false for any other name, "" included. A profile
+// other than off carries ARTEX_TARGET_USER_AGENT; off stays a strict passthrough.
+func ProfileByName(name string) (p Profile, ok bool) {
+	name = strings.ToLower(strings.TrimSpace(name))
+	if name == "off" {
+		return Profile{Name: "off"}, true
+	}
+	if p, ok = Profiles[name]; !ok {
+		return Profile{Name: "off"}, false
 	}
 	if ua := strings.TrimSpace(os.Getenv("ARTEX_TARGET_USER_AGENT")); strings.ContainsFunc(ua, unicode.IsControl) {
 		log.Printf("[egress] ARTEX_TARGET_USER_AGENT contains a control character; ignored")
 	} else {
 		p.UserAgent = ua
 	}
+	return p, true
+}
+
+// ProfileFromEnv returns the profile ARTEX_NOISE_PROFILE names; unset, "off" or
+// unknown is off.
+func ProfileFromEnv() Profile {
+	name := strings.TrimSpace(os.Getenv("ARTEX_NOISE_PROFILE"))
+	p, ok := ProfileByName(name)
+	if !ok && name != "" {
+		log.Printf("[egress] ARTEX_NOISE_PROFILE=%q is not off, quiet, balanced or aggressive; using off", name)
+	}
 	return p
 }
 
-// Shared is the one governor of the process, built from the environment on
-// first use; WebFetch, the http custom tools and the enrich probe all use it.
-// Under a profile it logs the noise counter of each host once a minute.
-var Shared = sync.OnceValue(func() *Governor {
-	g := New(ProfileFromEnv())
+// current is the governor new requests use. SetProfile replaces it; a request
+// already in flight keeps the governor it started on, so its slots are
+// released where they were taken.
+var (
+	current      atomic.Pointer[Governor]
+	initCurrent  sync.Once
+	reporterOnce sync.Once
+)
+
+// Current returns the governor of the process: the one SetProfile published
+// last, or, before any SetProfile, one built from the environment on first use.
+// WebFetch, the http custom tools and the enrich probe resolve it per request.
+func Current() *Governor {
+	if g := current.Load(); g != nil {
+		return g
+	}
+	initCurrent.Do(func() {
+		g := New(ProfileFromEnv())
+		if current.CompareAndSwap(nil, g) {
+			log.Printf("[egress] noise profile: %s", g.p.Name)
+		}
+		startReporter()
+	})
+	return current.Load()
+}
+
+// CurrentProfile is the profile of Current.
+func CurrentProfile() Profile { return Current().p }
+
+// SetProfile builds a governor for p and publishes it: new requests use it,
+// requests in flight finish on the previous one. The counters start afresh.
+func SetProfile(p Profile) *Governor {
+	g := New(p)
+	current.Store(g)
 	log.Printf("[egress] noise profile: %s", g.p.Name)
-	if !g.off() {
+	startReporter()
+	return g
+}
+
+// startReporter starts the one package-level ticker that logs, once a minute,
+// the noise counter of each host of the current governor. SetProfile never
+// starts another.
+func startReporter() {
+	reporterOnce.Do(func() {
 		go func() {
-			for range time.Tick(time.Minute) {
-				for _, l := range g.report() {
+			t := time.NewTicker(time.Minute)
+			defer t.Stop()
+			for range t.C {
+				for _, l := range Current().report() {
 					log.Print(l)
 				}
 			}
 		}()
-	}
-	return g
-})
+	})
+}
 
 // Governor holds the per-host state and the per-task response cache.
 type Governor struct {
@@ -123,6 +174,9 @@ func New(p Profile) *Governor {
 
 func (g *Governor) off() bool { return g.p.RPS <= 0 }
 
+// Profile is the profile g was built for.
+func (g *Governor) Profile() Profile { return g.p }
+
 // HostKey is the lowercased host, with the port when it is not the default.
 func HostKey(u *url.URL) string {
 	h, p := strings.ToLower(u.Hostname()), u.Port()
@@ -240,6 +294,35 @@ func (g *Governor) report() []string {
 	return out
 }
 
+// HostNoise is the noise counter of one host: the current minute (RPM,
+// DuplicatesAvoided, PeakInflight), the peak per minute so far, and the
+// requests in flight now.
+type HostNoise struct {
+	Host              string `json:"host"`
+	RPM               int    `json:"rpm"`
+	PeakRPM           int    `json:"peak_rpm"`
+	PeakInflight      int    `json:"peak_inflight"`
+	Inflight          int    `json:"inflight"`
+	DuplicatesAvoided int    `json:"duplicates_avoided"`
+}
+
+// Snapshot returns the counter of every host that has sent or deduplicated a
+// request, sorted by host. Unlike report it starts no new minute.
+func (g *Governor) Snapshot() []HostNoise {
+	g.mu.Lock()
+	defer g.mu.Unlock()
+	out := []HostNoise{}
+	for key, h := range g.hosts {
+		if h.sent == 0 && h.dupes == 0 && h.inflight == 0 && h.peakRPM == 0 {
+			continue
+		}
+		out = append(out, HostNoise{Host: key, RPM: h.sent, PeakRPM: max(h.peakRPM, h.sent),
+			PeakInflight: h.peakInflight, Inflight: h.inflight, DuplicatesAvoided: h.dupes})
+	}
+	sort.Slice(out, func(i, j int) bool { return out[i].Host < out[j].Host })
+	return out
+}
+
 var errNotShared = errors.New("egress: response not shared")
 
 // share runs fn once for the concurrent callers of key and keeps its value for
@@ -344,6 +427,25 @@ type transport struct {
 	base      http.RoundTripper
 }
 
+// Dynamic returns base (nil: http.DefaultTransport) governed by the governor
+// current at each request, for a client built once and kept: a later
+// SetProfile applies to its next request. Off, the request goes to base as is.
+func Dynamic(namespace string, base http.RoundTripper) http.RoundTripper {
+	if base == nil {
+		base = http.DefaultTransport
+	}
+	return dynamicTransport{namespace, base}
+}
+
+type dynamicTransport struct {
+	namespace string
+	base      http.RoundTripper
+}
+
+func (d dynamicTransport) RoundTrip(req *http.Request) (*http.Response, error) {
+	return Current().Transport(d.namespace, d.base).RoundTrip(req)
+}
+
 const maxSharedBody = 2 << 20 // a larger response is neither coalesced nor cached
 
 func (t *transport) RoundTrip(req *http.Request) (*http.Response, error) {

enrich/enrich.go

@@ -99,7 +99,8 @@ func New(as *db.AssetStore, proxy func() string, workers int) *Engine {
 // probe without a scope is refused. When the scope's gate is on, the probe
 // connects to the target itself, without the proxy, so that the dialer decides
 // on the target and connects only to the addresses a pin covers. Every request
-// goes through the shared egress governor (the noise profile; off by default).
+// goes through the egress governor current at that request (the noise profile;
+// off by default), so a changed profile applies without rebuilding the client.
 func buildClient(proxy func() string) *http.Client {
 	tr := &http.Transport{
 		TLSClientConfig:     &tls.Config{InsecureSkipVerify: true},
@@ -120,7 +121,7 @@ func buildClient(proxy func() string) *http.Client {
 		}
 	}
 	return &http.Client{
-		Transport: egress.Shared().Transport("enrich", tr),
+		Transport: egress.Dynamic("enrich", tr),
 		Timeout:   httpTimeout,
 		// cap redirects; keep them within scope by re-checking at probe time
 		CheckRedirect: func(*http.Request, []*http.Request) error { return http.ErrUseLastResponse },

server/customtool.go

@@ -566,13 +566,14 @@ func (s *Server) runHTTPTool(ctx context.Context, key string, execRaw json.RawMe
 	client := &http.Client{Timeout: timeoutOr(spec.TimeoutMs, 30000)}
 	// Every redirect hop goes through the target gate, as the rendered URL did.
 	client.CheckRedirect = intercept.RedirectCheck(key)
-	// The shared egress governor paces every request and redirect hop per host
-	// under the noise profile (off by default: the base transport itself).
+	// The current egress governor paces every request and redirect hop per host
+	// under the noise profile (off by default: the base transport itself). It is
+	// resolved per request, so a changed profile applies to the next call.
 	var base http.RoundTripper = http.DefaultTransport
 	if tr := s.httpToolTransport(ctx, key, spec); tr != nil {
 		base = tr
 	}
-	client.Transport = egress.Shared().Transport(key, base)
+	client.Transport = egress.Current().Transport(key, base)
 	resp, err := client.Do(req)
 	if err != nil {
 		return actool.Errorf("request failed: " + err.Error()), nil

server/manager.go

@@ -19,6 +19,7 @@ import (
 	"github.com/Autumn-27/artex/agent"
 	"github.com/Autumn-27/artex/config"
 	pgdb "github.com/Autumn-27/artex/db"
+	"github.com/Autumn-27/artex/egress"
 	"github.com/Autumn-27/artex/enrich"
 	"github.com/Autumn-27/artex/guard"
 	"github.com/Autumn-27/artex/intercept"
@@ -304,6 +305,9 @@ const (
 	// when on, the four agent kinds wired into the platform (planner/worker/main
 	// agent/chat) have context compaction taken over by noa, replacing the built-in compaction. Read once per run; toggling affects only runs started afterwards.
 	settingNoaCompaction = "noa_compaction"
+	// Target noise profile (off|quiet|balanced|aggressive). When stored it wins over
+	// ARTEX_NOISE_PROFILE, which stays the fallback; applied at startup and on PUT.
+	settingNoiseProfile = "noise_profile"
 	// defaultWebSearchBackend is used when web search is on but no backend was picked.
 	defaultWebSearchBackend = "ddgs"
 	// deepSeekWebSearchBackend borrows the active LLM profile instead of its own
@@ -401,6 +405,7 @@ func NewManager(dir, proxyAddr string) (*Manager, error) {
 		pg.Close()
 		return nil, fmt.Errorf("recover finding retests: %w", err)
 	}
+	egress.SetProfile(startupNoiseProfile(pg))
 	if err := pg.EnsureLLMRecordsTable(); err != nil {
 		log.Printf("[llmrec] create table: %v", err)
 	}

server/noise.go

@@ -0,0 +1,32 @@
+package server
+
+import (
+	"log"
+	"net/http"
+
+	"github.com/Autumn-27/artex/db"
+	"github.com/Autumn-27/artex/egress"
+)
+
+// startupNoiseProfile is the noise profile to apply at startup: the stored
+// noise_profile setting when there is a valid one, else ARTEX_NOISE_PROFILE.
+func startupNoiseProfile(pg *db.DB) egress.Profile {
+	v, ok, err := pg.GetSetting(settingNoiseProfile)
+	if err != nil {
+		log.Printf("[egress] read %s setting: %v; using ARTEX_NOISE_PROFILE", settingNoiseProfile, err)
+	}
+	if ok {
+		if p, valid := egress.ProfileByName(v); valid {
+			return p
+		}
+		log.Printf("[egress] stored %s=%q is not off, quiet, balanced or aggressive; using ARTEX_NOISE_PROFILE", settingNoiseProfile, v)
+	}
+	return egress.ProfileFromEnv()
+}
+
+// noiseStatus returns the current noise profile and the per-host counters of
+// its governor, read without starting a new minute.
+func (s *Server) noiseStatus(w http.ResponseWriter, r *http.Request) {
+	g := egress.Current()
+	writeJSON(w, 200, map[string]any{"profile": g.Profile().Name, "hosts": g.Snapshot()})
+}

server/noise_settings_test.go

@@ -0,0 +1,125 @@
+package server
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/Autumn-27/artex/egress"
+)
+
+func TestNoiseProfileSettingHTTP(t *testing.T) {
+	skipWithoutDSN(t)
+	prev := egress.CurrentProfile()
+	t.Cleanup(func() { egress.SetProfile(prev) })
+	t.Setenv("ARTEX_NOISE_PROFILE", "quiet")
+	t.Setenv("ARTEX_TARGET_USER_AGENT", "artex-noise-test/1")
+
+	m, err := NewManager(t.TempDir(), "")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer m.Close()
+	clear := func() {
+		if _, err := m.pg.Exec(`DELETE FROM settings WHERE key=$1`, settingNoiseProfile); err != nil {
+			t.Error(err)
+		}
+	}
+	clear()
+	defer clear() // before m.Close
+
+	// Precedence: no setting -> env; a valid setting wins; an invalid one falls back to env.
+	if p := startupNoiseProfile(m.pg); p.Name != "quiet" {
+		t.Fatalf("no setting: %q, want env quiet", p.Name)
+	}
+	if err := m.pg.SetSetting(settingNoiseProfile, "balanced"); err != nil {
+		t.Fatal(err)
+	}
+	m2, err := NewManager(t.TempDir(), "")
+	if err != nil {
+		t.Fatal(err)
+	}
+	m2.Close()
+	if p := egress.CurrentProfile(); p.Name != "balanced" || p.UserAgent != "artex-noise-test/1" {
+		t.Fatalf("NewManager with setting balanced applied %+v", p)
+	}
+	if err := m.pg.SetSetting(settingNoiseProfile, "loud"); err != nil {
+		t.Fatal(err)
+	}
+	if p := startupNoiseProfile(m.pg); p.Name != "quiet" {
+		t.Fatalf("invalid setting: %q, want env quiet", p.Name)
+	}
+	if err := m.pg.SetSetting(settingNoiseProfile, "balanced"); err != nil {
+		t.Fatal(err)
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+	s := New(ctx, m, t.TempDir(), t.TempDir(), t.TempDir())
+	defer stopTestServer(t, s, cancel)
+	token, err := signJWT(s.jwtKey)
+	if err != nil {
+		t.Fatal(err)
+	}
+	do := func(method, path, body string) (int, map[string]any) {
+		t.Helper()
+		req := httptest.NewRequest(method, path, strings.NewReader(body))
+		req.Header.Set("Authorization", "Bearer "+token)
+		rec := httptest.NewRecorder()
+		s.Handler().ServeHTTP(rec, req)
+		var out map[string]any
+		_ = json.Unmarshal(rec.Body.Bytes(), &out)
+		return rec.Code, out
+	}
+	egress.SetProfile(egress.Profiles["balanced"])
+	if code, out := do(http.MethodGet, "/api/settings", ""); code != 200 || out["noise_profile"] != "balanced" {
+		t.Fatalf("GET settings: %d noise_profile=%v", code, out["noise_profile"])
+	}
+	if code, out := do(http.MethodPut, "/api/settings", `{"noise_profile":"Aggressive"}`); code != 200 || out["noise_profile"] != "aggressive" {
+		t.Fatalf("PUT aggressive: %d noise_profile=%v", code, out["noise_profile"])
+	}
+	if v, _, _ := m.pg.GetSetting(settingNoiseProfile); v != "aggressive" || egress.CurrentProfile().Name != "aggressive" {
+		t.Fatalf("after PUT: stored %q, current %q", v, egress.CurrentProfile().Name)
+	}
+	for _, bad := range []string{`{"noise_profile":"loud"}`, `{"noise_profile":""}`, `{"noise_profile":1}`} {
+		if code, _ := do(http.MethodPut, "/api/settings", bad); code != 400 {
+			t.Errorf("PUT %s: %d, want 400", bad, code)
+		}
+	}
+	if code, out := do(http.MethodPut, "/api/settings", `{"noise_profile":null}`); code != 200 || out["noise_profile"] != "aggressive" {
+		t.Fatalf("PUT null: %d noise_profile=%v, want unchanged", code, out["noise_profile"])
+	}
+	if v, _, _ := m.pg.GetSetting(settingNoiseProfile); v != "aggressive" || egress.CurrentProfile().Name != "aggressive" {
+		t.Fatalf("after invalid and null PUTs: stored %q, current %q", v, egress.CurrentProfile().Name)
+	}
+
+	// The noise endpoint reads the current governor's counters.
+	target := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {}))
+	defer target.Close()
+	req, _ := http.NewRequest(http.MethodGet, target.URL, nil)
+	resp, err := egress.Current().Transport("noise-test", nil).RoundTrip(req)
+	if err != nil {
+		t.Fatal(err)
+	}
+	resp.Body.Close()
+	code, out := do(http.MethodGet, "/api/settings/noise", "")
+	hosts, _ := out["hosts"].([]any)
+	if code != 200 || out["profile"] != "aggressive" || len(hosts) != 1 {
+		t.Fatalf("GET noise: %d %v", code, out)
+	}
+	host, _ := hosts[0].(map[string]any)
+	for _, key := range []string{"host", "rpm", "peak_rpm", "peak_inflight", "inflight", "duplicates_avoided"} {
+		if _, ok := host[key]; !ok {
+			t.Errorf("noise host misses %q: %v", key, host)
+		}
+	}
+	if host["host"] != strings.TrimPrefix(target.URL, "http://") || host["rpm"] != float64(1) || host["inflight"] != float64(0) {
+		t.Fatalf("noise host = %v", host)
+	}
+	// A second read does not reset the minute.
+	if _, again := do(http.MethodGet, "/api/settings/noise", ""); again["hosts"].([]any)[0].(map[string]any)["rpm"] != float64(1) {
+		t.Fatalf("second GET noise reset the counter: %v", again)
+	}
+}

server/server.go

@@ -22,6 +22,7 @@ import (
 
 	"github.com/Autumn-27/artex/agent"
 	"github.com/Autumn-27/artex/db"
+	"github.com/Autumn-27/artex/egress"
 	"github.com/Autumn-27/artex/intercept"
 	"github.com/Autumn-27/artex/llmpool"
 	"github.com/Autumn-27/artex/llmrec"
@@ -833,6 +834,7 @@ func (s *Server) Handler() http.Handler {
 	mux.HandleFunc("GET /api/llm/records/{id}", s.pgGetLLMRecord)
 	mux.HandleFunc("GET /api/settings", s.getSettings)
 	mux.HandleFunc("PUT /api/settings", s.putSettings)
+	mux.HandleFunc("GET /api/settings/noise", s.noiseStatus) // current noise profile + per-host counters (no reset)
 	// Vulnerability IM push. Channels are "multi-instance + per-instance filter rules" resources, so they get their own group of
 	// REST endpoints instead of being stuffed into the flat /api/settings key-value store.
 	mux.HandleFunc("GET /api/notify/meta", s.notifyMeta)
@@ -3528,6 +3530,8 @@ func (s *Server) settingsPayload() map[string]any {
 		// Render limits of IM messages; 0 = no truncation.
 		"notify_summary_max_runes": limits.SummaryRunes,
 		"notify_assets_max_shown":  limits.AssetsShown,
+		// Effective target noise profile (off by default): the stored setting, else ARTEX_NOISE_PROFILE.
+		"noise_profile": egress.CurrentProfile().Name,
 	}
 }
 
@@ -3603,11 +3607,27 @@ func (s *Server) putSettings(w http.ResponseWriter, r *http.Request) {
 		// Render limits of IM messages: summary characters (0-4000) and asset names listed (0-50); 0 = no truncation.
 		NotifySummaryMaxRunes *int `json:"notify_summary_max_runes"`
 		NotifyAssetsMaxShown  *int `json:"notify_assets_max_shown"`
+		// Target noise profile: off|quiet|balanced|aggressive; null = unchanged. Applies to the next request, no agent rebuild.
+		NoiseProfile *string `json:"noise_profile"`
 	}
 	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
 		writeErr(w, 400, err.Error())
 		return
 	}
+	// Validated before any other field is written, so a bad value changes nothing.
+	var noise egress.Profile
+	if req.NoiseProfile != nil {
+		var ok bool
+		if noise, ok = egress.ProfileByName(*req.NoiseProfile); !ok {
+			writeErr(w, 400, "noise_profile must be off, quiet, balanced or aggressive")
+			return
+		}
+		if err := s.m.pg.SetSetting(settingNoiseProfile, noise.Name); err != nil {
+			writeErr(w, 500, err.Error())
+			return
+		}
+		egress.SetProfile(noise)
+	}
 	// A masked placeholder echoed back keeps the stored secret, like null.
 	req.BraveKey, req.TavilyKey = keepIfMasked(req.BraveKey), keepIfMasked(req.TavilyKey)
 	req.WebSearchProxy, req.GlobalProxy = keepIfMasked(req.WebSearchProxy), keepIfMasked(req.GlobalProxy)

web/src/app/(main)/system/settings/noise-profile-card.tsx

@@ -0,0 +1,150 @@
+"use client";
+
+import * as React from "react";
+
+import { GaugeIcon, RefreshCwIcon } from "lucide-react";
+import { toast } from "sonner";
+
+import { Button } from "@/components/ui/button";
+import { Card, CardContent, CardDescription, CardHeader, CardTitle } from "@/components/ui/card";
+import { Label } from "@/components/ui/label";
+import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@/components/ui/select";
+import { Table, TableBody, TableCell, TableHead, TableHeader, TableRow } from "@/components/ui/table";
+import { api } from "@/lib/api";
+import type { NoiseProfileName, NoiseStatus } from "@/lib/types";
+
+// Mirrors egress.Profiles in egress/egress.go; the jitter of one send is
+// min(Jitter/RPS, 250 ms).
+const profiles: { value: NoiseProfileName; label: string; limits: string }[] = [
+  { value: "off", label: "Off", limits: "Off: requests and their timing are unchanged, and nothing is counted." },
+  {
+    value: "quiet",
+    label: "Quiet",
+    limits:
+      "2 req/s per host (burst 4), 1 in flight per host, 8 overall, jitter up to 250 ms, identical GETs of a task cached 60 s, up to 3 retries on 429/503.",
+  },
+  {
+    value: "balanced",
+    label: "Balanced",
+    limits:
+      "5 req/s per host (burst 10), 2 in flight per host, 16 overall, jitter up to 40 ms, identical GETs of a task cached 30 s, up to 3 retries on 429/503.",
+  },
+  {
+    value: "aggressive",
+    label: "Aggressive",
+    limits:
+      "20 req/s per host (burst 40), 4 in flight per host, 32 overall, jitter up to 5 ms, identical GETs of a task cached 10 s, up to 2 retries on 429/503.",
+  },
+];
+
+// NoiseProfileCard sets the target noise profile and shows the per-host
+// counters of the current minute.
+export function NoiseProfileCard() {
+  const [status, setStatus] = React.useState<NoiseStatus | null>(null);
+  const [loading, setLoading] = React.useState(false);
+  const [saving, setSaving] = React.useState(false);
+
+  const refresh = React.useCallback(() => {
+    setLoading(true);
+    api
+      .noiseStatus()
+      .then(setStatus)
+      .catch((e) => toast.error(`Failed to load the noise counters: ${(e as Error).message}`))
+      .finally(() => setLoading(false));
+  }, []);
+  React.useEffect(() => {
+    refresh();
+  }, [refresh]);
+
+  const save = (value: NoiseProfileName) => {
+    setSaving(true);
+    api
+      .setSettings({ noise_profile: value })
+      .then(() => {
+        toast.success(`Noise profile set to ${value}`);
+        refresh();
+      })
+      .catch((e) => toast.error(`Save failed: ${(e as Error).message}`))
+      .finally(() => setSaving(false));
+  };
+
+  const current = profiles.find((p) => p.value === status?.profile) ?? profiles[0];
+  return (
+    <Card className="mb-4 break-inside-avoid md:mb-6">
+      <CardHeader>
+        <CardTitle className="flex items-center gap-2 text-base">
+          <GaugeIcon className="size-4" />
+          Target noise
+        </CardTitle>
+        <CardDescription>
+          Paces the requests ARTEX itself sends to targets (WebFetch, http custom tools, the enrich probe) and sets the
+          low-and-slow guidance in agent prompts. Commands run through Bash are not paced. This setting takes
+          precedence over ARTEX_NOISE_PROFILE and applies to the next request.
+        </CardDescription>
+      </CardHeader>
+      <CardContent className="flex flex-col gap-4">
+        <div className="flex items-center justify-between gap-4">
+          <Label htmlFor="noise-profile" className="text-sm font-normal text-muted-foreground">
+            Profile
+          </Label>
+          <Select
+            value={status?.profile ?? ""}
+            disabled={!status || saving}
+            onValueChange={(v) => save(v as NoiseProfileName)}
+          >
+            <SelectTrigger id="noise-profile" className="w-48 shrink-0">
+              <SelectValue placeholder="Loading…" />
+            </SelectTrigger>
+            <SelectContent>
+              {profiles.map((p) => (
+                <SelectItem key={p.value} value={p.value}>
+                  {p.label}
+                </SelectItem>
+              ))}
+            </SelectContent>
+          </Select>
+        </div>
+        <p className="text-muted-foreground text-xs">{current.limits}</p>
+        <div className="flex items-center justify-between gap-4">
+          <span className="font-medium text-sm">Hosts, current minute</span>
+          <Button variant="outline" size="sm" onClick={refresh} disabled={loading}>
+            <RefreshCwIcon data-icon="inline-start" className={loading ? "animate-spin" : undefined} />
+            Refresh
+          </Button>
+        </div>
+        {status?.hosts.length ? (
+          <Table aria-label="Noise counters per host">
+            <TableHeader>
+              <TableRow>
+                <TableHead>Host</TableHead>
+                <TableHead className="text-right">RPM</TableHead>
+                <TableHead className="text-right">Peak RPM</TableHead>
+                <TableHead className="text-right">In flight (peak)</TableHead>
+                <TableHead className="text-right">Duplicates</TableHead>
+              </TableRow>
+            </TableHeader>
+            <TableBody>
+              {status.hosts.map((h) => (
+                <TableRow key={h.host}>
+                  <TableCell className="max-w-48 truncate font-mono text-xs" title={h.host}>
+                    {h.host}
+                  </TableCell>
+                  <TableCell className="text-right">{h.rpm}</TableCell>
+                  <TableCell className="text-right">{h.peak_rpm}</TableCell>
+                  <TableCell className="text-right">
+                    {h.inflight} ({h.peak_inflight})
+                  </TableCell>
+                  <TableCell className="text-right">{h.duplicates_avoided}</TableCell>
+                </TableRow>
+              ))}
+            </TableBody>
+          </Table>
+        ) : (
+          <p className="text-muted-foreground text-sm">
+            {status?.profile === "off" ? "Off counts no request." : "No paced request yet."}
+          </p>
+        )}
+      </CardContent>
+    </Card>
+  );
+}

web/src/app/(main)/system/settings/page.tsx

@@ -15,6 +15,8 @@ import { api } from "@/lib/api";
 import { CHAT_SEND_MODE_OPTIONS, type ChatSendMode, setChatSendMode, useChatSendMode } from "@/lib/chat-send-mode";
 import type { Settings } from "@/lib/types";
 
+import { NoiseProfileCard } from "./noise-profile-card";
+
 export default function SystemSettingsPage() {
   const [trafficCapture, setTrafficCapture] = React.useState(false);
   const [agentTrafficBinding, setAgentTrafficBinding] = React.useState(false);
@@ -292,6 +294,8 @@ export default function SystemSettingsPage() {
           </CardContent>
         </Card>
 
+        <NoiseProfileCard />
+
         <Card className="mb-4 break-inside-avoid md:mb-6">
           <CardHeader>
             <CardTitle className="flex items-center gap-2 text-base">

web/src/lib/api.ts

@@ -826,6 +826,7 @@ export const api = {
   // ---- app settings (runtime toggles) ----
   settings: () => get<Settings>(`/settings`),
   setSettings: (patch: Partial<Settings>) => put<Settings>(`/settings`, patch),
+  noiseStatus: () => get<import("@/lib/types").NoiseStatus>(`/settings/noise`),
   // Run a real "test" search with the given (or saved) config to verify it works.
   testWebSearch: (patch: {
     web_search_backend?: string;

web/src/lib/types.ts

@@ -962,6 +962,23 @@ export interface Settings {
   // Render limits of IM messages; 0 = no truncation. The backend answers 400 outside the bounds.
   notify_summary_max_runes?: number; // summary characters per finding, 0-4000, default 120
   notify_assets_max_shown?: number; // asset names listed per finding, 0-50, default 3
+  // Target noise profile; the stored setting wins over ARTEX_NOISE_PROFILE. Applies to the next request.
+  noise_profile?: NoiseProfileName;
+}
+
+export type NoiseProfileName = "off" | "quiet" | "balanced" | "aggressive";
+
+// GET /api/settings/noise: the current profile and its per-host counters (current minute, no reset).
+export interface NoiseStatus {
+  profile: NoiseProfileName;
+  hosts: {
+    host: string;
+    rpm: number;
+    peak_rpm: number;
+    peak_inflight: number;
+    inflight: number;
+    duplicates_avoided: number;
+  }[];
 }
 
 // ---- Vulnerability IM push ----