diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8f76242..375f1c7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,6 +17,16 @@ and [`agents/peggy/CHANGELOG.md`](agents/peggy/CHANGELOG.md).
 
 ## Unreleased
 
+- **Actionable model-unavailable errors
+  (`providers.ModelUnavailableHint`, `Factory.ModelsListURL`).** A 404
+  / model-not-found failure previously surfaced as a raw provider
+  error with no recovery path (live case: NVIDIA's catalog lists
+  `moonshotai/kimi-k2.6` but some accounts 404 on it). One-shot runs
+  and the TUI now append which model was requested, that the account
+  may lack access, and how to pick another — including the provider's
+  model-catalog URL declared in the registry (gemini, nvidia,
+  openrouter). The TUI hint points at `/model <id>`. (#367)
+
 - **`glue run --continue` reopens the most recently updated session.**
   Resume previously existed only inside the TUI (`/resume` picker);
   from the CLI you had to remember the `--id` you used. `--continue`
diff --git a/cmd/glue/run.go b/cmd/glue/run.go
index b36ce1a..b0d1400 100644
--- a/cmd/glue/run.go
+++ b/cmd/glue/run.go
@@ -18,6 +18,7 @@ import (
 	"github.com/erain/glue"
 	"github.com/erain/glue/cmd/glue/atmentions"
 	"github.com/erain/glue/cmd/glue/tui"
+	"github.com/erain/glue/providers"
 	filestore "github.com/erain/glue/stores/file"
 	toolscoding "github.com/erain/glue/tools/coding"
 	// Register the shipped providers so they resolve through the
@@ -292,6 +293,9 @@ func runCommand(ctx context.Context, args []string, stdin io.Reader, stdout io.W
 		if wroteDelta {
 			fmt.Fprintln(stdout)
 		}
+		if hint := providers.ModelUnavailableHint(providerName, effectiveModel, err); hint != "" {
+			return fmt.Errorf("%w\nglue run: %s", err, hint)
+		}
 		return err
 	}
 	if wroteDelta {
diff --git a/cmd/glue/run_test.go b/cmd/glue/run_test.go
index 308adb7..52adda4 100644
--- a/cmd/glue/run_test.go
+++ b/cmd/glue/run_test.go
@@ -391,3 +391,20 @@ func TestRunCLIContinueEmptyStoreErrors(t *testing.T) {
 		t.Fatalf("stderr = %q, want no sessions found", stderr.String())
 	}
 }
+
+func TestRunCLIModelNotFoundHint(t *testing.T) {
+	t.Parallel()
+	provider := &scriptedProvider{err: errors.New(`loop: provider stream: nvidia: http 404: {"status":404,"detail":"Function 'f': Not found for account 'a'"}`)}
+	var stdout, stderr bytes.Buffer
+	code := runCLI(context.Background(), []string{
+		"run", "--provider", "nvidia", "--prompt", "hi", "--store", t.TempDir(),
+	}, &stdout, &stderr, fakeFactory(provider))
+	if code == 0 {
+		t.Fatal("code = 0, want nonzero")
+	}
+	for _, want := range []string{"may be unavailable", "--model", "integrate.api.nvidia.com/v1/models"} {
+		if !strings.Contains(stderr.String(), want) {
+			t.Fatalf("stderr = %q, want hint containing %q", stderr.String(), want)
+		}
+	}
+}
diff --git a/cmd/glue/tui/tui.go b/cmd/glue/tui/tui.go
index 7672ea5..6d1b8ee 100644
--- a/cmd/glue/tui/tui.go
+++ b/cmd/glue/tui/tui.go
@@ -21,6 +21,7 @@ import (
 
 	"github.com/erain/glue"
 	"github.com/erain/glue/cmd/glue/atmentions"
+	"github.com/erain/glue/providers"
 )
 
 // Config wires the TUI to a glue agent. Provider/Model/WorkDir are
@@ -1198,6 +1199,9 @@ func (m *Model) handleTurnDone(msg turnDoneMsg) {
 	}
 	if msg.Err != nil {
 		m.appendSystem("error: " + msg.Err.Error())
+		if hint := providers.ModelUnavailableHint(m.cfg.Provider, m.cfg.Model, msg.Err); hint != "" {
+			m.appendSystem("hint: " + hint + " — switch with /model <id>")
+		}
 	}
 	// Re-render the final assistant item through glamour so code blocks,
 	// lists, headings, and inline code settle into proper formatting after
diff --git a/providers/gemini/gemini.go b/providers/gemini/gemini.go
index 6987a3d..10ea4a1 100644
--- a/providers/gemini/gemini.go
+++ b/providers/gemini/gemini.go
@@ -43,9 +43,10 @@ const providerName = "gemini"
 
 func init() {
 	providers.Register(providerName, providers.Factory{
-		New:          func() loop.Provider { return New(Options{}) },
-		DefaultModel: DefaultModel,
-		EnvKey:       EnvKey,
+		New:           func() loop.Provider { return New(Options{}) },
+		DefaultModel:  DefaultModel,
+		EnvKey:        EnvKey,
+		ModelsListURL: "https://generativelanguage.googleapis.com/v1beta/models",
 		Capabilities: providers.Capabilities{
 			// Gemini 3.x Pro: 1M-token window; frontier model that
 			// prefers terse steering; prone to the narrate-then-stop
diff --git a/providers/nvidia/nvidia.go b/providers/nvidia/nvidia.go
index 07c5a23..e200339 100644
--- a/providers/nvidia/nvidia.go
+++ b/providers/nvidia/nvidia.go
@@ -26,9 +26,10 @@ const (
 
 func init() {
 	providers.Register(providerName, providers.Factory{
-		New:          func() loop.Provider { return New(Options{}) },
-		DefaultModel: DefaultModel,
-		EnvKey:       EnvKey,
+		New:           func() loop.Provider { return New(Options{}) },
+		DefaultModel:  DefaultModel,
+		EnvKey:        EnvKey,
+		ModelsListURL: "https://integrate.api.nvidia.com/v1/models",
 		Capabilities: providers.Capabilities{
 			// Open-weight hosting; window varies by model — 128k is a
 			// safe floor. Default (explicit) prompt variant; sequential
diff --git a/providers/openrouter/openrouter.go b/providers/openrouter/openrouter.go
index b961686..9059e26 100644
--- a/providers/openrouter/openrouter.go
+++ b/providers/openrouter/openrouter.go
@@ -35,9 +35,10 @@ const (
 
 func init() {
 	providers.Register(providerName, providers.Factory{
-		New:          func() loop.Provider { return New(Options{}) },
-		DefaultModel: DefaultModel,
-		EnvKey:       EnvKey,
+		New:           func() loop.Provider { return New(Options{}) },
+		DefaultModel:  DefaultModel,
+		EnvKey:        EnvKey,
+		ModelsListURL: "https://openrouter.ai/api/v1/models",
 		Capabilities: providers.Capabilities{
 			// Aggregator of mostly open-weight models; window varies —
 			// 128k is a safe floor. Default (explicit) prompt variant.
diff --git a/providers/registry.go b/providers/registry.go
index 046b313..c62929a 100644
--- a/providers/registry.go
+++ b/providers/registry.go
@@ -58,6 +58,11 @@ type Factory struct {
 	// APIKey is empty. Used by KeyAvailable.
 	EnvKey string
 
+	// ModelsListURL is the provider's model-catalog endpoint, used in
+	// recovery hints when a request fails because the selected model is
+	// unavailable. Empty when the provider has no such endpoint.
+	ModelsListURL string
+
 	// Capabilities declares harness-relevant facts about the
 	// provider's models. Optional; the zero value means unknown.
 	Capabilities Capabilities
@@ -120,6 +125,29 @@ func Known() []string {
 	return out
 }
 
+// ModelUnavailableHint returns actionable advice when err looks like a
+// model-not-found failure from the named provider — the model id was
+// wrong, or the account does not have access to it (some catalogs list
+// models the account still 404s on). Returns "" when err does not look
+// model-shaped, so callers can append the hint unconditionally.
+func ModelUnavailableHint(providerName, model string, err error) string {
+	if err == nil {
+		return ""
+	}
+	msg := strings.ToLower(err.Error())
+	if !strings.Contains(msg, "404") &&
+		!strings.Contains(msg, "not found") &&
+		!strings.Contains(msg, "does not exist") &&
+		!strings.Contains(msg, "model_not_found") {
+		return ""
+	}
+	hint := fmt.Sprintf("model %q may be unavailable on your %s account; pick another with --model <id>", model, providerName)
+	if f, ok := Lookup(providerName); ok && f.ModelsListURL != "" {
+		hint += fmt.Sprintf(" (list models: %s)", f.ModelsListURL)
+	}
+	return hint
+}
+
 // KeyAvailable reports whether the registered provider's env var is
 // non-empty in the process environment. Returns false for unknown
 // providers and for providers registered without an EnvKey.
diff --git a/providers/registry_test.go b/providers/registry_test.go
index b4e447a..141eb87 100644
--- a/providers/registry_test.go
+++ b/providers/registry_test.go
@@ -2,6 +2,7 @@ package providers
 
 import (
 	"context"
+	"errors"
 	"strings"
 	"testing"
 
@@ -106,3 +107,29 @@ func TestCapabilitiesForRegistered(t *testing.T) {
 		t.Fatalf("caps = %#v", caps)
 	}
 }
+
+func TestModelUnavailableHint(t *testing.T) {
+	Register("hinted", Factory{
+		DefaultModel:  "m-default",
+		ModelsListURL: "https://example.test/v1/models",
+	})
+
+	err := errors.New(`provider stream: hinted: http 404: {"status":404,"detail":"Function 'x': Not found for account 'y'"}`)
+	hint := ModelUnavailableHint("hinted", "some/model", err)
+	for _, want := range []string{`"some/model"`, "hinted", "--model", "https://example.test/v1/models"} {
+		if !strings.Contains(hint, want) {
+			t.Errorf("hint missing %q: %s", want, hint)
+		}
+	}
+
+	if got := ModelUnavailableHint("hinted", "m", errors.New("http 429: overloaded")); got != "" {
+		t.Errorf("non-404 error should give no hint, got %q", got)
+	}
+	if got := ModelUnavailableHint("hinted", "m", nil); got != "" {
+		t.Errorf("nil error should give no hint, got %q", got)
+	}
+	// Unknown provider still hints, just without a catalog URL.
+	if got := ModelUnavailableHint("mystery", "m", err); got == "" || strings.Contains(got, "http") {
+		t.Errorf("unknown-provider hint wrong: %q", got)
+	}
+}