diff --git a/app/src/hooks/useUsageState.test.ts b/app/src/hooks/useUsageState.test.ts
index 190283bbb..f4887143b 100644
--- a/app/src/hooks/useUsageState.test.ts
+++ b/app/src/hooks/useUsageState.test.ts
@@ -332,6 +332,79 @@ describe('useUsageState', () => {
     expect(result.current.isAtLimit).toBe(false);
   });
 
+  // -- #3767 — authoritative core-side BYO-key bypass flag --------------------
+
+  it('suppresses the budget banner when the core reports creditsBypass for the active mode (#3767)', async () => {
+    const { useUsageState } = await import('./useUsageState');
+
+    // Budget exhausted, and the raw routing strings still read as managed
+    // (kind=openhuman). The core reports the chat tier runs on a usable BYO
+    // provider (creditsBypass.chat=true), which must win for the default mode.
+    mockGetCurrentPlan.mockResolvedValue(basicPlan());
+    mockGetTeamUsage.mockResolvedValue(buildUsage({ remainingUsd: 0, cycleBudgetUsd: 10 }));
+    mockLoadAISettings.mockResolvedValue({
+      ...ALL_OPENHUMAN_AI_SETTINGS,
+      creditsBypass: { chat: true, reasoning: true },
+    });
+
+    const { result } = renderHook(() => useUsageState());
+
+    await waitFor(() => {
+      expect(result.current.isLoading).toBe(false);
+    });
+
+    expect(result.current.isFullyRoutedAway).toBe(true);
+    expect(result.current.shouldShowBudgetCompletedMessage).toBe(false);
+    expect(result.current.isBudgetExhausted).toBe(false);
+    expect(result.current.isAtLimit).toBe(false);
+  });
+
+  it('still shows the budget banner when creditsBypass is false for the active mode (#3767)', async () => {
+    const { useUsageState } = await import('./useUsageState');
+
+    // Neither chat-mode tier on a usable BYO provider → gate stays on.
+    mockGetCurrentPlan.mockResolvedValue(basicPlan());
+    mockGetTeamUsage.mockResolvedValue(buildUsage({ remainingUsd: 0, cycleBudgetUsd: 10 }));
+    mockLoadAISettings.mockResolvedValue({
+      ...ALL_OPENHUMAN_AI_SETTINGS,
+      creditsBypass: { chat: false, reasoning: false },
+    });
+
+    const { result } = renderHook(() => useUsageState());
+
+    await waitFor(() => {
+      expect(result.current.isLoading).toBe(false);
+    });
+
+    expect(result.current.isFullyRoutedAway).toBe(false);
+    expect(result.current.shouldShowBudgetCompletedMessage).toBe(true);
+    expect(result.current.isBudgetExhausted).toBe(true);
+    expect(result.current.isAtLimit).toBe(true);
+  });
+
+  it('gates per selected chat mode — Quick bypassed, Reasoning gated when only chat is BYO (#3767)', async () => {
+    const { useUsageState } = await import('./useUsageState');
+
+    // chat tier on BYO, reasoning tier still managed. Quick mode (chat) should
+    // bypass; Reasoning mode (reasoning) should stay gated.
+    mockGetCurrentPlan.mockResolvedValue(basicPlan());
+    mockGetTeamUsage.mockResolvedValue(buildUsage({ remainingUsd: 0, cycleBudgetUsd: 10 }));
+    mockLoadAISettings.mockResolvedValue({
+      ...ALL_OPENHUMAN_AI_SETTINGS,
+      creditsBypass: { chat: true, reasoning: false },
+    });
+
+    const quick = renderHook(() => useUsageState('chat'));
+    await waitFor(() => expect(quick.result.current.isLoading).toBe(false));
+    expect(quick.result.current.isAtLimit).toBe(false);
+    expect(quick.result.current.shouldShowBudgetCompletedMessage).toBe(false);
+
+    const reasoning = renderHook(() => useUsageState('reasoning'));
+    await waitFor(() => expect(reasoning.result.current.isLoading).toBe(false));
+    expect(reasoning.result.current.isAtLimit).toBe(true);
+    expect(reasoning.result.current.shouldShowBudgetCompletedMessage).toBe(true);
+  });
+
   it('still shows the budget banner when at least one chat workload remains on OpenHuman', async () => {
     const { useUsageState } = await import('./useUsageState');
 
diff --git a/app/src/hooks/useUsageState.ts b/app/src/hooks/useUsageState.ts
index 9bcd8f23f..8a7ca1256 100644
--- a/app/src/hooks/useUsageState.ts
+++ b/app/src/hooks/useUsageState.ts
@@ -1,3 +1,4 @@
+import debug from 'debug';
 import { useCallback, useEffect, useState } from 'react';
 
 import { useCoreState } from '../providers/CoreStateProvider';
@@ -35,6 +36,8 @@ export interface UsageState {
   refresh: () => void;
 }
 
+const logBillingGate = debug('openhuman:billing:gate');
+
 const CACHE_TTL_MS = 60_000;
 
 let _cache: {
@@ -114,7 +117,12 @@ async function fetchUsageData(): Promise<{
   return data;
 }
 
-export function useUsageState(): UsageState {
+/**
+ * @param activeChatRole the chat-mode tier the caller is gating on — `chat` for
+ * Quick mode (default), `reasoning` for Reasoning mode. The credits bypass is
+ * checked against this tier so the prompt reflects the mode the user selected.
+ */
+export function useUsageState(activeChatRole: 'chat' | 'reasoning' = 'chat'): UsageState {
   const { snapshot } = useCoreState();
   const isAuthenticated = snapshot.auth.isAuthenticated;
   const [teamUsage, setTeamUsage] = useState<TeamUsage | null>(null);
@@ -192,7 +200,17 @@ export function useUsageState(): UsageState {
   // user. Conservative on missing aiSettings (treat as still using
   // openhuman) so we never silently disable the gate after a transient
   // fetch failure (#2040, #2041).
-  const isFullyRoutedAway = aiSettings ? workloadsRoutedAway(aiSettings, CHAT_WORKLOADS) : false;
+  //
+  // #3767: prefer the authoritative, core-side `creditsBypass` decision for the
+  // selected chat-mode tier (Quick → `chat`, Reasoning → `reasoning`) — true when
+  // that tier runs on a usable non-managed provider the user funds themselves —
+  // and OR it with the existing routing-string heuristic. This closes the gap
+  // where the selected mode runs on a BYO provider but the raw routing strings
+  // still read as managed, so the buy-credits prompt stayed up.
+  const creditsBypassForMode = aiSettings?.creditsBypass?.[activeChatRole] === true;
+  const isFullyRoutedAway = aiSettings
+    ? creditsBypassForMode || workloadsRoutedAway(aiSettings, CHAT_WORKLOADS)
+    : false;
 
   const rawBudgetExhausted = teamUsage
     ? teamUsage.cycleBudgetUsd > 0.01 && teamUsage.remainingUsd <= 0.01
@@ -215,6 +233,24 @@ export function useUsageState(): UsageState {
   // despite custom provider).
   const isNearLimit = !isAtLimit && !isFullyRoutedAway && teamUsage !== null && usagePct >= 0.8;
 
+  // #3767: verbose gate-decision diagnostics — which branch (gated vs bypassed)
+  // and why. Keyed on the inputs so it only fires when the decision changes.
+  useEffect(() => {
+    if (!teamUsage && !aiSettings) return;
+    logBillingGate(
+      `[billing][gate] mode=${activeChatRole} budgetExhausted=${rawBudgetExhausted} ` +
+        `creditsBypass=${creditsBypassForMode} ` +
+        `fullyRoutedAway=${isFullyRoutedAway} -> ${isAtLimit ? 'GATED' : 'bypassed'}`
+    );
+  }, [
+    activeChatRole,
+    creditsBypassForMode,
+    rawBudgetExhausted,
+    isFullyRoutedAway,
+    isAtLimit,
+    teamUsage,
+  ]);
+
   return {
     teamUsage,
     currentPlan,
diff --git a/app/src/pages/Conversations.tsx b/app/src/pages/Conversations.tsx
index cbb3cf000..edb97d084 100644
--- a/app/src/pages/Conversations.tsx
+++ b/app/src/pages/Conversations.tsx
@@ -319,7 +319,10 @@ const Conversations = ({
     isFreeTier,
     shouldShowBudgetCompletedMessage,
     usagePct,
-  } = useUsageState();
+    // #3767: gate on the tier for the selected chat mode — Quick runs on the
+    // `chat` tier, Reasoning on the `reasoning` tier — so the credits prompt
+    // reflects the mode the user actually picked.
+  } = useUsageState(selectedAgentProfileId === 'reasoning' ? 'reasoning' : 'chat');
   const [deleteModal, setDeleteModal] = useState<ConfirmationModalType>({
     isOpen: false,
     title: '',
diff --git a/app/src/services/api/__tests__/aiSettingsApi.test.ts b/app/src/services/api/__tests__/aiSettingsApi.test.ts
index cf1490915..d3479fd70 100644
--- a/app/src/services/api/__tests__/aiSettingsApi.test.ts
+++ b/app/src/services/api/__tests__/aiSettingsApi.test.ts
@@ -311,6 +311,26 @@ describe('loadAISettings', () => {
     expect(settings.cloudProviders[0].has_api_key).toBe(false);
   });
 
+  it('parses per-tier credits_bypass into creditsBypass, defaulting to false (#3767)', async () => {
+    mockAuthListProviderCredentials.mockResolvedValue(makeAuthProfileResult([]));
+
+    // Absent in an older snapshot → both tiers conservative false.
+    mockOpenhumanGetClientConfig.mockResolvedValue(makeClientConfigResult({}));
+    expect((await loadAISettings()).creditsBypass).toEqual({ chat: false, reasoning: false });
+
+    // Per-tier: chat true, reasoning absent → chat true, reasoning false.
+    mockOpenhumanGetClientConfig.mockResolvedValue(
+      makeClientConfigResult({ credits_bypass: { chat: true } })
+    );
+    expect((await loadAISettings()).creditsBypass).toEqual({ chat: true, reasoning: false });
+
+    // Both present.
+    mockOpenhumanGetClientConfig.mockResolvedValue(
+      makeClientConfigResult({ credits_bypass: { chat: true, reasoning: true } })
+    );
+    expect((await loadAISettings()).creditsBypass).toEqual({ chat: true, reasoning: true });
+  });
+
   it('sets has_api_key=true when a matching provider:<slug> profile is stored', async () => {
     mockOpenhumanGetClientConfig.mockResolvedValue(
       makeClientConfigResult({
@@ -592,6 +612,7 @@ describe('saveAISettings', () => {
         subconscious: { kind: 'openhuman' },
       },
       modelRegistry: [],
+      creditsBypass: { chat: false, reasoning: false },
       ...overrides,
     };
   }
diff --git a/app/src/services/api/aiSettingsApi.ts b/app/src/services/api/aiSettingsApi.ts
index b2867d7ca..12c3b4c5d 100644
--- a/app/src/services/api/aiSettingsApi.ts
+++ b/app/src/services/api/aiSettingsApi.ts
@@ -148,6 +148,21 @@ export interface AISettings {
    * image attachments for custom/BYOK models.
    */
   modelRegistry: ModelRegistryEntry[];
+  /**
+   * #3767: authoritative, core-side per-tier decision (mirrors the Rust factory's
+   * real routing resolution). For each chat-mode tier (`chat` = Quick mode,
+   * `reasoning` = Reasoning mode), true when that tier runs on a non-managed
+   * provider the user funds themselves (a usable BYO key, local runtime, or
+   * claude-code). `useUsageState` checks the tier matching the selected mode so
+   * the "buy credits" prompt is hidden exactly when the core says that mode does
+   * not bill managed credits. Each entry is `false` when the core snapshot
+   * predates this field (conservative — keep gating).
+   *
+   * Optional: `loadAISettings` always populates it, but AIPanel reconstructs a
+   * draft `AISettings` for `saveAISettings` (which ignores this read-only field)
+   * and test fixtures may omit it — consumers treat a missing entry as `false`.
+   */
+  creditsBypass?: { chat: boolean; reasoning: boolean };
 }
 
 /** Re-export so callers (e.g. the AI panel) can reference the entry type. */
@@ -319,7 +334,15 @@ export async function loadAISettings(): Promise<AISettings> {
   // Per-model registry (vision flags). Defensive default for older snapshots.
   const modelRegistry: ModelRegistryEntry[] = config.model_registry ?? [];
 
-  return { cloudProviders, routing, modelRegistry };
+  // #3767: authoritative per-tier bypass flags from the core. Each entry
+  // defaults to false for older snapshots that don't carry it (conservative —
+  // keep the credits gate on).
+  const creditsBypass = {
+    chat: config.credits_bypass?.chat === true,
+    reasoning: config.credits_bypass?.reasoning === true,
+  };
+
+  return { cloudProviders, routing, modelRegistry, creditsBypass };
 }
 // ─── Write path: diff + save ───────────────────────────────────────────────
 
diff --git a/app/src/utils/tauriCommands/config.ts b/app/src/utils/tauriCommands/config.ts
index 6a03e5ec2..40a1ab44a 100644
--- a/app/src/utils/tauriCommands/config.ts
+++ b/app/src/utils/tauriCommands/config.ts
@@ -238,6 +238,15 @@ export interface ClientConfig {
   model_registry: ModelRegistryEntry[];
   /** Id of the `cloud_providers` entry resolved by the `"cloud"` sentinel. */
   primary_cloud: string | null;
+  /**
+   * #3767: authoritative, core-side per-tier flags — for each chat-mode tier
+   * (`chat` = Quick mode, `reasoning` = Reasoning mode), true when that tier runs
+   * on a non-managed provider the user funds themselves (a usable BYO key, local
+   * runtime, or claude-code). The UI checks whichever tier the user has selected;
+   * when true the "buy credits" prompt is suppressed for that mode. Optional for
+   * back-compat with older snapshots.
+   */
+  credits_bypass?: { chat?: boolean; reasoning?: boolean };
   /** Per-workload provider strings (e.g. `"cloud"`, `"ollama:llama3.1:8b"`, `"openai:gpt-4o"`). */
   chat_provider: string | null;
   reasoning_provider: string | null;
diff --git a/src/openhuman/config/ops/loader.rs b/src/openhuman/config/ops/loader.rs
index 7fa938cb1..f740c9d3d 100644
--- a/src/openhuman/config/ops/loader.rs
+++ b/src/openhuman/config/ops/loader.rs
@@ -277,6 +277,23 @@ pub fn client_config_json(config: &Config) -> serde_json::Value {
         "cloud_providers": cloud_providers,
         "model_registry": model_registry,
         "primary_cloud": config.primary_cloud,
+        // #3767: authoritative, core-side decision telling the UI whether the
+        // managed-credits gate should be bypassed, per chat-mode tier. The chat
+        // header's "Quick" mode runs on the `chat` tier and "Reasoning" mode on
+        // the `reasoning` tier, so each is reported separately and the UI checks
+        // the tier the user actually selected. True for a tier when it runs on a
+        // non-managed provider the user funds themselves (BYO key / local /
+        // claude-code) with usable creds. Managed tiers that run anyway surface
+        // credit errors per-call.
+        "credits_bypass": {
+            "chat": crate::openhuman::inference::provider::factory::role_bypasses_managed_credits(
+                "chat", config,
+            ),
+            "reasoning":
+                crate::openhuman::inference::provider::factory::role_bypasses_managed_credits(
+                    "reasoning", config,
+                ),
+        },
         "chat_provider": config.chat_provider,
         "reasoning_provider": config.reasoning_provider,
         "agentic_provider": config.agentic_provider,
diff --git a/src/openhuman/inference/openai_oauth/flow_tests.rs b/src/openhuman/inference/openai_oauth/flow_tests.rs
index aaea4df19..0f45fc7d5 100644
--- a/src/openhuman/inference/openai_oauth/flow_tests.rs
+++ b/src/openhuman/inference/openai_oauth/flow_tests.rs
@@ -602,6 +602,41 @@ fn lookup_openai_bearer_token_uses_oauth_when_api_key_missing() {
     assert_eq!(token.as_deref(), Some("oauth-access"));
 }
 
+#[test]
+fn credits_gate_bypassed_with_oauth_only_credentials() {
+    // #3767 regression: the per-tier credits-gate bypass chains through
+    // route_has_usable_credentials → lookup_key_for_slug, which falls back to
+    // the OpenAI OAuth token for the `openai` slug. Pin that OAuth-only
+    // credentials (no new-style provider key) bypass the gate when the chat tier
+    // is routed to a concrete OpenAI model.
+    use crate::openhuman::inference::provider::factory::role_bypasses_managed_credits;
+
+    let tmp = tempdir().unwrap();
+    let mut config = test_config(&tmp);
+    config.chat_provider = Some("openai:gpt-4o".into());
+
+    // No credential yet → gate stays on.
+    assert!(!role_bypasses_managed_credits("chat", &config));
+
+    let store = AuthProfilesStore::new(tmp.path(), false);
+    let oauth_profile = AuthProfile::new_oauth(
+        OPENAI_PROVIDER_KEY,
+        OPENAI_OAUTH_PROFILE_NAME,
+        TokenSet {
+            access_token: "oauth-access".into(),
+            refresh_token: Some("refresh".into()),
+            id_token: None,
+            expires_at: Some(Utc::now() + Duration::hours(1)),
+            token_type: Some("Bearer".into()),
+            scope: None,
+        },
+    );
+    store.upsert_profile(oauth_profile, true).unwrap();
+
+    // OAuth-only credential now backs the route → gate bypassed.
+    assert!(role_bypasses_managed_credits("chat", &config));
+}
+
 #[test]
 fn lookup_key_for_slug_uses_legacy_openai_api_key_when_new_style_is_empty() {
     let tmp = tempdir().unwrap();
diff --git a/src/openhuman/inference/ops_tests.rs b/src/openhuman/inference/ops_tests.rs
index 79abd073a..a176cf73d 100644
--- a/src/openhuman/inference/ops_tests.rs
+++ b/src/openhuman/inference/ops_tests.rs
@@ -161,6 +161,21 @@ async fn inference_get_client_config_returns_safe_snapshot() {
         .expect("client config snapshot");
     assert!(outcome.value.get("cloud_providers").is_some());
     assert!(outcome.value.get("api_key_set").is_some());
+    // #3767: authoritative per-tier credits-gate bypass map is present and, with
+    // no BYO provider configured, every tier defaults to false (inference still
+    // bills managed credits).
+    let credits_bypass = outcome
+        .value
+        .get("credits_bypass")
+        .expect("credits_bypass present");
+    assert_eq!(
+        credits_bypass.get("chat"),
+        Some(&serde_json::Value::Bool(false))
+    );
+    assert_eq!(
+        credits_bypass.get("reasoning"),
+        Some(&serde_json::Value::Bool(false))
+    );
 }
 
 #[tokio::test]
diff --git a/src/openhuman/inference/provider/factory.rs b/src/openhuman/inference/provider/factory.rs
index e207823e6..9d415d170 100644
--- a/src/openhuman/inference/provider/factory.rs
+++ b/src/openhuman/inference/provider/factory.rs
@@ -289,6 +289,77 @@ pub fn provider_for_role(role: &str, config: &Config) -> String {
     }
 }
 
+/// #3767: Whether the OpenHuman managed-credits gate should be bypassed for a
+/// single workload role.
+///
+/// Returns true when `role` resolves (via [`provider_for_role`]) to a non-managed
+/// provider the user funds themselves — a BYO cloud key (incl. OpenAI OAuth), a
+/// local runtime, or claude-code — with usable credentials. When the role is on
+/// the OpenHuman managed backend, or a BYO route has no usable key, it returns
+/// false (the gate stays on; #3767: "BYO key present but invalid/unverified →
+/// still gated").
+///
+/// The gate is evaluated per-tier so the UI can check the tier the user actually
+/// selected: the chat header's "Quick" mode runs on the `chat` tier and
+/// "Reasoning" mode on the `reasoning` tier, so each is checked respectively.
+/// These per-role results are surfaced under `credits_bypass` in the
+/// client-config snapshot. Tiers that stay managed and run anyway surface the
+/// per-call `USER_INSUFFICIENT_CREDITS` (402) error reactively.
+pub fn role_bypasses_managed_credits(role: &str, config: &Config) -> bool {
+    let resolved = provider_for_role(role, config);
+    let r = resolved.trim();
+    let is_managed =
+        r.is_empty() || r == "cloud" || r == PROVIDER_OPENHUMAN || r == BYOK_INCOMPLETE_SENTINEL;
+    let usable_byo = !is_managed && route_has_usable_credentials(r, config);
+    log::debug!(
+        "[billing] role_bypasses_managed_credits role={role} resolved={resolved} \
+         is_managed={is_managed} usable_byo={usable_byo}"
+    );
+    usable_byo
+}
+
+/// True when a resolved chat-tier provider string can actually run on the
+/// user's own funding: local runtimes / claude-code carry their own creds; a
+/// concrete cloud slug requires a non-empty stored key. Managed/sentinel
+/// strings are filtered by the caller and never reach here as "usable".
+fn route_has_usable_credentials(resolved: &str, config: &Config) -> bool {
+    let r = resolved.trim();
+    // Local runtimes (ollama/lmstudio/mlx/local-openai) and the local CLI
+    // delegates carry their own credentials / run on-device.
+    if crate::openhuman::inference::local::profile::is_local_provider_string(r)
+        || r.starts_with(crate::openhuman::inference::provider::claude_code::PROVIDER_PREFIX)
+        || r == CLAUDE_AGENT_SDK_PROVIDER
+        || r.starts_with(CLAUDE_AGENT_SDK_PREFIX)
+    {
+        return true;
+    }
+    // Concrete cloud slug "<slug>:<model>" — require a usable stored key.
+    if let Some((slug, _)) = r.split_once(':') {
+        let slug = slug.trim();
+        if !slug.is_empty() {
+            // Don't silently swallow auth-store / OAuth lookup failures — a
+            // transient Err would otherwise keep the credits gate on for a
+            // valid BYO setup with no diagnostics. Log and treat as not-usable.
+            match lookup_key_for_slug(slug, config) {
+                Ok(key) => {
+                    let usable = !key.trim().is_empty();
+                    log::debug!(
+                        "[billing] route_has_usable_credentials slug={slug} usable={usable}"
+                    );
+                    return usable;
+                }
+                Err(e) => {
+                    log::debug!(
+                        "[billing] route_has_usable_credentials slug={slug} lookup_error={e}"
+                    );
+                    return false;
+                }
+            }
+        }
+    }
+    false
+}
+
 /// Find the first BYOK cloud provider string configured across all workload
 /// routes, skipping local providers (ollama, lmstudio) and managed-backend
 /// sentinels ("openhuman", "cloud", empty).
diff --git a/src/openhuman/inference/provider/factory_tests.rs b/src/openhuman/inference/provider/factory_tests.rs
index e8a133221..777494407 100644
--- a/src/openhuman/inference/provider/factory_tests.rs
+++ b/src/openhuman/inference/provider/factory_tests.rs
@@ -1927,3 +1927,141 @@ fn resolve_model_for_hint_handles_unknown_hint_passthrough() {
     let result = resolve_model_for_hint("hint:unknown_tier", &config);
     assert_eq!(result, "hint:unknown_tier");
 }
+
+// ── #3767: managed-credits gate bypass (gate-only, per-tier) ───────────────
+//
+// Routing is NOT changed by this fix — selecting a BYO provider already routes
+// inference correctly. The gate is evaluated PER TIER so the UI checks whichever
+// tier the user actually selected: the chat header's "Quick" mode runs on the
+// `chat` tier and "Reasoning" mode on the `reasoning` tier. `role_bypasses_
+// managed_credits(role)` is true when that role runs on the user's own funding
+// (a BYO cloud key, a local runtime, or claude-code) with usable credentials.
+// Tiers that stay managed and run anyway surface the per-call 402 error.
+
+/// Store a usable provider key under the new-style `provider:<slug>` profile so
+/// `lookup_key_for_slug` resolves it.
+fn store_byo_key(config: &Config, slug: &str, token: &str) {
+    let auth = AuthService::from_config(config);
+    auth.store_provider_token(
+        &format!("provider:{slug}"),
+        "default",
+        token,
+        Default::default(),
+        true,
+    )
+    .expect("store provider token");
+}
+
+#[test]
+fn byo_chat_tier_with_key_bypasses() {
+    let tmp = TempDir::new().expect("tempdir");
+    // Quick mode runs on `chat`; routed to the user's own OpenAI provider + key.
+    let mut config = config_with_providers_in_tempdir(&tmp, vec![openai_entry("p_oai", "openai")]);
+    config.chat_provider = Some("openai:gpt-4o".to_string());
+    store_byo_key(&config, "openai", "sk-byo-test");
+
+    assert!(role_bypasses_managed_credits("chat", &config));
+}
+
+#[test]
+fn byo_reasoning_tier_with_key_bypasses() {
+    let tmp = TempDir::new().expect("tempdir");
+    // Reasoning mode runs on `reasoning`; routed to the user's own provider + key.
+    let mut config = config_with_providers_in_tempdir(&tmp, vec![openai_entry("p_oai", "openai")]);
+    config.reasoning_provider = Some("openai:gpt-4o".to_string());
+    store_byo_key(&config, "openai", "sk-byo-test");
+
+    assert!(role_bypasses_managed_credits("reasoning", &config));
+}
+
+#[test]
+fn per_tier_diverges_chat_byo_reasoning_managed() {
+    let tmp = TempDir::new().expect("tempdir");
+    // The crux of the per-tier check: chat on BYOK, reasoning explicitly managed.
+    // Quick mode (chat) bypasses; Reasoning mode (reasoning) stays gated.
+    let mut config = config_with_providers_in_tempdir(&tmp, vec![openai_entry("p_oai", "openai")]);
+    config.chat_provider = Some("openai:gpt-4o".to_string());
+    config.reasoning_provider = Some("openhuman".to_string());
+    store_byo_key(&config, "openai", "sk-byo-test");
+
+    assert!(role_bypasses_managed_credits("chat", &config));
+    assert!(!role_bypasses_managed_credits("reasoning", &config));
+}
+
+#[test]
+fn local_tier_bypasses_without_any_key() {
+    // A tier on a local on-device runtime → bypass, no cloud key needed.
+    let mut config = Config::default();
+    config.chat_provider = Some("ollama:qwen3:8b".to_string());
+    assert!(role_bypasses_managed_credits("chat", &config));
+}
+
+#[test]
+fn managed_chat_with_byo_agentic_stays_gated() {
+    let tmp = TempDir::new().expect("tempdir");
+    // chat explicitly managed; only tool-use (agentic) is BYOK. The chat tier
+    // still bills managed credits → chat role stays gated. (agentic itself is a
+    // BYO route, but it is not a chat-mode tier and surfaces errors per-call.)
+    let mut config = config_with_providers_in_tempdir(&tmp, vec![openai_entry("p_oai", "openai")]);
+    config.chat_provider = Some("openhuman".to_string());
+    config.reasoning_provider = Some("openhuman".to_string());
+    config.agentic_provider = Some("openai:gpt-4o".to_string());
+    store_byo_key(&config, "openai", "sk-byo-test");
+
+    assert!(!role_bypasses_managed_credits("chat", &config));
+    assert!(!role_bypasses_managed_credits("reasoning", &config));
+}
+
+#[test]
+fn managed_chat_with_byo_vision_stays_gated() {
+    let tmp = TempDir::new().expect("tempdir");
+    // Vision on BYOK but the chat-mode tiers stay managed → chat/reasoning gated.
+    let mut config = config_with_providers_in_tempdir(&tmp, vec![openai_entry("p_oai", "openai")]);
+    config.chat_provider = Some("openhuman".to_string());
+    config.reasoning_provider = Some("openhuman".to_string());
+    config.vision_provider = Some("openai:gpt-4o".to_string());
+    store_byo_key(&config, "openai", "sk-byo-test");
+
+    assert!(!role_bypasses_managed_credits("chat", &config));
+    assert!(!role_bypasses_managed_credits("reasoning", &config));
+}
+
+#[test]
+fn no_byo_provider_stays_gated() {
+    let tmp = TempDir::new().expect("tempdir");
+    // OpenAI entry exists but every tier is left on the managed default and no
+    // key is stored → chat-mode tiers managed → must NOT bypass.
+    let config = config_with_providers_in_tempdir(&tmp, vec![openai_entry("p_oai", "openai")]);
+
+    assert_eq!(provider_for_role("chat", &config), "openhuman");
+    assert!(!role_bypasses_managed_credits("chat", &config));
+    assert!(!role_bypasses_managed_credits("reasoning", &config));
+}
+
+#[test]
+fn default_config_with_no_key_stays_gated() {
+    // No BYO provider at all → both chat-mode tiers gated.
+    let config = Config::default();
+    assert!(!role_bypasses_managed_credits("chat", &config));
+    assert!(!role_bypasses_managed_credits("reasoning", &config));
+}
+
+#[test]
+fn byo_route_without_usable_key_stays_gated() {
+    let tmp = TempDir::new().expect("tempdir");
+    // chat tier points at a BYO slug with NO stored key — the route would fail
+    // with an auth error, not bill managed credits, but we must not bypass for a
+    // route that cannot run on the user's dime (#3767: "BYO key present but
+    // invalid/unverified → still gated").
+    let mut config = config_with_providers_in_tempdir(&tmp, vec![openai_entry("p_oai", "openai")]);
+    config.chat_provider = Some("openai:gpt-4o".to_string());
+
+    // The explicit route is still honored verbatim by provider_for_role…
+    assert_eq!(provider_for_role("chat", &config), "openai:gpt-4o");
+    // …but with no usable key the gate stays on.
+    assert!(!role_bypasses_managed_credits("chat", &config));
+
+    // Once a key is stored, the route becomes a genuine bypass.
+    store_byo_key(&config, "openai", "sk-byo-test");
+    assert!(role_bypasses_managed_credits("chat", &config));
+}