diff --git a/docs/plugins/architecture.md b/docs/plugins/architecture.md
index 8d6a6505d72..36efd4f699f 100644
--- a/docs/plugins/architecture.md
+++ b/docs/plugins/architecture.md
@@ -711,10 +711,18 @@ api.registerProvider({
 
 - Anthropic uses `resolveDynamicModel`, `capabilities`, `buildAuthDoctorHint`,
   `resolveUsageAuth`, `fetchUsageSnapshot`, `isCacheTtlEligible`,
-  `resolveDefaultThinkingLevel`, `applyConfigDefaults`, and `isModernModelRef`
-  because it owns Claude 4.6 forward-compat, provider-family hints, auth
-  repair guidance, usage endpoint integration, prompt-cache eligibility,
-  auth-aware config defaults, and Claude default/adaptive thinking policy.
+  `resolveDefaultThinkingLevel`, `applyConfigDefaults`, `isModernModelRef`,
+  and `wrapStreamFn` because it owns Claude 4.6 forward-compat,
+  provider-family hints, auth repair guidance, usage endpoint integration,
+  prompt-cache eligibility, auth-aware config defaults, Claude
+  default/adaptive thinking policy, and Anthropic-specific stream shaping for
+  beta headers, `/fast` / `serviceTier`, and `context1m`.
+- Anthropic's Claude-specific stream helpers stay in the bundled plugin's own
+  public `api.ts` / `contract-api.ts` seam for now. That package surface
+  exports `wrapAnthropicProviderStream`, `resolveAnthropicBetas`,
+  `resolveAnthropicFastMode`, `resolveAnthropicServiceTier`, and the lower-level
+  Anthropic wrapper builders instead of widening the generic SDK around one
+  provider's beta-header rules.
 - OpenAI uses `resolveDynamicModel`, `normalizeResolvedModel`, and
   `capabilities` plus `buildMissingAuthMessage`, `suppressBuiltInModel`,
   `augmentModelCatalog`, `supportsXHighThinking`, and `isModernModelRef`
diff --git a/docs/plugins/sdk-overview.md b/docs/plugins/sdk-overview.md
index dc6f3be7f45..bf5e9136139 100644
--- a/docs/plugins/sdk-overview.md
+++ b/docs/plugins/sdk-overview.md
@@ -294,6 +294,13 @@ Facade-loaded bundled plugin public surfaces (`api.ts`, `runtime-api.ts`,
 active runtime config snapshot when OpenClaw is already running. If no runtime
 snapshot exists yet, they fall back to the resolved config file on disk.
 
+Provider plugins can also expose a narrow plugin-local contract barrel when a
+helper is intentionally provider-specific and does not belong in a generic SDK
+subpath yet. Current bundled example: the Anthropic provider keeps its Claude
+stream helpers in its own public `api.ts` / `contract-api.ts` seam instead of
+promoting Anthropic beta-header and `service_tier` logic into a generic
+`plugin-sdk/*` contract.
+
 <Warning>
   Extension production code should also avoid `openclaw/plugin-sdk/<other-plugin>`
   imports. If a helper is truly shared, promote it to a neutral SDK subpath
diff --git a/docs/plugins/sdk-provider-plugins.md b/docs/plugins/sdk-provider-plugins.md
index b4e7fe10b0a..6cdb69c0edd 100644
--- a/docs/plugins/sdk-provider-plugins.md
+++ b/docs/plugins/sdk-provider-plugins.md
@@ -309,6 +309,14 @@ API key auth, and dynamic model resolution.
     - `openrouter`: `openrouter-thinking`
     - `zai`: `tool-stream-default-on`
 
+    Some stream helpers stay provider-local on purpose. Current bundled
+    example: `@openclaw/anthropic-provider` exports
+    `wrapAnthropicProviderStream`, `resolveAnthropicBetas`,
+    `resolveAnthropicFastMode`, `resolveAnthropicServiceTier`, and the
+    lower-level Anthropic wrapper builders from its public `api.ts` /
+    `contract-api.ts` seam. Those helpers remain Anthropic-specific because
+    they also encode Claude OAuth beta handling and `context1m` gating.
+
     <Tabs>
       <Tab title="Token exchange">
         For providers that need a token exchange before each inference call: