fix(providers): apply Kimi Coding default headers

docs/configuration.md

@@ -230,7 +230,7 @@ Tracing covers the providers that go through nanobot's OpenAI-compatible client
 > - **MiniMax Coding Plan**: Exclusive discount links for the nanobot community: [Overseas](https://platform.minimax.io/subscribe/coding-plan?code=9txpdXw04g&source=link) · [Mainland China](https://platform.minimaxi.com/subscribe/token-plan?code=GILTJpMTqZ&source=link)
 > - **MiniMax (Mainland China)**: If your API key is from MiniMax's mainland China platform (minimaxi.com), set `"apiBase": "https://api.minimaxi.com/v1"` in your minimax provider config.
 > - **MiniMax thinking mode**: `providers.minimaxAnthropic` is the config block for `reasoningEffort` / thinking mode. MiniMax exposes that capability through its Anthropic-compatible endpoint, so nanobot keeps it as a separate provider instead of guessing MiniMax-specific thinking parameters on the generic OpenAI-compatible `minimax` endpoint. It uses the same `MINIMAX_API_KEY`. Default Anthropic-compatible base URL: `https://api.minimax.io/anthropic`; for mainland China use `https://api.minimaxi.com/anthropic`.
-> - **Kimi Coding Plan**: Use `providers.kimiCoding` with `provider: "kimi_coding"` for Kimi's dedicated Anthropic Messages API endpoint. The endpoint **requires** `extraHeaders.User-Agent` set to a Claude-compatible value such as `claude-code/0.1.0`; omitting it returns `403`.
+> - **Kimi Coding Plan**: Use `providers.kimiCoding` with `provider: "kimi_coding"` for Kimi's dedicated Anthropic Messages API endpoint. The endpoint requires a Claude-compatible `User-Agent`; nanobot sends `claude-code/0.1.0` by default, and you can override it with `extraHeaders.User-Agent` if your account requires a different value.
 > - **VolcEngine / BytePlus Coding Plan**: Subscription endpoints are configured through dedicated providers `volcengineCodingPlan` or `byteplusCodingPlan`, separate from the pay-per-use `volcengine` / `byteplus` providers.
 > - **OpenCode Zen / Go**: `providers.opencodeZen` and `providers.opencodeGo` use the same `OPENCODE_API_KEY`, but route to different OpenCode gateways. These providers use OpenCode's OpenAI-compatible `chat/completions` endpoints; choose model IDs from that endpoint family.
 > - **Zhipu Coding Plan**: If you're on Zhipu's coding plan, set `"apiBase": "https://open.bigmodel.cn/api/coding/paas/v4"` in your zhipu provider config.

docs/provider-cookbook.md

@@ -18,7 +18,7 @@ Match the recipe to the credential or endpoint you already have:
 | An OpenCode Zen or Go key | [OpenCode Zen or Go](#recipe-opencode-zen-or-go) | `OPENCODE_API_KEY`, the Zen/Go provider key, and a model ID from the matching OpenCode endpoint |
 | An OpenAI platform API key and OpenAI model ID | [OpenAI Direct](#recipe-openai-direct) | `OPENAI_API_KEY`, `provider: "openai"`, and an OpenAI model available to that account |
 | An Anthropic API key and Anthropic model ID | [Anthropic Direct](#recipe-anthropic-direct) | `ANTHROPIC_API_KEY`, `provider: "anthropic"`, and a non-gateway model ID |
-| A Kimi Coding Plan key | [Kimi Coding Plan](#recipe-kimi-coding-plan) | `KIMI_CODING_API_KEY`, `provider: "kimi_coding"`, `model: "kimi-for-coding"`, and `extraHeaders.User-Agent` |
+| A Kimi Coding Plan key | [Kimi Coding Plan](#recipe-kimi-coding-plan) | `KIMI_CODING_API_KEY`, `provider: "kimi_coding"`, and `model: "kimi-for-coding"` |
 | An OpenAI-compatible `/v1` endpoint that is not a named nanobot provider | [Custom OpenAI-Compatible Provider](#recipe-custom-openai-compatible-provider) | `apiBase`, optional API key, and the model ID served by that endpoint |
 | Ollama already running locally | [Ollama Local Model](#recipe-ollama-local-model) | Ollama `apiBase`, pulled model name, and local server availability |
 | vLLM, LM Studio, or another local OpenAI-compatible server | [vLLM or LM Studio](#recipe-vllm-or-lm-studio) | Local `/v1` base URL, any required key, and served model name |
@@ -281,10 +281,7 @@ This recipe applies when your key comes from Kimi's Coding Plan endpoint. Nanobo
 {
   "providers": {
     "kimiCoding": {
-      "apiKey": "${KIMI_CODING_API_KEY}",
-      "extraHeaders": {
-        "User-Agent": "claude-code/0.1.0"
-      }
+      "apiKey": "${KIMI_CODING_API_KEY}"
     }
   },
   "modelPresets": {
@@ -311,7 +308,7 @@ nanobot status
 nanobot agent -m "Hello!"
 ```
 
-The default base URL is `https://api.kimi.com/coding/v1`. This endpoint **requires** the `User-Agent` header; omitting it returns `403`. Keep the value above or use another Claude-compatible value accepted by your Kimi account.
+The default base URL is `https://api.kimi.com/coding/v1`. This endpoint requires a Claude-compatible `User-Agent`; nanobot sends `claude-code/0.1.0` by default. If your account requires a different value, override it with `providers.kimiCoding.extraHeaders.User-Agent`.
 
 ## Recipe: Custom OpenAI-Compatible Provider
 

nanobot/providers/factory.py

@@ -5,10 +5,10 @@ from __future__ import annotations
 from dataclasses import dataclass
 from pathlib import Path
 
-from nanobot.config.schema import Config, InlineFallbackConfig, ModelPresetConfig
+from nanobot.config.schema import Config, InlineFallbackConfig, ModelPresetConfig, ProviderConfig
 from nanobot.providers.base import LLMProvider
 from nanobot.providers.fallback_provider import FallbackProvider
-from nanobot.providers.registry import create_dynamic_spec, find_by_name
+from nanobot.providers.registry import ProviderSpec, create_dynamic_spec, find_by_name
 
 
 @dataclass(frozen=True)
@@ -28,6 +28,16 @@ def _resolve_model_preset(
     return preset if preset is not None else config.resolve_preset(preset_name)
 
 
+def _provider_extra_headers(
+    spec: ProviderSpec | None,
+    provider_config: ProviderConfig | None,
+) -> dict[str, str] | None:
+    headers = dict(spec.default_extra_headers) if spec else {}
+    if provider_config and provider_config.extra_headers:
+        headers.update(provider_config.extra_headers)
+    return headers or None
+
+
 def _make_provider_core(
     config: Config,
     *,
@@ -89,7 +99,7 @@ def _make_provider_core(
             api_key=p.api_key if p else None,
             api_base=config.get_api_base(model, preset=resolved),
             default_model=model,
-            extra_headers=p.extra_headers if p else None,
+            extra_headers=_provider_extra_headers(spec, p),
         )
     elif backend == "bedrock":
         from nanobot.providers.bedrock_provider import BedrockProvider
@@ -109,7 +119,7 @@ def _make_provider_core(
             api_key=p.api_key if p else None,
             api_base=config.get_api_base(model, preset=resolved),
             default_model=model,
-            extra_headers=p.extra_headers if p else None,
+            extra_headers=_provider_extra_headers(spec, p),
             spec=spec,
             extra_body=p.extra_body if p else None,
             api_type=p.api_type if p and provider_name == "openai" else "auto",
@@ -191,13 +201,14 @@ def provider_signature(
 
     def _fallback_signature(fallback: ModelPresetConfig) -> tuple[object, ...]:
         fp = config.get_provider(fallback.model, preset=fallback)
+        provider_name = config.get_provider_name(fallback.model, preset=fallback)
         return (
             fallback.model,
             fallback.provider,
-            config.get_provider_name(fallback.model, preset=fallback),
+            provider_name,
             config.get_api_key(fallback.model, preset=fallback),
             config.get_api_base(fallback.model, preset=fallback),
-            fp.extra_headers if fp else None,
+            _provider_extra_headers(find_by_name(provider_name) if provider_name else None, fp),
             fp.extra_body if fp else None,
             fp.api_type if fp else "auto",
             fp.extra_query if fp else None,
@@ -209,13 +220,14 @@ def provider_signature(
             fallback.context_window_tokens,
         )
 
+    provider_name = config.get_provider_name(resolved.model, preset=resolved)
     return (
         resolved.model,
         resolved.provider,
-        config.get_provider_name(resolved.model, preset=resolved),
+        provider_name,
         config.get_api_key(resolved.model, preset=resolved),
         config.get_api_base(resolved.model, preset=resolved),
-        p.extra_headers if p else None,
+        _provider_extra_headers(find_by_name(provider_name) if provider_name else None, p),
         p.extra_body if p else None,
         p.api_type if p else "auto",
         p.extra_query if p else None,

nanobot/providers/registry.py

@@ -37,8 +37,9 @@ class ProviderSpec:
     # "openai_compat" | "anthropic" | "azure_openai" | "openai_codex" | "github_copilot" | "bedrock"
     backend: str = "openai_compat"
 
-    # extra env vars, e.g. (("ZHIPUAI_API_KEY", "{api_key}"),)
+    # extra env vars / request headers supplied by the provider integration.
     env_extras: tuple[tuple[str, str], ...] = ()
+    default_extra_headers: tuple[tuple[str, str], ...] = ()
 
     # gateway / local detection
     is_gateway: bool = False  # routes any model (OpenRouter, AiHubMix)
@@ -426,6 +427,7 @@ PROVIDERS: tuple[ProviderSpec, ...] = (
         display_name="Kimi Coding",
         backend="anthropic",
         default_api_base="https://api.kimi.com/coding/v1",
+        default_extra_headers=(("User-Agent", "claude-code/0.1.0"),),
     ),
     # MiniMax: OpenAI-compatible API
     ProviderSpec(

tests/providers/test_provider_default_headers.py

@@ -0,0 +1,50 @@
+from nanobot.config.schema import Config, ProviderConfig
+from nanobot.providers.factory import _provider_extra_headers, provider_signature
+from nanobot.providers.registry import find_by_name
+
+
+def test_kimi_coding_uses_default_user_agent_header() -> None:
+    spec = find_by_name("kimi_coding")
+
+    assert spec is not None
+    assert _provider_extra_headers(spec, ProviderConfig()) == {
+        "User-Agent": "claude-code/0.1.0",
+    }
+
+
+def test_provider_config_extra_headers_override_defaults() -> None:
+    spec = find_by_name("kimi_coding")
+    provider = ProviderConfig.model_validate({
+        "extraHeaders": {
+            "User-Agent": "custom-client/1.0",
+            "X-Test": "1",
+        },
+    })
+
+    assert _provider_extra_headers(spec, provider) == {
+        "User-Agent": "custom-client/1.0",
+        "X-Test": "1",
+    }
+
+
+def test_provider_signature_tracks_default_extra_headers() -> None:
+    config = Config.model_validate({
+        "providers": {
+            "kimiCoding": {
+                "apiKey": "sk-kimi-test",
+            },
+        },
+        "modelPresets": {
+            "primary": {
+                "provider": "kimi_coding",
+                "model": "kimi-for-coding",
+            },
+        },
+        "agents": {
+            "defaults": {
+                "modelPreset": "primary",
+            },
+        },
+    })
+
+    assert {"User-Agent": "claude-code/0.1.0"} in provider_signature(config)