diff --git a/packages/llm/src/provider-resolver.ts b/packages/llm/src/provider-resolver.ts
index 03c4bf66fc..809b1d7ef8 100644
--- a/packages/llm/src/provider-resolver.ts
+++ b/packages/llm/src/provider-resolver.ts
@@ -8,7 +8,7 @@ export interface ProviderResolution {
   readonly provider: ProviderIDType
   readonly protocol: Protocol
   readonly baseURL?: string
-  readonly auth?: ProviderAuth
+  readonly auth: ProviderAuth
   readonly capabilities?: CapabilitiesInput
 }
 
@@ -26,10 +26,11 @@ export interface ProviderResolver {
 export const make = (
   provider: string | ProviderIDType,
   protocol: Protocol,
-  options: Omit<ProviderResolution, "provider" | "protocol"> = {},
+  options: Partial<Omit<ProviderResolution, "provider" | "protocol">> = {},
 ): ProviderResolution => ({
   provider: ProviderID.make(provider),
   protocol,
+  auth: options.auth ?? "bearer",
   ...options,
 })
 
@@ -38,7 +39,7 @@ export const define = (input: ProviderResolver): ProviderResolver => input
 export const fixed = (
   provider: string | ProviderIDType,
   protocol: Protocol,
-  options: Omit<ProviderResolution, "provider" | "protocol"> = {},
+  options: Partial<Omit<ProviderResolution, "provider" | "protocol">> = {},
 ): ProviderResolver => {
   const resolution = make(provider, protocol, options)
   return define({ id: resolution.provider, resolve: () => resolution })
diff --git a/packages/llm/src/provider/openai-compatible-family.ts b/packages/llm/src/provider/openai-compatible-family.ts
index 2923ac2d80..19435cd7fe 100644
--- a/packages/llm/src/provider/openai-compatible-family.ts
+++ b/packages/llm/src/provider/openai-compatible-family.ts
@@ -18,8 +18,15 @@ export const byProvider: Record<string, ProviderFamily> = Object.fromEntries(
   Object.values(families).map((family) => [family.provider, family]),
 )
 
+const resolutions = Object.fromEntries(
+  Object.values(families).map((family) => [
+    family.provider,
+    ProviderResolver.make(family.provider, "openai-compatible-chat", { baseURL: family.baseURL }),
+  ]),
+)
+
 export const resolve = (provider: string) =>
-  ProviderResolver.make(provider, "openai-compatible-chat", { baseURL: byProvider[provider]?.baseURL, auth: "bearer" })
+  resolutions[provider] ?? ProviderResolver.make(provider, "openai-compatible-chat")
 
 export const resolver = ProviderResolver.define({
   id: ProviderResolver.make("openai-compatible", "openai-compatible-chat").provider,
diff --git a/packages/opencode/src/provider/llm-bridge.ts b/packages/opencode/src/provider/llm-bridge.ts
index 0d1f21a40e..63501050c4 100644
--- a/packages/opencode/src/provider/llm-bridge.ts
+++ b/packages/opencode/src/provider/llm-bridge.ts
@@ -65,7 +65,7 @@ const baseURL = (input: Input, resolution: ProviderResolution, options: Record<s
   return resolution.baseURL
 }
 
-const authHeader = (auth: ProviderAuth | undefined, apiKey: string | undefined): Record<string, string> => {
+const authHeader = (auth: ProviderAuth, apiKey: string | undefined): Record<string, string> => {
   if (!apiKey) return {}
   if (auth === "none") return {}
   if (auth === "anthropic-api-key") return { "x-api-key": apiKey }
@@ -87,7 +87,7 @@ const reasoningEfforts = (input: Input) =>
     REASONING_EFFORTS.has(effort as ReasoningEffort),
   )
 
-const mergeCapabilities = (base: CapabilitiesInput, override: CapabilitiesInput | undefined): CapabilitiesInput => ({
+const mergeCapabilities = (base: CapabilitiesInput, override: CapabilitiesInput): CapabilitiesInput => ({
   input: { ...base.input, ...override?.input },
   output: { ...base.output, ...override?.output },
   tools: { ...base.tools, ...override?.tools },
@@ -95,41 +95,38 @@ const mergeCapabilities = (base: CapabilitiesInput, override: CapabilitiesInput
   reasoning: { ...base.reasoning, ...override?.reasoning },
 })
 
-const capabilities = (input: Input, resolution: ProviderResolution) =>
-  LLM.capabilities(
-    mergeCapabilities(
-      {
-        input: {
-          text: input.model.capabilities.input.text,
-          image: input.model.capabilities.input.image,
-          audio: input.model.capabilities.input.audio,
-          video: input.model.capabilities.input.video,
-          pdf: input.model.capabilities.input.pdf,
-        },
-        output: {
-          text: input.model.capabilities.output.text,
-          reasoning: input.model.capabilities.reasoning,
-        },
-        tools: {
-          calls: input.model.capabilities.toolcall,
-          streamingInput: resolution.protocol !== "gemini" && input.model.capabilities.toolcall,
-        },
-        cache: {
-          // Both Anthropic Messages and Bedrock Converse honour positional cache
-          // markers — Anthropic via `cache_control` on content blocks, Bedrock via
-          // its `cachePoint` marker block (added to BedrockConverse in 9d7d518ac).
-          prompt: ["anthropic-messages", "bedrock-converse"].includes(resolution.protocol),
-          contentBlocks: ["anthropic-messages", "bedrock-converse"].includes(resolution.protocol),
-        },
-        reasoning: {
-          efforts: reasoningEfforts(input),
-          summaries: resolution.protocol === "openai-responses",
-          encryptedContent: resolution.protocol === "openai-responses" || resolution.protocol === "anthropic-messages",
-        },
-      },
-      resolution.capabilities,
-    ),
-  )
+const capabilities = (input: Input, resolution: ProviderResolution) => {
+  const base: CapabilitiesInput = {
+    input: {
+      text: input.model.capabilities.input.text,
+      image: input.model.capabilities.input.image,
+      audio: input.model.capabilities.input.audio,
+      video: input.model.capabilities.input.video,
+      pdf: input.model.capabilities.input.pdf,
+    },
+    output: {
+      text: input.model.capabilities.output.text,
+      reasoning: input.model.capabilities.reasoning,
+    },
+    tools: {
+      calls: input.model.capabilities.toolcall,
+      streamingInput: resolution.protocol !== "gemini" && input.model.capabilities.toolcall,
+    },
+    cache: {
+      // Both Anthropic Messages and Bedrock Converse honour positional cache
+      // markers — Anthropic via `cache_control` on content blocks, Bedrock via
+      // its `cachePoint` marker block (added to BedrockConverse in 9d7d518ac).
+      prompt: ["anthropic-messages", "bedrock-converse"].includes(resolution.protocol),
+      contentBlocks: ["anthropic-messages", "bedrock-converse"].includes(resolution.protocol),
+    },
+    reasoning: {
+      efforts: reasoningEfforts(input),
+      summaries: resolution.protocol === "openai-responses",
+      encryptedContent: resolution.protocol === "openai-responses" || resolution.protocol === "anthropic-messages",
+    },
+  }
+  return LLM.capabilities(resolution.capabilities ? mergeCapabilities(base, resolution.capabilities) : base)
+}
 
 export const toModelRef = (input: Input): ModelRef | undefined => {
   const options = { ...input.provider.options, ...input.model.options }