feat(provider): add FastRouter as an AI provider

packages/app/src/hooks/use-providers.ts

@@ -4,7 +4,16 @@ import { useParams } from "@solidjs/router"
 import { createMemo } from "solid-js"
 
 // kilocode_change start - Preferred providers list (order determines display priority)
-export const popularProviders = ["kilo", "anthropic", "github-copilot", "openai", "google", "openrouter", "vercel"]
+export const popularProviders = [
+  "kilo",
+  "anthropic",
+  "github-copilot",
+  "openai",
+  "google",
+  "openrouter",
+  "fastrouter",
+  "vercel",
+]
 // kilocode_change end
 const popularProviderSet = new Set(popularProviders)
 

packages/kilo-docs/lib/nav/ai-providers.ts

@@ -28,6 +28,7 @@ export const AiProvidersNav: NavSection[] = [
     title: "AI Gateways",
     links: [
       { href: "/ai-providers/openrouter", children: "OpenRouter" },
+      { href: "/ai-providers/fastrouter", children: "FastRouter" },
       { href: "/ai-providers/glama", children: "Glama" },
       { href: "/ai-providers/requesty", children: "Requesty" },
       { href: "/ai-providers/unbound", children: "Unbound" },

packages/kilo-docs/lychee.toml

@@ -34,6 +34,7 @@ exclude = [
   '^https?://vercel\.link/',
   # API base URL, returns 404 when fetched directly
   '^https?://api\.apertis\.ai/v1/?$',
+  '^https?://go\.fastrouter\.ai/api/v1/?$',
   # Redirects to authenticated Google Cloud console
   '^https?://console\.cloud\.google\.com',
   # Consistently times out in CI

packages/kilo-docs/pages/ai-providers/fastrouter.md

@@ -0,0 +1,50 @@
+---
+sidebar_label: FastRouter
+---
+
+# Using FastRouter With Kilo Code
+
+FastRouter is an LLM gateway that provides access to 150+ language models from providers like Anthropic, OpenAI, Google, and more — all through a single OpenAI-compatible API. It adds smart routing, observability, cost tracking, and fallback handling on top of the underlying providers.
+
+**Website:** [https://fastrouter.ai/](https://fastrouter.ai/)
+
+## Getting an API Key
+
+1.  **Sign Up/Sign In:** Go to the [FastRouter website](https://fastrouter.ai/) and create an account.
+2.  **Get an API Key:** Navigate to your dashboard and generate a new API key.
+3.  **Copy the Key:** Copy the displayed API key.
+
+## Supported Models
+
+Kilo Code automatically fetches the full list of available models from the FastRouter API. FastRouter provides access to models from:
+
+- **Anthropic:** Claude 4, Claude 3.5 Sonnet, Claude Haiku, and more
+- **OpenAI:** GPT-4o, GPT-4.1, o3, o4-mini, and more
+- **Google:** Gemini 2.5 Pro, Gemini 2.5 Flash, and more
+- **Meta, Mistral, DeepSeek, and many other open-source and proprietary models**
+
+Refer to the [FastRouter models page](https://go.fastrouter.ai/api/v1/models) for the full up-to-date list.
+
+## Configuration in Kilo Code
+
+1.  **Open Kilo Code Settings:** Click the gear icon ({% codicon name="gear" /%}) in the Kilo Code panel.
+2.  **Select Provider:** Choose "FastRouter" from the "API Provider" dropdown.
+3.  **Enter API Key:** Paste your FastRouter API key into the "FastRouter API Key" field.
+4.  **Select Model:** Choose your desired model from the "Model" dropdown. Models are grouped by the underlying provider.
+
+Alternatively, set the `FASTROUTER_API_KEY` environment variable before launching Kilo Code and the provider will be configured automatically.
+
+## Smart Routing
+
+FastRouter routes each request to the best available inference backend based on availability, latency, and cost. This means:
+
+- **Automatic failover** — if one backend is down, FastRouter retries on another
+- **Lower latency** — requests are routed to the fastest available provider for the chosen model
+- **Cost optimization** — routing can be tuned to prefer lower-cost backends
+
+## Tips and Notes
+
+- **Model IDs:** FastRouter uses the format `provider/model-name` (e.g., `anthropic/claude-haiku-4.5`, `openai/gpt-4o`), the same convention as OpenRouter.
+- **Pricing:** Pricing follows the underlying model's cost. See the [FastRouter documentation](https://docs.fastrouter.ai) for details.
+- **Multimodal support:** Many FastRouter models support image, audio, and video inputs in addition to text. Model capabilities are detected automatically.
+- **Streaming:** FastRouter fully supports streaming responses, which Kilo Code uses by default.

packages/kilo-docs/pages/ai-providers/index.md

@@ -38,6 +38,7 @@ Run models on your own hardware for privacy and offline use:
 Route requests through unified APIs with additional features:
 
 - **[OpenRouter](/docs/ai-providers/openrouter)** - Access multiple providers through one API
+- **[FastRouter](/docs/ai-providers/fastrouter)** - LLM gateway with smart routing and observability
 - **[Glama](/docs/ai-providers/glama)** - Enterprise AI gateway
 - **[Requesty](/docs/ai-providers/requesty)** - Smart routing and fallbacks
 

packages/kilo-docs/source-links.md

@@ -1,7 +1,7 @@
 # Source Code Links
 
 <!-- Auto-generated by script/extract-source-links.ts — DO NOT EDIT -->
-<!-- 77 unique URLs extracted from extension and CLI source -->
+<!-- 79 unique URLs extracted from extension and CLI source -->
 
 - <https://api.apertis.ai/v1>
   <!-- packages/opencode/src/provider/model-cache.ts -->
@@ -65,6 +65,10 @@
   <!-- packages/opencode/src/server/server.ts -->
 - <https://gitlab.com>
   <!-- packages/opencode/src/provider/provider.ts -->
+- <https://go.fastrouter.ai/api/v1/>
+  <!-- packages/opencode/src/provider/models.ts -->
+- <https://go.fastrouter.ai/api/v1/models>
+  <!-- packages/opencode/src/provider/model-cache.ts -->
 - <https://julialang.org/downloads/>
   <!-- packages/opencode/src/lsp/server.ts -->
 - <https://kilo.ai>

packages/opencode/src/kilocode/cli/cmd/tui/component/dialog-provider.tsx

@@ -21,6 +21,8 @@ export const PROVIDER_PRIORITY: Record<string, number> = {
   "github-copilot": 1,
   openai: 2,
   google: 3,
+  openrouter: 4,
+  fastrouter: 5,
 }
 
 // ---------------------------------------------------------------------------

packages/opencode/src/kilocode/provider/provider.ts

@@ -111,6 +111,24 @@ export function kiloCustomLoaders(dep: CustomDep): Record<string, CustomLoader>
         options: {},
       }),
 
+    fastrouter: Effect.fnUntraced(function* (input: any) {
+      const env = Env.all()
+      const apiKey = yield* Effect.gen(function* () {
+        const envKey = input.env.map((e: string) => env[e]).find(Boolean)
+        if (envKey) return envKey
+        const auth = yield* dep.auth(input.id)
+        if (auth?.type === "api") return auth.key
+        return (yield* dep.config()).provider?.["fastrouter"]?.options?.apiKey
+      })
+      return {
+        autoload: !!apiKey && Object.keys(input.models).length > 0,
+        options: {
+          ...(apiKey ? { apiKey } : {}),
+          headers: DEFAULT_HEADERS,
+        },
+      }
+    }),
+
     kilo: Effect.fnUntraced(function* (input: any) {
       const env = Env.all()
       const hasKey = yield* Effect.gen(function* () {
@@ -182,6 +200,7 @@ export function patchCustomLoaderResult(providerID: string, result: { options?:
       break
     }
     case "openrouter":
+    case "fastrouter":
     case "vercel":
     case "zenmux":
       result.options.headers = { ...result.options.headers, ...DEFAULT_HEADERS }

packages/opencode/src/provider/model-cache.ts

@@ -168,6 +168,9 @@ export namespace ModelCache {
     if (providerID === "apertis") {
       return fetchApertisModels(options)
     }
+    if (providerID === "fastrouter") {
+      return fetchFastRouterModels()
+    }
     // kilocode_change end
 
     // Other providers not implemented yet
@@ -225,6 +228,52 @@ export namespace ModelCache {
 
     return models
   }
+
+  async function fetchFastRouterModels(): Promise<Record<string, any>> {
+    const resp = await globalThis
+      .fetch("https://go.fastrouter.ai/api/v1/models", {
+        signal: AbortSignal.timeout(10 * 1000),
+      })
+      .catch((err) => {
+        log.error("fastrouter models fetch failed", { err })
+        return undefined
+      })
+    if (!resp) return {}
+    if (!resp.ok) {
+      log.error("fastrouter models fetch failed", { status: resp.status })
+      return {}
+    }
+    const data = await resp.json()
+    const models: Record<string, any> = {}
+    for (const m of data.data ?? []) {
+      if (!m.id) continue
+      const modality: string = m.architecture?.modality ?? "text->text"
+      const [rawInput = "text", rawOutput = "text"] = modality.split("->")
+      const allowed = ["text", "image", "audio", "video", "pdf"]
+      const inputs = rawInput.split("+").filter((p: string) => allowed.includes(p))
+      const outputs = rawOutput.split("+").filter((p: string) => allowed.includes(p))
+      models[m.id] = {
+        id: m.id,
+        name: m.name || m.id,
+        release_date: "",
+        attachment: inputs.includes("image"),
+        reasoning: false,
+        temperature: true,
+        tool_call: true,
+        cost: {
+          input: parseFloat(m.pricing?.prompt || "0") * 1_000_000,
+          output: parseFloat(m.pricing?.completion || "0") * 1_000_000,
+        },
+        limit: {
+          context: m.context_length || 128_000,
+          output: m.max_completion_tokens || 16_384,
+        },
+        modalities: { input: inputs, output: outputs },
+        options: {},
+      }
+    }
+    return models
+  }
   // kilocode_change end
 
   /**

packages/opencode/src/provider/models.ts

@@ -253,6 +253,29 @@ export namespace ModelsDev {
       }
     }
 
+    // kilocode_change start
+    const frAllowed = (!enabled || enabled.has("fastrouter")) && !disabled.has("fastrouter")
+    if (frAllowed) {
+      const priorFr = providers["fastrouter"]
+      const snapshotModels = priorFr?.models && Object.keys(priorFr.models).length > 0 ? priorFr.models : {}
+      let frModels = await ModelCache.fetch("fastrouter").catch(() => ({}))
+      if (Object.keys(frModels).length === 0) {
+        frModels = await ModelCache.refresh("fastrouter").catch(() => ({}))
+      }
+      const frModelsFinal = Object.keys(frModels).length > 0 ? frModels : snapshotModels
+      providers["fastrouter"] = {
+        id: "fastrouter",
+        name: "FastRouter",
+        env: ["FASTROUTER_API_KEY"],
+        api: "https://go.fastrouter.ai/api/v1/",
+        npm: "@openrouter/ai-sdk-provider",
+        models: frModelsFinal,
+      }
+    } else if (providers["fastrouter"]) {
+      delete providers["fastrouter"]
+    }
+    // kilocode_change end
+
     return providers
     // kilocode_change end
   }

packages/opencode/src/provider/transform.ts

@@ -921,14 +921,18 @@ export namespace ProviderTransform {
       }
       return { thinkingConfig: { thinkingBudget: 0 } }
     }
-    if (model.providerID === "openrouter" || model.api.npm === "@kilocode/kilo-gateway") {
-      // kilocode_change - add Kilo Gateway support
+    // kilocode_change start
+    if (
+      model.providerID === "openrouter" ||
+      model.providerID === "fastrouter" ||
+      model.api.npm === "@kilocode/kilo-gateway"
+    ) {
       if (model.api.id.includes("google")) {
         return { reasoning: { enabled: false } }
       }
-      // Other models use reasoningEffort (AI SDK format)
       return { reasoningEffort: "minimal" }
     }
+    // kilocode_change end
 
     if (model.providerID === "venice") {
       return { veniceParameters: { disableThinking: true } }