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An OpenRouter provider integration that provides type-safe, Effect-based access to multiple AI models through OpenRouter’s unified API.

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Installation

pnpm add @effect/ai-openrouter effect

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Overview

OpenRouter provides access to multiple AI models from different providers (OpenAI, Anthropic, Google, Meta, and more) through a single unified API. This package makes it easy to use any OpenRouter-supported model with Effect.

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Setup

Create an OpenRouter client by providing your API key: 
import { OpenRouterClient } from "@effect/ai-openrouter"
import { Effect, Layer, Redacted } from "effect"

const OpenRouterLive = OpenRouterClient.layer({
  apiKey: Redacted.make(process.env.OPENROUTER_API_KEY!)
})

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Language Model

Use any OpenRouter-supported model: 
import { OpenRouterLanguageModel } from "@effect/ai-openrouter"
import { Effect } from "effect"
import { LanguageModel } from "effect/unstable/ai"

const program = Effect.gen(function*() {
  const result = yield* LanguageModel.generate({
    prompt: "Explain the concept of immutability"
  })
  console.log(result)
}).pipe(
  Effect.provide(OpenRouterLanguageModel.model("anthropic/claude-3.5-sonnet")),
  Effect.provide(OpenRouterLive)
)

Effect.runPromise(program)

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Available Models

OpenRouter supports models from multiple providers: 
// Anthropic models
OpenRouterLanguageModel.model("anthropic/claude-3.5-sonnet")
OpenRouterLanguageModel.model("anthropic/claude-3-opus")

// OpenAI models
OpenRouterLanguageModel.model("openai/gpt-4o")
OpenRouterLanguageModel.model("openai/gpt-4-turbo")

// Google models
OpenRouterLanguageModel.model("google/gemini-pro")

// Meta models
OpenRouterLanguageModel.model("meta-llama/llama-3.1-70b-instruct")

// And many more...

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Streaming Responses

Stream responses for real-time text generation: 
import { OpenRouterLanguageModel } from "@effect/ai-openrouter"
import { Effect, Stream } from "effect"
import { LanguageModel } from "effect/unstable/ai"

const program = Effect.gen(function*() {
  const stream = yield* LanguageModel.streamText({
    prompt: "Write a haiku about functional programming"
  })
  
  yield* Stream.runForEach(stream, (chunk) =>
    Effect.sync(() => process.stdout.write(chunk.text))
  )
}).pipe(
  Effect.provide(OpenRouterLanguageModel.model("anthropic/claude-3.5-sonnet")),
  Effect.provide(OpenRouterLive)
)

Effect.runPromise(program)

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Tool Calling

Use tools with OpenRouter models that support function calling: 
import { OpenRouterLanguageModel } from "@effect/ai-openrouter"
import { Effect, Schema } from "effect"
import { LanguageModel, Tool, Toolkit } from "effect/unstable/ai"

const CalculatorTool = Tool.make("Calculator", {
  description: "Perform basic arithmetic operations",
  parameters: Schema.Struct({
    operation: Schema.Literal("add", "subtract", "multiply", "divide"),
    a: Schema.Number,
    b: Schema.Number
  }),
  success: Schema.Number
})

const program = Effect.gen(function*() {
  const toolkit = Toolkit.make(CalculatorTool)
  const toolkitLayer = toolkit.toLayer({
    Calculator: ({ operation, a, b }) => {
      switch (operation) {
        case "add": return Effect.succeed(a + b)
        case "subtract": return Effect.succeed(a - b)
        case "multiply": return Effect.succeed(a * b)
        case "divide": return Effect.succeed(a / b)
      }
    }
  })
  
  const result = yield* LanguageModel.generate({
    prompt: "What is 42 multiplied by 7?",
    toolkit
  })
  
  console.log(result)
}).pipe(
  Effect.provide(OpenRouterLanguageModel.model("openai/gpt-4o")),
  Effect.provide(toolkitLayer),
  Effect.provide(OpenRouterLive)
)

Effect.runPromise(program)

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Configuration

Customize the OpenRouter client: 
import { OpenRouterClient, OpenRouterConfig } from "@effect/ai-openrouter"
import { Redacted } from "effect"

const config: OpenRouterConfig.Config = {
  apiKey: Redacted.make(process.env.OPENROUTER_API_KEY!),
  baseUrl: "https://openrouter.ai/api/v1", // Optional: custom base URL
  siteUrl: "https://myapp.com", // Optional: for rankings
  siteName: "My App" // Optional: for rankings
}

const OpenRouterLive = OpenRouterClient.layer(config)

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Error Handling

Handle OpenRouter-specific errors: 
import { OpenRouterError } from "@effect/ai-openrouter"
import { Effect } from "effect"

const program = Effect.gen(function*() {
  // Your OpenRouter API calls
}).pipe(
  Effect.catchTag("HttpClientError", (error) =>
    Effect.sync(() => {
      console.error("OpenRouter API error:", error)
      // Handle rate limits, invalid models, etc.
    })
  )
)

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Model Pricing and Selection

OpenRouter provides access to models at different price points. Visit OpenRouter’s model page to compare models, pricing, and capabilities. 
// Cost-effective models
OpenRouterLanguageModel.model("meta-llama/llama-3.1-8b-instruct") // Free
OpenRouterLanguageModel.model("google/gemini-flash-1.5") // Low cost

// High-performance models
OpenRouterLanguageModel.model("anthropic/claude-3.5-sonnet") // Premium
OpenRouterLanguageModel.model("openai/gpt-4o") // Premium

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API Modules

  • OpenRouterClient: HTTP client for OpenRouter API
  • OpenRouterConfig: Configuration options
  • OpenRouterError: Error type augmentation
  • OpenRouterLanguageModel: Language model implementation

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Benefits of OpenRouter

  • Unified API: Access multiple AI providers through a single interface
  • Cost Optimization: Choose the most cost-effective model for your use case
  • Fallback Support: Automatically fall back to alternative models if one is unavailable
  • No Rate Limits: OpenRouter handles rate limiting across providers
  • Pay As You Go: Only pay for what you use, no monthly subscriptions

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