import { existsSync } from "node:fs"; import { homedir } from "node:os"; import { join } from "node:path"; import { supportsXhigh } from "./models.js"; import { type BedrockOptions, streamBedrock } from "./providers/amazon-bedrock.js"; import { type AnthropicOptions, streamAnthropic } from "./providers/anthropic.js"; import { type GoogleOptions, streamGoogle } from "./providers/google.js"; import { type GoogleGeminiCliOptions, type GoogleThinkingLevel, streamGoogleGeminiCli, } from "./providers/google-gemini-cli.js"; import { type GoogleVertexOptions, streamGoogleVertex } from "./providers/google-vertex.js"; import { type OpenAICodexResponsesOptions, streamOpenAICodexResponses } from "./providers/openai-codex-responses.js"; import { type OpenAICompletionsOptions, streamOpenAICompletions } from "./providers/openai-completions.js"; import { type OpenAIResponsesOptions, streamOpenAIResponses } from "./providers/openai-responses.js"; import type { Api, AssistantMessage, AssistantMessageEventStream, Context, KnownProvider, Model, OptionsForApi, SimpleStreamOptions, ThinkingBudgets, ThinkingLevel, } from "./types.js"; let cachedVertexAdcCredentialsExists: boolean | null = null; function hasVertexAdcCredentials(): boolean { if (cachedVertexAdcCredentialsExists === null) { // Check GOOGLE_APPLICATION_CREDENTIALS env var first (standard way) const gacPath = process.env.GOOGLE_APPLICATION_CREDENTIALS; if (gacPath) { cachedVertexAdcCredentialsExists = existsSync(gacPath); } else { // Fall back to default ADC path (lazy evaluation) cachedVertexAdcCredentialsExists = existsSync( join(homedir(), ".config", "gcloud", "application_default_credentials.json"), ); } } return cachedVertexAdcCredentialsExists; } /** * Get API key for provider from known environment variables, e.g. OPENAI_API_KEY. * * Will not return API keys for providers that require OAuth tokens. */ export function getEnvApiKey(provider: KnownProvider): string | undefined; export function getEnvApiKey(provider: string): string | undefined; export function getEnvApiKey(provider: any): string | undefined { // Fall back to environment variables if (provider === "github-copilot") { return process.env.COPILOT_GITHUB_TOKEN || process.env.GH_TOKEN || process.env.GITHUB_TOKEN; } // ANTHROPIC_OAUTH_TOKEN takes precedence over ANTHROPIC_API_KEY if (provider === "anthropic") { return process.env.ANTHROPIC_OAUTH_TOKEN || process.env.ANTHROPIC_API_KEY; } // Vertex AI uses Application Default Credentials, not API keys. // Auth is configured via `gcloud auth application-default login`. if (provider === "google-vertex") { const hasCredentials = hasVertexAdcCredentials(); const hasProject = !!(process.env.GOOGLE_CLOUD_PROJECT || process.env.GCLOUD_PROJECT); const hasLocation = !!process.env.GOOGLE_CLOUD_LOCATION; if (hasCredentials && hasProject && hasLocation) { return ""; } } if (provider === "amazon-bedrock") { // Amazon Bedrock supports multiple credential sources: // 1. AWS_PROFILE - named profile from ~/.aws/credentials // 2. AWS_ACCESS_KEY_ID + AWS_SECRET_ACCESS_KEY - standard IAM keys // 3. AWS_BEARER_TOKEN_BEDROCK - Bedrock API keys (bearer token) // 4. AWS_CONTAINER_CREDENTIALS_RELATIVE_URI - ECS task roles // 5. AWS_CONTAINER_CREDENTIALS_FULL_URI - ECS task roles (full URI) // 6. AWS_WEB_IDENTITY_TOKEN_FILE - IRSA (IAM Roles for Service Accounts) if ( process.env.AWS_PROFILE || (process.env.AWS_ACCESS_KEY_ID && process.env.AWS_SECRET_ACCESS_KEY) || process.env.AWS_BEARER_TOKEN_BEDROCK || process.env.AWS_CONTAINER_CREDENTIALS_RELATIVE_URI || process.env.AWS_CONTAINER_CREDENTIALS_FULL_URI || process.env.AWS_WEB_IDENTITY_TOKEN_FILE ) { return ""; } } const envMap: Record = { openai: "OPENAI_API_KEY", google: "GEMINI_API_KEY", groq: "GROQ_API_KEY", cerebras: "CEREBRAS_API_KEY", xai: "XAI_API_KEY", openrouter: "OPENROUTER_API_KEY", "vercel-ai-gateway": "AI_GATEWAY_API_KEY", zai: "ZAI_API_KEY", mistral: "MISTRAL_API_KEY", minimax: "MINIMAX_API_KEY", "minimax-cn": "MINIMAX_CN_API_KEY", opencode: "OPENCODE_API_KEY", }; const envVar = envMap[provider]; return envVar ? process.env[envVar] : undefined; } export function stream( model: Model, context: Context, options?: OptionsForApi, ): AssistantMessageEventStream { // Vertex AI uses Application Default Credentials, not API keys if (model.api === "google-vertex") { return streamGoogleVertex(model as Model<"google-vertex">, context, options as GoogleVertexOptions); } else if (model.api === "bedrock-converse-stream") { // Bedrock doesn't have any API keys instead it sources credentials from standard AWS env variables or from given AWS profile. return streamBedrock(model as Model<"bedrock-converse-stream">, context, (options || {}) as BedrockOptions); } const apiKey = options?.apiKey || getEnvApiKey(model.provider); if (!apiKey) { throw new Error(`No API key for provider: ${model.provider}`); } const providerOptions = { ...options, apiKey }; const api: Api = model.api; switch (api) { case "anthropic-messages": return streamAnthropic(model as Model<"anthropic-messages">, context, providerOptions); case "openai-completions": return streamOpenAICompletions(model as Model<"openai-completions">, context, providerOptions as any); case "openai-responses": return streamOpenAIResponses(model as Model<"openai-responses">, context, providerOptions as any); case "openai-codex-responses": return streamOpenAICodexResponses(model as Model<"openai-codex-responses">, context, providerOptions as any); case "google-generative-ai": return streamGoogle(model as Model<"google-generative-ai">, context, providerOptions); case "google-gemini-cli": return streamGoogleGeminiCli( model as Model<"google-gemini-cli">, context, providerOptions as GoogleGeminiCliOptions, ); default: { // This should never be reached if all Api cases are handled const _exhaustive: never = api; throw new Error(`Unhandled API: ${_exhaustive}`); } } } export async function complete( model: Model, context: Context, options?: OptionsForApi, ): Promise { const s = stream(model, context, options); return s.result(); } export function streamSimple( model: Model, context: Context, options?: SimpleStreamOptions, ): AssistantMessageEventStream { // Vertex AI uses Application Default Credentials, not API keys if (model.api === "google-vertex") { const providerOptions = mapOptionsForApi(model, options, undefined); return stream(model, context, providerOptions); } else if (model.api === "bedrock-converse-stream") { // Bedrock doesn't have any API keys instead it sources credentials from standard AWS env variables or from given AWS profile. const providerOptions = mapOptionsForApi(model, options, undefined); return stream(model, context, providerOptions); } const apiKey = options?.apiKey || getEnvApiKey(model.provider); if (!apiKey) { throw new Error(`No API key for provider: ${model.provider}`); } const providerOptions = mapOptionsForApi(model, options, apiKey); return stream(model, context, providerOptions); } export async function completeSimple( model: Model, context: Context, options?: SimpleStreamOptions, ): Promise { const s = streamSimple(model, context, options); return s.result(); } function mapOptionsForApi( model: Model, options?: SimpleStreamOptions, apiKey?: string, ): OptionsForApi { const base = { temperature: options?.temperature, maxTokens: options?.maxTokens || Math.min(model.maxTokens, 32000), signal: options?.signal, apiKey: apiKey || options?.apiKey, sessionId: options?.sessionId, headers: options?.headers, onPayload: options?.onPayload, }; // Helper to clamp xhigh to high for providers that don't support it const clampReasoning = (effort: ThinkingLevel | undefined) => (effort === "xhigh" ? "high" : effort); /** * Adjust maxTokens to account for thinking budget. * APIs like Anthropic and Bedrock require max_tokens > thinking.budget_tokens. * Returns { adjustedMaxTokens, adjustedThinkingBudget } */ const adjustMaxTokensForThinking = ( baseMaxTokens: number, modelMaxTokens: number, reasoningLevel: ThinkingLevel, customBudgets?: ThinkingBudgets, ): { maxTokens: number; thinkingBudget: number } => { const defaultBudgets: ThinkingBudgets = { minimal: 1024, low: 2048, medium: 8192, high: 16384, }; const budgets = { ...defaultBudgets, ...customBudgets }; const minOutputTokens = 1024; const level = clampReasoning(reasoningLevel)!; let thinkingBudget = budgets[level]!; // Caller's maxTokens is the desired output; add thinking budget on top, capped at model limit const maxTokens = Math.min(baseMaxTokens + thinkingBudget, modelMaxTokens); // If not enough room for thinking + output, reduce thinking budget if (maxTokens <= thinkingBudget) { thinkingBudget = Math.max(0, maxTokens - minOutputTokens); } return { maxTokens, thinkingBudget }; }; switch (model.api) { case "anthropic-messages": { // Explicitly disable thinking when reasoning is not specified if (!options?.reasoning) { return { ...base, thinkingEnabled: false } satisfies AnthropicOptions; } // Claude requires max_tokens > thinking.budget_tokens // So we need to ensure maxTokens accounts for both thinking and output const adjusted = adjustMaxTokensForThinking( base.maxTokens || 0, model.maxTokens, options.reasoning, options?.thinkingBudgets, ); return { ...base, maxTokens: adjusted.maxTokens, thinkingEnabled: true, thinkingBudgetTokens: adjusted.thinkingBudget, } satisfies AnthropicOptions; } case "bedrock-converse-stream": { // Explicitly disable thinking when reasoning is not specified if (!options?.reasoning) { return { ...base, reasoning: undefined } satisfies BedrockOptions; } // Claude requires max_tokens > thinking.budget_tokens (same as Anthropic direct API) // So we need to ensure maxTokens accounts for both thinking and output if (model.id.includes("anthropic.claude") || model.id.includes("anthropic/claude")) { const adjusted = adjustMaxTokensForThinking( base.maxTokens || 0, model.maxTokens, options.reasoning, options?.thinkingBudgets, ); return { ...base, maxTokens: adjusted.maxTokens, reasoning: options.reasoning, thinkingBudgets: { ...(options?.thinkingBudgets || {}), [clampReasoning(options.reasoning)!]: adjusted.thinkingBudget, }, } satisfies BedrockOptions; } // Non-Claude models - pass through return { ...base, reasoning: options?.reasoning, thinkingBudgets: options?.thinkingBudgets, } satisfies BedrockOptions; } case "openai-completions": return { ...base, reasoningEffort: supportsXhigh(model) ? options?.reasoning : clampReasoning(options?.reasoning), } satisfies OpenAICompletionsOptions; case "openai-responses": return { ...base, reasoningEffort: supportsXhigh(model) ? options?.reasoning : clampReasoning(options?.reasoning), } satisfies OpenAIResponsesOptions; case "openai-codex-responses": return { ...base, reasoningEffort: supportsXhigh(model) ? options?.reasoning : clampReasoning(options?.reasoning), } satisfies OpenAICodexResponsesOptions; case "google-generative-ai": { // Explicitly disable thinking when reasoning is not specified // This is needed because Gemini has "dynamic thinking" enabled by default if (!options?.reasoning) { return { ...base, thinking: { enabled: false } } satisfies GoogleOptions; } const googleModel = model as Model<"google-generative-ai">; const effort = clampReasoning(options.reasoning)!; // Gemini 3 models use thinkingLevel exclusively instead of thinkingBudget. // https://ai.google.dev/gemini-api/docs/thinking#set-budget if (isGemini3ProModel(googleModel) || isGemini3FlashModel(googleModel)) { return { ...base, thinking: { enabled: true, level: getGemini3ThinkingLevel(effort, googleModel), }, } satisfies GoogleOptions; } return { ...base, thinking: { enabled: true, budgetTokens: getGoogleBudget(googleModel, effort, options?.thinkingBudgets), }, } satisfies GoogleOptions; } case "google-gemini-cli": { if (!options?.reasoning) { return { ...base, thinking: { enabled: false } } satisfies GoogleGeminiCliOptions; } const effort = clampReasoning(options.reasoning)!; // Gemini 3 models use thinkingLevel instead of thinkingBudget if (model.id.includes("3-pro") || model.id.includes("3-flash")) { return { ...base, thinking: { enabled: true, level: getGeminiCliThinkingLevel(effort, model.id), }, } satisfies GoogleGeminiCliOptions; } // Models using thinkingBudget (Gemini 2.x, Claude via Antigravity) // Claude requires max_tokens > thinking.budget_tokens // So we need to ensure maxTokens accounts for both thinking and output const defaultBudgets: ThinkingBudgets = { minimal: 1024, low: 2048, medium: 8192, high: 16384, }; const budgets = { ...defaultBudgets, ...options?.thinkingBudgets }; const minOutputTokens = 1024; let thinkingBudget = budgets[effort]!; // Caller's maxTokens is the desired output; add thinking budget on top, capped at model limit const maxTokens = Math.min((base.maxTokens || 0) + thinkingBudget, model.maxTokens); // If not enough room for thinking + output, reduce thinking budget if (maxTokens <= thinkingBudget) { thinkingBudget = Math.max(0, maxTokens - minOutputTokens); } return { ...base, maxTokens, thinking: { enabled: true, budgetTokens: thinkingBudget, }, } satisfies GoogleGeminiCliOptions; } case "google-vertex": { // Explicitly disable thinking when reasoning is not specified if (!options?.reasoning) { return { ...base, thinking: { enabled: false } } satisfies GoogleVertexOptions; } const vertexModel = model as Model<"google-vertex">; const effort = clampReasoning(options.reasoning)!; const geminiModel = vertexModel as unknown as Model<"google-generative-ai">; if (isGemini3ProModel(geminiModel) || isGemini3FlashModel(geminiModel)) { return { ...base, thinking: { enabled: true, level: getGemini3ThinkingLevel(effort, geminiModel), }, } satisfies GoogleVertexOptions; } return { ...base, thinking: { enabled: true, budgetTokens: getGoogleBudget(geminiModel, effort, options?.thinkingBudgets), }, } satisfies GoogleVertexOptions; } default: { // Exhaustiveness check const _exhaustive: never = model.api; throw new Error(`Unhandled API in mapOptionsForApi: ${_exhaustive}`); } } } type ClampedThinkingLevel = Exclude; function isGemini3ProModel(model: Model<"google-generative-ai">): boolean { // Covers gemini-3-pro, gemini-3-pro-preview, and possible other prefixed ids in the future return model.id.includes("3-pro"); } function isGemini3FlashModel(model: Model<"google-generative-ai">): boolean { // Covers gemini-3-flash, gemini-3-flash-preview, and possible other prefixed ids in the future return model.id.includes("3-flash"); } function getGemini3ThinkingLevel( effort: ClampedThinkingLevel, model: Model<"google-generative-ai">, ): GoogleThinkingLevel { if (isGemini3ProModel(model)) { // Gemini 3 Pro only supports LOW/HIGH (for now) switch (effort) { case "minimal": case "low": return "LOW"; case "medium": case "high": return "HIGH"; } } // Gemini 3 Flash supports all four levels switch (effort) { case "minimal": return "MINIMAL"; case "low": return "LOW"; case "medium": return "MEDIUM"; case "high": return "HIGH"; } } function getGeminiCliThinkingLevel(effort: ClampedThinkingLevel, modelId: string): GoogleThinkingLevel { if (modelId.includes("3-pro")) { // Gemini 3 Pro only supports LOW/HIGH (for now) switch (effort) { case "minimal": case "low": return "LOW"; case "medium": case "high": return "HIGH"; } } // Gemini 3 Flash supports all four levels switch (effort) { case "minimal": return "MINIMAL"; case "low": return "LOW"; case "medium": return "MEDIUM"; case "high": return "HIGH"; } } function getGoogleBudget( model: Model<"google-generative-ai">, effort: ClampedThinkingLevel, customBudgets?: ThinkingBudgets, ): number { // Custom budgets take precedence if provided for this level if (customBudgets?.[effort] !== undefined) { return customBudgets[effort]!; } // See https://ai.google.dev/gemini-api/docs/thinking#set-budget if (model.id.includes("2.5-pro")) { const budgets: Record = { minimal: 128, low: 2048, medium: 8192, high: 32768, }; return budgets[effort]; } if (model.id.includes("2.5-flash")) { // Covers 2.5-flash-lite as well const budgets: Record = { minimal: 128, low: 2048, medium: 8192, high: 24576, }; return budgets[effort]; } // Unknown model - use dynamic return -1; }

Summary

Summary