📝 Add docstrings to feat/api-key-support

Docstrings generation was requested by @ZiuChen.

* #144 (comment)

The following files were modified:

* `src/lib/api-key-auth.ts`
* `src/start.ts`

Author: coderabbitai[bot]

src/lib/api-key-auth.ts

@@ -0,0 +1,68 @@
+import type { Context, MiddlewareHandler } from "hono"
+
+import { HTTPException } from "hono/http-exception"
+
+import { state } from "./state"
+
+/**
+ * Retrieve an API key from the incoming request.
+ *
+ * Checks common locations where clients supply keys (Authorization Bearer header, `x-api-key` header, or `apiKey` query parameter) and returns the first one found.
+ *
+ * @returns The extracted API key, or `undefined` if no key is present.
+ */
+function extractApiKey(c: Context): string | undefined {
+  // OpenAI format: Authorization header with Bearer prefix
+  const authHeader = c.req.header("authorization")
+  if (authHeader?.startsWith("Bearer ")) {
+    return authHeader.slice(7) // Remove 'Bearer ' prefix
+  }
+
+  // Anthropic format: x-api-key header
+  const anthropicKey = c.req.header("x-api-key")
+  if (anthropicKey) {
+    return anthropicKey
+  }
+
+  // Fallback: query parameter, for extra compatibility of `/usage` or `/token` route
+  const queryKey = c.req.query("apiKey")
+  if (queryKey) {
+    return queryKey
+  }
+
+  return undefined
+}
+
+/**
+ * API key authentication middleware
+ * Validates that the request contains a valid API key if API keys are configured
+ */
+export const apiKeyAuthMiddleware: MiddlewareHandler = async (c, next) => {
+  // If no API keys are configured, skip authentication
+  if (!state.apiKeys || state.apiKeys.length === 0) {
+    await next()
+    return
+  }
+
+  const providedKey = extractApiKey(c)
+
+  // If no API key is provided, return 401
+  if (!providedKey) {
+    throw new HTTPException(401, {
+      message:
+        "API key required. Please provide a valid API key in the Authorization header (Bearer token) or x-api-key header.",
+    })
+  }
+
+  // Check if the provided key matches any of the configured keys
+  const isValidKey = state.apiKeys.includes(providedKey)
+
+  if (!isValidKey) {
+    throw new HTTPException(401, {
+      message: "Invalid API key. Please provide a valid API key.",
+    })
+  }
+
+  // Key is valid, continue with the request
+  await next()
+}

src/start.ts

@@ -25,8 +25,30 @@ interface RunServerOptions {
   claudeCode: boolean
   showToken: boolean
   proxyEnv: boolean
+  apiKeys?: Array<string>
 }
 
+/**
+ * Start and configure the Copilot API server according to the provided options.
+ *
+ * Configures proxy and logging, initializes global state and credentials, ensures
+ * required paths and model data are cached, optionally generates a Claude Code
+ * launch command (and attempts to copy it to the clipboard), prints a usage
+ * viewer URL, and begins serving HTTP requests on the specified port.
+ *
+ * @param options - Server startup options:
+ *   - port: Port number to listen on
+ *   - verbose: Enable verbose logging
+ *   - accountType: Account plan to use ("individual", "business", "enterprise")
+ *   - manual: Require manual approval for requests
+ *   - rateLimit: Seconds to wait between requests (optional)
+ *   - rateLimitWait: Wait instead of erroring when rate limit is hit
+ *   - githubToken: GitHub token to use (optional; if omitted a token setup prompt may run)
+ *   - claudeCode: Generate a Claude Code environment launch command
+ *   - showToken: Expose GitHub/Copilot tokens in responses for debugging
+ *   - proxyEnv: Initialize proxy settings from environment variables
+ *   - apiKeys: Optional list of API keys to enable API key authentication
+ */
 export async function runServer(options: RunServerOptions): Promise<void> {
   if (options.proxyEnv) {
     initProxyFromEnv()
@@ -46,6 +68,13 @@ export async function runServer(options: RunServerOptions): Promise<void> {
   state.rateLimitSeconds = options.rateLimit
   state.rateLimitWait = options.rateLimitWait
   state.showToken = options.showToken
+  state.apiKeys = options.apiKeys
+
+  if (state.apiKeys && state.apiKeys.length > 0) {
+    consola.info(
+      `API key authentication enabled with ${state.apiKeys.length} key(s)`,
+    )
+  }
 
   await ensurePaths()
   await cacheVSCodeVersion()
@@ -184,13 +213,24 @@ export const start = defineCommand({
       default: false,
       description: "Initialize proxy from environment variables",
     },
+    "api-key": {
+      type: "string",
+      description: "API keys for authentication",
+    },
   },
   run({ args }) {
     const rateLimitRaw = args["rate-limit"]
     const rateLimit =
       // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
       rateLimitRaw === undefined ? undefined : Number.parseInt(rateLimitRaw, 10)
 
+    // Handle multiple API keys - citty may pass a string or array
+    const apiKeyRaw = args["api-key"]
+    let apiKeys: Array<string> | undefined
+    if (apiKeyRaw) {
+      apiKeys = Array.isArray(apiKeyRaw) ? apiKeyRaw : [apiKeyRaw]
+    }
+
     return runServer({
       port: Number.parseInt(args.port, 10),
       verbose: args.verbose,
@@ -202,6 +242,7 @@ export const start = defineCommand({
       claudeCode: args["claude-code"],
       showToken: args["show-token"],
       proxyEnv: args["proxy-env"],
+      apiKeys,
     })
   },
-})
+})