🖼️ refactor: Enhance Env Extraction & Agent Image Handling (#6131)

* refactor: use new image output format for agents using DALL-E tools

* refactor: Enhance image fetching with proxy support and adjust logging placement in DALL-E 3 integration

* refactor: Enhance StableDiffusionAPI to support agent-specific return values and display message for generated images

* refactor: Add unit test execution for librechat-mcp in backend review workflow

* refactor: Update environment variable extraction logic, export from serpate module to avoid circular refs, and remove deprecated tests

* refactor: Add unit tests for environment variable extraction and enhance StdioOptionsSchema to process env variables

packages/data-provider/src/azure.ts

@@ -6,8 +6,9 @@ import type {
   TValidatedAzureConfig,
   TAzureConfigValidationResult,
 } from '../src/config';
-import { errorsToString, extractEnvVariable, envVarRegex } from '../src/parsers';
+import { extractEnvVariable, envVarRegex } from '../src/utils';
 import { azureGroupConfigsSchema } from '../src/config';
+import { errorsToString } from '../src/parsers';
 
 export const deprecatedAzureVariables = [
   /* "related to" precedes description text */

packages/data-provider/src/index.ts

@@ -31,5 +31,6 @@ export { default as request } from './request';
 export { dataService };
 import * as dataService from './data-service';
 /* general helpers */
+export * from './utils';
 export * from './actions';
 export { default as createPayload } from './createPayload';

packages/data-provider/src/mcp.ts

@@ -1,4 +1,5 @@
 import { z } from 'zod';
+import { extractEnvVariable } from './utils';
 
 const BaseOptionsSchema = z.object({
   iconPath: z.string().optional(),
@@ -18,8 +19,22 @@ export const StdioOptionsSchema = BaseOptionsSchema.extend({
    * The environment to use when spawning the process.
    *
    * If not specified, the result of getDefaultEnvironment() will be used.
+   * Environment variables can be referenced using ${VAR_NAME} syntax.
    */
-  env: z.record(z.string(), z.string()).optional(),
+  env: z
+    .record(z.string(), z.string())
+    .optional()
+    .transform((env) => {
+      if (!env) {
+        return env;
+      }
+
+      const processedEnv: Record<string, string> = {};
+      for (const [key, value] of Object.entries(env)) {
+        processedEnv[key] = extractEnvVariable(value);
+      }
+      return processedEnv;
+    }),
   /**
    * How to handle stderr of the child process. This matches the semantics of Node's `child_process.spawn`.
    *

packages/data-provider/src/parsers.ts

@@ -19,6 +19,7 @@ import {
   compactAssistantSchema,
 } from './schemas';
 import { bedrockInputSchema } from './bedrock';
+import { extractEnvVariable } from './utils';
 import { alternateName } from './config';
 
 type EndpointSchema =
@@ -122,17 +123,6 @@ export function errorsToString(errors: ZodIssue[]) {
     .join(' ');
 }
 
-export const envVarRegex = /^\${(.+)}$/;
-
-/** Extracts the value of an environment variable from a string. */
-export function extractEnvVariable(value: string) {
-  const envVarMatch = value.match(envVarRegex);
-  if (envVarMatch) {
-    return process.env[envVarMatch[1]] || value;
-  }
-  return value;
-}
-
 /** Resolves header values to env variables if detected */
 export function resolveHeaders(headers: Record<string, string> | undefined) {
   const resolvedHeaders = { ...(headers ?? {}) };

packages/data-provider/src/utils.ts

@@ -0,0 +1,44 @@
+export const envVarRegex = /^\${(.+)}$/;
+
+/** Extracts the value of an environment variable from a string. */
+export function extractEnvVariable(value: string) {
+  if (!value) {
+    return value;
+  }
+
+  // Trim the input
+  const trimmed = value.trim();
+
+  // Special case: if it's just a single environment variable
+  const singleMatch = trimmed.match(envVarRegex);
+  if (singleMatch) {
+    const varName = singleMatch[1];
+    return process.env[varName] || trimmed;
+  }
+
+  // For multiple variables, process them using a regex loop
+  const regex = /\${([^}]+)}/g;
+  let result = trimmed;
+
+  // First collect all matches and their positions
+  const matches = [];
+  let match;
+  while ((match = regex.exec(trimmed)) !== null) {
+    matches.push({
+      fullMatch: match[0],
+      varName: match[1],
+      index: match.index,
+    });
+  }
+
+  // Process matches in reverse order to avoid position shifts
+  for (let i = matches.length - 1; i >= 0; i--) {
+    const { fullMatch, varName, index } = matches[i];
+    const envValue = process.env[varName] || fullMatch;
+
+    // Replace at exact position
+    result = result.substring(0, index) + envValue + result.substring(index + fullMatch.length);
+  }
+
+  return result;
+}