Require DwsApiClient via dependency injection, remove hidden fallbacks

Remove callNutrientApi legacy helper and inline axios fallbacks. All
perform* functions now require an explicit DwsApiClient parameter,
eliminating hidden coupling to environment variables and global state.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: tomassurin

src/dws/ai-redact.ts

@@ -5,7 +5,6 @@ import { CallToolResult } from '@modelcontextprotocol/sdk/types.js'
 import { handleApiError, handleFileResponse } from './utils.js'
 import { createErrorResponse } from '../responses.js'
 import { resolveReadFilePath, resolveWriteFilePath } from '../fs/sandbox.js'
-import { callNutrientApi } from './api.js'
 import { DwsApiClient } from './client.js'
 
 /**
@@ -15,9 +14,9 @@ export async function performAiRedactCall(
   filePath: string,
   criteria: string,
   outputPath: string,
+  apiClient: DwsApiClient,
   stage?: boolean,
   apply?: boolean,
-  apiClient?: DwsApiClient,
 ): Promise<CallToolResult> {
   // Resolve paths first to fail early
   try {
@@ -51,9 +50,7 @@ export async function performAiRedactCall(
     formData.append('file1', fileBuffer, { filename: fileName })
     formData.append('data', JSON.stringify(dataPayload))
 
-    const response = apiClient
-      ? await apiClient.post('ai/redact', formData)
-      : await callNutrientApi('ai/redact', formData)
+    const response = await apiClient.post('ai/redact', formData)
 
     return handleFileResponse(response, resolvedOutputPath, 'AI redaction completed successfully. Output saved to')
   } catch (e: unknown) {

src/dws/api.ts

@@ -1,6 +1,4 @@
-import FormData from 'form-data'
 import { DwsApiClient, createApiClientFromApiKey, createApiClientFromTokenResolver } from './client.js'
-import { getApiKey } from './utils.js'
 
 export type ApiClientAuthContext =
   | {
@@ -19,12 +17,3 @@ export function createApiClient(context: ApiClientAuthContext): DwsApiClient {
 
   return createApiClientFromTokenResolver(context.tokenResolver, context.baseUrl)
 }
-
-/**
- * Legacy helper retained for backwards compatibility with tests/imports.
- * Prefer using DwsApiClient directly.
- */
-export async function callNutrientApi(endpoint: string, data: FormData | Record<string, unknown>) {
-  const client = createApiClientFromApiKey(getApiKey())
-  return client.post(endpoint, data)
-}

src/dws/build.ts

@@ -7,7 +7,6 @@ import { CallToolResult } from '@modelcontextprotocol/sdk/types.js'
 import { FileReference } from './types.js'
 import { createErrorResponse } from '../responses.js'
 import { resolveReadFilePath, resolveWriteFilePath } from '../fs/sandbox.js'
-import { callNutrientApi } from './api.js'
 import { DwsApiClient } from './client.js'
 
 /**
@@ -16,7 +15,7 @@ import { DwsApiClient } from './client.js'
 export async function performBuildCall(
   instructions: Instructions,
   outputFilePath: string,
-  apiClient?: DwsApiClient,
+  apiClient: DwsApiClient,
 ): Promise<CallToolResult> {
   const { instructions: adjustedInstructions, fileReferences } = await processInstructions(instructions)
 
@@ -139,12 +138,12 @@ async function processFileReference(reference: string): Promise<FileReference> {
 async function makeApiBuildCall(
   instructions: Instructions,
   fileReferences: Map<string, FileReference>,
-  apiClient?: DwsApiClient,
+  apiClient: DwsApiClient,
 ) {
   const allInputsAreUrls = Array.from(fileReferences.values()).every((fileRef) => fileRef.url)
 
   if (allInputsAreUrls) {
-    return apiClient ? apiClient.post('build', instructions) : callNutrientApi('build', instructions)
+    return apiClient.post('build', instructions)
   } else {
     const formData = new FormData()
     formData.append('instructions', JSON.stringify(instructions))
@@ -155,6 +154,6 @@ async function makeApiBuildCall(
       }
     }
 
-    return apiClient ? apiClient.post('build', formData) : callNutrientApi('build', formData)
+    return apiClient.post('build', formData)
   }
 }

src/dws/credits.ts

@@ -1,6 +1,4 @@
-import axios from 'axios'
-import { getApiKey, pipeToString } from './utils.js'
-import { getVersion } from '../version.js'
+import { pipeToString } from './utils.js'
 import { CallToolResult } from '@modelcontextprotocol/sdk/types.js'
 import { DwsApiClient } from './client.js'
 
@@ -33,16 +31,8 @@ export function sanitizeAccountInfo(data: AccountInfoResponse): Omit<AccountInfo
 /**
  * Calls the DWS /account/info endpoint and returns credit information.
  */
-export async function performCheckCreditsCall(apiClient?: DwsApiClient): Promise<CallToolResult> {
-  const response = apiClient
-    ? await apiClient.get('account/info')
-    : await axios.get('https://api.nutrient.io/account/info', {
-        headers: {
-          Authorization: `Bearer ${getApiKey()}`,
-          'User-Agent': `NutrientDWSMCPServer/${getVersion()}`,
-        },
-        responseType: 'stream',
-      })
+export async function performCheckCreditsCall(apiClient: DwsApiClient): Promise<CallToolResult> {
+  const response = await apiClient.get('account/info')
 
   const raw = await pipeToString(response.data)
 

src/dws/sign.ts

@@ -2,7 +2,6 @@ import FormData from 'form-data'
 import { handleApiError, handleFileResponse } from './utils.js'
 import { CallToolResult } from '@modelcontextprotocol/sdk/types.js'
 import { SignatureOptions } from '../schemas.js'
-import { callNutrientApi } from './api.js'
 import { resolveReadFilePath, resolveWriteFilePath } from '../fs/sandbox.js'
 import fs from 'fs'
 import path from 'path'
@@ -14,10 +13,10 @@ import { DwsApiClient } from './client.js'
 export async function performSignCall(
   filePath: string,
   outputFilePath: string,
+  apiClient: DwsApiClient,
   signatureOptions: SignatureOptions = { signatureType: 'cms', flatten: false },
   watermarkImagePath?: string,
   graphicImagePath?: string,
-  apiClient?: DwsApiClient,
 ): Promise<CallToolResult> {
   try {
     // We resolve the output path first to fail early
@@ -38,7 +37,7 @@ export async function performSignCall(
       await addFileToFormData(formData, 'graphic', graphicImagePath)
     }
 
-    const response = apiClient ? await apiClient.post('sign', formData) : await callNutrientApi('sign', formData)
+    const response = await apiClient.post('sign', formData)
 
     return handleFileResponse(response, resolvedOutputPath, 'File signed successfully')
   } catch (e: unknown) {

src/dws/utils.ts

@@ -35,18 +35,6 @@ export async function pipeToBuffer(responseData: Readable): Promise<Buffer> {
   })
 }
 
-/**
- * Validates that the API key is set in the environment
- * @returns Object with error information if API key is not set
- */
-export function getApiKey(): string {
-  if (!process.env.NUTRIENT_DWS_API_KEY) {
-    throw new Error('NUTRIENT_DWS_API_KEY not set in environment')
-  }
-
-  return process.env.NUTRIENT_DWS_API_KEY
-}
-
 /**
  * Handles API errors and converts them to a standard format
  * @returns Object with error information

src/index.ts

@@ -127,10 +127,10 @@ Positioning:
           return await performSignCall(
             filePath,
             outputPath,
+            apiClient,
             signatureOptions,
             watermarkImagePath,
             graphicImagePath,
-            apiClient,
           )
         } catch (error) {
           return createErrorResponse(`Error: ${error instanceof Error ? error.message : String(error)}`)
@@ -160,7 +160,7 @@ By default (when neither stage nor apply is set), redactions are detected and im
         }
 
         try {
-          return await performAiRedactCall(filePath, criteria, outputPath, stage, apply, apiClient)
+          return await performAiRedactCall(filePath, criteria, outputPath, apiClient, stage, apply)
         } catch (error) {
           return createErrorResponse(`Error: ${error instanceof Error ? error.message : String(error)}`)
         }

tests/build-api-examples.test.ts

@@ -5,15 +5,19 @@ import path from 'path'
 import { performBuildCall } from '../src/dws/build.js'
 import { BuildAPIArgs } from '../src/schemas.js'
 import { setSandboxDirectory } from '../src/fs/sandbox.js'
+import { createApiClient } from '../src/dws/api.js'
+import { DwsApiClient } from '../src/dws/client.js'
 
 dotenvConfig()
 
 describe('performBuildCall with build-api-examples', () => {
   let outputDirectory: string
+  let apiClient: DwsApiClient
   beforeAll(async () => {
     const assetsDir = path.join(__dirname, `assets`)
     await setSandboxDirectory(assetsDir)
 
+    apiClient = createApiClient({ apiKey: process.env.NUTRIENT_DWS_API_KEY! })
     outputDirectory = `test-output-${new Date().toISOString().replace(/[:.]/g, '-')}`
   })
 
@@ -80,7 +84,7 @@ describe('performBuildCall with build-api-examples', () => {
   it.each(fileOutputExamples)('should process $name', async ({ example }) => {
     const { instructions, outputPath } = example
 
-    const result = await performBuildCall(instructions, `${outputDirectory}/${outputPath}`)
+    const result = await performBuildCall(instructions, `${outputDirectory}/${outputPath}`, apiClient)
 
     expect(result).toEqual(
       expect.objectContaining({
@@ -98,7 +102,7 @@ describe('performBuildCall with build-api-examples', () => {
   it.each(jsonOutputExamples)('should process $name', async ({ example }) => {
     const { instructions } = example
 
-    const result = await performBuildCall(instructions, 'dummy_path.pdf')
+    const result = await performBuildCall(instructions, 'dummy_path.pdf', apiClient)
 
     expect(result).toEqual(
       expect.objectContaining({

tests/signing-api-examples.test.ts

@@ -5,15 +5,19 @@ import { performSignCall } from '../src/dws/sign.js'
 import { SignAPIArgs } from '../src/schemas.js'
 import path from 'path'
 import { setSandboxDirectory } from '../src/fs/sandbox.js'
+import { createApiClient } from '../src/dws/api.js'
+import { DwsApiClient } from '../src/dws/client.js'
 
 dotenvConfig()
 
 describe('performSignCall with signing-api-examples', () => {
   let outputDirectory: string
+  let apiClient: DwsApiClient
   beforeAll(async () => {
     const assetsDir = path.join(__dirname, `assets`)
     await setSandboxDirectory(assetsDir)
 
+    apiClient = createApiClient({ apiKey: process.env.NUTRIENT_DWS_API_KEY! })
     outputDirectory = `test-output-${new Date().toISOString().replace(/[:.]/g, '-')}`
   })
 
@@ -44,6 +48,7 @@ describe('performSignCall with signing-api-examples', () => {
     const result = await performSignCall(
       filePath,
       `${outputDirectory}/${outputPath}`,
+      apiClient,
       signatureOptions,
       watermarkImagePath,
       graphicImagePath,