gh-christianlouis-docuelevate/docs/ConfigurationGuide.md

Configuration Guide

DocuElevate is designed to be highly configurable through environment variables. This guide explains all available configuration options and how to use them effectively.

Environment Variables

Configuration is primarily done through environment variables specified in a .env file.

Core Settings

Variable	Description	Example
DATABASE_URL	Path/URL to the SQLite database (or other SQL backend).	sqlite:///./app/database.db
REDIS_URL	URL for Redis, used by Celery for broker & result store.	redis://redis:6379/0
WORKDIR	Working directory for the application.	/workdir
GOTENBERG_URL	Gotenberg PDF processing URL.	http://gotenberg:3000
EXTERNAL_HOSTNAME	The external hostname for the application.	docuelevate.example.com
ALLOW_FILE_DELETE	Enable file deletion in the web interface (true/false).	true

Batch Processing Settings

Control how the /processall endpoint handles large batches of files to prevent overwhelming downstream APIs.

Variable	Description	Default
PROCESSALL_THROTTLE_THRESHOLD	Number of files above which throttling is applied. Files <= threshold are processed immediately.	20
PROCESSALL_THROTTLE_DELAY	Delay in seconds between each task submission when throttling is active.	3

Example Usage: When processing 25 files with default settings:

• Files are staggered: file 0 at 0s, file 1 at 3s, file 2 at 6s, etc.
• Total queue time: (25-1) × 3 = 72 seconds
• Prevents API rate limit issues and ensures smooth processing

Task Retry Settings

Failed Celery tasks are automatically retried with exponential backoff and optional jitter. Different task types use different default delays (OCR tasks wait longer than upload tasks to account for API rate limits).

Variable	Description	Default
TASK_RETRY_MAX_RETRIES	Maximum number of retry attempts for any failed task.	3
TASK_RETRY_DELAYS	Comma-separated list of countdown values in seconds for each retry attempt. Values beyond the list double the last entry for subsequent retries.	60,300,900
TASK_RETRY_JITTER	Apply ±20 % random jitter to countdowns to prevent thundering-herd problems when many tasks fail at the same time.	true

Per-task-type policies (not overridable via environment variables; set in code):

Task type	Default delays (s)	Notes
General tasks	60, 300, 900	Controlled by TASK_RETRY_DELAYS
OCR / AI tasks	120, 600, 1800	Longer waits for API rate-limit windows to clear
Cloud-storage uploads	60, 300, 900	Controlled by TASK_RETRY_DELAYS

Example – aggressive retries for a high-availability setup:

TASK_RETRY_MAX_RETRIES=5
TASK_RETRY_DELAYS=30,120,600,1800,3600
TASK_RETRY_JITTER=true

Example – conservative retries with longer back-off:

TASK_RETRY_MAX_RETRIES=3
TASK_RETRY_DELAYS=300,900,3600
TASK_RETRY_JITTER=true

Client-Side Upload Throttling

Control how the web UI queues and paces file uploads to avoid overwhelming the backend, especially when dragging large directories (potentially thousands of files) onto the upload area.

Variable	Description	Default
UPLOAD_CONCURRENCY	Maximum number of files uploaded simultaneously from the browser.	3
UPLOAD_QUEUE_DELAY_MS	Delay in milliseconds between starting each upload slot. Staggers upload starts to smooth out server load.	500

Adaptive back-off: The browser automatically slows down if the server responds with HTTP 429 (Too Many Requests). It reads the Retry-After header, pauses the queue for the indicated time, doubles the inter-slot delay (exponential back-off, capped at 30 s), and reduces concurrency to 1. After 5 consecutive successes it gradually recovers toward the configured values.

Example: With UPLOAD_CONCURRENCY=3 and UPLOAD_QUEUE_DELAY_MS=500, a directory of 5,000 files is uploaded ≈ 3 at a time with 500 ms pacing – the backend processes files at its own rate while the queue drains in the background without triggering API rate limits.

File Upload Size Limits

Security Feature: Control file upload sizes to prevent resource exhaustion attacks. See SECURITY_AUDIT.md for security details.

Variable	Description	Default
MAX_UPLOAD_SIZE	Maximum file upload size in bytes. Files exceeding this limit are rejected.	1073741824 (1GB)
MAX_SINGLE_FILE_SIZE	Optional: Maximum size for a single file chunk in bytes. Files exceeding this are split into smaller parts.	None (no splitting)
MAX_REQUEST_BODY_SIZE	Maximum request body size in bytes for non-file-upload requests (JSON, form data, etc.). File uploads use MAX_UPLOAD_SIZE instead.	1048576 (1MB)

Configuration Examples:

# Default: Allow up to 1GB uploads, no splitting, 1MB JSON/form body limit
MAX_UPLOAD_SIZE=1073741824
MAX_REQUEST_BODY_SIZE=1048576

# Conservative: 100MB max, split files over 50MB
MAX_UPLOAD_SIZE=104857600
MAX_SINGLE_FILE_SIZE=52428800

# Large files: 2GB max, split files over 500MB
MAX_UPLOAD_SIZE=2147483648
MAX_SINGLE_FILE_SIZE=524288000

File Splitting Behavior:

• When MAX_SINGLE_FILE_SIZE is configured and a PDF exceeds this size, it is automatically split into smaller chunks
• IMPORTANT: Splitting is done at PAGE BOUNDARIES, not by byte position
  • Uses pypdf to properly parse PDF structure
  • Each output file is a complete, valid PDF containing whole pages
  • No risk of corrupted or broken PDF files
  • Pages are distributed across output files to stay under size limit
• Each chunk is processed sequentially as a separate task
• Only works for PDF files (images and office documents are converted to PDF first)
• Original file is removed after successful splitting
• Useful for very large PDFs to prevent memory issues during processing

Use Cases:

• Default (1GB, no splitting): Suitable for most deployments handling typical documents
• With splitting: Recommended for servers with limited memory or when processing very large scanned documents
• Higher limits: For environments specifically designed to handle large architectural plans, books, or scanned archives

IMAP Configuration

DocuElevate can monitor multiple IMAP mailboxes for document attachments. Each mailbox uses a numbered prefix (e.g., IMAP1_, IMAP2_).

Variable	Description	Example
IMAP1_HOST	Hostname for first IMAP server.	mail.example.com
IMAP1_PORT	Port number (usually 993).	993
IMAP1_USERNAME	IMAP login (first mailbox).	user@example.com
IMAP1_PASSWORD	IMAP password (first mailbox).	*******
IMAP1_SSL	Use SSL (true/false).	true
IMAP1_POLL_INTERVAL_MINUTES	Frequency in minutes to poll for new mail.	5
IMAP_READONLY_MODE	When true, fetches and processes attachments but does not modify the mailbox (no starring, labeling, deleting, or flag changes). Use for pre-production instances sharing a mailbox with production. Default: false.	false

Authentication

Variable	Description
AUTH_ENABLED	Enable or disable authentication (true/false).
SESSION_SECRET	Secret key used to encrypt sessions and cookies (at least 32 chars).
ADMIN_USERNAME	Username for basic authentication (when not using OIDC).
ADMIN_PASSWORD	Password for basic authentication (when not using OIDC).
ADMIN_GROUP_NAME	Group name in OIDC claims that grants admin access. Default: admin.
AUTHENTIK_CLIENT_ID	Client ID for Authentik OAuth2/OIDC authentication.
AUTHENTIK_CLIENT_SECRET	Client secret for Authentik OAuth2/OIDC authentication.
AUTHENTIK_CONFIG_URL	Configuration URL for Authentik OpenID Connect.
OAUTH_PROVIDER_NAME	Display name for the OAuth provider button.

Security Headers

DocuElevate supports HTTP security headers to improve browser-side security. These headers are disabled by default since most deployments use a reverse proxy (Traefik, Nginx, etc.) that already adds them. Enable only if deploying directly without a reverse proxy. See Deployment Guide - Security Headers for detailed configuration examples.

Rate Limiting

DocuElevate implements rate limiting to protect against DoS attacks and API abuse. Rate limiting is enabled by default and uses Redis for distributed rate limiting across multiple workers.

Master Control

Variable	Description	Default
RATE_LIMITING_ENABLED	Enable/disable rate limiting middleware. Recommended for production.	true

Rate Limit Configuration

Rate limits are specified in the format count/period, where:

• count is the maximum number of requests allowed
• period is one of: second, minute, hour, day

Variable	Description	Default	Applies To
RATE_LIMIT_DEFAULT	Default rate limit for all API endpoints	100/minute	Most API endpoints
RATE_LIMIT_UPLOAD	Rate limit for file upload endpoints (prevents resource exhaustion)	600/minute	/api/ui-upload and similar
RATE_LIMIT_AUTH	Stricter rate limit for authentication (prevents brute force)	10/minute	Login, authentication endpoints

Note: Processing endpoints (OCR, metadata extraction) use built-in queue throttling via Celery to control processing rates and prevent upstream API overloads. No additional API-level rate limit is configured for processing endpoints.

How Rate Limiting Works

1. Per-User Tracking: For authenticated requests, limits are enforced per user ID
2. Per-IP Tracking: For unauthenticated requests, limits are enforced per IP address
3. 429 Response: When limit is exceeded, API returns 429 Too Many Requests with Retry-After header
4. Redis Backend: Uses Redis for distributed rate limiting (required for multi-worker deployments)
5. In-Memory Fallback: Falls back to in-memory storage if Redis is unavailable (not recommended for production)

Configuration Example

# Enable rate limiting (recommended for production)
RATE_LIMITING_ENABLED=true

# Configure Redis for distributed rate limiting
REDIS_URL=redis://redis:6379/0

# Customize rate limits
RATE_LIMIT_DEFAULT=100/minute     # 100 requests per minute per user/IP
RATE_LIMIT_UPLOAD=600/minute      # 600 uploads per minute
RATE_LIMIT_AUTH=10/minute         # 10 auth attempts per minute (brute force protection)

Recommended Limits by Deployment Size

Small Deployment (1-10 users):

RATE_LIMIT_DEFAULT=200/minute
RATE_LIMIT_UPLOAD=1200/minute
RATE_LIMIT_AUTH=20/minute

Medium Deployment (10-100 users):

RATE_LIMIT_DEFAULT=100/minute
RATE_LIMIT_UPLOAD=600/minute
RATE_LIMIT_AUTH=10/minute

Large Deployment (100+ users):

RATE_LIMIT_DEFAULT=50/minute
RATE_LIMIT_UPLOAD=300/minute
RATE_LIMIT_AUTH=5/minute

Disabling Rate Limiting (Development Only)

For development or testing, you can disable rate limiting:

RATE_LIMITING_ENABLED=false

Warning: Do not disable rate limiting in production environments.

Monitoring Rate Limits

When rate limits are exceeded, check application logs for details:

2024-02-10 16:00:00 - Rate limiting by user: testuser
2024-02-10 16:00:01 - Rate limit exceeded: 100 per 1 minute

For more information on handling rate-limited responses in API clients, see API Documentation - Rate Limiting.

---

Security Headers Configuration

DocuElevate supports HTTP security headers to improve browser-side security. These headers are disabled by default since most deployments use a reverse proxy (Traefik, Nginx, etc.) that already adds them. Enable only if deploying directly without a reverse proxy. See Deployment Guide - Security Headers for detailed configuration examples.

Master Control

Variable	Description	Default
SECURITY_HEADERS_ENABLED	Enable/disable security headers middleware. Set to true if deploying without reverse proxy.	false

Strict-Transport-Security (HSTS)

Forces browsers to use HTTPS for all future requests to this domain. Only effective over HTTPS.

Variable	Description	Default
SECURITY_HEADER_HSTS_ENABLED	Enable HSTS header.	true
SECURITY_HEADER_HSTS_VALUE	HSTS header value (max-age in seconds, subdomain support).	max-age=31536000; includeSubDomains

Common Values:

• max-age=31536000; includeSubDomains (1 year, recommended for production)
• max-age=300 (5 minutes, for testing)
• max-age=63072000; includeSubDomains; preload (2 years with HSTS preload)

Content-Security-Policy (CSP)

Controls which resources browsers are allowed to load. Helps prevent XSS attacks and code injection.

Variable	Description	Default
SECURITY_HEADER_CSP_ENABLED	Enable CSP header.	true
SECURITY_HEADER_CSP_VALUE	CSP policy directives.	See below

Default Policy:

default-src 'self'; script-src 'self' 'unsafe-inline'; style-src 'self' 'unsafe-inline'; img-src 'self' data: https:; font-src 'self' data:;

Common Customizations:

# Stricter CSP (remove 'unsafe-inline', use nonces)
SECURITY_HEADER_CSP_VALUE="default-src 'self'; script-src 'self'; style-src 'self';"

# Allow specific external domains
SECURITY_HEADER_CSP_VALUE="default-src 'self'; script-src 'self' https://cdn.example.com; style-src 'self' 'unsafe-inline';"

Note: The default policy includes 'unsafe-inline' for compatibility with Tailwind CSS and inline JavaScript. For stricter security, use nonces or hashes.

X-Frame-Options

Prevents the page from being loaded in frames/iframes. Protects against clickjacking attacks.

Variable	Description	Default
SECURITY_HEADER_X_FRAME_OPTIONS_ENABLED	Enable X-Frame-Options header.	true
SECURITY_HEADER_X_FRAME_OPTIONS_VALUE	X-Frame-Options header value.	DENY

Valid Values:

• DENY - Page cannot be displayed in a frame (most secure)
• SAMEORIGIN - Page can only be displayed in a frame on the same origin
• ALLOW-FROM uri - Deprecated: Page can only be displayed in a frame on the specified origin. This directive is deprecated in modern browsers; use CSP frame-ancestors directive instead.

X-Content-Type-Options

Prevents browsers from MIME-sniffing responses away from the declared content-type. Helps prevent XSS attacks.

Variable	Description	Default
SECURITY_HEADER_X_CONTENT_TYPE_OPTIONS_ENABLED	Enable X-Content-Type-Options header.	true

Note: This header is always set to nosniff when enabled (no configuration needed).

Configuration Examples

Reverse Proxy Deployment (Default - Traefik, Nginx):

# Headers disabled by default - reverse proxy handles them
# SECURITY_HEADERS_ENABLED=false  # Can be omitted

Direct Deployment (No Reverse Proxy):

# Enable all security headers
SECURITY_HEADERS_ENABLED=true
SECURITY_HEADER_HSTS_ENABLED=true
SECURITY_HEADER_CSP_ENABLED=true
SECURITY_HEADER_X_FRAME_OPTIONS_ENABLED=true
SECURITY_HEADER_X_CONTENT_TYPE_OPTIONS_ENABLED=true

Custom Configuration:

# Enable headers but customize values
SECURITY_HEADERS_ENABLED=true
SECURITY_HEADER_HSTS_VALUE="max-age=300"  # 5 minutes for testing
SECURITY_HEADER_X_FRAME_OPTIONS_VALUE="SAMEORIGIN"  # Allow same-origin framing
SECURITY_HEADER_CSP_VALUE="default-src 'self'; script-src 'self' https://trusted-cdn.com;"

See Also:

• Deployment Guide - Security Headers for Traefik/Nginx examples
• SECURITY_AUDIT.md for security rationale

AI Provider & Model Selection

DocuElevate supports multiple AI providers for metadata extraction and OCR text refinement. Select the provider via AI_PROVIDER and configure the matching credentials below.

Variable	Description	Default
AI_PROVIDER	Active AI provider. See supported values below.	openai
AI_MODEL	Model name for the selected provider. Falls back to OPENAI_MODEL when not set.	(unset)
OPENAI_MODEL	Default model name (used when AI_MODEL is not set).	gpt-4o-mini

Supported AI_PROVIDER values: openai, azure, anthropic, gemini, ollama, openrouter, portkey, litellm

---

OpenAI (default)

Variable	Description	Default
OPENAI_API_KEY	OpenAI API key.	(required)
OPENAI_BASE_URL	API base URL. Change for compatible proxies.	https://api.openai.com/v1

AI_PROVIDER=openai
OPENAI_API_KEY=sk-...
OPENAI_MODEL=gpt-4o-mini

Azure OpenAI

Variable	Description	Default
OPENAI_API_KEY	Azure OpenAI API key.	(required)
OPENAI_BASE_URL	Azure resource endpoint URL.	(required)
AZURE_OPENAI_API_VERSION	Azure OpenAI API version string.	2024-02-01

AI_PROVIDER=azure
OPENAI_API_KEY=<azure-key>
OPENAI_BASE_URL=https://my-resource.openai.azure.com
AI_MODEL=gpt-4o   # deployment name in Azure

Anthropic Claude

Variable	Description
ANTHROPIC_API_KEY	Anthropic API key.

AI_PROVIDER=anthropic
ANTHROPIC_API_KEY=sk-ant-...
AI_MODEL=claude-3-5-sonnet-20241022

Google Gemini

Variable	Description
GEMINI_API_KEY	Google AI Studio API key.

AI_PROVIDER=gemini
GEMINI_API_KEY=AIza...
AI_MODEL=gemini-1.5-pro

Ollama (local LLMs – CPU-friendly)

Run models locally using Ollama. Recommended for CPU-only deployments:

Variable	Description	Default
OLLAMA_BASE_URL	Ollama server URL.	http://localhost:11434

AI_PROVIDER=ollama
OLLAMA_BASE_URL=http://ollama:11434   # Docker service name
AI_MODEL=llama3.2                     # or qwen2.5, phi3, etc.

Recommended models for document processing on CPU:

• llama3.2 (3B) – good balance of speed and JSON output quality
• qwen2.5 (3B/7B) – excellent at structured extraction
• phi3 (3.8B) – strong reasoning, very fast on CPU

OpenRouter

OpenRouter provides access to 100+ models from a single endpoint using the provider/model name format.

Variable	Description	Default
OPENROUTER_API_KEY	OpenRouter API key.	(required)
OPENROUTER_BASE_URL	Override the gateway URL.	https://openrouter.ai/api/v1

AI_PROVIDER=openrouter
OPENROUTER_API_KEY=sk-or-...
AI_MODEL=anthropic/claude-3.5-sonnet

Portkey AI Gateway

Portkey is an AI gateway that adds observability, caching, fallbacks, and load balancing across 200+ models behind a single OpenAI-compatible endpoint.

Variable	Description	Default
PORTKEY_API_KEY	Portkey account API key.	(required)
PORTKEY_VIRTUAL_KEY	Optional Virtual Key (stores provider credentials in Portkey vault, keeping them out of your env file).	(unset)
PORTKEY_CONFIG	Optional saved Config ID (e.g. pc-fallback-abc123) for routing rules, fallbacks, and load balancing.	(unset)
PORTKEY_BASE_URL	Override the Portkey gateway URL (for self-hosted deployments).	https://api.portkey.ai/v1

AI_PROVIDER=portkey
PORTKEY_API_KEY=pk-...
PORTKEY_VIRTUAL_KEY=vk-openai-abc123   # optional – routes to your OpenAI key stored in Portkey
AI_MODEL=gpt-4o

Using a Config for fallback routing:

AI_PROVIDER=portkey
PORTKEY_API_KEY=pk-...
PORTKEY_CONFIG=pc-fallback-config-xyz  # applies your saved routing rules
AI_MODEL=gpt-4o

LiteLLM (aggregator proxy)

LiteLLM provides a unified provider/model interface for 100+ LLMs including OpenAI, Anthropic, Gemini, Cohere, Ollama, and many more.

Variable	Description	Default
OPENAI_API_KEY	API key forwarded to LiteLLM (provider-specific).	(depends on model)
OPENAI_BASE_URL	Optional proxy/gateway URL.	https://api.openai.com/v1

AI_PROVIDER=litellm
AI_MODEL=anthropic/claude-3-5-sonnet-20241022
OPENAI_API_KEY=sk-ant-...   # passed as the api_key to LiteLLM

---

OCR Providers

DocuElevate supports multiple OCR engines that can be used individually or in combination. Configure the list of active providers with OCR_PROVIDERS and tune each provider with the settings below.

Provider Selection

Variable	Description	Default
OCR_PROVIDERS	Comma-separated list of OCR engines to use, e.g. azure, mistral, azure,tesseract.	azure
OCR_MERGE_STRATEGY	Strategy for combining results from multiple providers: ai_merge, longest, or primary.	ai_merge

Supported OCR_PROVIDERS values: azure, tesseract, easyocr, mistral, google_docai, aws_textract

When multiple providers are listed, all run in parallel and their results are merged according to OCR_MERGE_STRATEGY.

Embedded Text Quality Check

DocuElevate can automatically assess whether the text already embedded in a PDF is of sufficient quality before deciding to skip OCR. This prevents poor OCR output from a previous scan being silently used for downstream processing.

Variable	Description	Default
ENABLE_TEXT_QUALITY_CHECK	Enable AI-based quality assessment of embedded PDF text.	true
TEXT_QUALITY_THRESHOLD	Minimum quality score (0–100) required to accept embedded text without re-OCR.	85
TEXT_QUALITY_SIGNIFICANT_ISSUES	Comma-separated issue labels that force re-OCR even when the score meets the threshold.	excessive_typos,garbage_characters,incoherent_text,fragmented_sentences

How it works:

1. When a PDF with embedded text is received, DocuElevate first examines the PDF metadata (/Producer, /Creator).
2. If the PDF was digitally created (e.g., exported from Word, LibreOffice, LaTeX, or any modern authoring tool), the embedded text is considered trustworthy and the quality check is skipped — digital text cannot be improved by re-OCRing.
3. If the PDF was previously OCR'd (Tesseract, ABBYY, ocrmypdf, etc.) or the origin is unknown, an AI model evaluates a sample of the extracted text for:
   • Excessive typos and character-substitution artefacts typical of OCR
   • Garbage characters or symbol soup
   • Incoherent or nonsensical sentences
   • Heavy fragmentation
4. The text is rejected (and re-OCR triggered) when either of these conditions is true:
   • The quality score is below TEXT_QUALITY_THRESHOLD (default 85), or
   • The AI identifies one or more issues listed in TEXT_QUALITY_SIGNIFICANT_ISSUES — even if the numeric score is above the threshold. This prevents edge cases such as a score of 68 with excessive_typos and garbage_characters being silently accepted.
5. After the re-OCR pass, the fresh OCR result is compared head-to-head against the original embedded text using an AI side-by-side review. The higher-quality text is passed to downstream processing (metadata extraction, AI analysis). This ensures re-OCR never degrades quality.
6. All quality decisions (score, source, AI feedback, comparison outcome) are recorded in the processing log for review.

Tip

: Set ENABLE_TEXT_QUALITY_CHECK=false to disable the check entirely and always use embedded text as-is. This is useful when the AI provider is unavailable or when processing speed is more important than text accuracy.

Tuning the threshold: The default of TEXT_QUALITY_THRESHOLD=85 is intentionally strict. Lower it (e.g., 70) for environments with consistently good existing OCR. Raise it (up to 100) for maximum quality enforcement.

Searchable PDF Text Layer

Not all OCR providers embed a searchable text layer in the output PDF. The table below summarises each provider's behaviour and how DocuElevate handles it:

Provider	Embeds text layer?	Notes
azure	✅ Yes	Azure Document Intelligence returns a PDF/A with an embedded text layer.
tesseract	❌ No (text only)	Text is extracted but the PDF is not modified. embed_text_layer post-processing is applied automatically.
easyocr	❌ No (text only)	Same as above.
mistral	❌ No (text only)	Mistral OCR API returns plain text; embed_text_layer post-processing is applied automatically.
google_docai	❌ No (text only)	Google Cloud Document AI returns plain text; embed_text_layer post-processing is applied automatically.
aws_textract	❌ No (text only)	AWS Textract returns plain text; embed_text_layer post-processing is applied automatically.

For providers that do not embed a text layer, DocuElevate automatically runs ocrmypdf --skip-text after OCR to add an invisible Tesseract-generated text layer to the PDF. This makes the file selectable and searchable in PDF viewers. The step is silently skipped if ocrmypdf is not available on PATH (a warning is logged).

Azure Document Intelligence

Variable	Description	How to Obtain
AZURE_DOCUMENT_INTELLIGENCE_KEY	Azure Document Intelligence API key for OCR.	Azure Portal
AZURE_DOCUMENT_INTELLIGENCE_ENDPOINT	Endpoint URL for Azure Document Intelligence API.	Azure Portal

Tesseract (self-hosted)

Requires tesseract-ocr to be installed in the Docker image or on the host. The default Docker image ships with Tesseract (English language data only).

Automatic language data download: DocuElevate automatically downloads missing Tesseract .traineddata files at startup using wget from the tessdata_fast repository. No manual installation is required — simply set TESSERACT_LANGUAGE to the desired language codes and the data files are fetched on first start. The container must have outbound internet access for this to work.

Variable	Description	Default
TESSERACT_CMD	Path to the tesseract binary (optional; auto-detected from PATH).	(auto)
TESSERACT_LANGUAGE	Tesseract language code(s), e.g. eng, eng+deu, deu.	eng+deu

OCR_PROVIDERS=tesseract
TESSERACT_LANGUAGE=eng+deu

Language codes: Use ISO 639-2 codes separated by +, e.g. eng+deu+fra for English + German + French. All codes supported by Tesseract are available. See the tessdata repository for the full list.

No internet access? Set TESSDATA_PREFIX to a writable directory and pre-populate it with the required .traineddata files. Alternatively, build a custom Docker image that installs the needed language packages via apt-get install tesseract-ocr-<lang>.

EasyOCR (self-hosted)

Requires the easyocr Python package. Install it separately as it is not included in the base requirements.

Automatic model download: EasyOCR model files are downloaded automatically on first use (or at startup) to ~/.EasyOCR/model/. The container must have outbound internet access. Model download can take several minutes depending on the language.

Variable	Description	Default
EASYOCR_LANGUAGES	Comma-separated EasyOCR language codes, e.g. en,de,fr.	en,de
EASYOCR_GPU	Enable GPU acceleration for EasyOCR (true/false).	false

Mistral OCR

Variable	Description	How to Obtain
MISTRAL_API_KEY	Mistral API key.	console.mistral.ai
MISTRAL_OCR_MODEL	Mistral OCR model name.	mistral-ocr-latest

Google Cloud Document AI

Variable	Description	Default
GOOGLE_DOCAI_PROJECT_ID	GCP project ID (required).	(required)
GOOGLE_DOCAI_PROCESSOR_ID	Document AI processor ID (required).	(required)
GOOGLE_DOCAI_LOCATION	Processor location, e.g. us or eu.	us
GOOGLE_DOCAI_CREDENTIALS_JSON	Service account JSON (optional; falls back to GOOGLE_DRIVE_CREDENTIALS_JSON).	(optional)

AWS Textract

Reuses the AWS credentials already configured for S3 integration.

Variable	Description
AWS_ACCESS_KEY_ID	AWS access key ID.
AWS_SECRET_ACCESS_KEY	AWS secret access key.
AWS_REGION	AWS region, e.g. us-east-1.

Multi-Provider Example

# Use both Azure (for accuracy) and Tesseract (for redundancy); merge via AI
OCR_PROVIDERS=azure,tesseract
OCR_MERGE_STRATEGY=ai_merge
AZURE_AI_KEY=...
AZURE_ENDPOINT=https://...
TESSERACT_LANGUAGE=eng+deu

Azure Document Intelligence (Legacy)

Note: This section documents the standalone Azure Document Intelligence credentials. When using OCR_PROVIDERS=azure these same credentials are used automatically.

Variable	Description	How to Obtain
AZURE_DOCUMENT_INTELLIGENCE_KEY	Azure Document Intelligence API key for OCR.	Azure Portal
AZURE_DOCUMENT_INTELLIGENCE_ENDPOINT	Endpoint URL for Azure Doc Intelligence API.	Azure Portal

Paperless NGX

Variable	Description
PAPERLESS_NGX_API_TOKEN	API token for Paperless NGX.
PAPERLESS_HOST	Root URL for Paperless NGX (e.g. https://paperless.example.com).
PAPERLESS_CUSTOM_FIELD_ABSENDER	(Optional, Legacy) Name of the custom field in Paperless-ngx to store the sender ("absender") information. If set, the extracted sender will be automatically set as a custom field after document upload. Example: Absender or Sender
PAPERLESS_CUSTOM_FIELDS_MAPPING	(Optional, Recommended) JSON mapping of extracted metadata fields to Paperless custom field names. This allows you to map multiple fields at once. Format: {"metadata_field": "CustomFieldName", ...}. See examples below.

Custom Fields Mapping Examples

Single Field (Legacy Method):

PAPERLESS_CUSTOM_FIELD_ABSENDER=Absender

Multiple Fields (Recommended Method):

# Map multiple metadata fields to custom fields in Paperless
PAPERLESS_CUSTOM_FIELDS_MAPPING='{"absender": "Sender", "empfaenger": "Recipient", "language": "Language"}'

All Available Metadata Fields: DocuElevate extracts the following fields that can be mapped to Paperless custom fields:

• absender - Sender/author of the document
• empfaenger - Recipient of the document
• correspondent - The issuing entity/company (shortened name)
• document_type - Type classification (Invoice, Contract, etc.)
• language - Document language (ISO 639-1 code, e.g., "de", "en")
• kommunikationsart - Communication type (German classification)
• kommunikationskategorie - Communication category (German classification)
• reference_number - Invoice/order/reference number if found
• title - Human-readable document title
• tags - List of thematic keywords (array)

Complete Example:

PAPERLESS_CUSTOM_FIELDS_MAPPING='{"absender": "Sender", "empfaenger": "Recipient", "correspondent": "Correspondent", "language": "Language", "reference_number": "ReferenceNumber"}'

Note: Custom fields must be created in your Paperless-ngx instance before DocuElevate can use them. The field names in the mapping (right side of the JSON) must exactly match the names in Paperless (case-sensitive).

Dropbox

Variable	Description
DROPBOX_APP_KEY	Dropbox API app key.
DROPBOX_APP_SECRET	Dropbox API app secret.
DROPBOX_REFRESH_TOKEN	OAuth2 refresh token for Dropbox.
DROPBOX_FOLDER	Default folder path for Dropbox uploads.

For detailed setup instructions, see the Dropbox Setup Guide.

Nextcloud

Variable	Description
NEXTCLOUD_UPLOAD_URL	Nextcloud WebDAV URL (e.g. https://nc.example.com/remote.php/dav/files/<USERNAME>).
NEXTCLOUD_USERNAME	Nextcloud login username.
NEXTCLOUD_PASSWORD	Nextcloud login password.
NEXTCLOUD_FOLDER	Destination folder in Nextcloud (e.g. "/Documents/Uploads").

Google Drive

Variable	Description
GOOGLE_DRIVE_USE_OAUTH	Set to true to use OAuth flow (recommended)
GOOGLE_DRIVE_CLIENT_ID	OAuth Client ID (required if using OAuth flow)
GOOGLE_DRIVE_CLIENT_SECRET	OAuth Client Secret (required if using OAuth flow)
GOOGLE_DRIVE_REFRESH_TOKEN	OAuth Refresh Token (required if using OAuth flow)
GOOGLE_DRIVE_FOLDER_ID	Google Drive folder ID for file uploads
GOOGLE_DRIVE_CREDENTIALS_JSON	JSON string containing service account credentials (alternative method)
GOOGLE_DRIVE_DELEGATE_TO	Email address to delegate permissions (optional for service accounts)

Note: For OAuth method with non-verified apps, refresh tokens expire after 7 days. For production use, either complete the Google verification process or use the Service Account method.

For detailed setup instructions, see the Google Drive Setup Guide.

WebDAV

Variable	Description
WEBDAV_URL	WebDAV server URL (e.g. https://webdav.example.com/path).
WEBDAV_USERNAME	WebDAV authentication username.
WEBDAV_PASSWORD	WebDAV authentication password.
WEBDAV_FOLDER	Destination folder on WebDAV server (e.g. "/Documents/Uploads").
WEBDAV_VERIFY_SSL	Whether to verify SSL certificates (default: True).

FTP

Variable	Description
FTP_HOST	FTP server hostname or IP address.
FTP_PORT	FTP port (default: 21).
FTP_USERNAME	FTP authentication username.
FTP_PASSWORD	FTP authentication password.
FTP_FOLDER	Destination folder on FTP server (e.g. "/Documents/Uploads").
FTP_USE_TLS	Try to use FTPS with TLS encryption first (default: True).
FTP_ALLOW_PLAINTEXT	Allow fallback to plaintext FTP if TLS fails (default: True).

SFTP

Variable	Description
SFTP_HOST	SFTP server hostname or IP address.
SFTP_PORT	SFTP port (default: 22).
SFTP_USERNAME	SFTP authentication username.
SFTP_PASSWORD	SFTP authentication password (if not using private key).
SFTP_FOLDER	Destination folder on SFTP server.
SFTP_PRIVATE_KEY	Path to private key file for authentication (optional).
SFTP_PRIVATE_KEY_PASSPHRASE	Passphrase for private key if required (optional).

Email

Variable	Description
EMAIL_HOST	SMTP server hostname.
EMAIL_PORT	SMTP port (default: 587).
EMAIL_USERNAME	SMTP authentication username.
EMAIL_PASSWORD	SMTP authentication password.
EMAIL_USE_TLS	Whether to use TLS (default: True).
EMAIL_SENDER	From address (e.g., "DocuElevate <docuelevate@example.com>").
EMAIL_DEFAULT_RECIPIENT	Default recipient email if none specified in the task.

OneDrive / Microsoft Graph

Variable	Description
ONEDRIVE_CLIENT_ID	Azure AD application client ID
ONEDRIVE_CLIENT_SECRET	Azure AD application client secret
ONEDRIVE_TENANT_ID	Azure AD tenant ID: use "common" for personal accounts or your tenant ID for corporate accounts
ONEDRIVE_REFRESH_TOKEN	OAuth 2.0 refresh token (required for personal accounts)
ONEDRIVE_FOLDER_PATH	Folder path in OneDrive for storing documents

For detailed setup instructions, see the OneDrive Setup Guide.

Amazon S3

Variable	Description
AWS_ACCESS_KEY_ID	AWS IAM access key ID
AWS_SECRET_ACCESS_KEY	AWS IAM secret access key
AWS_REGION	AWS region where your S3 bucket is located (default: us-east-1)
S3_BUCKET_NAME	Name of your S3 bucket
S3_FOLDER_PREFIX	Optional prefix/folder path for uploaded files
S3_STORAGE_CLASS	Storage class for uploaded objects (default: STANDARD)
S3_ACL	Access control for uploaded files (default: private)

For detailed setup instructions, see the Amazon S3 Setup Guide.

Notification System

Variable	Description
NOTIFICATION_URLS	Comma-separated list of Apprise notification URLs
NOTIFY_ON_TASK_FAILURE	Send notifications on task failures (True/False)
NOTIFY_ON_CREDENTIAL_FAILURE	Send notifications on credential failures (True/False)
NOTIFY_ON_STARTUP	Send notification when system starts (True/False)
NOTIFY_ON_SHUTDOWN	Send notification when system shuts down (True/False)

For detailed setup instructions, see the Notifications Setup Guide.

Webhooks

Webhooks notify external systems via HTTP POST when document events occur. Configurations are stored in the database and managed through the API (see API docs).

Variable	Description	Default
WEBHOOK_ENABLED	Enable or disable webhook delivery globally (True/False)	True

Webhook URLs, secrets, and subscribed events are configured per-webhook via the /api/webhooks/ endpoints (admin access required). Each delivery includes an optional HMAC-SHA256 signature for verification and is retried with exponential backoff on failure.

Uptime Kuma

Variable	Description
UPTIME_KUMA_URL	Uptime Kuma push URL for monitoring the application's health.
UPTIME_KUMA_PING_INTERVAL	How often to ping Uptime Kuma in minutes (default: 5).

UI / Appearance

DocuElevate supports a dark mode toggle in the navbar. Users can switch between light and dark themes at any time; their choice is stored in localStorage and persists across page reloads in the same browser.

Administrators can set the site-wide default colour scheme that is applied when a user has not yet made a personal choice:

Variable	Description	Default
UI_DEFAULT_COLOR_SCHEME	Default colour scheme for all users. Options: system (follow OS preference), light, dark. Users can always override with the navbar toggle.	system

How it works:

1. On page load an inline script checks the user's localStorage preference first.
2. If no stored preference exists, the server-supplied UI_DEFAULT_COLOR_SCHEME is used.
3. When the value is system (the default), the OS-level prefers-color-scheme media query is respected.
4. Clicking the 🌙 / ☀️ toggle in the navbar saves the new preference to localStorage immediately.

WCAG AA compliance: All dark-mode colour pairs have been chosen with a minimum 4.5:1 contrast ratio for normal text and 3:1 for large text.

Example:

# Force dark mode for all users by default
UI_DEFAULT_COLOR_SCHEME=dark

Duplicate Document Detection

DocuElevate detects and flags documents that share the same content, even if they arrive as separate uploads.

Exact Duplicate Detection (SHA-256)

When ENABLE_DEDUPLICATION=True (the default), each new document is hashed with SHA-256 before processing begins. If the hash matches an existing file record the new document is stored as a duplicate (is_duplicate=True, duplicate_of_id=<original_id>) and no further processing is performed.

Variable	Description	Default
ENABLE_DEDUPLICATION	Hash-based exact duplicate detection on ingest.	True
SHOW_DEDUPLICATION_STEP	Show the "Check for Duplicates" step in the processing timeline UI.	True

An immediate duplicate warning is also included in the /api/ui-upload JSON response so the frontend can alert the user before the pipeline completes.

Near-Duplicate Detection (Content Similarity)

Near-duplicate detection catches documents that contain the same content but carry different SHA-256 hashes — for example, the same letter scanned twice on different days.

After OCR processes a document, its extracted text is converted to a vector embedding using the configured AI provider. The cosine similarity between two documents' embeddings reflects how semantically similar their content is.

Variable	Description	Default
NEAR_DUPLICATE_THRESHOLD	Minimum cosine similarity (0–1) for two documents to be considered near-duplicates. 0.85 means ≥ 85 % semantic overlap.	0.85
EMBEDDING_MODEL	Model name for generating text embeddings via the OpenAI-compatible API. Must be supported by the endpoint configured with OPENAI_BASE_URL.	text-embedding-3-small
EMBEDDING_MAX_TOKENS	Maximum tokens to send to the embedding model. Text is truncated to approximately this many tokens before calling the API. Set below the model's context window (e.g. 8 000 for an 8 192-token model).	8000

Near-duplicate detection:

• Embeddings are computed automatically during document ingestion as a processing step ("Compute Embedding").
• A periodic backfill task (every 5 minutes) picks up any files that were processed before the embedding pipeline was enabled.
• The Similarity dashboard (/similarity) shows all pairs of documents above the threshold, ranked by score.
• The Duplicates management page (/duplicates → "Near-Duplicate Finder" tab) allows per-file lookup.
• Debug endpoints are available to inspect embedding status and trigger recomputation (see API docs).
• Documents without OCR text cannot be compared and are excluded from results.

A score of ≥ 0.90 reliably identifies the same document scanned twice. A score of 0.70–0.90 suggests partial content overlap. Adjust NEAR_DUPLICATE_THRESHOLD to tune sensitivity.

PDF/A Archival Conversion

DocuElevate can optionally generate PDF/A archival copies of both the original ingested file and the processed file. PDF/A copies are saved as parallel variants alongside the standard files—they do not replace the originals. This provides better legal coverage by producing time-stamped, self-contained archival documents suitable for long-term storage and compliance.

The conversion uses ocrmypdf (backed by Ghostscript), which is already bundled in the Docker images.

Note: PDF/A conversion may alter font rendering, especially for OCR text overlays produced by Microsoft Azure Document Intelligence. This is expected and is why PDF/A copies are kept as parallel variants rather than replacements.

Variable	Description	Default
ENABLE_PDFA_CONVERSION	Enable PDF/A archival variant generation for both original and processed files.	false
PDFA_FORMAT	PDF/A format variant: 1 (PDF/A-1b), 2 (PDF/A-2b), 3 (PDF/A-3b).	2
PDFA_UPLOAD_ORIGINAL	Upload the original-file PDF/A variant to all configured storage providers.	false
PDFA_UPLOAD_PROCESSED	Upload the processed-file PDF/A variant to all configured storage providers.	false
PDFA_UPLOAD_FOLDER	Subfolder name appended to each provider's folder for PDF/A uploads.	pdfa
GOOGLE_DRIVE_PDFA_FOLDER_ID	Google Drive folder ID for PDF/A uploads (uses folder IDs, not paths). Empty = use default folder.	(empty)
PDFA_TIMESTAMP_ENABLED	Enable RFC 3161 timestamping of PDF/A files (creates .tsr proof-of-existence files).	false
PDFA_TIMESTAMP_URL	URL of the RFC 3161 Timestamp Authority.	https://freetsa.org/tsr

Storage Layout

When enabled, PDF/A copies are stored under workdir/pdfa/:

workdir/
├── original/          # Immutable copy of ingested file
├── processed/         # Processed file with embedded metadata
├── pdfa/
│   ├── original/      # PDF/A copy of the ingested file
│   │   └── *.pdf.tsr  # RFC 3161 timestamps (when timestamping enabled)
│   └── processed/     # PDF/A copy of the processed file (with -PDFA suffix)
│       └── *.pdf.tsr  # RFC 3161 timestamps (when timestamping enabled)
└── tmp/               # Temporary processing area

Per-Provider Folder Overrides

When uploading PDF/A files to storage providers, DocuElevate appends the PDFA_UPLOAD_FOLDER value as a subfolder to each provider's configured folder. For example:

Provider	Regular Folder	PDF/A Upload Folder
Dropbox	/Documents	/Documents/pdfa
S3	docs/uploads/	docs/uploads/pdfa/
Nextcloud	/Files	/Files/pdfa
OneDrive	Documents/Uploads	Documents/Uploads/pdfa
Google Drive	(folder ID)	GOOGLE_DRIVE_PDFA_FOLDER_ID

Set PDFA_UPLOAD_FOLDER to an empty string to upload PDF/A files into the same folder as regular uploads.

RFC 3161 Timestamping

When PDFA_TIMESTAMP_ENABLED=true, each PDF/A file is timestamped using the configured TSA (default: FreeTSA). This creates a .tsr file alongside each PDF/A file, providing cryptographic proof that the document existed at a specific point in time.

Requires openssl on the PATH (included in Docker images).

Other TSA options:

• GlobalSign – enterprise, eIDAS qualified
• DigiStamp – high assurance, legal
• IdenTrust – legal, free with certificate purchase

Configuration Example

# Enable PDF/A archival copies
ENABLE_PDFA_CONVERSION=true

# Use PDF/A-2b format (default, recommended for most use cases)
PDFA_FORMAT=2

# Upload both original and processed PDF/A to providers
PDFA_UPLOAD_ORIGINAL=true
PDFA_UPLOAD_PROCESSED=true

# PDF/A files go into a 'pdfa' subfolder on each provider
PDFA_UPLOAD_FOLDER=pdfa

# Enable RFC 3161 timestamping via FreeTSA
PDFA_TIMESTAMP_ENABLED=true
PDFA_TIMESTAMP_URL=https://freetsa.org/tsr

Performance & Caching

DocuElevate automatically optimizes database access and uses Redis as a caching layer for frequently accessed data.

Database Indexes

On startup the application creates indexes on columns used for filtering, sorting, and joining in the file listing and status computation queries:

Table	Column	Purpose
files	created_at	Default sort order
files	mime_type	MIME type filter & dropdown
processing_logs	file_id	Log retrieval by file
processing_logs	timestamp	Log ordering
file_processing_steps	status	Status filter sub-queries

These indexes are created idempotently on every startup so no manual migration step is required.

Redis Query Cache

When Redis is available (configured via REDIS_URL), DocuElevate caches selected query results to avoid redundant database round-trips:

Cache Key	TTL	Description
mime_types	120 s	Distinct MIME types shown in the file-list filter dropdown

The cache is fail-open: if Redis is unreachable the application falls back to querying the database directly with no user-visible impact.

Configuration Examples

Minimal Configuration

This is the minimal configuration needed to run DocuElevate with local storage only:

DATABASE_URL=sqlite:///./app/database.db
REDIS_URL=redis://redis:6379/0
WORKDIR=/workdir
GOTENBERG_URL=http://gotenberg:3000

Full Configuration with All Services

# Core settings
DATABASE_URL=sqlite:///./app/database.db
REDIS_URL=redis://redis:6379/0
WORKDIR=/workdir
GOTENBERG_URL=http://gotenberg:3000
EXTERNAL_HOSTNAME=docuelevate.example.com
ALLOW_FILE_DELETE=true

# IMAP settings
IMAP1_HOST=mail.example.com
IMAP1_PORT=993
IMAP1_USERNAME=user@example.com
IMAP1_PASSWORD=password
IMAP1_SSL=true
IMAP1_POLL_INTERVAL_MINUTES=5
IMAP1_DELETE_AFTER_PROCESS=false

# AI services
OPENAI_API_KEY=sk-...
AZURE_DOCUMENT_INTELLIGENCE_KEY=...
AZURE_DOCUMENT_INTELLIGENCE_ENDPOINT=https://...

# Authentication
AUTH_ENABLED=true
SESSION_SECRET=a-very-long-and-secure-random-secret-key-string-for-session-encryption
ADMIN_USERNAME=admin
ADMIN_PASSWORD=your_secure_password
ADMIN_GROUP_NAME=admin
AUTHENTIK_CLIENT_ID=...
AUTHENTIK_CLIENT_SECRET=...
AUTHENTIK_CONFIG_URL=https://auth.example.com/.well-known/openid-configuration
OAUTH_PROVIDER_NAME=Authentik SSO

# Storage services
PAPERLESS_NGX_API_TOKEN=...
PAPERLESS_HOST=https://paperless.example.com

DROPBOX_APP_KEY=...
DROPBOX_APP_SECRET=...
DROPBOX_REFRESH_TOKEN=...
DROPBOX_FOLDER=/Documents/Uploads

NEXTCLOUD_UPLOAD_URL=https://nc.example.com/remote.php/dav/files/username
NEXTCLOUD_USERNAME=username
NEXTCLOUD_PASSWORD=password
NEXTCLOUD_FOLDER=/Documents/Uploads

# Google Drive
GOOGLE_DRIVE_CREDENTIALS_JSON={"type":"service_account","project_id":"..."}
GOOGLE_DRIVE_FOLDER_ID=1a2b3c4d5e6f7g8h9i0j
GOOGLE_DRIVE_DELEGATE_TO=optional-user@example.com
GOOGLE_DRIVE_USE_OAUTH=true
GOOGLE_DRIVE_CLIENT_ID=your_client_id
GOOGLE_DRIVE_CLIENT_SECRET=your_client_secret
GOOGLE_DRIVE_REFRESH_TOKEN=your_refresh_token

# WebDAV
WEBDAV_URL=https://webdav.example.com/path
WEBDAV_USERNAME=username
WEBDAV_PASSWORD=password
WEBDAV_FOLDER=/Documents/Uploads
WEBDAV_VERIFY_SSL=True

# FTP
FTP_HOST=ftp.example.com
FTP_PORT=21
FTP_USERNAME=username
FTP_PASSWORD=password
FTP_FOLDER=/Documents/Uploads
FTP_USE_TLS=True
FTP_ALLOW_PLAINTEXT=True

# SFTP
SFTP_HOST=sftp.example.com
SFTP_PORT=22
SFTP_USERNAME=username
SFTP_PASSWORD=password
SFTP_FOLDER=/Documents/Uploads
# SFTP_PRIVATE_KEY=/path/to/key.pem
# SFTP_PRIVATE_KEY_PASSPHRASE=passphrase

# Email
EMAIL_HOST=smtp.example.com
EMAIL_PORT=587
EMAIL_USERNAME=docuelevate@example.com
EMAIL_PASSWORD=password
EMAIL_USE_TLS=True
EMAIL_SENDER=DocuElevate System <docuelevate@example.com>
EMAIL_DEFAULT_RECIPIENT=recipient@example.com

# Notification Settings
# Configure notification services using Apprise URL format
NOTIFICATION_URLS=discord://webhook_id/webhook_token,mailto://user:pass@gmail.com,tgram://bot_token/chat_id
NOTIFY_ON_TASK_FAILURE=True
NOTIFY_ON_CREDENTIAL_FAILURE=True
NOTIFY_ON_STARTUP=True
NOTIFY_ON_SHUTDOWN=False

# OneDrive (Personal Account)
ONEDRIVE_CLIENT_ID=12345678-1234-1234-1234-123456789012
ONEDRIVE_CLIENT_SECRET=your_client_secret
ONEDRIVE_TENANT_ID=common
ONEDRIVE_REFRESH_TOKEN=your_refresh_token
ONEDRIVE_FOLDER_PATH=Documents/Uploads

# Amazon S3
AWS_ACCESS_KEY_ID=AKIAIOSFODNN7EXAMPLE
AWS_SECRET_ACCESS_KEY=wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY
AWS_REGION=us-east-1
S3_BUCKET_NAME=my-document-bucket
S3_FOLDER_PREFIX=documents/uploads/2023/  # Will place files in this subfolder
S3_STORAGE_CLASS=STANDARD
S3_ACL=private

# Uptime Kuma
UPTIME_KUMA_URL=https://kuma.example.com/api/push/abcde12345?status=up
UPTIME_KUMA_PING_INTERVAL=5

Selective Service Configuration

You can choose which document storage services to use by only including the relevant environment variables. For example, if you only want to use Dropbox, include only the Dropbox variables and omit the Paperless NGX and Nextcloud variables.

Configuration File Location

The .env file should be placed at the root of the project directory. When using Docker Compose, you can reference it with the env_file directive in your docker-compose.yml.