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How We Used OpenAI API to Translate Our Website

How We Used OpenAI API to Translate Our Website

Introduction

When we set out to make our GoHugo.io-based website multilingual, we wanted an efficient, scalable, and cost-effective way to generate translations. Instead of manually translating each page, we leveraged OpenAI’s API to automate the process. This article walks through how we integrated OpenAI API with Hugo, using the HugoPlate theme from Zeon Studio, to generate translations quickly and accurately.

Why We Chose OpenAI API for Translation

Traditional translation services often require significant manual effort, and automated tools like Google Translate, while useful, don’t always provide the level of customization we needed. OpenAI’s API allowed us to:

  • Automate translations in bulk
  • Customize the translation style
  • Maintain better control over quality
  • Integrate seamlessly with our Hugo-based site
  • Flag individual pages for retranslation
  • Add new languages with minimal effort

Step-by-Step Process

1. Preparing the Hugo Website

Our site was already set up using the HugoPlate theme, which supports multilingual functionality. The first step was to enable language support in our Hugo config/_default/languages.toml file:


```toml
################ English language ##################
[en]
languageName = "English"
languageCode = "en-us"
contentDir = "content/english"
weight = 1

################ Arabic language ##################
[ar]
languageName = "العربية"
languageCode = "ar"
contentDir = "content/arabic"
languageDirection = 'rtl'
weight = 2
```

This configuration ensures that Hugo can generate separate language versions of our content.

2. Automating Translations with OpenAI API

We developed a Bash script to automate the translation of Markdown files. This script:

  • Reads English .md files from the source directory.
  • Uses OpenAI API to translate the text while preserving Markdown formatting.
  • Writes translated content to the appropriate language directories.
  • Keeps track of translation status using a JSON file.

Here’s our bash script for automating translations. Feel free to use and modify it for your needs:


```bash
# MIT License
# Copyright (c) 2024 Williston Technical Inc.
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

#!/bin/bash
# ===========================================
# Hugo Content Translation and Update Script (Sequential Processing & New-Language Cleanup)
# ===========================================
# This script translates Hugo Markdown (.md) files from English to all supported target languages
# sequentially (one file at a time). It updates a JSON status file after processing each file.
# At the end of the run, it checks translation_status.json and removes any language from
# translate_new_language.txt only if every file for that language is marked as "success".
# ===========================================

set -euo pipefail

# --- Simple Logging Function (writes to stderr) ---
log_step() {
    echo "[$(date '+%Y-%m-%d %H:%M:%S')] $*" >&2
}

# --- Environment Setup ---
export PATH="/opt/homebrew/opt/coreutils/libexec/gnubin:$PATH"
# (Removed "Script starting." log)

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
log_step "SCRIPT_DIR set to: $SCRIPT_DIR"

if [ -f "$SCRIPT_DIR/.env" ]; then
    log_step "Loading environment variables from .env"
    set -o allexport
    source "$SCRIPT_DIR/.env"
    set +o allexport
fi

# Load new languages from translate_new_language.txt (if available)
declare -a NEW_LANGUAGES=()
if [ -f "$SCRIPT_DIR/translate_new_language.txt" ]; then
    while IFS= read -r line || [[ -n "$line" ]]; do
        NEW_LANGUAGES+=("$line")
    done <"$SCRIPT_DIR/translate_new_language.txt"
else
    log_step "No new languages file found; proceeding with empty NEW_LANGUAGES."
fi

API_KEY="${OPENAI_API_KEY:-}"
if [ -z "$API_KEY" ]; then
    log_step "❌ Error: OPENAI_API_KEY environment variable is not set."
    exit 1
fi

# Supported Languages (full list)
SUPPORTED_LANGUAGES=("ar" "bg" "bn" "cs" "da" "de" "el" "es" "fa" "fi" "fr" "ha" "he" "hi" "hr" "hu" "id" "ig" "it" "ja" "ko" "ml" "mr" "ms" "nl" "no" "pa" "pl" "pt" "ro" "ru" "sk" "sn" "so" "sr" "sv" "sw" "ta" "te" "th" "tl" "tr" "uk" "vi" "xh" "yo" "zh" "zu")

STATUS_FILE="$SCRIPT_DIR/translation_status.json"
SRC_DIR="$SCRIPT_DIR/Content/english"
log_step "Source directory: $SRC_DIR"

# Check dependencies
for cmd in jq curl; do
    if ! command -v "$cmd" >/dev/null 2>&1; then
        log_step "❌ Error: '$cmd' is required. Please install it."
        exit 1
    fi
done

MAX_RETRIES=5
WAIT_TIME=2 # seconds

# Create/initialize status file if missing
if [ ! -f "$STATUS_FILE" ]; then
    echo "{}" >"$STATUS_FILE"
    log_step "Initialized status file at: $STATUS_FILE"
fi

# --- Locking for Status Updates ---
lock_status() {
    local max_wait=10
    local start_time
    start_time=$(date +%s)
    while ! mkdir "$STATUS_FILE.lockdir" 2>/dev/null; do
        sleep 0.01
        local now
        now=$(date +%s)
        if ((now - start_time >= max_wait)); then
            log_step "WARNING: Lock wait exceeded ${max_wait}s. Forcibly removing stale lock."
            rm -rf "$STATUS_FILE.lockdir"
        fi
    done
}

unlock_status() {
    rmdir "$STATUS_FILE.lockdir"
}

update_status() {
    local file_path="$1" lang="$2" status="$3"
    lock_status
    jq --arg file "$file_path" --arg lang "$lang" --arg status "$status" \
        '.[$file][$lang] = $status' "$STATUS_FILE" >"$STATUS_FILE.tmp" && mv "$STATUS_FILE.tmp" "$STATUS_FILE"
    unlock_status
}

# --- Translation Function ---
translate_text() {
    local text="$1" lang="$2"
    local retry_count=0
    while [ "$retry_count" -lt "$MAX_RETRIES" ]; do
        user_message="Translate the following text to $lang. Preserve all formatting exactly as in the original.
$text"
        json_payload=$(jq -n \
            --arg system "Translate from English to $lang. Preserve original formatting exactly." \
            --arg user_message "$user_message" \
            '{
                "model": "gpt-4o-mini",
                "messages": [
                    {"role": "system", "content": $system},
                    {"role": "user", "content": $user_message}
                ],
                "temperature": 0.3
            }')
        response=$(curl -s https://api.openai.com/v1/chat/completions \
            -H "Content-Type: application/json" \
            -H "Authorization: Bearer $API_KEY" \
            -d "$json_payload")
        log_step "📥 Received API response."
        local error_type
        error_type=$(echo "$response" | jq -r '.error.type // empty')
        local error_message
        error_message=$(echo "$response" | jq -r '.error.message // empty')
        if [ "$error_type" == "insufficient_quota" ]; then
            sleep "$WAIT_TIME"
            retry_count=$((retry_count + 1))
        elif [[ "$error_type" == "rate_limit_reached" || "$error_type" == "server_error" || "$error_type" == "service_unavailable" ]]; then
            sleep "$WAIT_TIME"
            retry_count=$((retry_count + 1))
        elif [ "$error_type" == "invalid_request_error" ]; then
            return 1
        elif [ -z "$error_type" ]; then
            if ! translated_text=$(echo "$response" | jq -r '.choices[0].message.content' 2>/dev/null); then
                return 1
            fi
            if [ "$translated_text" == "null" ] || [ -z "$translated_text" ]; then
                return 1
            else
                translated_text=$(echo "$translated_text" | sed -e 's/^```[[:space:]]*//; s/[[:space:]]*```$//')
                echo "$translated_text"
                return 0
            fi
        else
            return 1
        fi
    done
    return 1
}

# --- Process a Single File (Sequential Version) ---
process_file() {
    local src_file="$1" target_file="$2" lang="$3" rel_src="$4"
    # If target file exists and is non-empty, mark status as success.
    if [ -s "$target_file" ]; then
        update_status "$rel_src" "$lang" "success"
        return 0
    fi
    content=$(<"$src_file")
    if [[ "$content" =~ ^[---|\+\+\+]([:space:)]*$ ]] && [[ "$content" =~ [[:space:]]*[---|\+\+\+\+]([:space:)]*$ ]]; then
        front_matter=$(echo "$content" | sed -n '/^\(---\|\+\+\+\)$/,/^\(---\|\+\+\+\)$/p')
        body_content=$(echo "$content" | sed -n '/^\(---\|\+\+\+\)$/,/^\(---\|\+\+\+\)$/d')
    else
        front_matter=""
        body_content="$content"
    fi
    log_step "Translating [$rel_src] to $lang..."
    translated_body=$(translate_text "$body_content" "$lang")
    if [ $? -ne 0 ]; then
        update_status "$rel_src" "$lang" "failed"
        return 1
    fi
    mkdir -p "$(dirname "$target_file")"
    if [ -n "$front_matter" ]; then
        echo -e "$front_matter\n$translated_body" >"$target_file"
    else
        echo -e "$translated_body" >"$target_file"
    fi
    updated_content=$(echo "$content" | sed -E 's/^retranslate:\s*true\b/retranslate: false/')
    echo "$updated_content" >"$src_file"
    update_status "$rel_src" "$lang" "success"
}

# --- Main Sequential Processing ---
ALL_SUCCESS=true
for TARGET_LANG in "${SUPPORTED_LANGUAGES[@]}"; do
    log_step "Processing language: $TARGET_LANG"
    TARGET_DIR="$SCRIPT_DIR/Content/$TARGET_LANG"
    while IFS= read -r -d '' src_file; do
        rel_src="${src_file#$SCRIPT_DIR/}"
        target_file="$TARGET_DIR/${src_file#$SRC_DIR/}"
        # If file is marked not to retranslate, check that target file exists and is non-empty.
        if ! [[ " ${NEW_LANGUAGES[@]:-} " =~ " ${TARGET_LANG} " ]] && grep -q '^retranslate:\s*false' "$src_file"; then
            if [ -s "$target_file" ]; then
                update_status "$rel_src" "$TARGET_LANG" "success"
            else
                update_status "$rel_src" "$TARGET_LANG" "failed"
            fi
            continue
        fi
        process_file "$src_file" "$target_file" "$TARGET_LANG" "$rel_src"
    done < <(find "$SRC_DIR" -type f -name "*.md" -print0)
done

log_step "Translation run completed."
end_time=$(date +%s)
duration=$((end_time - $(date +%s)))
log_step "Execution Time: $duration seconds"

if [ "$ALL_SUCCESS" = true ]; then
    log_step "🎉 Translation completed successfully for all supported languages!"
else
    log_step "⚠️ Translation completed with some errors."
fi

# --- Clean Up Fully Translated New Languages ---
if [ -f "$SCRIPT_DIR/translate_new_language.txt" ]; then
    log_step "Cleaning up fully translated new languages..."
    for lang in "${NEW_LANGUAGES[@]:-}"; do
        incomplete=$(jq --arg lang "$lang" 'to_entries[] | select(.value[$lang] != null and (.value[$lang] != "success")) | .key' "$STATUS_FILE")
        if [ -z "$incomplete" ]; then
            log_step "All translations for new language '$lang' are marked as success. Removing from translate_new_language.txt."
            sed -E -i '' "/^[[:space:]]*$lang[[:space:]]*$/d" "$SCRIPT_DIR/translate_new_language.txt"
        else
            log_step "Language '$lang' still has incomplete translations."
        fi
    done
fi
```

3. Managing Translation Status

To prevent redundant translations and track progress, we used a JSON file (translation_status.json). The script updates this file after processing each document, ensuring only new or updated content gets translated.

4. Error Handling and API Rate Limits

We implemented retries and error handling to deal with rate limits, API failures, and quota issues. The script waits before retrying if OpenAI API returns an error like rate_limit_reached or service_unavailable.

5. Deployment

Once translated content is generated, running hugo --minify builds the multilingual static site, ready for deployment.

Challenges and Solutions

1. Translation Accuracy

While OpenAI’s translations were generally accurate, some technical terms may need manual review, but we are just a team of two, so we’re hoping for the best. We fine-tuned prompts to maintain context and tone.

2. Formatting Issues

Markdown syntax sometimes got altered in translation. To fix this, we added post-processing logic to preserve formatting.

3. API Cost Optimization

To reduce costs, we implemented caching to avoid re-translating unchanged content.

4. Handling Retranslations Efficiently

To retranslate specific pages, we added a retranslate: true front matter parameter. The script retranslates only the pages marked with this parameter. This allows us to update translations as needed without having to retranslate the entire site.

Conclusion

By integrating OpenAI API with Hugo, we automated the translation of our website while maintaining quality and flexibility. This approach saved time, ensured consistency, and allowed us to scale effortlessly. If you’re looking to make your Hugo site multilingual, OpenAI’s API offers a powerful solution.

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