Bulk Face Swap API: Safe Batch Processing

# Download this guide's companion example.py first.
# targets.txt: one direct target image URL per line, up to 100 images.
import os
from pathlib import Path
import subprocess
import sys

targets = [line.strip() for line in Path("targets.txt").read_text().splitlines() if line.strip()]
if not 1 <= len(targets) <= 100:
    raise SystemExit("Start with 1–100 target images")
if not os.environ.get("SOURCE_FACE_URL") or not os.environ.get("MAGIC_HOUR_API_KEY"):
    raise SystemExit("Set SOURCE_FACE_URL and MAGIC_HOUR_API_KEY")
Path("batch-logs").mkdir(exist_ok=True)
for index, target in enumerate(targets):
    log = Path(f"batch-logs/{index:03d}.log")
    complete = log.with_suffix(".complete")
    if complete.exists():
        if not log.exists():
            raise SystemExit(f"Completion marker is missing its log: {complete}")
        print(log, "already complete")
        continue
    # A log without a completion marker means submitted OR uncertain.
    if log.exists():
        raise SystemExit(f"Review existing log before continuing: {log}")
    env = dict(os.environ, TARGET_IMAGE_URL=target)
    env.pop("PROJECT_ID", None)
    with log.open("x") as output:
        result = subprocess.run([sys.executable, "example.py"], env=env,
                                stdout=output, stderr=subprocess.STDOUT)
    if result.returncode != 0:
        print(log, "needs review")
        raise SystemExit(result.returncode)  # Reconcile before submitting more.
    complete.touch(exist_ok=False)
    print(log, "complete")

// Download this guide's companion example.mjs first.
// Save this as batch.mjs; run: node batch.mjs
import { readFileSync, mkdirSync, existsSync, openSync, closeSync } from "node:fs";
import { spawnSync } from "node:child_process";

const targets = readFileSync("targets.txt", "utf8")
  .split(/\r?\n/)
  .map((s) => s.trim())
  .filter(Boolean);
if (targets.length < 1 || targets.length > 100) throw new Error("Start with 1–100 images");
if (!process.env.SOURCE_FACE_URL || !process.env.MAGIC_HOUR_API_KEY) {
  throw new Error("Set SOURCE_FACE_URL and MAGIC_HOUR_API_KEY");
}
mkdirSync("batch-logs", { recursive: true });
for (const [index, target] of targets.entries()) {
  const log = "batch-logs/" + String(index).padStart(3, "0") + ".log";
  const complete = log.slice(0, -4) + ".complete";
  if (existsSync(complete)) {
    if (!existsSync(log)) throw new Error("Completion marker is missing its log: " + complete);
    console.log(log, "already complete");
    continue;
  }
  if (existsSync(log)) throw new Error("Review existing log before continuing: " + log);
  const env = { ...process.env, TARGET_IMAGE_URL: target };
  delete env.PROJECT_ID;
  const fd = openSync(log, "wx");
  const result = spawnSync(process.execPath, ["example.mjs"], { env, stdio: ["ignore", fd, fd] });
  closeSync(fd);
  if (result.status !== 0) {
    console.log(log, "needs review");
    process.exit(result.status ?? 1);
  }
  const completeFd = openSync(complete, "wx");
  closeSync(completeFd);
  console.log(log, "complete");
}

#!/usr/bin/env bash
# Download this guide's companion example.sh first.
# targets.txt: one direct target image URL per line. Run: bash batch.sh
set -euo pipefail
: "${SOURCE_FACE_URL:?Set SOURCE_FACE_URL}"
: "${MAGIC_HOUR_API_KEY:?Set MAGIC_HOUR_API_KEY}"
target_count=$(sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//' targets.txt \
  | awk 'length($0) > 0 { count++ } END { print count + 0 }')
if [ "$target_count" -lt 1 ] || [ "$target_count" -gt 100 ]; then
  echo "Start with 1–100 target images" >&2
  exit 1
fi
mkdir -p batch-logs
index=0
while IFS= read -r target || [ -n "$target" ]; do
  target=$(printf '%s' "$target" | sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//')
  [ -z "$target" ] && continue
  log=$(printf 'batch-logs/%03d.log' "$index")
  complete=$(printf 'batch-logs/%03d.complete' "$index")
  index=$((index + 1))
  if [ -e "$complete" ]; then
    if [ ! -e "$log" ]; then echo "Completion marker is missing its log: $complete" >&2; exit 1; fi
    echo "$log already complete"
    continue
  fi
  if [ -e "$log" ]; then echo "Review existing log before continuing: $log" >&2; exit 1; fi
  # Reserve the log before POST; never overwrite an uncertain submission.
  (set -o noclobber; : > "$log")
  if env -u PROJECT_ID TARGET_IMAGE_URL="$target" bash example.sh > "$log" 2>&1; then
    (set -o noclobber; : > "$complete")
    echo "$log complete"
  else
    echo "$log needs review"
    exit 1
  fi
done < targets.txt