zai-video-skill

What I do

I provide the exact recipe for an agent to generate a video via the Z.AI CogVideoX-3 API and save it to a local file. Generation is asynchronous: POST /videos/generations returns a task id, and the finished MP4 URL only appears after polling GET /async-result/{id}. OpenCode's provider layer is chat-only, so this endpoint is reachable only through direct HTTP calls.

Why a skill (not a provider)

• OpenCode providers speak chat completions — they cannot hit /videos/generations or return binary files.
• Video tasks take minutes; the agent must submit, then poll in the background (PTY pattern below) instead of blocking the session in a synchronous loop.
• The result is a URL — a file must be downloaded and its path returned.

Prerequisite — API key resolution

KEY="${ZAI_API_KEY:-$(jq -r '.["zai"].key // .["zai-coding-plan"].key // empty' \
     ~/.local/share/opencode/auth.json 2>/dev/null)}"
[ -z "$KEY" ] && { echo "ZAI_API_KEY not found — set it (export ZAI_API_KEY) or run \`opencode auth login\` (Z.AI)."; exit 1; }

If neither source has the key, stop and report — do not proceed.

Recipe

1. Submit the task

# --- options ---
PROMPT="A slow dolly shot through a neon-lit city street at night, rain on asphalt"  # REQUIRED
IMAGE=""                                              # optional first-frame image URL or base64 (i2v)
DURATION="${DURATION:-5}"                             # 5 | 10 (seconds)
FPS="${FPS:-30}"                                      # 30 | 60
SIZE="${SIZE:-1920x1080}"                             # up to 4K; e.g. 1280x720, 1920x1080, 3840x2160
WITH_AUDIO="${WITH_AUDIO:-false}"                     # true adds generated audio track
BASE="${ZAI_MEDIA_ENDPOINT:-https://api.z.ai/api/paas/v4}"  # pay-as-you-go ONLY (not on the coding plan)

BODY=$(python3 -c 'import json,sys
b={"model":"cogvideox-3","prompt":sys.argv[1],"duration":int(sys.argv[2]),"fps":int(sys.argv[3]),"size":sys.argv[4],"with_audio":sys.argv[5]=="true"}
if sys.argv[6]: b["image_url"]=sys.argv[6]
print(json.dumps(b))' "$PROMPT" "$DURATION" "$FPS" "$SIZE" "$WITH_AUDIO" "$IMAGE")

RESP=$(curl -sS --max-time 60 -X POST "$BASE/videos/generations" \
  -H "Authorization: Bearer $KEY" -H 'Content-Type: application/json' -d "$BODY")

TASK_ID=$(printf '%s' "$RESP" | python3 -c '
import sys, json
d = json.load(sys.stdin)
if d.get("error"):
    sys.stderr.write("API error: " + json.dumps(d["error"]) + "\n"); sys.exit(1)
print(d.get("id",""))') || { echo "Submit failed. Response: $RESP"; exit 1; }
[ -z "$TASK_ID" ] && { echo "No task id in response: $RESP"; exit 1; }
echo "SUBMITTED: $TASK_ID (billable ~\$0.20/video once it runs)"