PostNitro vs Shotstack

PostNitro

A hosted MCP server and REST API let an agent turn a topic, article or own slides into a branded carousel, image or slide video and schedule it, with OAuth, numbered rate limits and Markdown docs. No status page, security contact or idempotency key was found, and the privacy policy contradicts the vendor's no-training statement.

Shotstack

A public OpenAPI definition, Markdown docs, a hosted MCP server with OAuth and a free watermarked sandbox let an agent draft, check and render video with little setup. API keys have no scopes, webhooks are unsigned, no security contact or certification of Shotstack's own was found, and the published Node and Python SDKs date from July 2024.

PostNitro

1. Call postnitro_set_defaults once with a template, brand and AI preset, or every generate call must carry those IDs
2. Pass the designId from postnitro_get_output to scheduling, never the embedPostId, or the call fails with Design not found
3. For a LinkedIn PDF post, set linkedinPostSettings.postType to document with a 5 to 90 character postTitle
4. Ask for the DESIGN output or save as DRAFT when a person must approve before anything publishes
5. Keep to 5 create calls a minute per key and wait for Retry-After on a 429

Shotstack

1. Fetch https://shotstack.io/docs/api/api.edit.json and the conventions guide before writing an edit. Track order is reversed, so the first track renders on top
2. Render in stage first. It is free and watermarked, but AI generation there is charged from the production credit balance
3. Call POST /generate/quote before POST /generate, and send an Idempotency-Key header on generation. POST /render has no idempotency key, so do not resubmit blindly
4. Do not store the url from the render status response. It expires after 24 hours. Use the CDN address built from owner and the render id
5. On a 429, wait for the 60-second window to reset and retry with backoff. Limits are per API key, 300 a minute on the Edit API in production