Guides
Sume guides: the API, Formats, agents, models, media tools and pricing, each answer dated and sourced.
EventBridge API destinations: call a paid API without Lambda
An EventBridge API destination calls an HTTPS API straight from a rule, with a 5-second timeout and retries on 409, 429 and 5xx. Key every call.
IFTTT webhooks: call an API that needs an API key
IFTTT's Webhooks service can send any web request with custom headers, on Pro plans. Route paid API calls through your own endpoint.
HubSpot custom coded actions: call an outside API safely
A HubSpot custom code action runs Node.js or Python in a workflow for 20 seconds, with secrets as env vars. Start slow API jobs there; don't wait.
Power Automate HTTP Webhook action: wait for a callback
The HTTP Webhook action sends a subscribe request with the flow's callback URL, then pauses until something POSTs to it. How to use it with a slow API.
Workato HTTP connector: call an API with a key and JSON
Workato's HTTP connector calls any HTTP API: a Header auth connection holds the key, and Send request via HTTP POSTs a JSON body and maps the reply.
Salesforce Apex HTTP callout: POST JSON to an external API
An Apex HTTP callout builds an HttpRequest, sends it with Http.send and reads the HttpResponse. From a trigger or after DML, it must run asynchronously.
Tenacity retry in Python: safe settings for a paid API POST
Bare @retry in tenacity retries forever with no wait. For a paid POST, cap attempts, add jittered backoff, retry only transient errors, and reuse one key.
Polly retry policy for an HttpClient POST to a paid API
A Polly retry for a paid POST: handle only transient failures, back off exponentially with jitter, honor Retry-After, and resend one idempotency key.
Guzzle retry middleware: retry a paid POST without paying twice
Guzzle's Middleware::retry takes a decider and a delay in milliseconds. Retry only transient answers, honor Retry-After, and keep one idempotency key.
Spring Retry and @Retryable for a paid API call in Spring 7
Spring Retry is archived; Spring Framework 7 has @Retryable in core. For a paid API call, narrow the exceptions, back off, and pass one idempotency key in.
p-retry npm: retry a paid API POST and stop on errors
p-retry reruns an async function with exponential backoff. Throw AbortError on answers a resend can't fix, and keep one Idempotency-Key per job.
Python API rate limiting: stay under a per-minute limit
Pace Python API calls with an asyncio limiter set under the API's per-minute budget, keep polling on its own budget, and back off on 429 retry-after.
Promise.allSettled vs Promise.all for a batch of API jobs
Promise.allSettled waits for every promise and reports each outcome; Promise.all rejects on the first failure. For paid API jobs, use allSettled.
API throttling vs rate limiting: what's the difference?
Rate limiting refuses requests over a quota with a 429; throttling slows or queues the excess instead. What each one means for your client.
API sandbox environment: test a paid API without paying
An API sandbox is a separate test environment with fake or free results. Sume has none, so test with its spec, free checks and spend caps.
C# HttpClient default timeout: 100 seconds, and how to set it
HttpClient.Timeout defaults to 100 seconds per request and throws TaskCanceledException. How to set it, and why slow API jobs need polling instead.
Java HttpClient timeout: no default, so set two of them
Java's HttpClient has no request timeout unless you set one: connectTimeout on the client, timeout on each request, and HttpTimeoutException.
Python requests default timeout: there isn't one
Python Requests has no default timeout: without timeout= a call can hang indefinitely. Set (connect, read) on every call, and keep it short for job APIs.
httpx retry: what HTTPTransport(retries=n) covers
httpx retries only ConnectError and ConnectTimeout, via HTTPTransport(retries=n). For read errors, 429 and 503, write a loop that keeps one Idempotency-Key.
Golang HTTP client retry: what net/http retries on POST
Go's http.Transport retries only network errors on reused connections, and a POST only with an Idempotency-Key header. Write the 429 and 5xx loop yourself.
Stripe checkout webhook: start a paid job once per payment
Listen for checkout.session.completed, verify the signature on the raw body, answer 2xx fast, then start the job keyed by the Checkout Session id.
Bash for loop with curl: one API request per line
Loop over a file with while IFS= read -r, build each JSON body with jq --arg, send it with curl --fail-with-body, and pace it under the API's rate limit.
How much does closed captioning cost? Per clip and per minute
Automated captions on Sume cost $0.20 per job for a video up to 60 seconds. What a 10-minute video costs, and open vs closed captions.
Etsy listing video size: length, resolution, and file limits
Etsy listing videos run 3 to 15 seconds, up to 100 MB, and play without sound; Etsy calls 1080 px ideal. The rules, and making a clip from a photo.
JSON to video API: render an MP4 from a timeline document
A JSON to video API renders one MP4 from a document that says which clips play when, over which audio. How Sume's Timeline 1.0 does it, and costs.
Batch video processing by API: one edit, many videos
Batch video processing by API is a loop: one edit job per file, each with its own idempotency key, collected by webhook. How it works on Sume, and costs.
Bulk add a watermark to videos: same logo, every file
To bulk add a watermark to videos, run one overlay job per video with the same logo and layout. How to keep it identical by API, and what it costs.
Automate video editing in Python with an editing API
Automate video editing in Python by calling an editing API with Requests: submit a caption, cut, or crop job, poll until it ends, chain the output.
Automate video editing with n8n: caption and cut by API
Automate video editing with n8n: an HTTP Request node submits a caption or cut job, a Wait node resumes on the webhook, a last node reads the file.
Java subtitle generator API: burn captions with HttpClient
Generate subtitles from Java with the JDK HttpClient: POST the video URL to a captions API, poll the job, then read the captioned video_url.
Captions vs subtitles: what's the difference?
Captions write down what is heard, sound cues included, for viewers who can't hear. Subtitles translate the dialogue for viewers who don't speak it.
How to sync subtitles with video: offset, drift, re-time
Sync subtitles by shifting every timestamp when all lines are off by the same amount, or scaling them when the gap grows. How to fix both for good.
FFmpeg burn subtitles into video: subtitles filter, force_style
Burn subtitles into a video with FFmpeg's subtitles filter: -vf subtitles=subs.srt re-encodes the picture, and force_style overrides the font and colour.
FFmpeg crop video: crop=w:h:x:y, centre, and 9:16
Crop a video with FFmpeg's crop filter: -vf crop=w:h:x:y keeps a w×h area whose top-left corner is at x,y; leave out x and y to crop the centre.
FFmpeg fade in fade out: video and audio, from and to black
Fade a video in and out with FFmpeg: fade=t=in and fade=t=out on the picture, afade on the sound, with the fade-out starting at the length minus its duration.
FFmpeg change frame rate: the fps filter vs -r
Change a video's frame rate with FFmpeg's fps filter: -vf fps=30 drops or duplicates frames and keeps the running time. How -r and framerate differ.
FFmpeg: add a watermark image to a video with overlay
Add a watermark image to a video with FFmpeg: pass the logo as a second input and use overlay=W-w-10:H-h-10 for the bottom-right corner.
Can AI make a lyric video? Yes, if you time the lines
AI can make a lyric video: pictures under the song, plus each lyric line burned in at the time it is sung. You supply the line timings.
How to make a video montage: clips cut to one music track
To make a video montage, pick the music first, mark where the cuts go, then lay short clips over the track at those times in one render.
How to colorize a black and white video with AI
Colorize a black and white video with an AI video-to-video edit: send the clip and a prompt naming the colors. The model invents them.
AI outfit change video: change clothes in a clip with AI
Change someone's outfit in an existing video with an AI video-to-video edit: name the garment, what it becomes, and what must stay the same.
AI color grading for video: AI edit or a fixed grade?
AI color grading for video means an AI edit that re-renders a clip toward a look, or a fixed filter grade applied the same way to every frame.
AI Santa video: a personal message with the child's name
Make an AI Santa video in three steps: a Santa character still, the message as speech, then lip sync. One short job per child, billed per second.
Can I use AI images on Pinterest? What the AI label means
Yes. Pinterest labels Pins it detects as AI-generated or AI-edited "AI modified", from metadata or its classifiers, and you can appeal a wrong label.
LinkedIn content credentials: what the CR label means
LinkedIn shows a C2PA icon on images and videos signed with Content Credentials; clicking it shows whether AI was used, the tool, and who signed it.
Can ChatGPT make podcasts? Script, voices and one audio file
ChatGPT can write a podcast script. For a finished episode, give it speech tools over MCP: it voices each host's lines and joins them into one file.
Can ChatGPT create a video of me talking? Photo plus voice
Yes, with a connected tool: in developer mode ChatGPT can voice your script and lip sync a photo of you to it over MCP, then link the finished clip.
AI architecture video generator: renders to moving shots
An AI architecture video generator animates a still render: the render is the first frame, the prompt names one camera move. Limits, walkthroughs, cost.