See if your line takes more pieces to send
On the same model, fewer pieces cost less to send and more pieces cost more.
Simplified illustration: not how an AI tool works inside.
“Refunds take five days.”
Pieces: Refu, nds, space, take, space, five, space, days, full stop.
9 pieces. This is the example sentence. Same number of pieces as the example sentence, so about the same cost to send.
Same number of pieces as the example sentence, so about the same cost to send.
A token is a piece of text the model counts. Real models split text their own way (Tokens card).
Where it comes from Anthropic · OpenAILast checked 2026-10-21
Build with AI that actually holds up.
Short cards and hands-on labs take you from your first prompt to something you can ship. Each week we show you what changed and what it means for what you're building.
Neutral. Every claim is sourced and dated. No account needed.
Decide, practice, and know what changed.
Changes to act on
All changesWhat are you trying to do?
Sources on every lesson and card
Use AI at work
- Get better answers from my AI toolYou'll be able to state the task, the facts, the reader, and the shape, then follow up.
Where it comes from Anthropic · Google AI for DevelopersLast checked 2026-10-19
- Check if an answer is rightYou'll catch a wrong date, name or number before you pass it on.
Where it comes from Anthropic · Google AI for Developers · OpenAI API docsLast checked 2026-10-19
- Use AI safely at workYou'll be able to get help on a work task without sharing private details.
Where it comes from Anthropic Privacy Center · Google · Google Workspace HelpLast checked 2026-10-19
- Pick the right AI tool for the jobYou'll be able to match the job to a tool you can use, and to the rule you follow.
Where it comes from Anthropic · OpenAI API docsLast checked 2026-10-20
Not sure which AI tool to reach for? See what AI can help with, using tools you may already have →
- Save time on tasks I repeatYou'll be able to keep the instructions and add only what is new.
Where it comes from Anthropic · Anthropic · GoogleLast checked 2026-10-19
You've finished Lessons 3, 5, 6 and 7. Next: Know what to hand over and what to keep → Builder path.
Build with AI
- Answer from your own documentsSplit your files, find the right passage, and tie the reply to it.
Where it comes from Gemini · LlamaIndex · OpenAILast checked 2026-10-17
- Spot made-up answersCatch claims your prompt and sources don't support.
Where it comes from Anthropic · Gemini API · OpenAILast checked 2026-10-17
- Cut the cost of repeated promptsPut the unchanging part first, so repeat requests cost less.
Where it comes from Anthropic · Gemini API · OpenAILast checked 2026-10-23
- Get answers in a fixed formatRequest the fields you actually read, so code can read them.
Where it comes from Anthropic · Gemini API · OpenAILast checked 2026-10-17
- Build an agentLet AI models call your tools, run each task to a clear stop, check what goes in and out, make risky actions wait for a person, find why a run went wrong and score whole tasks, and review a coding agent's change before you merge it.Read Structured Outputs first if you haven't, then Tool calling.
Where it comes from OpenAI · Anthropic · OpenAI · GitHub DocsLast checked 2026-10-18
- Ship it to productionCatch a broken change before users do, see why a request failed, check cost, speed, privacy and the model's license, and spot quality drops after launch.
Where it comes from Anthropic · LangSmith · OpenAI · OpenAI · OpenAI · Meta · OpenAI · LangSmithLast checked 2026-10-18
Or search for what you need
See how a support assistant answers with sources
Ask a question and see which passages it uses to answer. Example: the answer is simulated.
What's new
All updates-
Is your judge right?
Compare a language-model judge with human labels on eight scripted replies before that judge gates a release.
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Price an agent run
Price one recorded agent run from its steps and how often the loop fires, then again after the cache expires.
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Model facts and a migration replay
Look up a model ID's window, output cap, rate link, cache rules, and shutdown date, then replay five recorded requests before you rename.