Prediction market template using Chainlink Data Streams

[ejacquier]

Summary

New starter template: prediction-market-data-streams-ts, a mirror of the existing prediction-market-ts template, but using the Chainlink Data Streams REST API (off-chain, HMAC-authenticated) instead of on-chain Data Feeds for price
resolution.

Same three-workflow lifecycle, byte-identical shared PredictionMarket.sol contract, same pre-deployed Sepolia address — only the price source changes.

What's different from prediction-market-ts

Aspect	Data Feeds (existing)	Data Streams (this PR)
Price source	On-chain PriceFeedAggregator contract	Off-chain Data Streams REST API
Price read	priceFeed.latestAnswer(runtime) + priceFeed.decimals(runtime)	HTTP GET + HMAC-SHA256 auth + ABI decode (v3 Crypto Advanced report)
Decimals	Read from the feed (8 for BTC/USD)	18 from report → scaled down to 8
Capabilities	cron, log-trigger, chain-read, chain-write	+ http
Secrets	None used by workflows	DATA_STREAMS_API_KEY, DATA_STREAMS_API_SECRET

[github-actions]

👋 ejacquier, thanks for creating this pull request!

To help reviewers, please consider creating future PRs as drafts first. This allows you to self-review and make any final changes before notifying the team.

Once you're ready, you can mark it as "Ready for review" to request feedback. Thanks!

[dz235]

Suggestion:

• Consider changing market definition from "Will BTC be above $100,000 by {expirationDate}?" to "Will BTC be above $100,000 on {expirationDate}?" See: https://polymarket.com/event/bitcoin-above-on-may-2

• The current dispute workflow fetches the latest Data Streams price at the time the dispute workflow runs, then uses that fresh price to re-resolve the market. This means the dispute is not verifying the price used during the original resolution, nor the price at the market’s intended expiration/resolution time. For this template, the simplest fix is to document the current behavior explicitly.

Reviewed under the assumption that this is a template and not intended for product design advise.