Stock Snapshot Skill

Stock prices are the live-data request with the highest stakes-to-availability mismatch: everyone asks, keyless official sources barely exist, and the standard keyless answer — Yahoo Finance's public chart endpoint — is unofficial, reshapeable, and possibly delayed. This skill uses it the only defensible way: clearly sourced, timestamped, delay-flagged, wrapped in the no-advice line, and honest that anything portfolio-grade belongs with a real brokerage feed. Within those fences, it's genuinely useful: quotes, day moves, and recent ranges in one curl.

What This Skill Produces

• The snapshot — last price, day change, day range, volume — with its timestamp and delay flag
• Context on request — 52-week position, recent trend from the chart series (described, not extrapolated)
• The command — exact curl, rerunnable
• The fences — unofficial-source note and the no-advice line, every single time

Required Inputs

Ask for these if not provided:

• The ticker — resolved carefully: company names map to multiple listings ("did you mean the NYSE or Frankfurt listing?"); exchange suffixes matter (SAP.DE vs SAP) and the wrong-listing answer is confidently wrong in the wrong currency
• What they actually want — a number, a day summary, or a range/history — shapes which fields get read
• Why (lightly) — curiosity gets the snapshot; anything that smells like a trading decision gets the snapshot plus the this-is-not-the-data-for-that sentence

Framework: The Fetch and the Fences

1. The call: curl -s -A "Mozilla/5.0" "https://query1.finance.yahoo.com/v8/finance/chart/AAPL?range=1d&interval=1d" — the meta object carries regularMarketPrice, previousClose, regularMarketTime (epoch — convert and show), currency, exchangeName. History: range=1mo&interval=1d → the timestamp + indicators.quote arrays. The User-Agent header is required — without it the endpoint often refuses.
2. Unofficial means fragile, and the skill says so: the endpoint is publicly served but undocumented; it can reshape or gate without notice. On a weird response: report it, don't improvise a price. The source line always reads "Yahoo Finance public endpoint (unofficial)."
3. Timestamp and delay honesty: regularMarketTime gets converted and displayed; outside market hours the snapshot says "as of Friday's close" not "currently"; data may be delayed 15+ minutes depending on exchange — flagged, not assumed away.
4. Currency and exchange discipline: the currency and exchangeName fields are printed with the price — a right number in an unstated currency is a wrong number.
5. The advice fence is absolute: no buy/sell/hold, no price targets, no pattern-reading, no "looks like a good entry." "Should I buy?" gets the snapshot, the volatility fact, and the clean refusal — same posture as crypto-prices, because the reasons are identical.

Output Format

[Ticker] — [exchange, currency]

[Price] · [±change, ±%] on the day · as of [converted timestamp] ([market open / after close])

[Day range · volume · on request: 52-week position, the 1-month shape in one descriptive sentence]

Source: Yahoo Finance public endpoint (unofficial; may be delayed) · rerun: [exact curl] Informational snapshot, not investment advice or trading-grade data — decisions belong on a brokerage feed.

Quality Checks

• The ticker's exchange and currency are printed with the price
• The timestamp is converted and the open/closed state stated
• The unofficial-and-possibly-delayed line appears verbatim in spirit
• Weird responses are reported, never smoothed into a made-up price
• The no-advice fence held, including against indirect asks

Anti-Patterns

• Do not answer prices from memory — a remembered stock price is historical fiction
• Do not resolve ambiguous tickers silently — the wrong listing is the classic confident error
• Do not describe chart history in predictive language — shapes are described, futures are not
• Do not present this endpoint as trading-grade — the fence is part of the answer
• Do not give investment advice under any phrasing — the refusal is the skill working