# Watch Xch Price

> Notify when XCH spot price crosses a configured threshold in any CoinGecko-supported currency (USD, EUR, GBP, BTC, SATS, etc.). Use when the user asks for a price alert, wants to know when XCH "hits $X", or sets a target. Accepts threshold, currency, direction, channel as arguments for programmatic invocation.

- Skill: `spacetime-technology/watch-xch-price` (Agent Skill)
- Install (CLI): `npx skillmds@latest add spacetime-technology/watch-xch-price`
- Raw SKILL.md: https://api.skillmd.com/api/skills/spacetime-technology/watch-xch-price/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: Spacetime-Technology (https://skillmd.com/u/spacetime-technology)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/spacetime-technology/watch-xch-price

---


# Watch XCH price

You are watching the XCH spot price and notifying when it crosses a configured threshold. Price comes from chia-explorer's CoinGecko-backed tool. Read-only. Schedulable.

This skill follows the conventions in this repo's `SKILLS.md`. Read that if anything below is unclear.

## Required capabilities

- **chia-explorer** (`mcp__chia-explorer__*`) — mandatory.
- **A notification MCP** — pick whichever is installed. If none, fall back to `~/.chia-skills/alerts/`.

## Resolve inputs

You need: `$threshold`, `$currency`, `$direction`, `$channel`.

- `$threshold` — a numeric price target. Required.
- `$currency` — three-letter currency code (e.g. `usd`, `eur`, `gbp`, `btc`, `sats`). Default `usd`. Lowercase.
- `$direction` — one of `above` (alert when price ≥ threshold), `below` (alert when price ≤ threshold), `cross` (alert on either-side crossing of the threshold). Default `cross`.
- `$channel` — notification channel, default `auto`.

Resolve: arguments → context → ask user.

Validate:

- `$threshold` must be a positive number.
- `$currency` must match a CoinGecko-supported code. If the chia-explorer price tool returns an error for the code, surface it.
- `$direction` must be one of the three values above. Anything else → ask the user to clarify.

## Load or initialise state

State file: `~/.chia-skills/state/watch-xch-price__<currency>_<threshold>_<direction>.json`.

Shape:

```json
{
  "threshold": 50.0,
  "currency": "usd",
  "direction": "cross",
  "last_price": 47.32,
  "last_check_iso": "2026-05-19T14:33:00Z",
  "last_alerted_at": null,
  "skill_version": "0.1.0"
}
```

On first run: fetch current price, record it as `last_price`, save state, emit `STATUS: success`, `EVENTS: 0` with a message like "price watch started at $47.32 — will alert on threshold". Don't fire an alert on first run even if the price already satisfies the condition; the user just set this watch up.

## Check the price

Fetch current XCH price in `$currency` via chia-explorer's price tool.

## Decide whether to alert

Compute crossing logic:

- `direction = above` → alert if `last_price < $threshold` and `current_price >= $threshold`.
- `direction = below` → alert if `last_price > $threshold` and `current_price <= $threshold`.
- `direction = cross` → alert if either of the above is true.

Apply a small **debounce**: if `last_alerted_at` is within the last 60 minutes, suppress duplicate alerts. This stops "flickering" when the price hovers exactly on the threshold.

If no crossing happened, this is a `no_change` run.

## Compose the notification

```
XCH crossed $50.00 (USD)

  Now:        $50.42
  Previous:   $47.32
  Threshold:  $50.00 (above)
  Move:       +6.6% since last check

  Not advice — just a heads-up.
```

For non-fiat currencies (BTC, sats), format appropriately: 5 decimals for BTC, integer for sats.

Add the "Not advice" line to every message. The skill is not a trading bot.

## Send the notification

Pick a channel by priority (same as other watch skills). Fall back to `~/.chia-skills/alerts/` if none available.

## Update state

Update `last_price`, `last_check_iso`, and (if alert fired) `last_alerted_at`. Write state atomically.

If the alert channel failed, still update `last_price` and `last_check_iso` to keep the price tracker current, but **don't** update `last_alerted_at`. Next scheduled run will retry the alert if the condition still holds (and debounce permits).

## Scheduling

This skill is one-shot. Wire to:

- **`schedule` skill / cron** — every 15 minutes is plenty for price alerts. Don't poll faster than every minute (CoinGecko free tier rate limits).
- **`/loop`** — fine for short windows ("watch through the close").

## Hard rules

- **No advice.** Report the price; don't recommend buy/sell.
- **No retroactive alerts on first run.** Record current price and start fresh.
- **Debounce 60 minutes** to avoid flicker alerts.
- **Respect CoinGecko rate limits.** Don't poll faster than 1/minute without an API key.

## Recovery patterns

- **CoinGecko 429 / rate-limited.** Don't update state. Emit `STATUS: failed`, `REASON: price API rate-limited`. Next scheduled run picks up.
- **CoinGecko returns weird value (negative, zero, NaN).** Treat as a transient error; don't update state; emit `STATUS: failed`.
- **State file says we already alerted today within debounce window.** Suppress alert, emit `STATUS: no_change`, `REASON: debounced`.

## Output

```
STATUS: success | no_change | partial | failed | aborted
ALERTED: true | false
PRICE: <current price formatted>
CURRENCY: <code>
THRESHOLD: <threshold>
DIRECTION: above | below | cross
CHANNEL: <channel used> | inline | none
ARTIFACT: <path to inline alert file> | none
REASON: <one line, only when STATUS is failed, partial, or aborted, or when no_change is due to debounce>
```