indexer-setup

Check the local indexer before calling it, not after it fails

The indexer module's four tools (watch_address, query_kupo_matches, get_rollup_status, query_custom_indexer — src/modules/indexer/index.ts) all assume a local sidecar process is already running: Kupo for the first three, Yaci Store for the fourth. Nothing calls them proactively — KUPO_URL and YACI_STORE_URL just default to http://localhost:1442 and http://localhost:8080 (src/config.ts) whether or not anything is actually listening there. If no sidecar is running, the tool call fails with a raw fetch/connection error that doesn't say "start Kupo" — it says something like ECONNREFUSED.

Workflow

1. Before calling any watch_address, query_kupo_matches, get_rollup_status, or query_custom_indexer tool, check reachability directly:

   • Kupo: curl -sf -m 3 "${KUPO_URL:-http://localhost:1442}/health"
   • Yaci Store: curl -sf -m 3 "${YACI_STORE_URL:-http://localhost:8080}" (or whatever base path the specific query in question targets — Yaci Store doesn't have a single fixed health path the way Kupo does, so a plain reachability check against the configured base URL is the honest floor here).

2. If unreachable, tell the user plainly that no local sidecar is running at that URL — don't call the tool and let it fail first. Point them at:

   • Kupo: the official setup docs (https://cardanosolutions.github.io/kupo/)
   • Yaci Store: https://github.com/bloxbean/yaci-store (already linked in query_custom_indexer's own tool description)

   Do not invent a specific docker run one-liner unless you have actually verified the exact flags for the user's setup (node socket path, network magic, etc.) — Kupo in particular needs either a local node connection or Ogmios, which varies by environment, so a wrong guessed command would send the user down the wrong path.

3. If KUPO_URL/YACI_STORE_URL are unset, note they're defaulting to localhost, which only works if the sidecar happens to be running on this same machine — remote indexer setups need the env var set explicitly.

4. Once reachable, proceed with the requested indexer tool call normally.