SIP-01 — Search Index Protocol (kind 39697)

SIP-01 — Search Index Protocol (kind 39697)

This project is the canonical documentation and exploration site for SIP-01, the Search Index Protocol. The protocol itself defines one custom event kind:

Summary

One addressable event per (indexer pubkey, normalized URL) — an indexer's signed statement: "I observed this web page at this time, and here is its public metadata."

• d = "widx:" + sha256(normalized_url)[0:32] — deterministic URL identity,

identical across all independent indexers (group-by-d / count-pubkey gives the independent-observation count).

• u = canonical URL, normalized per SIP-01 §7 (www-stripping, tracking-param

removal, query-param sorting, trailing-slash removal).

• x = sha256(title + "\n" + description) — content-agreement hash.
• v = "1" — schema version.
• content = { title, description?, image? } JSON.
• Modularity: optional core tags (t, l, published, source) plus a

registered extension-tag registry (type, platform, category, network, country, mime) with an x- prefix rule for experiments.

All events carry an alt tag with a human-readable description ("Web index observation: …").

This site

• /spec — the full submission-ready specification (also downloadable as

raw markdown from /spec/SIP-01.md).

• /registry — the core + extension tag registry and how to extend it.
• /query — query reference (NIP-01 filters, NIP-50 operators, NIP-11

capability advertisement, NIP-77 federation).

• /audit — the cross-implementation fact-check / bug-check report.
• /explorer — live kind 39697 explorer with a client-side validator and a

URL → d-tag calculator implementing SIP-01 §7/§8 byte-compatibly.

Reference implementations (cross-checked by the audit)

• 0xSearchstr — search engine + reference client impl
• 0xPresearchstr — search engine (clearnet + tor/i2p)
• UNCAGED-ENGINE — engine template / reference impl
• Crwalstr — browser crawler (pure SIP-01 publisher)
• UNCAGED-Index-Relay — validating index relay (NIP-50/NIP-77)

This site only reads kind 39697 from public relays (plus a local validator/calculator). It publishes nothing.