Rangefind MCP server

Rangefind

Rangefind is a static search engine for large sites that cannot or should not run a search server.

It builds a sparse inverted index into static files, then lets the browser query that index with HTTP Range requests. The core idea is simple: keep the logical search shards small, but pack them into a small number of static files so deploys and cold starts stay practical.

This repository is the standalone extraction of a production prototype built for a large thesis corpus.

What Is Implemented

The list below is the compact overview. The complete feature guide explains every supported search lane, build mode, runtime, integration, feature combination, fallback, and deliberate boundary with runnable examples.

with data-rangefind-* attributes for body scoping, metadata, facets, and sorts.

• JSONL document input.
• Static-site crawler: rangefind build ./dist indexes built HTML directly,

engine over local index directories (positional file reads) or remote HTTP(S) indexes, with browser-equivalent caching — immutable content-addressed objects cached on disk and in a memory LRU, manifests revalidated with ETags.

• Schema-driven weighted fields.
• BM25F-style field scoring.
• Phrase signals for title/heading fields.
• Adaptive posting segments.
• Independently compressed posting segments packed into terms/packs/*.bin.gz.
• Single ESM browser runtime bundle at dist/runtime.browser.js.
• Node runtime (rangefind/node) for MCP servers, CLIs, and SSR: same query

embedded JS hosts: fully offline search over a bundled or downloaded index via positional file reads, or remote HTTP(S) indexes with memory + persistent caching — see docs/mobile.md (covers WebView, Flutter, and native apps too).

• Mobile runtime (rangefind/mobile) for React Native/Hermes and other

and terms/directory-pages/*.bin.gz.

• Lazy paged binary range directories at terms/directory-root..bin.gz

records for low-transfer result fetching.

• ZFS-inspired object pointers with SHA-256 verification before decompression.
• Content-addressed immutable pack and directory filenames for CDN caching.
• Exact compressed-object deduplication during index construction.
• Locality-ordered doc packs with a tiny doc-id ordinal table and dense pointer

where original document ids are clustered.

• Dense binary doc-page payload packs for browse, filter, and sort result pages

changing the main inverted index; a single title authority also supplies bounded prefix autocomplete without a second large build structure.

• Range-packed result payloads with capped display fields.
• Range-addressable posting-block sidecar for high-df terms.
• Optional authority sidecar for exact title/entity/alias rescue without

spools, raw/compressed document spools, heap-based segment merge, and sampled build telemetry.

• Range-packed binary facet dictionaries for high-cardinality metadata.
• File-backed build pipeline with immutable posting segments, selected-term

executes only the strongest corrected searches when first-page results are empty or weak.

• Minimal runtime manifest with lazy full-manifest and telemetry sidecars.
• Browser runtime with adaptive HTTP Range coalescing and bounded overfetch.
• Main-index typo correction that uses bounded vocabulary shard probes and

sorting.

• Multi-value keyword facets with lazy dictionary loading.
• Range-addressed typed numeric, date, and boolean doc-values for filters and

early-stop browsing.

• Lazy binary sorted doc-value trees for range-pruned top-k sort and doc-order

bounding-box and radius filters, exact nearest-neighbor distance sort with early-stop proofs (with or without a text query), text-plus-geo filtering, per-cell filter summaries, and distance boosts.

• Lucene-style geo point fields with a range-addressed static KD tree:

indexes for one-range map results and

• Optional compact geo result capsules and multi-resolution facet-to-cell

Shortened. The full README is on GitHub.