redifind 0.1.1

Redis-backed ranked search for your workspace

redifind — Redis-backed Ranked Search for Your Workspace (CLI + Python)

A fast, hackable, TF/IDF-ranked search index for local workspaces (code, docs, notes) built on Redis and redis-py.

Think: ripgrep + persistence + ranking + filters — with a simple schema you can extend (boosts, tags, metadata, negative filters, recency, etc.).

Scope note: redifind is intentionally aimed at small → medium corpora (developer workspaces, docs exports, internal knowledge bases). Redis keeps the index in memory, so size grows with the index.

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Why Redis for Search?

Redis gives us:

• Incremental updates (reindex only changed files)
• Fast set/zset math (union/intersection + weighted scoring)
• Low operational complexity (single redis instance; optional persistence/replication)
• Flexibility (custom tokens, custom boosts, custom filters)

Core trick:

• For each term we store a ZSET: term -> {doc_id: TF}
• On query, compute IDF per term, then do ZUNIONSTORE with weights = IDF
• Optionally combine with metadata / boosts (filename, headings, recency)

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Features (MVP)

• Index a directory of files (code + docs)
• Ranked search (TF/IDF-ish) with Redis ZSET unions
• Filters and facets using special tokens (ext:py, path:src/)
• Required (+term) and excluded (-term) terms
• Snippet previews with query-term highlighting and fixed-width context windows
• Structured JSON output across all primary commands (index, query, show, remove, prune, stats, doctor, watch)
• Query explain mode (query --explain) with DF/IDF term weights and per-result score contributions
• Namespace isolation via --prefix so you can run multiple indexes in one Redis

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Non-Goals (for the first release)

• Exact phrase search with positional indexes (possible later)
• Fuzzy phonetic matching / stemming (easy add-on later)
• Billion-doc scale (Redis memory + merge latency will bite)

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Installation (Linux Only)

redifind currently supports Linux only. On first run, redifind will:

• verify you are on Linux
• check whether Redis is reachable
• if Redis is missing, ask if you want redifind to install it for you

1) Clone and install

git clone <your-repo-url>
cd redifind
python -m venv .venv
source .venv/bin/activate
pip install -e .

2) Redis (automatic or manual)

When you run a command (e.g. redifind index), redifind will check Redis. If Redis is not found, it will ask to install via your system package manager. You can also install manually, for example:

sudo apt-get update
sudo apt-get install -y redis-server
sudo systemctl enable --now redis-server

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Quick Start

Index your workspace:

redifind index ~/work/myrepo \
  --include "**/*.py" "**/*.ts" "**/*.md" \
  --exclude ".git/**" "node_modules/**" \
  --redis "redis://localhost:6379/0" \
  --prefix "myrepo:"

Query:

redifind query "redis pipeline +zunionstore -lua ext:py" --top 15 --prefix "myrepo:"

Watch for changes (incremental):

redifind watch ~/work/myrepo --include "**/*.py" "**/*.md" --prefix "myrepo:"

Inspect a document:

redifind show "/abs/path/to/file.py" --prefix "myrepo:"

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Development (uv)

Install dev tools and run tests using uv:

uv add --dev pytest
cd /tmp
UV_CACHE_DIR=/tmp/uv-cache PYTHONPATH=/home/redifind/src uv --project /home/redifind run pytest /home/redifind

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CLI Command Reference

redifind index <PATH...>

Index one or more paths (directories or files).

Options:

• --include <glob...>: include patterns (repeatable)
• --exclude <glob...>: exclude patterns (repeatable)
• --max-bytes <n>: skip very large files (default: 2_000_000)
• --redis <url>: Redis URL (default: redis://localhost:6379/0)
• --prefix <ns>: namespace prefix for all keys (default: rsearch:)
• --drop: drop existing index namespace before indexing
• --json: output structured JSON

Examples:

redifind index . --include "**/*.py" "**/*.md"
redifind index ~/notes --include "**/*.md" --prefix "notes:"

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redifind query <QUERY>

Query language:

• plain terms: redis zunionstore
• required terms: +pipeline
• excluded terms: -lua
• filters: ext:py, path:src/, name:README
• quoted strings are treated as multiple tokens in MVP (phrase search later)

Options:

• --top <n>: number of results (default 10)
• --offset <n>: pagination offset (default 0)
• --json: output JSON
• --explain: show term DF/IDF weights and per-result score breakdown
• --with-scores: show numeric scores

Examples:

redifind query "rate limit +redis -memcached ext:md" --top 20
redifind query "deployment path:infra/ ext:yml"
redifind query "redis pipeline ext:py" --explain --with-scores
redifind query "redis pipeline ext:py" --json --explain

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redifind show <DOC_ID>

Print document metadata + a snippet preview.

DOC_ID is the canonical file path (for workspace indexing).

In other ingestion modes you could use UUIDs; MVP uses full path.

Options:

• --query <text>: optional query for snippet context
• --json: output structured JSON

Notes:

• With --query, snippet output highlights matched query terms in the terminal.

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redifind remove <PATH...>

Remove documents from the index (by file path).

Options:

• --json: output structured JSON
• --size-unit <auto|bytes|kb|mb|gb>: choose size display units for indexed/Redis memory values

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redifind prune <ROOT>

Remove indexed docs that no longer exist on disk under ROOT.

Options:

• --json: output structured JSON

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redifind stats

Show index stats:

• docs
• total_terms (unique indexed term keys, including filter tokens)
• indexed_size_bytes_approx and humanized size
• Redis memory usage (used_memory, used_memory_human) when available

Options:

• --json: output structured JSON

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redifind doctor

Run environment checks (Linux + Redis reachability).

Options:

• --json: output structured JSON

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redifind watch <PATH>

Watch a directory and auto-update the index on file changes.

Notes:

• Uses filesystem events
• Debounces rapid saves (future enhancement)

Options:

• --json: output structured JSON startup payload

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Output Examples

Human output

1) src/search/indexer.py  score=2.884
   ... use a non-transactional pipeline to reduce round-trips ...

2) docs/redis-notes.md    score=2.102
   ... zunionstore combines TF scores and applies IDF weights ...

Human explain output (query --explain)

┏━━━━━━━━━━┳━━━━━━━┳━━━━┳━━━━━━━┓
┃ Term     ┃ Count ┃ DF ┃ IDF   ┃
┡━━━━━━━━━━╇━━━━━━━╇━━━━╇━━━━━━━┩
│ redis    │ 1     │ 42 │ 0.251 │
│ pipeline │ 1     │ 13 │ 1.943 │
└──────────┴───────┴────┴───────┘

Explain: /abs/path/src/app.py
pipeline: value=0.583 (tf=0.300, idf=1.943, count=1)
redis: value=0.126 (tf=0.500, idf=0.251, count=1)

JSON output (--json)

{
  "query": "redis pipeline ext:py",
  "offset": 0,
  "count": 10,
  "results": [
    {"doc_id": "/abs/path/src/app.py", "score": 2.884, "path": "/abs/path/src/app.py"},
    {"doc_id": "/abs/path/src/cache.py", "score": 2.102, "path": "/abs/path/src/cache.py"}
  ]
}

JSON explain output (query --json --explain)

{
  "query": "redis pipeline ext:py",
  "offset": 0,
  "count": 10,
  "results": [
    {
      "doc_id": "/abs/path/src/app.py",
      "score": 0.709,
      "path": "/abs/path/src/app.py"
    }
  ],
  "explain": {
    "total_docs": 250,
    "term_weights": [
      {"term": "redis", "df": 42, "idf": 0.251, "count": 1},
      {"term": "pipeline", "df": 13, "idf": 1.943, "count": 1}
    ],
    "results": [
      {
        "doc_id": "/abs/path/src/app.py",
        "score": 0.709,
        "contributions": [
          {"term": "pipeline", "count": 1, "tf": 0.3, "idf": 1.943, "value": 0.583},
          {"term": "redis", "count": 1, "tf": 0.5, "idf": 0.251, "value": 0.126}
        ]
      }
    ]
  }
}

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Redis Data Model (MVP)

All keys are prefixed, e.g. rsearch: or myrepo:.

Core keys:

• prefix:indexed (SET) All indexed doc_ids

• prefix:term:<token> (ZSET) Members: doc_id Score: TF (term frequency normalized), or 1 for boolean index mode

• prefix:doc:<doc_id> (HASH) Metadata:

  • path
  • mtime
  • size
  • sha1 (optional)

• prefix:doc_terms:<doc_id> (SET) All tokens indexed for that doc, so removal is O(#tokens)

Filter tokens (stored same as terms):

• ext:py
• path:src/ (can be hierarchical tokens: path:src, path:src/search)
• name:readme

So filters are just “terms” you can include/require.

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Ranking

MVP ranking:

• TF = normalized term frequency per doc (count / total_terms_in_doc)
• IDF = max(log2(total_docs / df), 0)
• Score(doc) for query terms = Σ (TF(term, doc) * IDF(term))

Implementation uses:

• ZCARD prefix:term:<token> to get document frequencies (df)
• ZUNIONSTORE tmp weights={termkey: idf} to compute weighted union

Exclusion (-term) can be implemented by:

• retrieving results then filtering client-side (MVP), or
• using Redis set/zset diff patterns (later optimization)