xerj vs paradedb
Two of the top projects in RAG and search, side by side: who leads on each score part and who each one suits, then setup, license, activity and what each review found.
xerj
Elasticsearch-compatible search server that auto-indexes folders for coding agents
paradedb
Postgres extension adding BM25 full-text, vector and hybrid search
Verdict
xerj ranks higher, 86 to 76. Of the 4 score parts we measure for both, xerj leads on 3, paradedb on none and 1 is even.
- Adoptionxerj leads by 15 points, 82 to 67: a wide gap.
- FreshnessEven at 100.
- Maintenancexerj leads by 9 points, 96 to 87.
- Agent-readyxerj leads by 30 points, 30 to 0: a wide gap.
Pick xerj if you are
Developers giving coding agents local code and document search or memory
- Single static binary, no JVM; prebuilt for Linux, macOS and Windows on x86-64 and arm64
- Works with existing Elasticsearch clients pointed at localhost:9200; 1366/1369 ES-YAML conformance tests
Pick paradedb if you are
Teams adding search and vector retrieval to an existing Postgres
- Search and application data share one Postgres with ACID transactions
- Covers BM25, vector and hybrid search, facets and aggregates in SQL
| What we compare | xerj | paradedb |
|---|---|---|
| Score parts, out of 100 | ||
| Adoption | 82, widely used | 67, popular |
| Freshness | 100, active | 100, active |
| Maintenance | 96, healthy | 87, healthy |
| Agent-ready | 30, minimal | 0, none |
| Facts from GitHub and the README | ||
| Stars | 18.9k | 9.5k |
| License | Apache-2.0 (permissive) | AGPL-3.0 (copyleft) |
| Last commit | Nov 2026 | Nov 2026 |
| Last release | Nov 2026 | Nov 2026 |
| Language | Rust | Rust |
| Docker | No | Yes |
| GPU | Not needed | Not needed |
| arm64 or Apple Silicon | Mentioned | Mentioned |
xerj
XERJ is a single Rust binary that speaks the Elasticsearch API. `xerj autoindex <folder>` infers datasets from code, docs, logs, PDFs, SQLite and CSV, and creates one typed index per dataset, with tree-sitter symbols and line numbers for code. It supports BM25, kNN and hybrid search, a `/_memory` agent memory API, and a `xerj mcp` stdio server exposing 13 tools. Its main pitch is cutting agent token use by retrieving passages instead of reading files.
Who it is for: Developers giving coding agents local code and document search or memory
Strengths
- Single static binary, no JVM; prebuilt for Linux, macOS and Windows on x86-64 and arm64
- Works with existing Elasticsearch clients pointed at localhost:9200; 1366/1369 ES-YAML conformance tests
- Autoindex needs no schema; handles code, PDF, DOCX, XLSX, SQLite, mail and logs
- Default lexical embedder runs offline; air-gapped deployment recipe is documented
Weaknesses
- Token savings come from the project's own 16-run study; neutral to negative on popular libraries
- Default embedder is lexical feature-hashing; neural mode is opt-in and downloads about 90 MB
- `--insecure` quick start disables TLS and auth; every caller becomes a superuser
- Optional Jev rerank sends result text to TypeSafe's servers
- Rust, lexical embedder (default, offline), neural embedder (opt-in, ~90 MB download), Jev reranker (optional, external service)
paradedb
ParadeDB is a Rust Postgres extension that adds a custom index for BM25 full-text search, vector search, filters, facets, aggregations and joins. Search runs inside Postgres with standard SQL and ACID transactions, so no separate search engine is needed. It builds on pgrx, Tantivy and Apache DataFusion, and offers ORM integrations plus agent skills and MCP docs.
Who it is for: Teams adding search and vector retrieval to an existing Postgres
Strengths
- Search and application data share one Postgres with ACID transactions
- Covers BM25, vector and hybrid search, facets and aggregates in SQL
- ORM integrations for Drizzle, Django, SQLAlchemy, Rails and EF Core
- Built on Tantivy and DataFusion rather than a custom engine
Weaknesses
- Community edition is AGPL-3.0; Enterprise needs a commercial license
- Self-hosting Enterprise requires contacting sales
- No embedding or document ingestion pipeline included
- Prisma integration is not yet available
- Rust
- Needs PostgreSQL
- Docker
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