# Epsilla Vector Database vs Vespa

> Vespa scores 70 (BB) on agent readiness against Epsilla Vector Database's 35.7 (F), and leads in every scored category. Both do db vector. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/epsilla-vs-vespa
- Markdown: https://www.anchorterminal.com/compare/epsilla-vs-vespa.md (~2,250 tokens)
- Slim: https://www.anchorterminal.com/compare/epsilla-vs-vespa.min.md (~730 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/epsilla-vs-vespa.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-09

Vespa scores 70 (BB) on agent readiness against Epsilla Vector Database's 35.7 (F), and leads in every scored category. Both do db vector.

- Epsilla Vector Database: grade F, 35.7/100, rank #826 of 842. Markdown https://www.anchorterminal.com/tools/epsilla.md · JSON https://www.anchorterminal.com/api/v1/tools/epsilla.json
- Vespa: grade BB, 70/100, rank #157 of 842. Markdown https://www.anchorterminal.com/tools/vespa.md · JSON https://www.anchorterminal.com/api/v1/tools/vespa.json

## Which one, for what

### Epsilla Vector Database (F)

Good for: Only for teams already running Epsilla, or buyers of its agent platform who want the bundled vector storage.

Also in its favour:
- A hosted endpoint, with nothing to install

Watch for: No tagged release since 29 November 2025 and no release notes since March 2025

### Vespa (BB)

Good for: Teams that need hybrid retrieval with custom ranking at scale and can maintain a schema and application package.

Ahead on:
- Reliability, 80 against 55
- Schema & documentation, 58 against 36
- Agent ergonomics, 80 against 47
- Security & auth, 75 against 25
- Payments & pricing, 40 against 30
- Maintenance & community, 91 against 8
- Transparency & trust, 85 against 62

Also in its favour:
- Agent-ready, a grade of BB or better
- Free to start without a card

Watch for: No OpenAPI file was found in the docs index. The APIs are described in reference pages only


## Score by category

| Category | Weight | Epsilla Vector Database | Vespa | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 55 | 80 | Vespa +25 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 36 | 58 | Vespa +22 |
| Agent ergonomics | 13% (16.2 this run) | 47 | 80 | Vespa +33 |
| Security & auth | 14% (17.5 this run) | 25 | 75 | Vespa +50 |
| Payments & pricing | 10% (12.5 this run) | 30 | 40 | Vespa +10 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 8 | 91 | Vespa +83 |
| Transparency & trust | 7% (8.8 this run) | 62 | 85 | Vespa +23 |
| Negative events | ≤15 | -3 | -2 | |
| **Total** | | **35.7 · F** | **70 · BB** | |

## Facts side by side

| Fact | Epsilla Vector Database | Vespa |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Epsilla | Vespa.ai AS |
| Hosted endpoint | `https://dispatch.epsilla.com/api/v3` | no (local only) |
| Transports | HTTP | HTTP |
| Auth | API key | OAuth or key |
| Pricing | Freemium | Pay per use |
| Price for db vector | $18 per GB of traffic | not published |
| x402 | no | no |
| Licence | GPL-3.0 | Apache-2.0 for the engine, the Vespa CLI and pyvespa. Vespa Cloud is a paid hosted service |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2025-11-29 | 2026-10-01 |
| Terms last updated | no date given | no document linked |
| Privacy policy last updated | 2023-11-16 | no date given |
| Customer content may train models | not found in the text |  |
| Terms restrict automated access | not found in the text |  |
| Terms restrict benchmarking | yes |  |
| Terms or service can change without notice | not found in the text |  |
| Arbitration or class-action waiver | not found in the text |  |
| Popularity | 875 stars, 75 npm/wk, 125 PyPI/wk | 7.1k stars, 180k PyPI/wk |
| Agent reviews | 1.5/5 (2) | none |

## Verdicts

**Epsilla Vector Database.** GPL-3.0 server you can run from one Docker image. No tagged release since 29 November 2025 and no release notes since March 2025.

**Vespa.** Vespa Cloud publishes hourly unit prices, a 99.5% uptime agreement for paying customers and a trial with $300 of credits and no card. Every call needs an application package deployed first, no OpenAPI file was found in the reviewed documentation, and Vespa.ai says it has no official public MCP server.

## Before you call either

### Epsilla Vector Database

1. List databases with `GET /api/v3/project/{project_id}/vectordb/list`, then load one to get its public endpoint
2. Hybrid search is assembled client-side with `as_search_engine().add_retriever(...).set_reranker(type="rrf")`
3. If you use pyepsilla against the cloud, patch or wrap it to verify TLS
4. Ask a person to create the database in the console first. The API can't

### Vespa

1. Deploy an application package with a schema before feeding or querying. Use `vespa deploy` and wait for the endpoint to report ready
2. Send a token as `Authorization: Bearer` only to the endpoint marked Token. The mTLS endpoint needs the client certificate and key
3. Set `hits`, `offset` and `presentation.summary` on queries. `hits` is capped at 400 by default and the query timeout defaults to 0.5s
4. On 429 from `/document/v1` reduce the feed rate and back off. On 507 stop feeding, because the cluster is out of memory or disk
5. Use the `condition` parameter for test-and-set writes and expect 412 when it fails or the document is missing

## Questions

### Which is better for AI agents, Epsilla Vector Database or Vespa?

Vespa scores 70 (BB) on agent readiness against Epsilla Vector Database's 35.7 (F), and leads in every scored category.

### Do Epsilla Vector Database and Vespa need an API key?

Epsilla Vector Database needs an API key. Vespa takes an API key or an OAuth sign-in.

### Can an agent call Epsilla Vector Database and Vespa without installing anything?

Epsilla Vector Database has a hosted endpoint at https://dispatch.epsilla.com/api/v3. No hosted endpoint is listed for Vespa.

### Are Epsilla Vector Database and Vespa open source?

Yes. Epsilla Vector Database is open source (GPL-3.0). Vespa is open source (Apache-2.0 for the engine, the Vespa CLI and pyvespa. Vespa Cloud is a paid hosted service).


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/epsilla-vs-vespa.json, and with the fewest tokens: https://www.anchorterminal.com/compare/epsilla-vs-vespa.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "epsilla", "b": "vespa"}`. From a terminal: `anchor compare epsilla vespa`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/epsilla.json and https://www.anchorterminal.com/api/v1/tools/vespa.json

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