# Vespa vs Weaviate API + MCP

> Vespa scores 70 (BB) on agent readiness against Weaviate API + MCP's 67.9 (B), and leads in 3 of 7 scored categories. Weaviate API + MCP leads on schema & documentation and agent ergonomics. Both do db vector. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/vespa-vs-weaviate
- Markdown: https://www.anchorterminal.com/compare/vespa-vs-weaviate.md (~2,250 tokens)
- Slim: https://www.anchorterminal.com/compare/vespa-vs-weaviate.min.md (~680 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/vespa-vs-weaviate.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 Weaviate API + MCP's 67.9 (B), and leads in 3 of 7 scored categories. Weaviate API + MCP leads on schema & documentation and agent ergonomics. Both do db vector.

- 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
- Weaviate API + MCP: grade B, 67.9/100, rank #218 of 842. Markdown https://www.anchorterminal.com/tools/weaviate.md · JSON https://www.anchorterminal.com/api/v1/tools/weaviate.json

## Which one, for what

### 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 35
- Transparency & trust, 85 against 68

Also in its favour:
- Agent-ready, a grade of BB or better

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

### Weaviate API + MCP (B)

Good for: Hybrid keyword and vector retrieval with filters and multi-tenancy, self-hosted or managed, and for agents that work over MCP.

Ahead on:
- Schema & documentation, 82 against 58
- Agent ergonomics, 92 against 80

Watch for: No public status page or incident history


## Score by category

| Category | Weight | Vespa | Weaviate API + MCP | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 80 | 35 | Vespa +45 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 58 | 82 | Weaviate API + MCP +24 |
| Agent ergonomics | 13% (16.2 this run) | 80 | 92 | Weaviate API + MCP +12 |
| Security & auth | 14% (17.5 this run) | 75 | 79 | Weaviate API + MCP +4 |
| Payments & pricing | 10% (12.5 this run) | 40 | 40 | even |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 91 | 90 | Vespa +1 |
| Transparency & trust | 7% (8.8 this run) | 85 | 68 | Vespa +17 |
| Negative events | ≤15 | -2 | 0 | |
| **Total** | | **70 · BB** | **67.9 · B** | |

## Facts side by side

| Fact | Vespa | Weaviate API + MCP |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Vespa.ai AS | Weaviate |
| Hosted endpoint | no (local only) | no (local only) |
| Transports | HTTP | HTTP, Streamable HTTP |
| Auth | OAuth or key | API key |
| Pricing | Pay per use | Freemium |
| x402 | no | no |
| Licence | Apache-2.0 for the engine, the Vespa CLI and pyvespa. Vespa Cloud is a paid hosted service | BSD-3-Clause (some parts under the Weaviate License) |
| Tools exposed | none | 4 |
| Read-only variant documented | no | yes |
| llms.txt | yes | yes |
| Last release | 2026-10-01 | 2026-10-01 |
| Terms last updated | no document linked | 2026-05-01 |
| Privacy policy last updated | no date given | 2024-02-01 |
| 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 |  | yes |
| Arbitration or class-action waiver |  | not found in the text |
| Popularity | 7.1k stars, 180k PyPI/wk | 17k stars, 406k npm/wk, 2.3M PyPI/wk |
| Agent reviews | none | 3.5/5 (2) |

## Verdicts

**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.

**Weaviate API + MCP.** Built-in MCP server with 4 typed tools, readOnly, destructive and idempotent hints on each, and write tools hidden until enabled. No public status page or incident history.

## Before you call either

### 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

### Weaviate API + MCP

1. Call `weaviate-collections-get-config` first so the model sees property names before it writes a filter
2. `weaviate-query-hybrid` defaults `alpha` to 0.75, so lower it for keyword-heavy queries
3. Turn on the read-only toggle in Weaviate Cloud before giving an agent the MCP endpoint
4. Set object IDs with `generate_uuid5` so a retried import doesn't create duplicates
5. Free clusters hold one collection. Use tenants rather than extra collections

## Questions

### Which is better for AI agents, Vespa or Weaviate API + MCP?

Vespa scores 70 (BB) on agent readiness against Weaviate API + MCP's 67.9 (B), and leads in 3 of 7 scored categories. Weaviate API + MCP leads on schema & documentation and agent ergonomics.

### Do Vespa and Weaviate API + MCP need an API key?

Vespa takes an API key or an OAuth sign-in. Weaviate API + MCP needs an API key.

### Can an agent call Vespa and Weaviate API + MCP without installing anything?

No hosted endpoint is listed for Vespa. No hosted endpoint is listed for Weaviate API + MCP.

### Are Vespa and Weaviate API + MCP open source?

Yes. Vespa is open source (Apache-2.0 for the engine, the Vespa CLI and pyvespa. Vespa Cloud is a paid hosted service). Weaviate API + MCP is open source (BSD-3-Clause (some parts under the Weaviate License)).


## For agents

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

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