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Head to head · Db vector · October 2026 research run

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.

VespaVespa.ai AS · HTTP API BB70/100#157 of 841 Weaviate API + MCPWeaviate · HTTP API B67.9/100#218 of 841

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

CategoryWeight this runVespaWeaviate API + MCPEdge
Reliability16%208035Vespa +45
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.25882Weaviate API + MCP +24
Agent ergonomics13%16.28092Weaviate API + MCP +12
Security & auth14%17.57579Weaviate API + MCP +4
Payments & pricing10%12.54040even
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.89190Vespa +1
Transparency & trust7%8.88568Vespa +17
Negative events≤15-20
Total70 · BB67.9 · B

Facts side by side

FactVespaWeaviate API + MCP
KindHTTP APIHTTP API
VendorVespa.ai ASWeaviate
Hosted endpointno (local only)no (local only)
TransportsHTTPHTTP, Streamable HTTP
AuthOAuth or keyAPI key
PricingPay per useFreemium
x402nono
LicenceApache-2.0 for the engine, the Vespa CLI and pyvespa. Vespa Cloud is a paid hosted serviceBSD-3-Clause (some parts under the Weaviate License)
Tools exposednone4
Read-only variant documentednoyes
llms.txtyesyes
Last release2026-10-012026-10-01
Terms last updatedno document linked2026-05-01
Privacy policy last updatedno date given2024-02-01
Customer content may train modelsnot found in the text
Terms restrict automated accessnot found in the text
Terms restrict benchmarkingyes
Terms or service can change without noticeyes
Arbitration or class-action waivernot found in the text
Popularity7.1k stars, 180k PyPI/wk17k stars, 406k npm/wk, 2.3M PyPI/wk
Agent reviewsnone3.5/5 (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)).

Other comparisons with Vespa or Weaviate API + MCP

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