Seltz

Seltz is a San Francisco-based AI infrastructure company building the web retrieval and knowledge layer for the agentic internet. Its Web Knowledge API gives LLMs, RAG pipelines, and autonomous agents real-time, context-engineered web data through a single call: POST /v1/search returns ranked, cleaned source documents, POST /v1/answer returns a direct RAG answer with citations, and an OpenAI-compatible /v1/chat/completions endpoint serves web-grounded chat. Rather than returning raw snippets like a traditional search API, Seltz shapes web content to maximize usefulness for machine reasoning. Founded in 2025 by Antonio Mallia (Amazon, Pinecone) and backed by Speedinvest and B Capital, Seltz ships official Python and TypeScript SDKs, a hosted MCP server, and integrations for OpenAI, Anthropic, Mistral, LlamaIndex, Agno, Langroid, Dify, n8n, and Zapier.

Seltz publishes 2 API contracts indexed on the APIs.io network: Answer API and Search API. Tagged areas include Company, Web Search, AI Infrastructure, Retrieval, and RAG.

The Seltz catalog on APIs.io includes 1 Spectral governance ruleset.

Seltz’s developer surface includes documentation, API reference, getting-started guide, sandbox, pricing, signup flow, engineering blog, and 20 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

53.3/100 developing ▬ flat Agent 47/100 agent ready Front door AI 6/6 dominant Heartbeat 100/100 alive saas Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

AccessPaid

1 published contract 1 MCP Servers 2 Agent Skills

Company Web Search AI Infrastructure Retrieval RAG Agents LLMKnowledge APIDeveloper Tools MCP

Kin Score

Kin Score How this is scored →
scored 2026-11-06 · rubric v0.27.0

Composite quality — 53.3/100 · developing

Contract Quality 8.6 / 19

Developer Ergonomics 8.5 / 15

Access Clarity 13.0 / 15

Operational Transparency 1.8 / 10

Contract Governance 1.6 / 9

Discoverability 5.6 / 8

Regulatory Posture 4.1 / 15

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 47/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

MCP Server 12 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 7 / 7

Rate-Limit Signaling 0 / 7

Typed Event Surface 0 / 6

Agent Skills 5 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 6 / 6

Protected Resource Metadata 5 / 5

Registration Without a Human 6 / 6

Agentic Commerce Well-Known Document 0 / 5

Pagination 5 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

Regulatory Posture applies to this provider. Its tags matched the Horizontal (data, software, accessibility, platform) regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

Create-or-Update Ergonomics applies to this provider. This API accepts writes, so it carries 10 points of the composite. It is scored from the published contracts themselves: whether a caller can create-or-update in one call, whether the write accepts a key the caller already holds, and whether the response says which branch ran. Without that, every write needs a search-and-branch in front of it, and the first time that check is skipped a duplicate record is created. Scored against the observed mean rather than raw — a provider at the catalog average is unchanged by this facet, not penalised by it.

The six quality facets above are damped to 75 points between them, because the conditional facet above carries the other 25. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 75% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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Agent readiness — checks not met, largest first (exact, from this profile):

Agentic Access Contract +10 pts — agentic_access artifact present (x-agentic-access), graded by author
Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented)
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Rate-Limit Signaling +7 pts — OpenAPI responses document X-RateLimit-* / RateLimit headers (verified), else a rate_limits artifact or RateLimits link (documented)
Typed Event Surface +6 pts — AsyncAPI document, OR webhooks/callbacks objects in the as-published OpenAPI, OR common[].type includes Webhooks
Documented Reversibility +6 pts — a reversal operation in the contract, graded up when a window is documented too

4 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Contract Quality scores 45.9 — up to +13.5 composite points
Operational Transparency scores 18.4 — up to +10.6 composite points
Contract Governance scores 18.2 — up to +9.8 composite points

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from the provider profile at artifacts.apis.io/seltz/apis.yml: open an issue on github.com/api-evangelist/seltz to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Standards implemented 5

Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.

Model Context Protocol (MCP)

measured — observed by APIs.io (verified)

The OpenAI Interface

prose — states compatibility; nothing published to check it against

2 core of 338 operations graded · api-commons/models

OAuth 2.0 Protected Resource Metadata

measured — observed by APIs.io (verified)

Dynamic Client Registration

measured — observed by APIs.io (published)

OpenAPI

measured — observed by APIs.io (published)

APIs 2

Individual APIs this provider publishes, each with its own machine-readable definition.

Seltz Answer API

Answer operations

Seltz Search API

Search operations

Open Collections 2

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

Seltz answer API

OPEN COLLECTION

Seltz answer search API

OPEN COLLECTION

MCP Servers 1

Model Context Protocol servers that expose these APIs to AI agents.

Seltz MCP Server

Official Seltz MCP server. Native integration for Claude Desktop, Cursor, VS Code, Windsurf, and other MCP-compatible AI tools. Remote HTTP/SSE server.

MCP SERVER

Agent Skills 2

Packaged agent skills for driving this provider's APIs from an AI assistant.

Get a cited answer grounded in live web search

AGENT SKILL

Search the live web for agent context

AGENT SKILL

Seltz API pricing

Prices published by Seltz, read 2026-10-07 from seltz.ai/pricing.

Plan	Price
Search	$5 per 1,000
Fetch	$10 per 1,000
Monitor	$5 per 1,000 checks
Answer	$7 per 1,000
Agent (Low)	$0.25 per run
Agent (Medium)	$0.50 per run
Enterprise	Custom pricing. Includes: Batch queries, isolated infra, private cloud deployment, premium support

Plan details, limits and sources →

Billed by: 1,000 requests · FinOps profile →

Pricing Plans 2

Published pricing tiers and plan structures.

Seltz Plans Pricing

7 plans

PLANS

Seltz Price Estimates

0 plans

PLANS

Service Levels 1

Uptime the provider promises or reports, as SLA4OAI. Read from its own pages; APIs.io runs no monitors.

Seltz

SLA

FinOps 1

Cost, billing, and metering signals for API financial operations.

Seltz Finops

FINOPS

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Seltz API Rules

56 rules · 54 errors 1 warnings 1 info

SPECTRAL

OpenAPI Overlays 1

Overlays applied on top of this provider's contracts. Each card says who wrote it: a document the provider publishes, or one API Evangelist derived or generated.

Seltz Openapi Overlay

3 actions · update · seltz-openapi-original.json

DERIVED

Security Posture 3

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Seltz Authentication

apiKey · 2 schemes

SECURITY

Seltz Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Seltz Trust Center

trust center published

SECURITY

Resources

Get Started 4

Portal, sign-up, and the first successful call

DeveloperPortal

GettingStarted

Sandbox

SignUp

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

MCPServer

LLMsTxt

WellKnown

AgentSkill

Design & Contract 2

Pagination, idempotency, versioning, errors, and events

Conformance

Conformance

Lifecycle

Lifecycle

Build 3

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

GitHubOrganization

Packages

Packages

SDKs

SDKs

Access & Security 3

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Compliance

Compliance

TrustCenter

TrustCenter

Operate 2

Status, limits, changes, and where to get help

Support

Support

ChangeLog

ChangeLog

Commercial 4

Pricing, plans, and the legal terms of use

Plans

Pricing

TermsOfService

PrivacyPolicy

Company 2

The organization behind the API

Website

Website

Blog

Blog

Other 1

Properties that don't map to a standard resource type

Overlay

Overlay

Source (apis.yml)

aid: seltz
name: Seltz
description: 'Seltz is a San Francisco-based AI infrastructure company building the web retrieval and knowledge layer for
  the agentic internet. Its Web Knowledge API gives LLMs, RAG pipelines, and autonomous agents real-time, context-engineered
  web data through a single call: POST /v1/search returns ranked, cleaned source documents, POST /v1/answer returns a direct
  RAG answer with citations, and an OpenAI-compatible /v1/chat/completions endpoint serves web-grounded chat. Rather than
  returning raw snippets like a traditional search API, Seltz shapes web content to maximize usefulness for machine reasoning.
  Founded in 2025 by Antonio Mallia (Amazon, Pinecone) and backed by Speedinvest and B Capital, Seltz ships official Python
  and TypeScript SDKs, a hosted MCP server, and integrations for OpenAI, Anthropic, Mistral, LlamaIndex, Agno, Langroid, Dify,
  n8n, and Zapier.'
url: https://raw.githubusercontent.com/api-evangelist/seltz/refs/heads/main/apis.yml
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: true
  label: Hosted service · you call their endpoint
  confidence: high
  source:
  - openapi
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: paid
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Paid
  confidence: medium
  source:
  - plans
  - authentication
  - security
  generated: '2026-11-06'
  method: derived
image: https://seltz.ai/favicon.ico
x-type: company
x-source: vc-portfolio
x-backed-by:
- speedinvest
- b-capital
x-tier: profiled
x-tier-reason: has-public-api
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-07-21'
x-docs-platform: mintlify
x-docs-platform-confidence: medium
x-docs-platform-checked: 2026-10-04
tags:
- Company
- Web Search
- AI Infrastructure
- Retrieval
- RAG
- Agents
- LLM
- Knowledge API
- Developer Tools
- MCP
apis:
- aid: seltz:seltz-answer-api
  name: Seltz Answer API
  description: Answer operations
  humanURL: https://docs.seltz.ai
  baseURL: https://api.seltz.ai
  tags:
  - Answers
  tags_raw:
  - answer
  properties:
  - type: OpenAPI
    url: openapi/seltz-answer-api-openapi.yml
  - type: Documentation
    url: https://docs.seltz.ai
  - type: APIReference
    url: https://docs.seltz.ai/api-reference/introduction
  - type: Authentication
    url: authentication/seltz-authentication.yml
  - type: ErrorCatalog
    url: errors/seltz-problem-types.yml
  - type: Conventions
    url: conventions/seltz-conventions.yml
  - type: DataModel
    url: data-model/seltz-data-model.yml
- aid: seltz:seltz-search-api
  name: Seltz Search API
  description: Search operations
  humanURL: https://docs.seltz.ai
  baseURL: https://api.seltz.ai
  tags:
  - Search
  tags_raw:
  - search
  properties:
  - type: OpenAPI
    url: openapi/seltz-search-api-openapi.yml
  - type: Documentation
    url: https://docs.seltz.ai
  - type: APIReference
    url: https://docs.seltz.ai/api-reference/introduction
  - type: Authentication
    url: authentication/seltz-authentication.yml
  - type: ErrorCatalog
    url: errors/seltz-problem-types.yml
  - type: Conventions
    url: conventions/seltz-conventions.yml
  - type: DataModel
    url: data-model/seltz-data-model.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: Plans
  url: plans/seltz-plans-pricing.yml
- type: Website
  url: https://www.seltz.ai/
- type: Overlay
  url: overlays/seltz-openapi-overlay.yaml
- type: DomainSecurity
  url: security/seltz-domain-security.yml
- type: DeveloperPortal
  url: https://console.seltz.ai
- type: Documentation
  url: https://docs.seltz.ai
- type: APIReference
  url: https://docs.seltz.ai/api-reference/introduction
- type: GettingStarted
  url: https://docs.seltz.ai/quickstart
- type: Sandbox
  url: https://console.seltz.ai/playground
- type: Pricing
  url: https://seltz.ai/pricing
- type: SignUp
  url: https://console.seltz.ai
- type: TermsOfService
  url: https://seltz.ai/terms
- type: PrivacyPolicy
  url: https://seltz.ai/privacy-policy
- type: Blog
  url: https://seltz.ai/blog
- type: Support
  url: https://seltz.ai/contact
- type: GitHubOrganization
  url: https://github.com/seltz-ai
- type: Packages
  url: packages/seltz-packages.yml
- type: SDKs
  url: packages/seltz-packages.yml
- type: MCPServer
  url: mcp/seltz-mcp.yml
- type: LLMsTxt
  url: llms/seltz-llms.txt
- type: WellKnown
  url: well-known/seltz-well-known.yml
- type: Conformance
  url: conformance/seltz-conformance.yml
- type: Compliance
  url: https://trust.seltz.ai/
- type: TrustCenter
  url: security/seltz-trust-center.yml
- type: Lifecycle
  url: lifecycle/seltz-lifecycle.yml
- type: ChangeLog
  url: changelog/seltz-changelog.yml
- type: AgentSkill
  url: skills/_index.yml
x-enrichment:
  date: '2026-07-21'
  status: enriched
  artifacts_added: 18
  pass: local-v1

Seltz API — frequently asked questions

Does Seltz have an API?

Yes. APIs.io lists 2 APIs from Seltz, including Seltz Answer API and Seltz Search API.

Is there an OpenAPI specification for the Seltz API?

Yes. APIs.io indexes 2 OpenAPI specifications for Seltz, each linked for download from this page.

How do I authenticate with the Seltz API?

Seltz documents its authentication (apiKey · 2 schemes). The details are profiled on APIs.io as Seltz Authentication.

How much does the Seltz API cost?

Seltz publishes its prices; its Search plan is $5 per 1,000 as of 2026-10-07. APIs.io lists 7 pricing plans for Seltz, with each plan's price, limits and inclusions under Pricing on this page.

Does Seltz have an MCP server?

Yes. APIs.io lists 1 MCP server for Seltz: Official Seltz MCP server. Native integration for Claude Desktop, Cursor, VS Code, Windsurf, and other MCP-compatible AI tools. Remote HTTP/SSE server.

Is the Seltz API ready for AI agents?

Seltz has a Kin Score of 53.3 out of 100 (developing) and an Agent Readiness score of 46.9 (agent-ready), scored by API Evangelist on 2026-11-06.

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