aid: machinelibrary-ai

name: Space Frontiers

description: 'Space Frontiers is a Wyoming corporation whose search and AI product, Machine Library (formerly Space Frontiers search, moved to
  machinelibrary.ai on 2026-09-12), is a full-text retrieval API and hosted MCP server over a corpus of roughly 2.9 billion records: peer-reviewed
  papers (CrossRef, PubMed, arXiv), books, USPTO patents, Wikipedia, technical standards, YouTube transcripts, and live Reddit, Telegram and Discord
  posts. It is built for AI agents doing literature review, fact-checking, citation walking and grounded research synthesis, returning compact
  reranked hits with canonical source URIs (DOI, arXiv, PMID, ISBN) and token-bounded full text. Three surfaces share one account and API key:
  a REST API at api.machinelibrary.ai (OpenAPI 3.1, pay-as-you-go), a Streamable-HTTP MCP server at mcp.machinelibrary.ai (OAuth 2.1 with PKCE
  and RFC 7591 dynamic registration, or a Bearer API key), and an A2A agent at machinelibrary.ai/a2a. It also ships a PDF/EPUB/DJVU-to-Markdown
  recognition API and Stripe-settled prepaid credit packages for agents (ACP checkout, MPP top-up). The company also publishes Hermes, an open-source
  Rust search engine with a gRPC contract and Python/TypeScript clients.'

url: https://raw.githubusercontent.com/api-evangelist/machinelibrary-ai/refs/heads/main/apis.yml

deliveryModel:
  model: saas
  license_evidence:
    not_product:
    - spacefrontiers/hermes
    - spacefrontiers/mcp
  open_source: unknown
  commercial: true
  callable_host: true
  label: Hosted service · you call their endpoint
  confidence: low
  source:
  - openapi
  - pricing
  - repository-not-product
  generated: '2026-09-25'
  method: derived

image: https://machinelibrary.ai/press/icon-512.png

x-type: company

x-source: harvest:a2a-registry

x-tier: profiled

x-tier-reason: enrichment pipeline local-v3 pass on 2026-09-19 found a live OpenAPI 3.1, hosted MCP server, A2A agent card, llms.txt, RFC 8414/9728
  metadata and an RFC 9727 api-catalog

website: https://machinelibrary.ai

x-legal-name: Space Frontiers

x-headquarters: Sheridan, Wyoming, United States

x-product-name: Machine Library

x-former-domain: spacefrontiers.org

specificationVersion: '0.20'

created: '2026-09-19'

modified: '2026-09-19'

tags:
- Research
- Scholarly Search
- Full-Text Search
- Retrieval
- RAG
- Patents
- Documents
- OCR
- Document Recognition
- MCP
- A2A
- Agent-Native
- AI Agents
- Data
- Search

tags_raw:
- research
- scholarly-search
- full-text-search
- retrieval
- rag
- patents
- documents
- ocr
- document-recognition
- mcp
- a2a
- agent-native
- ai-agents
- data
- search

maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io

common:
- type: AgenticAccess
  url: agentic-access/machinelibrary-ai-agentic-access.yml
- type: Spectral
  url: rules/machinelibrary-ai-rules.yml
- type: JSONLD
  url: json-ld/machinelibrary-ai-context.jsonld
- type: Vocabulary
  url: vocabulary/machinelibrary-ai-vocabulary.yml
- type: Security
  url: security/machinelibrary-ai-vulnerability-disclosure.yml
- type: Hosts
  url: hosts/machinelibrary-ai-hosts.yml
- type: Vendors
  url: vendors/machinelibrary-ai-vendors.yml
- type: StatusPage
  url: https://machinelibrary.ai/status
- type: VulnerabilityDisclosure
  url: security/machinelibrary-ai-vulnerability-disclosure.yml
- type: Overlay
  url: overlays/machinelibrary-ai-openapi-overlay.yaml
- type: Website
  url: https://machinelibrary.ai/
- type: Documentation
  url: https://machinelibrary.ai/docs/api
- type: APIReference
  url: https://machinelibrary.ai/docs/api/reference
- type: GettingStarted
  url: https://machinelibrary.ai/docs/api
- type: Pricing
  url: https://machinelibrary.ai/pricing
- type: Support
  url: https://machinelibrary.ai/contacts
- type: Newsroom
  url: https://machinelibrary.ai/press
- type: GitHubOrganization
  url: https://github.com/SpaceFrontiers
- type: SignUp
  url: https://machinelibrary.ai/auth/signup
- type: Login
  url: https://machinelibrary.ai/auth/signin
- type: TermsOfService
  url: https://machinelibrary.ai/terms-of-service
- type: PrivacyPolicy
  url: https://machinelibrary.ai/privacy
- type: LLMsTxt
  url: llms/machinelibrary-ai-llms.txt
- type: MCPServer
  url: mcp/machinelibrary-ai-mcp.yml
- type: ToolCrosswalk
  url: mcp/machinelibrary-ai-tool-crosswalk.yml
- type: AgentCard
  url: a2a/machinelibrary-ai-a2a.yml
- type: WellKnown
  url: well-known/machinelibrary-ai-well-known.yml
- type: Packages
  url: packages/machinelibrary-ai-packages.yml
- type: SDKs
  url: packages/machinelibrary-ai-packages.yml
- type: Conformance
  url: conformance/machinelibrary-ai-conformance.yml
- type: Authentication
  url: authentication/machinelibrary-ai-authentication.yml
- type: OAuthScopes
  url: scopes/machinelibrary-ai-scopes.yml
- type: Conventions
  url: conventions/machinelibrary-ai-conventions.yml
- type: Idempotency
  url: conventions/machinelibrary-ai-conventions.yml
- type: ErrorCatalog
  url: errors/machinelibrary-ai-problem-types.yml
- type: Lifecycle
  url: lifecycle/machinelibrary-ai-lifecycle.yml
- type: DomainSecurity
  url: security/machinelibrary-ai-domain-security.yml
- type: Plans
  url: plans/machinelibrary-ai-plans-pricing.yml
- type: RateLimits
  url: rate-limits/machinelibrary-ai-rate-limits.yml
- type: ChangeLog
  url: changelog/machinelibrary-ai-changelog.yml
- type: DataModel
  url: data-model/machinelibrary-ai-data-model.yml
- type: AgentSkill
  url: skills/_index.yml
- type: RegulatoryPosture
  url: regulatory/machinelibrary-ai-regulatory-posture.yml
- type: Protobuf
  url: grpc/machinelibrary-ai-hermes.proto

apis:
- name: Machine Library MCP Server
  description: >-
    Hosted Streamable-HTTP MCP server at https://mcp.machinelibrary.ai (legacy https://mcp.spacefrontiers.org
    still served) exposing four read-only, idempotent retrieval tools (spacefrontiers_search_documents,
    spacefrontiers_search_social, spacefrontiers_fetch_document, spacefrontiers_search_in_document), a
    hosted spacefrontiers_top_up_balance payment tool, a deep_research_agent prompt and a spacefrontiers://document/{uri_b64}
    resource template. OAuth 2.1 with PKCE and RFC 7591 dynamic client registration against https://api.spacefrontiers.org,
    or a Bearer API key. Listed in the official MCP registry as io.github.SpaceFrontiers/mcp; source is
    MIT-licensed on GitHub.
  humanURL: https://machinelibrary.ai/mcp
  baseURL: https://mcp.machinelibrary.ai
  tags:
  - MCP
  - Agent-Native
  - Retrieval
  - Research
  tags_raw:
  - mcp
  - agent-native
  - retrieval
  - research
  properties:
  - type: MCPServer
    url: mcp/machinelibrary-ai-mcp.yml
  - type: ToolCrosswalk
    url: mcp/machinelibrary-ai-tool-crosswalk.yml
  - type: Documentation
    url: https://machinelibrary.ai/mcp
  - type: GettingStarted
    url: https://machinelibrary.ai/install.md
  - type: SourceCode
    url: https://github.com/SpaceFrontiers/mcp
  - type: MCPRegistry
    url: https://registry.modelcontextprotocol.io/v0/servers?search=spacefrontiers
  aid: machinelibrary-ai:machine-library-mcp-server
- name: Machine Library A2A Agent
  description: >-
    A2A (protocolVersion 0.3.0) research and commerce agent at https://machinelibrary.ai/a2a over JSON-RPC:
    grounded research answers with citation artifacts, search-access guidance, and prepaid-credit sales
    settled through Stripe (ACP checkout sessions and MPP payment challenges), with two AP2 merchant-role
    extensions declared. The agent card is served at /.well-known/agent-card.json on machinelibrary.ai
    and spacefrontiers.org. Unauthenticated message/send is answered live with authentication guidance.
  humanURL: https://machinelibrary.ai/.well-known/agent-card.json
  baseURL: https://machinelibrary.ai/a2a
  x-baseurl-note: >-
    JSON-RPC endpoint; answers POST message/send (200) and 404s a plain GET, so the humanURL is the served
    agent card rather than the endpoint.
  tags:
  - A2A
  - Agent-Native
  - Research
  - Payments
  tags_raw:
  - a2a
  - agent-native
  - research
  - payments
  properties:
  - type: AgentCard
    url: a2a/machinelibrary-ai-a2a.yml
  - type: Documentation
    url: https://api.machinelibrary.ai/auth.md
  aid: machinelibrary-ai:machine-library-a2a-agent
- name: Hermes Search Engine gRPC API
  description: >-
    Self-hosted, MIT-licensed Rust search engine published by Space Frontiers (github.com/SpaceFrontiers/hermes)
    with a published protobuf wire contract: hermes.SearchService (Search, GetDocument, GetIndexInfo,
    GetTextStats) and hermes.IndexService (index creation, streaming ingestion, primary-key deletion and
    upsert, commit, merge, vector-index retraining), plus hermes.broker.BrokerService for shard topology.
    Distributed as crates (hermes-core, hermes-server, hermes-broker, hermes-tool), PyPI (hermes-client-python),
    npm (hermes-client-typescript, hermes-wasm). There is no hosted endpoint: you run hermes-server yourself.
  humanURL: https://github.com/SpaceFrontiers/hermes
  x-deployment: self-hosted
  x-no-hosted-base-url: >-
    The gRPC server is run by the consumer (cargo install hermes-server); Space Frontiers publishes no
    hosted Hermes endpoint, so no baseURL is recorded rather than inventing one.
  tags:
  - Search
  - gRPC
  - Open Source
  tags_raw:
  - search
  - grpc
  - open-source
  - Open Source
  - Open-Source
  properties:
  - type: Protobuf
    url: grpc/machinelibrary-ai-hermes.proto
  - type: Protobuf
    url: grpc/machinelibrary-ai-hermes-broker.proto
  - type: Documentation
    url: https://github.com/SpaceFrontiers/hermes/blob/main/hermes-proto/README.md
  - type: SourceCode
    url: https://github.com/SpaceFrontiers/hermes
  aid: machinelibrary-ai:hermes-search-engine-grpc-api
- aid: machinelibrary-ai:machinelibrary-ai-documents-api
  name: Space Frontiers Documents API
  description: Fetch documents by ID or canonical URI.
  humanURL: https://machinelibrary.ai/docs/api
  baseURL: https://api.machinelibrary.ai
  tags:
  - Documents
  properties:
  - type: OpenAPI
    url: openapi/machinelibrary-ai-documents-api-openapi.yml
  - type: Documentation
    url: https://machinelibrary.ai/docs/api
  - type: APIReference
    url: https://machinelibrary.ai/docs/api/reference
  - type: Authentication
    url: authentication/machinelibrary-ai-authentication.yml
  - type: OAuthScopes
    url: scopes/machinelibrary-ai-scopes.yml
  - type: Conventions
    url: conventions/machinelibrary-ai-conventions.yml
  - type: Idempotency
    url: conventions/machinelibrary-ai-conventions.yml
  - type: ErrorCatalog
    url: errors/machinelibrary-ai-problem-types.yml
  - type: DataModel
    url: data-model/machinelibrary-ai-data-model.yml
  - type: RateLimits
    url: rate-limits/machinelibrary-ai-rate-limits.yml
  - type: Plans
    url: plans/machinelibrary-ai-plans-pricing.yml
  - type: Pricing
    url: https://api.machinelibrary.ai/v1/pricing
  - type: JSONSchema
    url: json-schema/machinelibrary-ai-by-uri-response-schema.json
  - type: JSONSchema
    url: json-schema/machinelibrary-ai-v2-document-response-schema.json
- aid: machinelibrary-ai:machinelibrary-ai-payments-api
  name: Space Frontiers Payments API
  description: The Payments API from Space Frontiers — 1 operation(s) for payments.
  humanURL: https://machinelibrary.ai/docs/api
  baseURL: https://api.machinelibrary.ai
  tags:
  - Payments
  properties:
  - type: OpenAPI
    url: openapi/machinelibrary-ai-payments-api-openapi.yml
  - type: Documentation
    url: https://machinelibrary.ai/docs/api
  - type: APIReference
    url: https://machinelibrary.ai/docs/api/reference
  - type: Authentication
    url: authentication/machinelibrary-ai-authentication.yml
  - type: OAuthScopes
    url: scopes/machinelibrary-ai-scopes.yml
  - type: Conventions
    url: conventions/machinelibrary-ai-conventions.yml
  - type: Idempotency
    url: conventions/machinelibrary-ai-conventions.yml
  - type: ErrorCatalog
    url: errors/machinelibrary-ai-problem-types.yml
  - type: DataModel
    url: data-model/machinelibrary-ai-data-model.yml
  - type: RateLimits
    url: rate-limits/machinelibrary-ai-rate-limits.yml
  - type: Plans
    url: plans/machinelibrary-ai-plans-pricing.yml
  - type: Pricing
    url: https://api.machinelibrary.ai/v1/pricing
- aid: machinelibrary-ai:machinelibrary-ai-raw-document-downloads-api
  name: Space Frontiers Raw document downloads API
  description: Authenticated, feature-gated streaming of PDF, EPUB, and DJVU library originals.
  humanURL: https://machinelibrary.ai/docs/api
  baseURL: https://api.machinelibrary.ai
  tags:
  - Raw document downloads
  properties:
  - type: OpenAPI
    url: openapi/machinelibrary-ai-raw-document-downloads-api-openapi.yml
  - type: Documentation
    url: https://machinelibrary.ai/docs/api
  - type: APIReference
    url: https://machinelibrary.ai/docs/api/reference
  - type: Authentication
    url: authentication/machinelibrary-ai-authentication.yml
  - type: OAuthScopes
    url: scopes/machinelibrary-ai-scopes.yml
  - type: Conventions
    url: conventions/machinelibrary-ai-conventions.yml
  - type: Idempotency
    url: conventions/machinelibrary-ai-conventions.yml
  - type: ErrorCatalog
    url: errors/machinelibrary-ai-problem-types.yml
  - type: DataModel
    url: data-model/machinelibrary-ai-data-model.yml
  - type: RateLimits
    url: rate-limits/machinelibrary-ai-rate-limits.yml
  - type: Plans
    url: plans/machinelibrary-ai-plans-pricing.yml
  - type: Pricing
    url: https://api.machinelibrary.ai/v1/pricing
- aid: machinelibrary-ai:machinelibrary-ai-recognition-api
  name: Space Frontiers Recognition API
  description: 'Document recognition: PDF, EPUB, and DJVU to structured Markdown with quality reports.'
  humanURL: https://machinelibrary.ai/docs/api
  baseURL: https://api.machinelibrary.ai
  tags:
  - Recognition
  properties:
  - type: OpenAPI
    url: openapi/machinelibrary-ai-recognition-api-openapi.yml
  - type: Documentation
    url: https://machinelibrary.ai/docs/api
  - type: APIReference
    url: https://machinelibrary.ai/docs/api/reference
  - type: Authentication
    url: authentication/machinelibrary-ai-authentication.yml
  - type: OAuthScopes
    url: scopes/machinelibrary-ai-scopes.yml
  - type: Conventions
    url: conventions/machinelibrary-ai-conventions.yml
  - type: Idempotency
    url: conventions/machinelibrary-ai-conventions.yml
  - type: ErrorCatalog
    url: errors/machinelibrary-ai-problem-types.yml
  - type: DataModel
    url: data-model/machinelibrary-ai-data-model.yml
  - type: RateLimits
    url: rate-limits/machinelibrary-ai-rate-limits.yml
  - type: Plans
    url: plans/machinelibrary-ai-plans-pricing.yml
  - type: Pricing
    url: https://api.machinelibrary.ai/v1/pricing
  - type: JSONSchema
    url: json-schema/machinelibrary-ai-recognition-job-status-schema.json
  - type: JSONSchema
    url: json-schema/machinelibrary-ai-recognition-submission-schema.json
- aid: machinelibrary-ai:machinelibrary-ai-search-api
  name: Space Frontiers Search API
  description: Ranked retrieval and document similarity.
  humanURL: https://machinelibrary.ai/docs/api
  baseURL: https://api.machinelibrary.ai
  tags:
  - Search
  properties:
  - type: OpenAPI
    url: openapi/machinelibrary-ai-search-api-openapi.yml
  - type: Documentation
    url: https://machinelibrary.ai/docs/api
  - type: APIReference
    url: https://machinelibrary.ai/docs/api/reference
  - type: Authentication
    url: authentication/machinelibrary-ai-authentication.yml
  - type: OAuthScopes
    url: scopes/machinelibrary-ai-scopes.yml
  - type: Conventions
    url: conventions/machinelibrary-ai-conventions.yml
  - type: Idempotency
    url: conventions/machinelibrary-ai-conventions.yml
  - type: ErrorCatalog
    url: errors/machinelibrary-ai-problem-types.yml
  - type: DataModel
    url: data-model/machinelibrary-ai-data-model.yml
  - type: RateLimits
    url: rate-limits/machinelibrary-ai-rate-limits.yml
  - type: Plans
    url: plans/machinelibrary-ai-plans-pricing.yml
  - type: Pricing
    url: https://api.machinelibrary.ai/v1/pricing
  - type: JSONSchema
    url: json-schema/machinelibrary-ai-search-request-v2-schema.json
  - type: JSONSchema
    url: json-schema/machinelibrary-ai-v2-search-response-schema.json
  - type: JSONSchema
    url: json-schema/machinelibrary-ai-similar-request-v2-schema.json
  - type: JSONSchema
    url: json-schema/machinelibrary-ai-search-feedback-schema.json
  - type: JSONSchema
    url: json-schema/machinelibrary-ai-feedback-accepted-schema.json
- aid: machinelibrary-ai:machinelibrary-ai-conversations-api
  name: Space Frontiers Conversations API
  description: Retrieval-augmented conversation workflows.
  humanURL: https://machinelibrary.ai/mcp
  baseURL: https://mcp.machinelibrary.ai
  tags:
  - Conversations
  properties:
  - type: OpenAPI
    url: openapi/machinelibrary-ai-conversations-api-openapi.yml
  - type: Documentation
    url: https://machinelibrary.ai/docs/api
  - type: APIReference
    url: https://machinelibrary.ai/docs/api/reference
  - type: Authentication
    url: authentication/machinelibrary-ai-authentication.yml
  - type: OAuthScopes
    url: scopes/machinelibrary-ai-scopes.yml
  - type: Conventions
    url: conventions/machinelibrary-ai-conventions.yml
  - type: Idempotency
    url: conventions/machinelibrary-ai-conventions.yml
  - type: ErrorCatalog
    url: errors/machinelibrary-ai-problem-types.yml
  - type: DataModel
    url: data-model/machinelibrary-ai-data-model.yml
  - type: RateLimits
    url: rate-limits/machinelibrary-ai-rate-limits.yml
  - type: Plans
    url: plans/machinelibrary-ai-plans-pricing.yml
  - type: Pricing
    url: https://api.machinelibrary.ai/v1/pricing
  - type: JSONSchema
    url: json-schema/machinelibrary-ai-search-request-v2-schema.json
  - type: JSONSchema
    url: json-schema/machinelibrary-ai-conversation-response-schema.json
  - type: JSONSchema
    url: json-schema/machinelibrary-ai-conversation-request-schema.json
  - type: JSONSchema
    url: json-schema/machinelibrary-ai-v2-search-response-schema.json
  - type: JSONSchema
    url: json-schema/machinelibrary-ai-agent-comment-submission-schema.json
  - type: JSONSchema
    url: json-schema/machinelibrary-ai-recognition-job-status-schema.json
x-a2a:
  verified: true
  probed: '2026-09-26'
  url: https://machinelibrary.ai/.well-known/agent-card.json
  grade: conformant
  protocol_version: 0.3.0
  control: 404

x-correction-request:
  requested: '2026-09-28'
  source:
  - https://github.com/api-evangelist/machinelibrary-ai/pull/1
  request: 'Provider PR #1 (ppodolsky, 2026-09-26), verified live 2026-09-28; not merged because it predates the 09-27 per-area OpenAPI split.
    Its rate-limits file is committed (12/60/30 requests per minute per source IP; https://machinelibrary.ai/docs/api/operations#limits). Capture:
    OAuth authorization server issuer https://api.machinelibrary.ai, scopes_supported [search], PKCE S256, dynamic client registration at /v2/oauth/register,
    protected-resource metadata on mcp.machinelibrary.ai naming that issuer (legacy spacefrontiers hosts serve the same issuer); pages Operations
    https://machinelibrary.ai/docs/api/operations, ChangeLog https://machinelibrary.ai/changelog, StatusPage https://machinelibrary.ai/status,
    Datasets https://machinelibrary.ai/datasets; security.txt and api-catalog. MCP tools are renamed machinelibrary_* and number 9 in the live
    llms.txt (comment_on_document, vote_on_comment added); live OpenAPI https://machinelibrary.ai/docs/openapi.json has 21 paths. Note: their
    api-catalog links mcp.machinelibrary.ai/.well-known/mcp/server-card.json, which returns 404.'
  earlier:
    requested: '2026-09-27'
    source: https://github.com/api-search/inbox/issues/39
    request: 'Correction (with source-artifact PR https://github.com/api-evangelist/machinelibrary-ai/pull/1 -- review, do NOT merge wholesale):
      provider page links https://apis.io/servers/machinelibrary-ai/space-frontiers-mcp-server/ which 404s -- use the current MCP product name
      so a working server page is generated; fix inconsistent counts and stale scope data. Re-profile from current sources.'
x-enrichment:
  date: '2026-09-28'
  status: enriched
  artifacts_added: 21
  pass: modular-v1
  engine: identity=local,contract=local,surfaces=local,docs=local,regulatory=local