# Machine Library API

**Canonical:** https://apis.io/apis/machinelibrary-ai/machine-library-api/  
**Provider:** Space Frontiers — https://apis.io/providers/machinelibrary-ai/  
**Base URL:** https://api.machinelibrary.ai  
**Documentation:** https://machinelibrary.ai/docs/api

Machine Library API is one of 4 APIs that [Space Frontiers](https://apis.io/providers/machinelibrary-ai/) publishes on the [APIs.io](https://apis.io/) network, described by a machine-readable OpenAPI specification. Tagged areas include Research, Scholarly Search, Full-Text Search, Retrieval, and Documents. The published artifact set on APIs.io includes an OpenAPI specification, API documentation, an API reference, authentication docs, rate-limit docs, and pricing.

REST API over the Machine Library corpus: hybrid full-text search across the documents and social indexes (POST /v2/search/), similarity search, token-bounded document fetch by ID or canonical URI (DOI/arXiv/PMID/ISBN), in-document passage search via text_filter, original PDF/EPUB/DJVU streaming with byte ranges, retrieval-augmented conversation turns (JSON or SSE stream), PDF/EPUB/DJVU-to-Markdown recognition jobs, and a Stripe MPP prepaid-credit top-up. Authenticated with an X-Api-Key header or the same key / an OAuth 2.0 access token as a Bearer token; billed per request from a prepaid USD balance.

## Operations (19)

| Method | Path | Summary |
|---|---|---|
| POST | `/v2/search/` | Search across one or more Machine Library indexes. |
| POST | `/v2/search/feedback` | — |
| GET | `/v2/documents/by-uri/{uri}` | Fetch a document by canonical URI, or search inside it with `text_filter`. |
| GET | `/v2/documents/{document_id}` | Fetch a document and its public metadata by Machine Library document ID. |
| POST | `/v2/search/similar` | Find documents similar to a source document. |
| GET | `/v2/conversations/` | List conversations owned by the authenticated user. |
| POST | `/v2/conversations/` | Run a retrieval-augmented conversation turn. |
| POST | `/v2/conversations/stream` | Run a conversation turn and stream newline-delimited progress events. |
| GET | `/v2/conversations/{slug}` | Fetch a conversation and all recorded request/response steps. |
| DELETE | `/v2/conversations/{slug}` | Delete a conversation owned by the authenticated user. |
| PUT | `/v2/conversations/{conversation_id_or_slug}/edit-step/{step_id}` | Replace a request step and recompute the conversation from that point. |
| PUT | `/v2/conversations/{conversation_id_or_slug}/edit-step/{step_id}/stream` | Replace a request step and stream the recomputation as newline-delimited events. |
| POST | `/v1/recognitions` | Submit a document for recognition |
| GET | `/v1/recognitions/{id}` | Job status |
| GET | `/v1/recognitions/{id}/report` | Structured recognition report |
| GET | `/v1/recognitions/{id}/result` | Recognized Markdown |
| GET | `/v2/downloads/{filename}` | Original document by ID |
| GET | `/v2/downloads/by-uri/{uri}` | Original document by URI |
| POST | `/v2/payments/mpp/top-up` | Fund the authenticated account balance using Stripe MPP |

## Machine-readable artifacts (16)

- **OpenAPI** — https://raw.githubusercontent.com/api-evangelist/machinelibrary-ai/refs/heads/main/openapi/machinelibrary-ai-openapi.yml
- **OpenAPI** — https://machinelibrary.ai/openapi.json
- **OpenAPI** — https://raw.githubusercontent.com/api-evangelist/machinelibrary-ai/refs/heads/main/openapi/machinelibrary-ai-recognition-openapi.yml
- **Documentation** — https://machinelibrary.ai/docs/api
- **APIReference** — https://machinelibrary.ai/docs/api/reference
- **Authentication** — https://raw.githubusercontent.com/api-evangelist/machinelibrary-ai/refs/heads/main/authentication/machinelibrary-ai-authentication.yml
- **OAuthScopes** — https://raw.githubusercontent.com/api-evangelist/machinelibrary-ai/refs/heads/main/scopes/machinelibrary-ai-scopes.yml
- **Conventions** — https://raw.githubusercontent.com/api-evangelist/machinelibrary-ai/refs/heads/main/conventions/machinelibrary-ai-conventions.yml
- **Idempotency** — https://raw.githubusercontent.com/api-evangelist/machinelibrary-ai/refs/heads/main/conventions/machinelibrary-ai-conventions.yml
- **ErrorCatalog** — https://raw.githubusercontent.com/api-evangelist/machinelibrary-ai/refs/heads/main/errors/machinelibrary-ai-problem-types.yml
- **DataModel** — https://raw.githubusercontent.com/api-evangelist/machinelibrary-ai/refs/heads/main/data-model/machinelibrary-ai-data-model.yml
- **Overlay** — https://raw.githubusercontent.com/api-evangelist/machinelibrary-ai/refs/heads/main/overlays/machinelibrary-ai-openapi-overlay.yaml
- **RateLimits** — https://raw.githubusercontent.com/api-evangelist/machinelibrary-ai/refs/heads/main/rate-limits/machinelibrary-ai-rate-limits.yml
- **Plans** — https://raw.githubusercontent.com/api-evangelist/machinelibrary-ai/refs/heads/main/plans/machinelibrary-ai-plans-pricing.yml
- **Pricing** — https://api.machinelibrary.ai/v1/pricing
- **APIsJSON** — https://raw.githubusercontent.com/api-evangelist/machinelibrary-ai/refs/heads/main/apis.yml

## Other Space Frontiers APIs (3)

- [Machine Library MCP Server](https://apis.io/apis/machinelibrary-ai/machine-library-mcp-server/)
- [Machine Library A2A Agent](https://apis.io/apis/machinelibrary-ai/machine-library-a2a-agent/)
- [Hermes Search Engine gRPC API](https://apis.io/apis/machinelibrary-ai/hermes-search-engine-grpc-api/)

## Tags

Research, Scholarly Search, Full-Text Search, Retrieval, Documents, OCR, Patents

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/apis/machinelibrary-ai/machine-library-api/). The API's provider profile, Kin Score and agent-readiness rating are at https://apis.io/providers/machinelibrary-ai/.