Conceptio Search

conceptio-search

Search 1M+ open-access documents — papers, standards, textbooks, and case law — right from your terminal or your AI agent.

conceptio-search is a CLI and Model Context Protocol (MCP) server for the Conceptio Open Knowledge Archive — 1M+ open-access documents from 500+ living sources, indexed daily. Every source is open access or public domain. The CLI authenticates with an API key: sign in once, save the key, search from anywhere.

• For humans — search, export citations in 11 formats (BibTeX, APA, MLA, Chicago, IEEE, Harvard, RIS, Bluebook, OSCOLA, ISO 690, ANSI Z39), and download PDFs to disk with one command.
• For AI agents — a stdio MCP server with nine tools, so Claude, Cursor, Windsurf, OpenCode, or any MCP client can search, queue batch searches, resolve identifiers (RFC, DOI, arXiv, PMID, PMCID, NIST/FIPS, W3C, US case citation), walk the reference graph, save PDFs into your workspace, and hand a document to Zotero or Obsidian.
• 100% self-contained — talks only to the public HTTPS API. No internal infrastructure; your key lives in ~/.conceptio/config.json.

Install

pip install conceptio-search

Requires Python 3.8+. (Checked, not just claimed: the suite parses every source file at the declared floor's grammar, so the promise cannot rot silently.)

The console script is conceptio; python -m conceptio_cli is the same entry point for a virtualenv that was never activated.

Authenticate (one time)

The CLI needs an API key before it can search:

conceptio auth ckey_live_...

Get the key by signing in at conceptio.app and creating one on your profile (Free, Dev, Pro, or Enterprise). The key is stored in ~/.conceptio/config.json and sent as X-Api-Key with every request. conceptio quota reports your tier at any time. Every command below assumes this step is done — without a key the CLI refuses to run and tells you exactly this.

Quick start

# Search — supports source:/lang:/category: directives

conceptio search "attention is all you need" --limit 5 conceptio search "source:nist zero trust" --license commercial-ok conceptio search "source:eurlex AI act" --json conceptio search "meditations marcus aurelius" --markdown # for Obsidian/Notion conceptio search "diffusion models" --offset 20 # paginate past the first page

Multi-query programmatic search — two modes:

conceptio search --batch queries.json --json # queue 1–50 searches, print the job handle conceptio search --batch queries.json --wait --json # queue, then block until done and print results conceptio search --batch queries.json --wait --timeout 60 # …but never block longer than a minute conceptio search --batch queries.json --sync --json # run 1–10 immediately, no queue (one request) conceptio search-job --json # poll once; repeat on your own cadence conceptio search-job --wait --json # poll until done, then print results

Resolve a known identifier straight to its document(s)

conceptio resolve "RFC 2119" conceptio resolve "doi:10.1109/access.2020.2986772" conceptio resolve "2604.08499" # arXiv conceptio resolve "PMID 41961061" # PubMed conceptio resolve "PMC10601397" # PubMed Central conceptio resolve "NIST FIPS 199" conceptio resolve "347 U.S. 483" # US case citation (Supreme Court) conceptio resolve "20-5364" # federal docket conceptio resolve "RFC 2119" --json

Download the original PDF

conceptio download 297465 -o paper.pdf # by document ID conceptio download "https://arxiv.org/pdf/2604.21816v1.pdf" # by URL

Citations — 11 formats: bibtex, apa, mla, chicago, ieee, harvard,

ris, bluebook, oscola, iso690, ansiz39

conceptio cite 7288 --format bibtex conceptio cite 7288 --format apa conceptio cite 7288 --format iso690

Document metadata

conceptio info 2844 conceptio proof 2844 # machine-readable evidence bundle conceptio proof 2844 -q "quantum" # passage-level proof for a phrase

License key (Pro) or API key + quota

conceptio auth CONCEPTIO-XXXX-XXXX-XXXX # Pro license (one-time, account-bound) conceptio auth ckey_live_... # API key (agent/machine credential) conceptio quota conceptio quota --json # {tier, auth, credits…} for a status surface

The flag may come before the subcommand, the way machine callers write it

conceptio --json search "zero trust"

Version

conceptio --version

AI agent server

conceptio mcp

Example

$ conceptio search "source:nist zero trust" --limit 3

Conceptio - 3 results for "source:nist zero trust"

Year Title Author Source PDF

1 n.d. NIST SP 1800-35: Implementing a Zero Trust Scott Rose (NIST); … NIST [x] 2 n.d. NIST SP 800-207: Zero Trust Architecture Scott Rose (NIST); … NIST [x] 3 n.d. NIST SP 800-207A: A Zero Trust Architecture Ramaswamy Chandramo… NIST [x]

Tip: conceptio download 2844 saves the PDF, conceptio cite 2844 exports a citation.

Query words are highlighted in gold in the title column. The PDF column shows [x] when a direct PDF link is available; [ ] rows still surface the source URL via conceptio info .

Search directives

The CLI understands the same directives as the Conceptio web app — they are stripped from the query and applied as real filters:

Directives can be combined freely: conceptio search "cat:\"Computer Science & Tech\" source:nist lattice cryptography".

Resolve

conceptio resolve recognises several identifier shapes and returns a typed response (kind: rfc | doi | arxiv | pmid | pmcid | nist | w3c | case plus fallback null for plain text). Unrecognised identifiers degrade to a regular search so the command never fails silently.

The kind describes the identifier, not the archive: a well-formed DOI this archive does not hold answers with kind: "doi", total: 0 and an empty results list, which is a correct empty answer rather than a failure. Every example above resolves to at least one document today — the suite that drives the shipped CLI against the live API asserts exactly that, so an example can only rot if that check is skipped.

Model Context Protocol (MCP)

The conceptio mcp command starts a stdio JSON-RPC MCP server. It is dependency-free (no MCP SDK required) and works with any MCP client.

The server is dual-era: it answers the current 2026-07-28 revision — per-request _meta, server/discover, resultType, cache hints — and still serves the older initialize handshake (2024-11-05 … 2025-11-25) for clients that predate it. A client that speaks both eras probes with server/discover first and finds us; a handshake client is served exactly as before.

A key is required for tool calls. The server starts without one, so a host can discover it and read its tool list — and then answers every tools/call with an in-band error carrying the setup steps. Hand it the key either way: run conceptio auth once, or give it to the host through the host's own environment, which is how the official registry listing declares it:

{ "mcpServers": { "conceptio": { "command": "conceptio", "args": ["mcp"],

"env": { "CONCEPTIO_API_KEY": "ckey_live_…" } } } }

Tools

Claude Desktop

Add to claude_desktop_config.json:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json

{

"mcpServers": { "conceptio": { "command": "conceptio", "args": ["mcp"] } } }

Cursor

Settings → Cursor Settings → MCP → Add new MCP server:

{

"mcpServers": { "conceptio": { "command": "conceptio", "args": ["mcp"] } } }

OpenCode / Windsurf / Antigravity

The same JSON shape works in any MCP-aware client — point it at conceptio mcp and the nine tools above are exposed automatically. An MCP host may supply the credential by environment (CONCEPTIO_API_KEY, or CONCEPTIO_BEARER_TOKEN for a signed-in session) instead of writing ~/.conceptio/config.json.

After adding, restart the client and you can ask, for example:

*"Find the NIST post-quantum encryption standard and download the PDF into my workspace."*

Manual smoke test

echo '{"jsonrpc":"2.0","id":1,"method":"tools/list"}' | conceptio mcp

Windows PowerShell quirk: pwsh pipes text to native commands as UTF-16,

which the server (UTF-8 JSON-RPC) answers with a Parse error. Real MCP

hosts speak UTF-8 and are unaffected — this only bites hand-rolled

echo ... | conceptio mcp probes from pwsh. Save the request as UTF-8

first instead:

`powershell

'{"jsonrpc":"2.0","id":1,"method":"tools/li