CAIN-42 · For developers

Hosted service catalog

Every hosted service you can call with one key.

Last reviewed 2026-10-01

Live   Studio apps & labs · Studio app

Where it fits

Part of For developers: SDKs, CLI, MCP server, APIs and offline verifiers. Every CAIN-42 product runs behind the same rule: an AI agent's action is checked before it runs (identity, authority, policy, risk), decided as allow, hold for a human, or block, and recorded as signed evidence. Unknown or error never becomes allow.

Use it

• Open it https://cainstudio.online/catalog

Live now

Checked from your browser when this page opened, not from a cached list.

Fire a real decision

Send an action through the live CAIN-42 pipeline from this page, with no account, and watch every stage decide. This is the same pipeline every product here sits behind; it runs for a throwaway demo tenant and is rate limited.

For AI engineers

Every product sits behind one decision path: your agent proposes an action with the exact arguments, CAIN runs it through identity, authority, policy, risk, trust and quorum consensus, and answers ALLOW, REQUIRE_APPROVAL or DENY with an Ed25519-signed record. A timeout, outage or unknown verdict never becomes ALLOW. A brand-new agent has no trust history, so its first actions usually come back REQUIRE_APPROVAL.

Python (zero dependencies)

pip install https://cainstudio.online/cainstudio-0.3.0-py3-none-any.whl
export CAIN_API_KEY=...   # free key: https://cainstudio.online/signup

import cainstudio

@cainstudio.guard()
def transfer(amount_usd: float, to: str) -> str:
    ...  # runs only if CAIN allows this call, with these arguments

try:
    transfer(5000, "acme")
except cainstudio.ApprovalRequired as e:
    print("held for a human:", e.approval_id)
except cainstudio.ActionBlocked as e:
    print("refused:", e.decision.reasons)
except cainstudio.CainUnavailable:
    print("CAIN unreachable: not run")   # fail-closed

See a real decision with no account

cainstudio try          # live pipeline, stage by stage
cainstudio try --list   # the other attack scenarios

MCP clients (Claude Code, Cursor)

claude mcp add --transport http cain https://cainstudio.online/mcp

More: Python SDK · TypeScript SDK · framework integrations · AI quickstart · decision signing key

Tested guarantees in this area

Every rule in these niches has its own page with its recorded result.

• Tools, MCP, protocols & adapters: 684 tested invariants — How agents reach tools, APIs and each other, safely.
• Benchmarks, coverage & performance: 1269 tested invariants — How fast it runs and how much was tested.

Related

• CAIN MCP server — Plug CAIN into Claude, Cursor or any MCP client with one command.
• cainstudio CLI — Decide, explain and approve actions from your terminal.
• cainstudio Python SDK — Add one line to your Python agent and every risky action is checked first.
• Decision API — One HTTP call: send the action, get allow / hold / block and a signed record.
• Framework integrations — Works with LangChain, CrewAI, AutoGen, OpenAI Agents, MCP, Claude Code and Cursor.
• TypeScript SDK — Guard agent actions from Node.js and TypeScript.