Decision infrastructure

Decision API for humans + agents.

Get one clear verdict: yes, no, or tie. Route agent actions to deterministic MCP notaries. Add Krafthaus signals only when ranking subjective choices.

Run a decision Open live demo

How decide works

Decision API resolves ambiguity. MCP notaries execute deterministic actions. Krafthaus is optional and used only for preference-heavy choices.

Decision API (humans)

Binary verdicts for direct questions, with tie when options are equivalent.

Decision API (agents)

Structured outputs so agents can gate actions before invoking a notary.

MCP notaries

Refund, cancel, return, and trial checks. Stateless, policy-sourced, deterministic.

Krafthaus (optional)

Optional sentiment ranking for best-of-N choices. Notary execution stays deterministic.

Flow in practice

1

Ask

A human or agent sends a decision request.

2

Resolve

Engine returns yes, no, or tie.

3

Execute

If action is needed, call the matched notary.

Decision API

Clear verdicts.

When models hedge, decide returns one verdict: yes, no, or tie. No debate loop.

Ask one question. We return yes, no, or tie.
High-risk categories are blocked (finance / legal / medical). See Terms & Safety.
Input → single verdict Tie when equivalent Deterministic rationale Sentiment optional (off by default) 
{
  \"endpoint\": \"/api/decide\",
  \"request\": { \"question\": \"ship this launch today?\", \"mode\": \"single\" },
  \"response\": { \"c\": \"yes\", \"v\": \"yes\", \"request_id\": \"abc123\" },
  \"field_map\": { \"c\": \"decision_class\", \"v\": \"decision\" }
}
Deterministic outputsTie detectionStateless decisionsSafety filtersDeterministic outputsTie detectionStateless decisionsSafety filters

Why it works

Built for fast choices, clear outputs, and safe defaults.

Deterministic Verdict

One output for one input: yes, no, or tie.

Tie Detection

If options are equivalent, decide says tie.

Clean Context

Each decision is stateless, so old chat drift does not leak in.

Actionable Output

Response format is short and easy to route into workflows.

Safety Filters

Finance, legal, and medical prompts are blocked by policy.

How it works

1

Ask

Ask a yes/no question or a multi-option prompt.

2

Resolve

Receive one verdict: yes, no, or tie.

3

Act

Execute, escalate, or skip with confidence.

Run your next decision.

One question. One verdict.

Run decision
MCP Servers

Decision tools for agents.

Deterministic MCP servers that give your AI agents clear, auditable answers.

Open live demo

Refund Notary

refund.decide.fyi
Last policy sync: updated daily
Live

Deterministic refund eligibility checker for US consumer subscriptions. Returns ALLOWED, DENIED, or UNKNOWN based on each vendor's official refund policy window.

64 vendors Stateless Updated daily Free / No auth
Visit GitHub

Cancel Notary

cancel.decide.fyi
Last policy sync: updated daily
Live

Cancellation penalty checker for US consumer subscriptions. Returns FREE_CANCEL, PENALTY, or LOCKED based on each vendor's cancellation terms.

64 vendors Stateless ETF detection Free / No auth
Visit GitHub

Return Notary

return.decide.fyi
Last policy sync: updated daily
Live

Return eligibility checker for US consumer subscriptions. Returns RETURNABLE, EXPIRED, or NON_RETURNABLE with return type (full refund, prorated, credit) and method.

64 vendors Stateless Return method Free / No auth
Visit GitHub

Trial Notary

trial.decide.fyi
Last policy sync: updated daily
Live

Free trial availability and terms checker for US consumer subscriptions. Returns TRIAL_AVAILABLE or NO_TRIAL with trial length, card requirement, and auto-conversion status.

64 vendors Stateless Card & auto-convert Free / No auth
Visit GitHub
Missing a vendor? Request a vendor

Live demo + audit trail

Trust Suite: not run

Run real MCP calls, inspect responses, and keep a scoped trail of recent runs.

Run Request
Advanced tools
No monitors yet.
Vendor requests (network)
    Missing a vendor? Request a vendor
    Share redaction:
    Audit scope: loading…
    Assertions
    Latest response
    Run a request to see output.
    Diff vs previous response
    Run twice to compare output changes.
    Audit Trail
    Showing 0 of 0 runs.
    Time Notary Mode Status Assert Latency Req hash Actions
    No runs yet. Run your first request.

    Connect your agent

    Add decide notaries to any MCP-compatible client in seconds.

    Add to Cursor Add to VS Code Add to Claude Add to ChatGPT Add to Codex Add to Gemini
    Claude Desktop / Cursor / Windsurf
    {
  "mcpServers": {
    "refund-decide": {
      "url": "https://refund.decide.fyi/api/mcp"
    },
    "cancel-decide": {
      "url": "https://cancel.decide.fyi/api/mcp"
    },
    "return-decide": {
      "url": "https://return.decide.fyi/api/mcp"
    },
    "trial-decide": {
      "url": "https://trial.decide.fyi/api/mcp"
    }
  }
}
    JSON-RPC — tools/call
    curl -X POST https://refund.decide.fyi/api/mcp \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "tools/call",
    "params": {
      "name": "refund_eligibility",
      "arguments": {
        "vendor": "adobe",
        "days_since_purchase": 12,
        "region": "US",
        "plan": "individual"
      }
    }
  }'
    REST API
    curl -X POST https://refund.decide.fyi/api/v1/refund/eligibility \
  -H "Content-Type: application/json" \
  -d '{"vendor":"spotify","days_since_purchase":5,"region":"US","plan":"individual"}'

    Simple pricing

    Start free, then upgrade when your team needs higher volume and workflows.

    Starter
    $0 / forever
    4 notaries + live demo
    Basic audit trail + trust suite
    Best for evaluation and solo builds
    Use live demo
    Pro
    $49 / month
    Higher request limits
    Saved cases + monitor workflows
    Commercial usage + exports
    Start pilot
    Enterprise
    Custom / contract
    Custom limits + usage plans
    Custom policy packs
    Security questionnaire + invoicing
    Talk to sales

    Support is async and best-effort on Starter and Pro. No SLA outside Enterprise contracts.

    Built for agents

    No API keys. No databases. No side effects.

    Deterministic

    Same input, same output. Every time. Fully auditable decisions your agent can cite.

    Stateless

    No sessions, no tokens, no stored data. Pure function over HTTP.

    MCP Native

    JSON-RPC 2.0 over HTTP POST. Works with Claude Desktop, Cursor, and any MCP client.

    64 Vendors

    Adobe, Netflix, Spotify, Microsoft 365, and 60 more. Updated daily via automated checks.

    Zero Config

    No API keys, no auth, no sign-up. Point your agent at the endpoint and go.

    Open Source

    Full rules, policy sources, and server code on GitHub. Verify everything.

    Ship decisions.

    Give your agents the tools to stop hedging.

    View on GitHub