> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cardinalweb3.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Knowledge Base

> Find Cardinal product guides, integration instructions, security guidance, pilot resources, and troubleshooting help.

Use the Cardinal Knowledge Base to find the right guide for your role, product, and implementation stage.

<Note>
  Current capability boundary: Protection API pre-transaction decisioning is available; SafeSend is a controlled Arbitrum Sepolia testnet MVP; Programmable Escrow remains in final testing and security hardening.
</Note>

## Start here

<CardGroup cols={2}>
  <Card title="Cardinal overview" icon="house" href="/">
    Understand how Cardinal protects digital-asset transactions before value moves.
  </Card>

  <Card title="Protection API quickstart" icon="bolt" href="/quickstart">
    Make your first transaction check and interpret the decision.
  </Card>

  <Card title="Integration guide" icon="code" href="/integration-guide">
    Add Cardinal safely to a backend, policy engine, and signing flow.
  </Card>

  <Card title="Product status" icon="signal" href="/product-status">
    Separate available, pilot, testnet, and in-development capabilities.
  </Card>
</CardGroup>

## Choose by role

| You are…                           | Recommended starting point                                                                                         |
| ---------------------------------- | ------------------------------------------------------------------------------------------------------------------ |
| Product or business leader         | [Cardinal overview](/), [Product status](/product-status), [Pilot onboarding](/pilot-onboarding)                   |
| Backend or platform engineer       | [Protection API](/protection-api), [Quickstart](/quickstart), [Integration guide](/integration-guide)              |
| Wallet provider                    | [Wallet integration](/wallet-integration), [Security best practices](/security-best-practices)                     |
| Exchange or payment platform       | [Exchange integration](/exchange-integration), [FAQ & Troubleshooting](/faq)                                       |
| Custodian or vault provider        | [Custodian & vault integration](/custodian-vault-integration), [Security best practices](/security-best-practices) |
| RWA or high-value business         | [RWA & high-value payments](/rwa-high-value-payments), [Pilot onboarding](/pilot-onboarding)                       |
| Security, risk, or compliance team | [Security best practices](/security-best-practices), [Product status](/product-status)                             |
| Pilot operator or reviewer         | [Pilot onboarding](/pilot-onboarding), [FAQ & Troubleshooting](/faq)                                               |

## Product guides

<CardGroup cols={3}>
  <Card title="Protection API" icon="shield-check" href="/protection-api">
    Request fields, authentication, decision handling, and capability boundaries.
  </Card>

  <Card title="SafeSend" icon="clock-rotate-left" href="/safesend">
    Protected-transfer states, cancellation concepts, and testnet limitations.
  </Card>

  <Card title="Programmable Escrow" icon="handshake" href="/escrow">
    Funding, acceptance, release, refund, disputes, resolver settlement, and fees.
  </Card>
</CardGroup>

### Protection API learning path

1. Read the [Protection API overview](/protection-api).
2. Complete the [Protection API quickstart](/quickstart).
3. Design your backend flow with the [Integration Guide](/integration-guide).
4. Apply the [Security Best Practices](/security-best-practices).
5. Test error handling with [FAQ & Troubleshooting](/faq).

### SafeSend learning path

1. Review the [SafeSend product guide](/safesend).
2. Confirm the controlled Arbitrum Sepolia testnet scope.
3. Review wallet, network, gas, transfer-state, and cancellation handling.
4. Apply the [Security Best Practices](/security-best-practices).
5. Use [Pilot Onboarding](/pilot-onboarding) before partner testing.

### Escrow learning path

1. Read the [Programmable Escrow guide](/escrow).
2. Map participant roles and permitted state transitions.
3. Separate confirmed contract behaviour from production readiness.
4. Complete security, legal, AML, custody, and regulatory review.
5. Test only the lifecycle included in the signed pilot scope.

## Integration guides

<CardGroup cols={2}>
  <Card title="Wallet providers" icon="wallet" href="/wallet-integration">
    Add transaction decisioning before wallet confirmation and signature.
  </Card>

  <Card title="Exchanges" icon="arrow-right-arrow-left" href="/exchange-integration">
    Protect withdrawals, treasury movements, and platform settlement.
  </Card>

  <Card title="Custodians and vaults" icon="building-columns" href="/custodian-vault-integration">
    Combine Cardinal decisions with policies, approvals, and signing infrastructure.
  </Card>

  <Card title="RWA and high-value payments" icon="gem" href="/rwa-high-value-payments">
    Structure property, OTC, luxury, milestone, and tokenised-asset workflows.
  </Card>
</CardGroup>

## Decision handling

| Decision                       | Required response                                                  |
| ------------------------------ | ------------------------------------------------------------------ |
| `ALLOW`                        | Continue only when every partner control also passes               |
| `REVIEW`                       | Pause automatic execution and follow the documented review process |
| `BLOCK`                        | Stop the proposed transaction and preserve the evidence            |
| Error, timeout, or unavailable | Fail closed; pause or queue rather than allowing                   |

<Card title="Canonical intent" icon="fingerprint">
  The Cardinal result must remain bound to the exact sender, recipient, network, token, amount, transaction type, contract, approval scope, and permissions that the user or authorised operator will sign.
</Card>

## Security and operations

<CardGroup cols={2}>
  <Card title="Security Best Practices" icon="shield" href="/security-best-practices">
    Protect API keys, signing flows, approvals, logs, environments, and incident response.
  </Card>

  <Card title="FAQ & Troubleshooting" icon="screwdriver-wrench" href="/faq">
    Diagnose API, wallet, network, SafeSend, Escrow, and pilot issues.
  </Card>
</CardGroup>

### Essential security rules

* Keep Cardinal API keys behind a trusted backend.
* Never collect or send private keys or seed phrases.
* Construct and hash a canonical transaction intent.
* Re-check when any security-relevant field changes.
* Fail closed on errors, timeouts, or unavailable service.
* Separate transaction initiation, approval, and release duties.
* Verify the final signed or settled transaction matches the checked intent.
* Record the Cardinal `request_id`, decision, policy result, and final outcome.

## Pilot programme

<CardGroup cols={2}>
  <Card title="Pilot Onboarding" icon="rocket" href="/pilot-onboarding">
    Plan a controlled 60–90 day design-partner pilot.
  </Card>

  <Card title="RWA & high-value pilot" icon="building" href="/rwa-high-value-payments">
    Apply Cardinal to a narrow commercial payment workflow.
  </Card>
</CardGroup>

A pilot should have:

* One clearly defined transaction flow
* Explicit networks, assets, addresses, contracts, users, and value limits
* Named business, technical, security, compliance, and operational owners
* Agreed `ALLOW`, `REVIEW`, `BLOCK`, error, and unavailable handling
* A completed technical and security test plan
* Measurable success criteria and baselines
* Weekly operational reviews
* A final production-readiness and commercial decision

## Troubleshooting by symptom

| Symptom                            | Go to                                                           |
| ---------------------------------- | --------------------------------------------------------------- |
| Authentication or validation error | [API troubleshooting](/faq#api-troubleshooting)                 |
| Unexpected decision                | [Protection API questions](/faq#protection-api-questions)       |
| Wrong wallet network               | [Networks and tokens](/faq#networks-and-tokens)                 |
| Wallet will not connect            | [Wallet troubleshooting](/faq#wallet-troubleshooting)           |
| SafeSend action unavailable        | [SafeSend questions](/faq#safesend-questions)                   |
| Escrow cannot release              | [Escrow questions](/faq#escrow-questions)                       |
| Pilot setup question               | [Pilot questions](/faq#pilot-questions)                         |
| Suspected credential exposure      | [Incident response](/security-best-practices#incident-response) |

## Release information

<Card title="Changelog & Release Notes" icon="clock-rotate-left" href="/changelog">
  Review confirmed product, pilot, testnet, and documentation updates.
</Card>

Use the [Product Status](/product-status) page for the current capability boundary. Use the [Changelog](/changelog) for dated updates. A roadmap or planned item is not a released capability.

## Compliance boundary

Cardinal does not replace:

* KYC or KYB
* AML or KYT
* Sanctions screening
* Source-of-funds or source-of-wealth checks
* Regulated custody
* Legal, title, or contractual verification
* Licensed or regulated escrow services
* Jurisdiction-specific regulatory advice

Incoming-funds tracing and stolen or hacked-funds detection remain roadmap capabilities.

## Contact Cardinal

If the Knowledge Base does not resolve your question:

* **Email:** [contact@cardinalweb3.com](mailto:contact@cardinalweb3.com)
* **Telephone:** [+971 58 512 0045](tel:+971585120045)
* **Application:** [app.cardinalweb3.com](https://app.cardinalweb3.com)

For technical support, include the product, environment, network, approximate time, Cardinal `request_id` where available, business impact, and non-secret reproduction details.

Never include API keys, private keys, seed phrases, passwords, authentication tokens, identity documents, or confidential transaction records.