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What you will learn

  • When and why transactions require human approval
  • The three approval modes (CLI, web, auto)
  • How approval tokens provide single-use authorization
  • How the web approval dashboard and Telegram bot work

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When approval is required

The policy engine determines whether a transaction needs human confirmation:
Policy DecisionApproval Required?
allowNo — transaction proceeds automatically
require_approvalYes — operator must confirm
denyN/A — transaction is rejected
A transaction triggers require_approval when:
  • Its value exceeds requireApprovalAbove.valueWei
  • Its risk score exceeds maxRiskScore

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Approval modes

Set the mode via ISCL_APPROVAL_MODE environment variable:
Mode: cli (default)A readline prompt appears in the ISCL Core terminal:
┌──────────────────────────────────────────┐
│  APPROVAL REQUEST                         │
│  Action: Transfer 100 USDC to 0xAlice    │
│  Chain: Base (8453)                       │
│  Risk Score: 15/100                       │
│  Gas Estimate: ~0.0001 ETH               │
│                                           │
│  Approve? (y/n):                         │
└──────────────────────────────────────────┘
Best for: development, single-user setups where someone watches the terminal.

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Approval tokens

When a transaction is approved, ISCL Core issues an approval token:
PropertyValue
FormatUUID v4
TTL300 seconds (5 minutes)
UsageSingle-use (consumed on first sign-and-send)
BindingCryptographically bound to the intent’s canonical hash
The token prevents:
  • Replay attacks — tokens cannot be reused
  • Substitution attacks — approving intent A and signing intent B is impossible (hash binding)
  • Stale approvals — expired tokens are rejected

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Token lifecycle

approve-request
    │
    ▼
┌──────────────┐
│ Token Created │  ← TTL starts (300s)
│ Hash-bound    │
└──────┬───────┘
       │
       ▼
sign-and-send
    │
    ▼
┌──────────────┐
│ Token Verified│  ← Hash matches? Not expired? Not consumed?
│ Token Consumed│  ← Marked as used (single-use)
└──────┬───────┘
       │
       ▼
   Signing

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Web approval dashboard

The built-in web dashboard at http://localhost:3100/approval-ui provides:
  • Real-time polling for pending requests (1-second interval)
  • Approve / Deny buttons for each pending request
  • Risk score with color coding (green/yellow/red)
  • Recent audit history (5-second polling)
  • Dark theme, zero external dependencies
No authentication is required because the API is bound to localhost.

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Telegram approval

The Telegram bot (@clavion/adapter-telegram) provides inline approval keyboards: 
Transfer 100.0 USDC to 0xAbCd...1234

Chain: Base (8453)
Risk Score: 15/100

[Approve] [Deny]
Security: only the user who initiated the command can tap Approve/Deny (same-sender enforcement). Requires ISCL_APPROVAL_MODE=web on ISCL Core.

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PendingApprovalStore

In web mode, pending requests are stored in an in-memory Map:
  • TTL: 300 seconds per request
  • Cleanup: Every 30 seconds, expired entries are removed
  • Blocking: The approve-request HTTP call blocks until the operator submits a decision or the TTL expires

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Next steps