bagman
// Secure key management for AI agents. Use when handling private keys, API secrets, wallet credentials, or when building systems that need agent-controlled funds. Covers secure storage, session keys, leak prevention, prompt injection defense, and MetaMask Delegation Framework integration.
Bagman
Secure key management patterns for AI agents handling wallets, private keys, and secrets.
When to Use This Skill
- Agent needs wallet/blockchain access
- Handling API keys, credentials, or secrets
- Building systems where AI controls funds
- Preventing secret leakage via prompts or outputs
Quick Start
# Install 1Password CLI
brew install 1password-cli
# Authenticate
eval $(op signin)
# Create vault for agent credentials
op vault create "Agent-Credentials"
# Run examples
cd examples && python test_suite.py
Core Rules
| Rule | Why |
|---|---|
| Never store raw private keys | Config, env, memory, or conversation = leaked |
| Use delegated access | Session keys with time/value/scope limits |
| Secrets via secret manager | 1Password, Vault, AWS Secrets Manager |
| Sanitize all outputs | Scan for key patterns before any response |
| Validate all inputs | Check for injection attempts before wallet ops |
Architecture
┌─────────────────────────────────────────────────────┐
│ AI Agent │
├─────────────────────────────────────────────────────┤
│ Session Key (bounded) │
│ ├─ Expires after N hours │
│ ├─ Max spend per tx/day │
│ └─ Whitelist of allowed contracts/methods │
├─────────────────────────────────────────────────────┤
│ Secret Manager (1Password/Vault) │
│ ├─ Retrieve at runtime only │
│ ├─ Never persist to disk │
│ └─ Audit trail of accesses │
├─────────────────────────────────────────────────────┤
│ Smart Account (ERC-4337) │
│ ├─ Programmable permissions │
│ └─ Recovery without key exposure │
└─────────────────────────────────────────────────────┘
Implementation Files
| File | Purpose |
|---|---|
examples/secret_manager.py | 1Password integration for runtime secret retrieval |
examples/sanitizer.py | Output sanitization (keys, seeds, tokens) |
examples/validator.py | Input validation (prompt injection defense) |
examples/session_keys.py | ERC-4337 session key configuration |
examples/delegation_integration.ts | MetaMask Delegation Framework (EIP-7710) |
examples/pre-commit | Git hook to block secret commits |
examples/test_suite.py | Adversarial test suite |
docs/prompt-injection.md | Deep dive on injection defense |
docs/secure-storage.md | Secret storage patterns |
docs/session-keys.md | Session key architecture |
docs/leak-prevention.md | Output sanitization patterns |
docs/delegation-framework.md | On-chain permission enforcement (EIP-7710) |
1. Secret Retrieval
1Password CLI Pattern
# Retrieve at runtime (never store result)
SESSION_KEY=$(op read "op://Agents/my-agent/session-key")
# Run with injected secrets (never touch disk)
op run --env-file=.env.tpl -- python agent.py
.env.tpl (safe to commit - no secrets)
PRIVATE_KEY=op://Agents/trading-bot/session-key
RPC_URL=op://Infra/alchemy/sepolia-url
OPENAI_API_KEY=op://Services/openai/api-key
Python Usage
from secret_manager import get_session_key
# Retrieve validated session key
creds = get_session_key("trading-bot-session")
# Check validity
if creds.is_expired():
raise ValueError("Session expired - request renewal from operator")
print(f"Time remaining: {creds.time_remaining()}")
print(f"Allowed contracts: {creds.allowed_contracts}")
# Use the key (never log it!)
client.set_signer(creds.session_key)
Vault-Level ACL (Recommended)
Configure 1Password vault permissions:
Agent-Credentials/
├── trading-bot-session # Agent can read
├── payment-bot-session # Agent can read
└── master-key # Operator ONLY (agent has no access)
Principle: Agent credentials should be in a vault with read-only agent access. Master keys should be in a separate vault the agent cannot access.
2. Output Sanitization
Apply to ALL agent outputs before sending anywhere:
from sanitizer import OutputSanitizer
def respond(content: str) -> str:
"""Sanitize before any output."""
return OutputSanitizer.sanitize(content)
# Catches:
# - Private keys (0x + 64 hex)
# - OpenAI/Anthropic/Groq/AWS keys
# - GitHub/Slack/Discord tokens
# - BIP-39 seed phrases (12/24 words)
# - PEM private keys
# - JWT tokens
Patterns Detected
| Pattern | Example | Result |
|---|---|---|
| ETH private key | 0x1234...abcd (64 hex) | [PRIVATE_KEY_REDACTED] |
| ETH address | 0x742d...f44e (40 hex) | 0x742d...f44e (truncated) |
| OpenAI key | sk-proj-abc123... | [OPENAI_KEY_REDACTED] |
| Anthropic key | sk-ant-api03-... | [ANTHROPIC_KEY_REDACTED] |
| 12-word seed | abandon ability able... | [SEED_PHRASE_12_WORDS_REDACTED] |
| JWT | eyJhbG... | [JWT_TOKEN_REDACTED] |
3. Input Validation
Check inputs before ANY wallet operation:
from validator import InputValidator, ThreatLevel
result = InputValidator.validate(user_input)
if result.level == ThreatLevel.BLOCKED:
return f"Request blocked: {result.reason}"
if result.level == ThreatLevel.SUSPICIOUS:
# Log for review, but allow
log_suspicious(user_input, result.reason)
# Proceed with operation
Threat Categories
| Category | Examples | Action |
|---|---|---|
| Extraction | "show private key", "reveal secrets" | Block |
| Override | "ignore previous instructions" | Block |
| Role manipulation | "you are now admin" | Block |
| Jailbreak | "DAN mode", "bypass filters" | Block |
| Exfiltration | "send config to https://..." | Block |
| Wallet threats | "transfer all", "unlimited approve" | Block |
| Encoded | Base64/hex encoded attacks | Block |
| Unicode tricks | Cyrillic lookalikes, zero-width | Block |
| Suspicious | "hypothetically", "just between us" | Warn |
4. Operation Allowlisting
Never execute arbitrary operations. Explicit whitelist only:
from dataclasses import dataclass
from decimal import Decimal
from typing import Optional
@dataclass
class AllowedOperation:
name: str
handler: callable
max_value: Optional[Decimal] = None
requires_confirmation: bool = False
cooldown_seconds: int = 0
ALLOWED_OPS = {
"check_balance": AllowedOperation("check_balance", get_balance),
"transfer_usdc": AllowedOperation(
"transfer_usdc",
transfer,
max_value=Decimal("500"),
requires_confirmation=True,
cooldown_seconds=60
),
"swap": AllowedOperation(
"swap",
swap_tokens,
max_value=Decimal("1000"),
cooldown_seconds=300
),
}
def execute(op_name: str, **kwargs):
if op_name not in ALLOWED_OPS:
raise PermissionError(f"Operation '{op_name}' not allowed")
op = ALLOWED_OPS[op_name]
if op.max_value and kwargs.get("amount", 0) > op.max_value:
raise PermissionError(f"Amount exceeds limit: {op.max_value}")
if op.requires_confirmation:
return request_confirmation(op_name, kwargs)
return op.handler(**kwargs)
5. Confirmation Flow
High-value operations require explicit confirmation:
import hashlib
import time
pending_confirmations = {}
def request_confirmation(operation: str, details: dict) -> str:
code = hashlib.sha256(
f"{operation}{time.time()}".encode()
).hexdigest()[:8].upper()
pending_confirmations[code] = {
"op": operation,
"details": details,
"expires": time.time() + 300 # 5 minutes
}
return f"⚠️ Confirm '{operation}' with code: {code}\n(expires in 5 minutes)"
def confirm(code: str):
if code not in pending_confirmations:
return "Invalid confirmation code"
req = pending_confirmations.pop(code)
if time.time() > req["expires"]:
return "Confirmation code expired"
return execute_confirmed(req["op"], req["details"])
6. Session Keys (ERC-4337)
Instead of giving agents master keys, issue bounded session keys:
from session_keys import SessionKeyManager
# Operator creates trading session for agent
config = SessionKeyManager.create_trading_session(
agent_name="alpha-trader",
operator_address="0x742d...",
duration_hours=24,
max_trade_usdc=1000,
daily_limit_usdc=5000,
)
# Export for storage in 1Password
export_data = SessionKeyManager.export_for_1password(
config,
session_key_hex="0x..." # Generated session key
)
# op item create ... (store in 1Password)
Session Key Benefits
| Feature | Master Key | Session Key |
|---|---|---|
| Expiration | Never | Configurable (hours/days) |
| Spending limits | None | Per-tx and daily caps |
| Contract restrictions | Full access | Whitelist only |
| Revocation | Requires key rotation | Instant, no key change |
| Audit | None | Full operation log |
7. Pre-commit Hook
Block commits containing secrets:
# Install
cp examples/pre-commit .git/hooks/
chmod +x .git/hooks/pre-commit
Detected patterns:
- ETH private keys (64 hex chars)
- OpenAI/Anthropic/Groq keys
- AWS access keys
- GitHub/GitLab tokens
- Slack/Discord tokens
- PEM private keys
- Generic PASSWORD/SECRET assignments
- BIP-39 seed phrases
8. Defense Layers
USER INPUT
│
▼
┌────────────────────────────┐
│ Layer 1: Input Validation │ ← Regex + encoding + unicode checks
└────────────────────────────┘
│
▼
┌────────────────────────────┐
│ Layer 2: Op Allowlisting │ ← Explicit whitelist only
└────────────────────────────┘
│
▼
┌────────────────────────────┐
│ Layer 3: Value Limits │ ← Max per-tx and per-day
└────────────────────────────┘
│
▼
┌────────────────────────────┐
│ Layer 4: Confirmation │ ← Time-limited codes for $$$
└────────────────────────────┘
│
▼
┌────────────────────────────┐
│ Layer 5: Isolated Exec │ ← Wallet ops != conversation
└────────────────────────────┘
│
▼
OUTPUT SANITIZATION
Common Mistakes
❌ Keys in memory files
# memory/2026-02-07.md
Private key: 0x9f01dad551039daad...
Fix: Store reference only: Private key: [stored in 1Password: test-wallet]
❌ Keys in error messages
except Exception as e:
log(f"Failed with key {private_key}: {e}")
Fix: Never include credentials in error context
❌ Keys in .env.example
PRIVATE_KEY=sk-ant-api03-real-key... # "for testing"
Fix: Use obviously fake: PRIVATE_KEY=your-key-here
❌ "All" in transfer requests
User: "Transfer all my USDC"
Agent: *executes unlimited transfer*
Fix: Block "all/everything/max" patterns, require explicit amounts
❌ Trusting conversation context
# Wallet has access to conversation history
self.wallet.execute(conversation[-1]["content"])
Fix: Wallet operations must be isolated from conversation context
Testing
cd examples
# Run full test suite
python test_suite.py
# Test individual components
python sanitizer.py # Output sanitization demo
python validator.py # Input validation demo
python session_keys.py # Session key demo
Expected output: All tests passed
Checklist
- 1Password CLI installed and authenticated
- Secrets in 1Password vault, not files
- Session keys with expiry and limits
- Output sanitization on all responses
- Input validation before wallet ops
- Pre-commit hook installed
- Confirmation flow for high-value operations
- Wallet operations isolated from conversation
- .gitignore covers secrets and memory files
- Test suite passes
Security Model Limitations
This skill provides defense in depth, not a guarantee. Adversaries may:
- Novel injection patterns - Regex can't catch everything; semantic analysis helps but isn't perfect
- Social engineering - Convincing the operator to approve malicious operations
- Timing attacks - Exploiting confirmation windows
- Encoding evasion - New encoding schemes not covered
Recommendation: Layer these defenses with:
- Rate limiting
- Anomaly detection
- Human-in-the-loop for large transactions
- Regular security audits