This is an exactly-once execution guard that prevents AI agents from firing duplicate tool calls when Claude retries after errors or crashes. It exposes a /claim endpoint that returns PROCEED on the first call for a given request_id and SKIP on any repeat, blocking double charges, duplicate emails, or repeated orders. The server runs on Railway with pay-per-call pricing via x402 ($0.001 per claim), plus a free /claim/test endpoint for integration testing. Also includes a local SQLite guard you can embed directly in Python agents. The repo shows a real trading bot that prevented duplicate buy orders across 23 executions using stable keys derived from symbol, side, quantity, and bar timestamp. Useful when you're building agents that interact with payment APIs, email services, webhooks, or any broker where firing the same action twice causes real problems.
POST /claim · safeagent-production.up.railway.app
Dashboard: safeagent-dashboard-2.vercel.app
# Claim an action — free, no payment header required
curl -s -X POST https://safeagent-production.up.railway.app/claim \
-H "Content-Type: application/json" \
-d '{"request_id":"order:TQQQ:buy:6:2026-05-19T13:31:00-04:00","action":"order"}'
# → {"status":"PROCEED","request_id":"..."}
# Settle after the action fires
curl -s -X POST https://safeagent-production.up.railway.app/settle/order:TQQQ:buy:6:2026-05-19T13:31:00-04:00 \
-H "Content-Type: application/json" \
-d '{"result":{"status":"completed"}}'
# → {"status":"committed","request_id":"..."}
# Retry with the same request_id — returns SKIP
curl -s -X POST https://safeagent-production.up.railway.app/claim \
-H "Content-Type: application/json" \
-d '{"request_id":"order:TQQQ:buy:6:2026-05-19T13:31:00-04:00","action":"order"}'
# → {"status":"SKIP","request_id":"...","existing":{...}}
# Free test endpoint — same logic, limited to 10 calls per IP
curl -s -X POST https://safeagent-production.up.railway.app/claim/test \
-H "Content-Type: application/json" \
-d '{"agent_id":"bot-1","action_type":"order","scope":"TQQQ:buy:bar:2026-05-19T13:31:00-04:00"}'
# → {"status":"PROCEED","request_id":"...","test":true,"calls_remaining":9}
Indexed on Bazaar.
This implementation is a Mycelium Provider.
Each completed action submits a trail to ARGENTUM with a content-addressed action_ref
(JCS+SHA-256 over the four preimage fields). The returned mycelium_trail_id is included
in every receipt for independent verification.
SafeAgent is the first verified external integrator on Soma — the Mycelium agent catalog. Every production execution is anchored on-chain via Mycelium Trails and independently verifiable without going through the operator.
SafeAgent is an exactly-once execution guard. It prevents AI agents and SaaS applications from firing the same action twice — on crash-retry, duplicate signal, webhook replay, or concurrent execution across multiple instances.
Every action gets a stable request_id derived from what the agent is doing and when. The first call commits. Every subsequent call with the same key returns SKIP and the original result. No double charges. No double emails. No double orders. No duplicate webhooks.
State machine: PENDING → COMMITTED | SKIP
Common failure modes SafeAgent prevents:
| Scenario | Without SafeAgent | With SafeAgent |
|---|---|---|
| Stripe charge times out, retry fires | Customer charged twice | Second charge returns SKIP |
| Welcome email on signup retried | User gets two welcome emails | Second send returns SKIP |
| Webhook delivered twice (Stripe/GitHub/Twilio guarantee at-least-once) | Event processed twice | Second processing returns SKIP |
| Workspace provisioned on retry | Two workspaces created | Second provision returns SKIP |
| AI agent tool call retried after crash | Duplicate side effect | Second call returns SKIP |
SafeAgent is the exactly-once enforcement layer in a formally specified agent execution integrity stack:
Polaris (commit-gated authorization)
└── AgentGraph safety verdict (pre-execution safety gate)
└── SafeAgent (exactly-once execution guard) ← you are here
└── Mycelium Trails (on-chain anchor)
Each layer is independently authored and independently verifiable. None trusts the others.
Gate an action. Returns PROCEED on first call, SKIP on any repeat.
Request body:
{
"request_id": "order:TQQQ:buy:6:2026-05-19T13:31:00-04:00",
"action": "order"
}
request_id — stable identifier derived from what the agent is doing. Same inputs = same key.action — the action type being gated (e.g. payment.send, email, trade, order)Response:
{ "status": "PROCEED", "request_id": "order:TQQQ:buy:6:2026-05-19T13:31:00-04:00" }
Retry with the same payload:
{ "status": "SKIP", "request_id": "order:TQQQ:buy:6:2026-05-19T13:31:00-04:00", "existing": {...} }
Settle a claim after the action fires. Advances status from PENDING to COMMITTED.
curl -s -X POST https://safeagent-production.up.railway.app/settle/order:TQQQ:buy:6:2026-05-19T13:31:00-04:00 \
-H "Content-Type: application/json" \
-d '{"result":{"status":"completed","txid":"abc123"}}'
{ "status": "committed", "request_id": "..." }
Free test endpoint — same logic, no payment required. Limited to 10 calls per IP total.
curl -s -X POST https://safeagent-production.up.railway.app/claim/test \
-H "Content-Type: application/json" \
-d '{"agent_id":"bot-1","action_type":"order","scope":"TQQQ:buy:6:bar:2026-05-19T13:31:00-04:00"}'
{ "status": "PROCEED", "request_id": "...", "test": true, "calls_remaining": 9 }
Full claim history. Filter by agent_id, action, status, or timestamp range.
curl "https://safeagent-production.up.railway.app/audit?agent_id=bot-1&status=COMMITTED"
{"items": [...], "total": 5, "limit": 100, "offset": 0}
Parameters: agent_id, action, status, from_ts, to_ts, limit (max 1000), offset.
import requests
def claim(request_id: str, action: str) -> dict:
r = requests.post(
"https://safeagent-production.up.railway.app/claim",
headers={"Content-Type": "application/json"},
json={"request_id": request_id, "action": action}
)
return r.json() # {"status": "PROCEED"|"SKIP", "request_id": "..."}
def settle(request_id: str, result: dict) -> dict:
r = requests.post(
f"https://safeagent-production.up.railway.app/settle/{request_id}",
headers={"Content-Type": "application/json"},
json={"result": result}
)
return r.json()
# Usage
response = claim("payment:customer-123:invoice-456", "payment.send")
if response["status"] == "PROCEED":
result = send_payment(...)
settle("payment:customer-123:invoice-456", {"status": "completed"})
elif response["status"] == "SKIP":
print("Already executed, skipping")
import requests
def safe_stripe_charge(customer_id, amount, idempotency_key):
request_id = f"stripe:charge:{customer_id}:{idempotency_key}"
response = requests.post(
"https://safeagent-production.up.railway.app/claim",
headers={"Content-Type": "application/json"},
json={"request_id": request_id, "action": "stripe_charge"}
).json()
if response["status"] == "SKIP":
return response.get("existing")
charge = stripe.PaymentIntent.create(amount=amount, customer=customer_id)
requests.post(
f"https://safeagent-production.up.railway.app/settle/{request_id}",
headers={"Content-Type": "application/json"},
json={"result": {"charge_id": charge.id}}
)
return charge
Webhook deduplication — Stripe, GitHub, and Twilio all guarantee at-least-once delivery. SafeAgent turns at-least-once into exactly-once:
def handle_stripe_webhook(event):
response = requests.post(
"https://safeagent-production.up.railway.app/claim",
headers={"Content-Type": "application/json"},
json={"request_id": event["id"], "action": "stripe_event"}
).json()
if response["status"] == "SKIP":
return {"ok": True}
provision_subscription(event)
requests.post(
f"https://safeagent-production.up.railway.app/settle/{event['id']}",
headers={"Content-Type": "application/json"},
json={"result": {"processed": True}}
)
from crewai import Agent
import sqlite3
guard_con = sqlite3.connect("safeagent_orders.db", check_same_thread=False)
# ... same guard pattern, keyed on tool_name + input hash + session_id
PR crewAIInc/crewAI#5822 adds pluggable idempotency backends. SafeAgent's SQLite schema is compatible.
WisePick is a deterministic routing layer for agent runtimes. The integration splits capability selection from durable, idempotent execution — WisePick answers what and which provider, SafeAgent answers whether this logical work already ran.
Stack:
WisePick /v1/decide → DashClaw → SafeAgent → Mycelium Trails → Base/Arbitrum
adapters/safeagent_adapter.pydocs/integrations/safeagent.mdThe same guarantee without the network call. Drop this into any Python agent:
import sqlite3
_SA_DB = "safeagent_orders.db"
_sa_con = sqlite3.connect(_SA_DB, check_same_thread=False)
_sa_con.execute("""CREATE TABLE IF NOT EXISTS orders (
request_id TEXT PRIMARY KEY,
result TEXT,
status TEXT DEFAULT 'PENDING',
created_at TEXT DEFAULT (datetime('now'))
)""")
_sa_con.commit()
def place_order_with_guard(symbol, qty, side, bar_ts):
request_id = f"order:{symbol}:{side}:{qty}:{bar_ts}"
_sa_con.execute(
"INSERT OR IGNORE INTO orders (request_id, status) VALUES (?, 'PENDING')",
(request_id,)
)
_sa_con.commit()
row = _sa_con.execute(
"SELECT status, result FROM orders WHERE request_id = ?",
(request_id,)
).fetchone()
if row and row[0] == 'COMMITTED':
print(f"SAFEAGENT SKIP: {request_id}")
return row[1]
result = place_order(symbol, qty, side)
_sa_con.execute(
"UPDATE orders SET status='COMMITTED', result=? WHERE request_id=?",
(json.dumps(str(result)), request_id)
)
_sa_con.commit()
return result
A trading bot fires a market order to buy 6 shares of TQQQ. The broker accepts it. The bot crashes before updating state. On restart — same signal, same bar — the bot fires again. The broker fills it twice. The agent now holds 12 shares when it intended to hold 6.
This is not theoretical. It happens on any unhandled exception between order submission and state persistence.
SafeAgent derives a stable key before touching the broker:
request_id = "order:TQQQ:buy:6:2026-05-19T13:31:00-04:00"
First call: PROCEED. Side effect fires. Settle writes COMMITTED.
Crash and retry: SKIP. Broker never touched again.
Six confirmed SKIP events from a live session on the full stack: DashClaw, SafeAgent, Mycelium Trails, Base/Arbitrum, broker Alpaca.
Full session data: https://gist.github.com/azender1/b9112b6519c935df4a75cb05cd250e26
SafeAgent participates in the A2A cross-implementation conformance corpus. Byte-verified fixtures across four independent implementations:
A2A #1920 closed. All four implementations satisfy freshness and replay requirements.
action_ref derivationJCS (RFC 8785), aligned with argentum-core, Nobulex, and APS:
import hashlib
import rfc8785
def compute_action_ref(
agent_id: str,
action_type: str,
scope: str,
timestamp: str, # RFC 3339 UTC, 3-digit ms: "2026-05-15T10:00:00.123Z"
) -> str:
payload = {
"agent_id": agent_id,
"action_type": action_type,
"scope": scope,
"timestamp": timestamp,
}
canonical = rfc8785.dumps(payload)
return hashlib.sha256(canonical).hexdigest()
timestamp is an RFC 3339 UTC string with exactly 3 millisecond digits. The trailing Z is mandatory.
Conformance fixtures: giskard09/argentum-core tag action-ref-v1.0
Railway · Serverless OFF · always-on
PyPI: pip install safeagent-exec-guard
npm: npm install n8n-nodes-safeagent
MCP Registry: io.github.azender1/safeagent
Dashboard: safeagent-dashboard-2.vercel.app
Apache-2.0