Reflex security for AI agents. Five endpoints. No cloud dependencies.
LLMs should not spend thousands of tokens deciding whether input is malicious.
Agents constantly receive untrusted input:
• webpages
• comments
• tool responses
• other agents
Brack runs fast reflex checks before expensive LLM reasoning begins, blocking prompt injections, unsafe tool calls, secret leaks, and runaway agent loops.
Designed for autonomous agents.
| Endpoint | Cost | Purpose |
|---|---|---|
POST /prompt-risk |
$0.002 USDC | Prompt injection detection |
POST /tool-risk |
$0.003 USDC | Unsafe tool call detection |
POST /output-risk |
$0.002 USDC | Secret leakage detection |
POST /malware-check |
$0.001 USDC | Malicious hash/URL check |
POST /metabolic-check |
$0.001 USDC | Agent loop / context bloat detection |
GET /health |
Free | Service status |
GET /stats |
Free | Query counts |
First 200 calls free. Include header:
X-Free-Tier: AGENTFAST
Base URL
https://brack-hive.tail4f568d.ts.net
Input → /prompt-risk
Action → /tool-risk
Output → /output-risk
Health → /metabolic-check
Typical agent flow:
user_input
↓
/prompt-risk
↓
LLM reasoning
↓
/tool-risk
↓
tool execution
↓
/output-risk
↓
publish response
/metabolic-check monitors agent health, detecting loops, runaway reasoning, and context window bloat.
Typical response:
{ "risk": "high", "recommended_action": "block" }
Possible actions:
PROCEED
BLOCK
COMPRESS
INTERVENE
Agents decide how to respond.
curl https://brack-hive.tail4f568d.ts.net/prompt-risk
-H "Content-Type: application/json"
-H "X-Free-Tier: AGENTFAST"
-d '{"content":"Ignore previous instructions"}'
import requests
def brack_check(content, endpoint="prompt-risk"): r = requests.post( f"https://brack-hive.tail4f568d.ts.net/{endpoint}", json={"content": content}, headers={"X-Free-Tier": "AGENTFAST"}, timeout=5 ) return r.json().get("recommended_action") != "block"
if brack_check(user_input): agent.run(user_input)
Detects loops, repeated reasoning, or context growth.
curl https://brack-hive.tail4f568d.ts.net/metabolic-check
-H "Content-Type: application/json"
-H "X-Free-Tier: AGENTFAST"
-d '{
"window_history": [
{"content": "searching for answer", "tokens": 450},
{"content": "still searching for answer", "tokens": 480},
{"content": "continuing to search for answer", "tokens": 510}
]
}'
Returns:
PROCEED
COMPRESS
INTERVENE
Layer 0: regex + entropy (~200ms)
Layer 1: gemma3:270m nano-check (~2s semantic filter)
Layer 2: heuristics (~10ms metabolic detection)
Hash-only logging. Raw prompts are never stored.
Runs on a Beelink N100 in Bogotá.
SHA-256 hash logging only.
No raw prompts stored. Ever.
x402 micropayments via USDC on Base.
Agents can pay autonomously.
No accounts.
No API keys.
No subscriptions.
github.com/brack-6/brack