Prove what was blocked
Every call returns a structured outcome with the policy code, request_id, and docs URL. Successful responses also carry a cryptographic safety signature your auditor can verify.
A firewall for outbound agent requests.
Intercepts, validates, and enforces policy on every API call — before it leaves your agent.
Signed requests. Cryptographic receipts on every call. Inline at the edge of Cloudflare's network.
// npm install @sphyr/sdk import { SphyrClient } from '@sphyr/sdk'; const guard = new SphyrClient({ apiKey: process.env.SPHYR_API_KEY, hmacSecret: process.env.SPHYR_HMAC_SECRET, }); const result = await guard.agentGuard.call({ url: 'https://api.example.com/data', mthd: 'GET', cat: 'api-call', });
Built on real infrastructure
What Sphyr enforces
Security you can show your auditor.
Four capabilities that move agent security from promise to receipt.
Stop SSRF-class attacks
Agents reach for the unexpected: metadata endpoints, private IPs, payment APIs. Sphyr enforces network, DNS, and domain policy before the request leaves.
Budget guardrails, per-agent
Spend, rate, and call-count limits enforced at the gateway — not inferred from logs. Agents hit their cap and stop. No surprise bills, ever.
Stop credential exposure before your keys hit a hostile endpoint.
Entropy detection scans every outbound request for high-entropy strings — keys, tokens, secrets — and blocks the call before sensitive material reaches an unintended destination.
How it works
From npm install to signed receipts in three steps.
Sphyr ships as an SDK and a gateway. Install, route, audit — no infrastructure to run.
01
Install the SDK
Add @sphyr/sdk to your Node or Python app. Point it at your API key and HMAC secret.
# Node.js npm install @sphyr/sdk # Python pip install sphyr-sdk
02
Route outbound requests
Wrap any outbound call in agentGuard.call. Sphyr runs the 12-phase pipeline — HMAC, SSRF, entropy, credits — before the request leaves.
const result = await guard.agentGuard.call({ url: "https://api.example.com/data", mthd: "GET", cat: "api-call", });
03
Audit every call
Every request emits structured telemetry with the outcome, policy code, and request_id. Successful responses also carry a cryptographic safety signature. Filter the full trail from the admin console.
# Open the admin console open https://console.sphyr.io # Or query the usage summary guard.usageSummary({ window: "7d" });
Pricing
Start free. Scale when you see traffic.
No credit card to start. Pay-as-you-go with prepaid credits — no recurring fees, no surprise overage.
Free Trial
$0 no card required
For trying Sphyr on a side project or proof of concept. Free grant valid for 12 months from signup.
- ✓1,000 free requests (one-time signup grant)
- ✓HMAC signature verification
- ✓SSRF protection
- ✓Basic entropy scanning
- ✓Community support
Prepaid Credits
$5 / pack
Prepaid top-up. No recurring fees. Credits burn oldest-first with 12-month validity.
- ✓$0.0001 per request
- ✓Everything in Free Trial
- ✓Credits valid for 12 months
- ✓Preflight / dry-run mode
- ✓Admin dashboard access
- ✓Priority support
Ship agents with receipts, not hope.
1,000 free requests. No credit card. Near-zero latency overhead on Cloudflare's global network. Sign up, wire the SDK, and ship.