Agents act. You hold the receipts.
Every block returns a signed denial receipt. Every allowed call carries a verifiable safety signature.
# One-line setup for Python or Node agents: from sphyr_sdk import auto_instrument auto_instrument( credential=os.environ["SPHYR_CREDENTIAL"], ) # → Every fetch(), requests.get(), httpx call now flows through Sphyr
Built on real infrastructure
Four capabilities that move agent security from promise to receipt.
Each block carries an Ed25519-signed denial_proof — block reason, request ID, session, and timestamp. Verify it offline using the public key embedded directly in the receipt — no fetch, no caching, no "trust the gateway." Successful responses carry an HMAC-SHA256 safety_sig — a session-scoped integrity receipt.
Agents reach for the unexpected: metadata endpoints, private IPs, payment APIs. Sphyr enforces network, DNS, and domain policy before the request leaves.
Set a per-key credit cap (lifetime or hourly) and Sphyr enforces it atomically at the gateway on every call routed through sphyr_net. When the cap is hit, subsequent calls are rejected immediately. Blocked calls cost zero credits.
Entropy detection scans every outbound request for high-entropy strings — keys, tokens, secrets — and blocks the call before sensitive material reaches an unintended destination.
Sphyr enforces policy on every outbound HTTPS call your agent makes. Here is exactly what that means — and what it does not.
Sphyr is
Sphyr is not
No per-call wrapping. No middleware to configure. Import auto_instrument and every outbound request your agent makes flows through Sphyr's 12-stage pipeline automatically — Python: requests, httpx — Node.js: fetch, axios. Coverage applies to standard HTTP libraries; custom socket transports and libraries that bypass the patched layer require manual wrapping. See the full compatibility matrix. Sphyr's own gateway host and RFC1918 / loopback addresses are auto-excluded.
# Python from sphyr_sdk import auto_instrument auto_instrument( credential=os.environ["SPHYR_CREDENTIAL"], ) // TypeScript import { autoInstrument } from "@sphyr/sdk"; autoInstrument({ credential: process.env.SPHYR_CREDENTIAL }); # → Every outbound call now carries an HMAC-SHA256 safety_sig
Every session is a security receipt. See which requests were blocked, what triggered each block, and how risky each session was — directly in the console, without digging through raw logs.
# session · a3f8b2c1… · 12 requests · 3 blocked · risk 71 GET https://api.openai.com/v1/chat/completions ALLOWED risk 4 GET https://api.stripe.com/v1/charges ALLOWED risk 11 POST https://api.example.com/upload BLOCKED risk 71 ↳ Entropy threshold exceeded — Shannon entropy 6.42 bits/char on URL parameter value; pattern matches API key format. # session · c92a1f3d… · 8 requests · 0 blocked · risk 12
Drop the SDK in, wrap your agent's calls, and every request flows through Sphyr's 12-stage security pipeline automatically.
One line wraps every outbound call — requests, httpx, fetch, axios — automatically. No per-call wrapping required.
from sphyr_sdk import auto_instrument auto_instrument( credential=os.environ["SPHYR_CREDENTIAL"], ) # → requests.get(), httpx.get() all flow through Sphyr automatically
The MCP proxy intercepts every outbound HTTPS request your agent routes through sphyr_net — no SDK code to write. Sphyr runs the 12-stage pipeline — HMAC, SSRF, entropy, credits — before the request leaves.
# Your agent's tool call (handled automatically): sphyr_net({ url: "https://api.example.com/data", mthd: "GET", cat: "api-call", })
Every request emits structured telemetry with the outcome code and request_id. Blocked calls return an Ed25519 denial_proof — independently verifiable by any third party using the public_key embedded in the receipt; use the key_url embedded in the receipt to retrieve the verification key for higher-assurance cross-check. Allowed calls return an HMAC-SHA256 safety_sig — a session-scoped integrity receipt attesting to the inbound safety scan result, confirming the response was analyzed for injection patterns and secret leakage. Filter the full trail from the admin console.
# Open the admin console open https://console.sphyr.io # Allowed: request_id + outcome + HMAC-SHA256 safety_sig (session-scoped integrity receipt). # Blocked: request_id + outcome + Ed25519 denial_proof (self-contained: public key embedded in receipt). # denial_proof verifies offline using the public_key embedded directly in the receipt — no dependency on Sphyr's infrastructure.
No tiers, no subscriptions. Every account starts with 1,000 complimentary credits — no card required. Top up with $5 packs when you need more.
1,000 complimentary credits. No credit card. Policy checks run inline at the Cloudflare edge, close to the agent. Sign up, wire the SDK, and ship.