Action firewall for AI agents: blocks the wrong action before it runs, every verdict Ed25519-signed.
An MCP server implementing an action firewall for AI agents. It blocks the wrong action before it runs, using an integrity mechanism where every verdict is Ed25519-signed. The server is identified by the slug io-github-lucaslubi-fidacy-mcp and exposes the behavior described in its name and description.
๐ ๏ธ Key Features
Action firewall behavior for AI agents
Blocks incorrect actions before execution
Ed25519-signed verdicts for each decision
๐ Use Cases
Enforcing safety by preventing disallowed or incorrect agent actions prior to running them
Verifying firewall verdicts with Ed25519 signatures
โก Developer Benefits
Signed verdicts can support auditability and integrity checks
Open verification + SDK for Fidacy โ the external, signed trust layer for agent payments.
Verify any Fidacy verdict yourself, against our public JWKS. Don't trust us โ check.
Every verdict Fidacy issues is signed. These packages let you fetch our public keys
and cryptographically verify that a risk payload or webhook genuinely came from Fidacy
and was not tampered with โ entirely client-side, with no need to call back to us.
"Anyone can verify" is a testable claim here, not a slogan: a
conformance corpus ships signed fixtures plus
expected outcomes, so a port of the verifier in any language proves
compatibility offline (node packages/verify/conformance/run.mjs from the repo
root, 8/8 or it is not compatible).
Packages
Package
Description
@fidacy/verify
Isomorphic signature verification against Fidacy's public JWKS. Zero trust in the SDK transport โ verify the verdict itself.
@fidacy/sdk
Thin, typed client for the public Fidacy API. Calls the API and verifies every response via @fidacy/verify.
fidacy-spec
The open specification for Fidacy's signed payloads, JWKS, and webhook formats. See spec/.
Quickstart
Run it in 30 seconds (assess + verify a real signed verdict):
bash
git clone https://github.com/fidacy/fidacy-open && cd fidacy-open/quickstart
npm install
FIDACY_API_KEY=fky_test_โฆ node quickstart.mjs # a TEST key from app.fidacy.com (mode: test)
Output: a signed verdict and signature valid: true โ cryptographically verified against
the public JWKS, client-side, with no call back to Fidacy. See quickstart/.
Or add the packages to your own project (published on npm, Apache-2.0):