AgentIndex icon
AgentIndex
heddle logo
heddle
★ 14
vs
assay logo
assay
★ 13

heddle vs assay

heddle: Heddle provides a policy-and-trust layer for Model Context Protocol (MCP) tool servers, enabling secure and declarative exposure of APIs as AI agent tools. It offers built-in security features such as trust enforcement, credential brokering, and tamper-evident audit logging, alongside containerized sandboxing and AI-powered configuration generation.; assay: Assay provides an open, recomputable evidence profile for privileged AI agent tool actions, enforcing policies deterministically and fail-closed. It records decisions, observations, and unproven claims into tamper-evident bundles for offline verification and security auditing.

01

TL;DR

heddle logo
heddleSecurity & Safety · ★ 14

Securely Exposing APIs to LLMs

Read heddle full review →
assay logo
assaySecurity & Safety · ★ 13

Generating small, reviewable CI artifacts for bounded auditability from existing evaluation outputs, runtime decisions, or MCP tool-call tests.

Read assay full review →
02

Side-by-Side Comparison

Field
heddle logoheddle
assay logoassay
Category
Security & Safety
Security & Safety
Stars
★ 14
★ 13
License
MIT
MIT
Install Command
git clone https://github.com/goweft/heddle.git && cd heddle && python -m venv venv && source venv/bin/activate && pip install -e ".[dev]"
curl -fsSL https://getassay.dev/install.sh | sh
Updated
1mo ago
1d ago
Open Source
Yes
Yes
Website
↗ Visit
↗ Visit
GitHub
↗ GitHub
↗ GitHub
Tags
AI Agent Security, Policy Enforcement, Declarative Configuration
AI Agent Security, Tool Call Enforcement, Evidence Auditing
03

Features

heddle logoheddle
01Declarative YAML Tool Configuration
02Comprehensive Security Controls
03AI-Powered Configuration Generation
04Containerized Sandboxing
assay logoassay
01Deterministic, fail-closed policy enforcement for tool calls, including optional kernel-level enforcement on Linux.
02Generates offline-verifiable, tamper-evident evidence bundles for audit and replay, integrated with CI without a hosted backend.
03Classifies claims by their trust basis (verified, self_reported, inferred, absent) to ensure honesty and prevent claims from exceeding observed facts.
04Policy gate (`assay mcp wrap`) for pre-execution allow/deny decisions on privileged tool calls, with clear reasons.
05Integrates with CI/CD pipelines via GitHub Actions and SARIF, enabling policy gates on pull requests and security-tab integration.
04

Use Cases

heddle logoheddle
↳Securely Exposing APIs to LLMs
↳Building AI Agent Tool Meshes
↳Automating Daily Operations with AI
↳Managing GPU Resources for LLMs
assay logoassay
↳Generating small, reviewable CI artifacts for bounded auditability from existing evaluation outputs, runtime decisions, or MCP tool-call tests.
↳Processing Promptfoo JSONL output from CI evaluations to produce evidence receipts and verified bundles.
↳Auditing and enforcing policies on MCP (Multi-Modal Command Protocol) tool calls, providing an allow/deny audit trail and observed-behavior evidence.
↳Implementing GitHub PR gates based on Trust Basis diffs and policy status, with SARIF/JUnit-ready output.
↳Generating inventory receipts and verified bundles from CycloneDX ML-BOM model components for model inventory and provenance.
FAQ

FAQ

What is the difference between heddle and assay?
Both heddle and assay are in the Security & Safety category. heddle has 14 stars, while assay has 13 stars.
Which is better, heddle or assay?
The best choice depends on your use case. Choose heddle if Securely Exposing APIs to LLMs, and assay if Generating small, reviewable CI artifacts for bounded auditability from existing evaluation outputs, runtime decisions, or MCP tool-call tests..
Is heddle free or open source?
Yes, heddle is open source on GitHub (MIT).
Is assay free or open source?
Yes, assay is open source on GitHub (MIT).
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