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Syrin - Static Contract Analysis for MCP Servers vs three.dev
Short answer: Pick Syrin - Static Contract Analysis for MCP Servers if you want budget-controlled, safe multi-agent AI systems; pick three.dev if you want live failure detection & automated fixes for AI agents. Syrin - Static Contract Analysis for MCP Servers is free and open source; three.dev has a free plan, paid from $79/month.
Syrin - Static Contract Analysis for MCP ServersCatch MCP failures before the agent does
three.devFind out how your AI agent fails. Before your users do.Which to pick
Pick Syrin - Static Contract Analysis for MCP Servers if you want…
- Budget-controlled, safe multi-agent AI systems
- MCP contract analysis
- A free, open-source tool
- Integrations with Google, Ollama or Datadog (on Syrin - Static Contract Analysis for MCP Servers' list, not three.dev's)
Pick three.dev if you want…
- Live failure detection & automated fixes for AI agents
- Integrations with Gemini, Azure OpenAI or Claude Code (on three.dev's list, not Syrin - Static Contract Analysis for MCP Servers')
Side by side
- What it is
- Syrin - Static Contract Analysis for MCP Servers:Syrin is a Python library that adds budget enforcement, memory management, sandboxed code execution and guardrails to LLM agents.
- three.dev:three.dev scores live AI agent traffic, groups failures into modes, and helps coding agents fix them.
- Best for
- Syrin - Static Contract Analysis for MCP Servers:Budget-controlled, safe multi-agent AI systems
- three.dev:Live failure detection & automated fixes for AI agents
- Who it’s for
- Syrin - Static Contract Analysis for MCP Servers:Python developers building production AI agents.
- three.dev:Teams building production AI agents who need to detect and remediate failures.
- Pricing
- Syrin - Static Contract Analysis for MCP Servers:Open source
- three.dev:Freemium
- Starting price
- Syrin - Static Contract Analysis for MCP Servers:Free
- three.dev:$79/month (Starter)
- Free plan or trial
- Syrin - Static Contract Analysis for MCP Servers:Free to use
- three.dev:Free plan (Free)
- Plans
- Syrin - Static Contract Analysis for MCP Servers:—
- three.dev:Free $0 per month · Starter $79 per month · Pro $249 per month
- Open source
- Syrin - Static Contract Analysis for MCP Servers:Yes, 48 GitHub stars
- three.dev:Yes, 1 GitHub stars
- Works with
- Syrin - Static Contract Analysis for MCP Servers:OpenAI, Anthropic, Google, Ollama, Datadog, PagerDuty
- three.dev:OpenAI, Anthropic, Gemini, Azure OpenAI, Claude Code, Cursor, Codex, MCP server
Syrin - Static Contract Analysis for MCP Servers features
- First-class budget enforcement. Set dollar limits per agent; stop, warn or switch models when the budget is exceeded.
- Budget-aware persistent memory. Four memory types with decay, import-rank and token-cost awareness, persisting across sessions.
- Isolated sandbox execution. Run LLM-generated Python, Bash or JavaScript in subprocesses with timeouts and no shared state.
- 72+ lifecycle hooks. Typed events fire on every LLM request, tool call, memory read, sandbox exec, etc., for observability.
- Built-in guardrails. PII redaction, prompt-injection detection, content filtering, fact verification and output length limits.
- Multi-agent orchestration. Swarm topologies and recursive sub-agent spawning share budget, memory and observability.
- Agent identity & signing. Each agent has a cryptographic Ed25519 identity; messages are signed to prevent impersonation.
- Token-Oriented Object Notation (TOON). Compact schema format reduces token usage on tool calls by ~40%.
three.dev features
- Live traffic scoring. Scores every production request in real-time with no added latency.
- Failure mode grouping. Aggregates similar issues into named failure modes ranked by severity.
- Evidence-backed issues. Each failure includes the exact line or prompt that caused it.
- Coding-agent integration (MCP). Your coding agent can query failure modes and apply fixes automatically.
- Before/after comparison. Compare metrics across two traffic slices to see impact of a fix.
- Chat interface. Ask natural-language questions about traffic and get links to underlying requests.
- Replay & experiment. Test new versions on recorded traffic before releasing to users.
Syrin - Static Contract Analysis for MCP Servers vs three.dev FAQ
What is the difference between Syrin - Static Contract Analysis for MCP Servers and three.dev?+
Syrin catches MCP server contract failures; three.dev detects runtime response failures in agents.
Should I use Syrin - Static Contract Analysis for MCP Servers or three.dev?+
Pick Syrin - Static Contract Analysis for MCP Servers if you want budget-controlled, safe multi-agent AI systems, MCP contract analysis or a free, open-source tool. Pick three.dev if you want live failure detection & automated fixes for AI agents or integrations with Gemini, Azure OpenAI or Claude Code (on three.dev's list, not Syrin - Static Contract Analysis for MCP Servers').
Is Syrin - Static Contract Analysis for MCP Servers or three.dev free?+
Syrin - Static Contract Analysis for MCP Servers is free and open source. three.dev has a free plan; paid plans start at $79/month (Starter).
Which is cheaper, Syrin - Static Contract Analysis for MCP Servers or three.dev?+
Syrin - Static Contract Analysis for MCP Servers is free, so it costs less. three.dev starts at $79/month (Starter).
Is Syrin - Static Contract Analysis for MCP Servers or three.dev open source?+
Yes, both are open source: Syrin - Static Contract Analysis for MCP Servers (syrin-labs/cli on GitHub, ISC license) and three.dev (round3ai/skills on GitHub, MIT license).
Do Syrin - Static Contract Analysis for MCP Servers and three.dev integrate with the same tools?+
Partly. Both list OpenAI and Anthropic. Syrin - Static Contract Analysis for MCP Servers also lists Google, Ollama, Datadog and PagerDuty; three.dev also lists Gemini, Azure OpenAI, Claude Code, Cursor and 2 more.
On DevHunt
Syrin - Static Contract Analysis for MCP Servers
24 upvotes · Launched on DevHunt on Feb 3, 2026
Based on each tool's website and DevHunt data. Details may change; check the official sites.