Spend enforcement vs LLM application debugging — complementary, not competing.
LangSmith (by LangChain) is an LLM application development platform. It traces chains, evaluates prompts, and helps you debug complex agent workflows. It's the right tool when you're building and testing agent behavior.
AgentShield is a transaction-level spend firewall. Once your agent is in production, it evaluates every API call against budget rules before execution. It catches the failure modes that cost money: retry storms, context accumulation, tool call loops.
Check Your Risk Score →| Capability | AgentShield | LangSmith |
|---|---|---|
| Block transactions before execution | ✅ <1ms eval | ❌ No spend blocking |
| Transaction limit rules | ✅ Per-call dollar limits | ❌ Not available |
| Daily spend caps per agent | ✅ Hard enforcement | ❌ Alerts only |
| Velocity / burst detection | ✅ Rolling window alerts | ❌ Not available |
| Merchant allowlists | ✅ Block unknown APIs | ❌ Not available |
| Chain tracing & debugging | ❌ Not a debugging tool | ✅ Core feature |
| Prompt evaluation | ❌ Not available | ✅ Built-in evaluation |
| Datasets & test cases | ✅ 50-scenario eval gym | ✅ Custom datasets |
| LangChain integration | ✅ Callback handler | ✅ Native (same company) |
| Self-hosted option | ✅ 60-second deploy | ❌ Cloud-only |
| Zero dependencies | ✅ Python stdlib | ❌ Requires LangChain ecosystem |
| Pricing model | ✅ Flat $19/mo (Dev tier) | ❌ Per-seat + usage |
You're developing an LLM application and need to trace execution chains, evaluate prompt quality, and debug why your agent made a specific decision.
Your agent is in production and you need to prevent runaway spending. You want hard dollar limits that block transactions before they execute, not alerts that arrive after.
LangSmith during development to build and debug. AgentShield in production to enforce spend limits. The AgentShield LangChain callback handler integrates seamlessly — it sits alongside LangSmith's tracing without conflict.
If an agent enters a retry loop at 3 AM, making 21 premium API calls: