Envoy AI Gateway vs LangSmith
Envoy AI Gateway
aigateway.envoyproxy.io
LangSmith
langchain.comSide by side
| Figure | Envoy AI Gateway | LangSmith |
|---|---|---|
| Price from | Free | $39/mo |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| Web | — | Yes |
| Windows | — | Yes |
| macOS | Yes | Yes |
| Linux | Yes | Yes |
| API | Yes | Yes |
| Self-hosted | Yes | Yes |
| Plans published | 1 | 3 |
| Spec score · LLM Gateway Software | 8.4 (#8) | 9.2 (#1) |
| Spec score · LLM gateways | 8.4 (#10) | 9.3 (#2) |
| Deployment | The CLI can run locally on Linux and macOS, and production deployment uses Kubernetes with Envoy Gateway. | Deployment provides managed or self-hosted agent servers with streaming, cron scheduling, authentication, MCP support and more than 30 API endpoints. |
| Founded | 2024 | 2023 |
| Observability | The CLI supports OpenTelemetry tracing and can record request and response details; the documentation describes configuration to hide input and output content. | Its observability features include agent tracing, cost tracking, online LLM-as-judge and code evaluations, trajectory monitoring, and webhook or PagerDuty alerts. |
| Purpose | The open-source project routes and manages generative AI traffic between applications and AI services, with rate limiting and policy control. | LangSmith is a commercial agent engineering platform for building, testing, deploying, monitoring, and improving AI agents. |
| Security | The project describes upstream authentication for securing connections to AI services and says provider credentials can be kept out of application workloads. | LangSmith's trust center lists SOC 2 Type II, ISO 27001:2022, GDPR and HIPAA compliance. |
| Support | The project directs users to its community Discord and GitHub issues for help. | The Developer plan includes community support, and the Enterprise plan lists a support SLA. |
Plans
In their own words
Envoy AI Gateway
Envoy AI Gateway, now named Agent Router, is an open-source control plane for managing AI and agent traffic through Envoy. It provides an OpenAI-compatible API for hosted and self-hosted models and MCP servers, with integrations for providers including OpenAI, Azure OpenAI, Google Gemini, AWS Bedrock, Mistral, and Anthropic. Traffic controls include model virtualization, provider failover, token quotas, and usage-based rate limiting. Its MCP gateway supports server multiplexing, tool routing, OAuth authentication, and observability; InferencePool support adds routing and load balancing for inference endpoints. Credentials can be managed centrally, and supported short-lived credential flows include AWS Bedrock, Azure OpenAI, and GCP Vertex AI. The project describes metrics collection and monitoring for AI workloads. The free open-source project is listed at free. Its CLI supports local use on Linux and macOS; production Kubernetes deployment uses Envoy Gateway and requires compatible dependencies. The project uses the Apache 2.0 license and points users to Discord and GitHub issues for help.
LangSmith
LangSmith is a commercial agent-engineering platform for building, evaluating, deploying, monitoring, and improving AI agents. It supports offline evaluations on curated datasets and real-time scoring of production interactions. Evaluation methods include human review, heuristic checks, LLM-as-judge evaluators, pairwise comparisons, and custom Python or TypeScript evaluators. Annotation queues route runs to subject-matter experts for feedback that can calibrate evaluations, improve prompts, or augment datasets. The Playground compares prompt versions or model providers, and LangSmith chat can auto-improve prompts. Observability includes agent and retrieval tracing, token and general cost tracking, trajectory monitoring, online evaluations, and webhook or PagerDuty alerts. Traces can arrive through SDKs or an API from LangGraph, custom Python, or other stacks; SDKs are listed for Python, TypeScript, Go, and Java. Hosting ranges from cloud to hybrid and self-hosted Enterprise options. The Developer plan costs nothing, Plus costs $39 a month, and Enterprise pricing is custom.