LangSmith Fleet: No-Code Agent Platform
Fleet is LangSmith's no-code agent builder (rebranded from Agent Builder, March 2026). The critical first decision is the authorization model: Assistants (user's OAuth, private inbox) vs Claws (fixed credentials, shared access). This article covers that decision, channels, schedules, Skills, the Tool Server, observability, permissions, cost model, and self-hosted deployment.
Quick Reference
- →Fleet = no-code agent creation within LangSmith (formerly Agent Builder, rebranded March 2026)
- →Two authorization types: Assistants (user's OAuth, per-user inbox) vs Claws (fixed credentials, shared access)
- →Channels: event-driven triggers from Gmail, Slack (dedicated bot handles), Teams, webhooks
- →Schedules: thread-bound (state accumulates across runs) vs stateless (fresh each run) cron tasks
- →Skills: shareable instruction sets with domain knowledge — AI-assisted, template, or manual creation
- →Tool Server: standalone MCP framework with Agent Auth; acts as MCP gateway for external services
- →Agent Inbox: centralized HITL — review, approve, or reject agent actions before they execute
- →Pricing (Apr 2026): Developer = 1 agent, 50 runs free; Plus = $39/seat, runs billed as LangSmith traces
Should You Use Fleet or Write Code?
Fleet is not a replacement for code-based agents — it covers a specific slice of the problem space. If the reader of this article needs to decide between Fleet and `create_agent` / `create_deep_agent`, the right question is not 'which is better?' but 'what does my use case actually require?'
Fleet stack — UI sits on Agent Server + LangGraph; Channels, Schedules, Skills, and Tool Server are the extension points
| Criterion | Fleet (no-code) | Code (create_agent / create_deep_agent) |
|---|---|---|
| Version control | Config lives in UI only — no Git | Full Git history, PR reviews, CI/CD |
| Custom state management | Not supported | Full LangGraph state, reducers, checkpointers |
| Multi-agent orchestration | Not supported | create_deep_agent + subagent spawning |
| Non-technical team members | Self-service via Fleet UI | Requires developer involvement |
| Event-driven automation | Channels: Gmail, Slack, Teams, webhooks | Requires custom webhook infrastructure |
| Time to first deploy | Minutes from template | Hours to days for production code |
| Middleware / guardrails | Not customizable | Full hook system, custom validators |
| Ops automation, quick prototypes | Excellent fit | Overkill for simple flows |
Fleet configurations live in the LangSmith UI, not in a file. If your team requires Git-based review and rollback for agent changes, Fleet is the wrong choice — use code-based agents with the LangGraph CLI and deploy via LangGraph Platform.