Introduction

Build with the Herm Agents API — create reusable agents, start user-scoped sessions, and stream agent events.

Herm gives you persistent, self-learning agents through a REST API. Bring your system prompt, skills, tools, and MCP servers; Herm manages versioned agent definitions, user-scoped sessions and memory, persistent workspaces, credentials, and real-time event streams.

The API is available at:

https://api.herm.run

How it works

1. Create an agent once with its model, system prompt, tools, MCP servers, and configured skills.
2. Create sessions from that agent. Pass a stable subjectId to isolate each person, organization, workspace, or team.
3. Send messages and stream events to render message deltas, tool calls, confirmations, status updates, and automatic session-title updates in your UI.

Infrastructure and deployment are managed for you. The API is centered on agents and sessions.

What you can do

Agents

Create, version, inspect, and archive reusable agent definitions.

Sessions

Start conversations with a stable subjectId identity scope.

Send Message

Send a message to a session and start or steer agent work.

Stream Events

Subscribe to deltas, tool calls, confirmations, status updates, and title changes.

Files

Read and write the persistent sandbox volume for each agent and subject.

Authentication

Send your workspace API key in the x-api-key header. All request bodies use JSON. Examples name the local environment variable HERM_API_KEY.

curl "https://api.herm.run/v1/agents" \
  -H "x-api-key: $HERM_API_KEY"

Open Herm, create or select a workspace, then create a key under Settings → API keys. Keys are shown once; store them in your secret manager and never expose them in browser code.

The machine-readable OpenAPI 3.1 specification describes the documented core REST surface, including agents, sessions, files, memory, and vaults. Product-specific integration endpoints may be released separately.

Build your first agent with the Quickstart.