MCP server

Endpoint: https://api.hermios.app/mcp (streamable HTTP, POST only, protocol version 2025-06-18). Assistants that support MCP OAuth (such as Codex and Claude) only need the URL: they discover sign-in through /.well-known/oauth-protected-resource/mcp, and the person picks a workspace and approves. Each call then runs with that person’s role. An API key also works as a bearer token for server-side agents. For Codex there is a ready-made plugin, see Hermios for Codex.

How tools are exposed

By default tools/list returns a small set of entry tools, and the assistant discovers the rest:

Tool	Does
`get_tool_catalog`	Lists every tool available to the caller
`learn_tools`	Returns input schemas for chosen tools
`execute_read_tool`	Runs a read-only tool
`execute_tool`	Runs any tool, including writes
`list_object_metadata_names`	Lists the workspace’s objects
`list_skills`, `load_skills`	Workspace skills (playbooks) for the assistant
`search_help_center`	Searches these docs and the help center

Generated record tools behind execute_tool follow the object names: find_many_companies, find_one_company, group_by_companies, create_one_company, create_many_companies, update_one_company, update_many_companies, upsert_many_companies, delete_one_company, delete_many_companies, and so on for every object. Add ?mode=direct (https://api.hermios.app/mcp?mode=direct) to list every tool directly instead, for clients that do not do discovery.

Hermios tools

Tool	Does
`open_hermios`	Opens the Hermios panel in the assistant
`get_hermios_workspace`	Pipeline, people, companies, tasks or vault view, filtered to what the person can read
`get_hermios_today`	Today’s briefing
`get_hermios_profile`	The connected account and workspace
`list_hermios_workspaces`, `switch_hermios_workspace`	Work across the person’s workspaces
`get_hermios_record`, `open_hermios_record`	Read or open one record
`search_hermios_mentions`	Find people, companies and deals to mention
`create_hermios_record`, `update_hermios_record`	Create or update with stale-write protection
`draft_hermios_follow_up`	A form that returns a follow-up draft; it never sends anything
`read_hermios_settings`, `update_hermios_settings`	The person’s Hermios assistant settings
`read_hermios_modules`, `configure_hermios_module`	Modules and industry packs
`open_hermios_csv`	Opens a CSV file in the Hermios viewer and editor (the assistant’s host controls file access; it never imports records)
`get_hermios_runtime`	Reads permitted AI configuration, workflows, connections and available tools (never runs them)

execute_tool is marked destructive in its annotations, so clients ask before running writes.

Resources

ui://hermios/workspace.html and ui://hermios/csv.html (text/html;profile=mcp-app): the embedded Hermios panels.
hermios://records/{view}/{recordId}, where view is pipeline, people, companies, tasks or vault. Each read is authorized again.

Errors

A missing or expired token gets 401 with WWW-Authenticate: Bearer resource_metadata="https://api.hermios.app/.well-known/oauth-protected-resource/mcp", which tells clients where to sign in. Methods other than POST get 405.

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APIs

Reference

How tools are exposed

Hermios tools

Resources

Errors

​How tools are exposed

​Hermios tools

​Resources

​Errors

How tools are exposed

Hermios tools

Resources

Errors