Tools & permissions

Tools let an agent search the web, run commands, call external services, and more. An agent can use only the tools listed in its current config. Changing that set requires an explicit config update, so you can always see exactly what the agent has access to. Omnara has exactly three kinds of tools, distinguished by who executes them:

Kind	Executed by	Declared as	Default permission
Built-in	Omnara	A name from the built-in set, e.g. `web_search`	`always_allow`
MCP	A Model Context Protocol server you point at	An entry under `mcp:`, exposed as `mcp__{server}__{tool}`	`always_ask`
Custom	Your own system, via the API	`type: custom` with a description and input schema	`always_allow`

Permission modes

Each tool has one of three permission modes. For MCP tools, you can set a default for the server and override it for individual tools:

Mode	What happens on each call
`always_allow`	Runs immediately. No human involved.
`always_ask`	The call pauses in `awaiting_permission` and a permission interaction opens. A human approves or denies; the agent continues either way, knowing the outcome.
`always_deny`	The call is refused and the model is told so. Useful for explicitly fencing off one tool from a server that’s otherwise allowed.

tools:
  web_search: {}               # built-in, default always_allow
  run_command:
    permission:
      mode: always_ask         # every command needs approval
mcp:
  linear:
    url: https://mcp.linear.app/mcp
    permission:
      mode: always_ask         # server-wide default
    tools:
      get_issue:
        permission:
          mode: always_allow   # reads are fine
      delete_issue:
        permission:
          mode: always_deny    # never, even with approval

A permission mode applies to every call. Changing it requires creating a new config and updating the agent.

send_integration_message supports only always_allow, so agents can deliver replies to integrations such as Slack without opening another approval prompt.

What an `always_ask` call looks like

When an agent calls a tool with always_ask, its turn pauses and a permission interaction opens. Until someone approves or denies it, the tool call has state awaiting_permission. Approvals & questions shows the form and how to respond.

Check available tools

GET /tool-catalog lists the built-in tools available in your deployment, including each tool’s description, default permission, and supported modes:

curl "$OMNARA_API/tool-catalog" -H "Authorization: Bearer $OMNARA_TOKEN"

The response also includes the supported modes and defaults for custom and MCP tools in custom_tool_permissions and mcp_tool_permissions. Use it to build or validate configs against your deployment’s current tool catalog.

Built-in tools

Available tools, with inputs and defaults

Custom tools

Declare a tool, execute it in your system, post the result back

MCP servers

Connect third-party tool servers, including the OAuth flow

Skills

Versioned instruction packages agents load on demand

Get started

Agents

Inputs & events

Tools

Machines

Organization

Integrations

Examples

Tools & permissions

Permission modes

What an `always_ask` call looks like

Check available tools

Next

Built-in tools

Custom tools

MCP servers

Skills

​Permission modes

​What an always_ask call looks like

​Check available tools

​Next

Built-in tools

Custom tools

MCP servers

Skills

Permission modes

What an `always_ask` call looks like

Check available tools

Next