Agent Composer

Agent Composer is a built-in agent that creates and changes agents with you in a conversation. It reads the workspace's models, skills, connections, environment templates and agents, proposes a configuration, and saves it after you approve each write.

Start Agent Composer

In Console, open Agents, expand the Create agent menu and choose Create with AI. To change an existing agent, open its detail page and choose Edit with AI. Console prepares Agent Composer and opens a new conversation with it.

Through the API, prepare it, then start a session with the returned agent:

curl -X POST "$A13N_URL/api/v1/workspaces/$WORKSPACE/agent-composer" \
  -H "Authorization: Bearer $A13N_API_KEY"

Preparing requires write in the workspace. The first call creates the workspace's built-in agent with key agent-composer (source: "builtin"). Later calls refresh its name and description and add a revision only when its configuration changed. Anyone with run can converse with it once it exists.

Choose its model

Agent Composer needs an enabled model the caller can use. Preparing picks, in order:

1. the model its current revision already uses, while it stays usable;
2. otherwise the first available model whose upstream name appears in the deployment's composer.models list, in list order (a vendor/ prefix is ignored);
3. otherwise the first usable model of the workspace, by key.

When the workspace has no usable model, preparing fails with 409 conflict and reason model_required, and Console points you to model setup. Add a model, then prepare again.

What it can do

Agent Composer uses the configuration toolset. Every tool acts as the principal who started the run, within that principal's permissions:

Tool	Effect	Default permission
find_resources	Lists agents, models, skills, connections or environment templates, 20 at a time.	allow
read_resource	Reads one of them; an agent is returned at its default revision, or the named revision_id.	allow
describe_agent_config	Returns the agent configuration schema and the toolset catalog.	allow
create_agent	Creates an agent with a key, name, description and configuration.	ask
create_agent_revision	Adds a complete configuration as a new revision of an agent, by default making it the default revision.	ask

Each write stops the run and waits for your approval; Console shows the proposed call to approve or deny. Refusals, such as a validation error or a missing permission, are returned to Agent Composer, which reports them.

To change an agent, Agent Composer reads the revision you name, or else its default revision, and writes a whole new revision that keeps every field you did not ask to change. It uses only resource IDs its tools returned.

Agent Composer does not rename agents or change their keys or labels, archive them, or manage connections, secrets and providers. It never asks for credential values: set up connections and secrets yourself, then ask Agent Composer to use them.

Built-in agent rules

Agent Composer cannot be edited, revised, archived or given an avatar (409 conflict, reason builtin); only preparing changes it. Duplicate it to create a custom agent you can change. If a custom agent already uses the key agent-composer, preparing fails with reason key_in_use.

Use the toolset in your own agents

Any agent can enable the configuration toolset in its revision. Its write tools default to ask; a revision can set another permission for each tool.