> ## Documentation Index
> Fetch the complete documentation index at: https://docs.apostra.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Create an agent in a Developer account

> The kinds of agent you can build, what a sales mode and an operator are, and how to start from Ask Apostra, the Agents screen or MCP.

Every agent you build lives in your organization's **Developer account**. The
first Developer account in an organization is free and does not use an
account-capacity slot. Switch to it before you create an agent. If the
organization has none, create it from the organization's **Accounts** screen or
with the `manage_organization` task.

Only a directly authenticated administrator of the Developer account can
create an agent. Service tokens, delegated sessions and impersonation cannot.

## Start building

Any of these opens the same Create Agent task:

* **Ask Apostra.** In the Developer account, ask for the agent you want, for
  example "build a sales agent for my publisher". Apostra opens the Create Agent
  task. Ask Apostra's starter prompts in a Developer account cover building a
  sales, creative or buyer agent, testing an agent and getting it certified.
* **The Agents screen.** Choose **Create Agent**.
* **MCP.** Call `open_create_agent_task` on the organization MCP surface. From a
  Developer account's `/mcp/v3` connection, call `open_agents_page`, then choose
  **Create Agent**.
* **REST.** `POST /api/v2/agents`. See [Create an Agent](/v2/storefront/agents/tasks/create-agent)
  for the request and errors.

Creation registers the agent's identity only. It does not publish the agent,
connect a source or request credentials. See [Agents](/v2/concepts/agents).

## Kinds of agent

| Kind | What it does |
| - | - |
| Sales agent | Sells a publisher's inventory to buyers. It needs a sales mode. |
| Creative agent | Defines creative formats and builds or renders creative for buyers and sellers. It has no sales mode. |
| Buyer agent | Buys on behalf of an advertiser, using the advertiser grants an organization gives it. |

The Create Agent task registers sales and creative agents today. To set up a
buyer agent, follow [Manage buyer agents](/v2/setup/buyer-agent-credentials).

## Sales modes

A sales agent declares how it sells. The mode follows the AdCP buying modes the
agent supports.

| Mode | Meaning |
| - | - |
| Wholesale | The agent lists its products as a catalog, and a buyer can browse and buy them as declared. |
| Composing | The agent builds products to answer a buyer's brief. |
| Both | The agent does both. |

When Apostra refreshes a connected sales agent's capabilities, the agent's own
declaration keeps the mode current. An organization administrator can confirm or
override the mode with `save_agent`, recording a reason.

## Operators

An operator is the company or provider identity behind an agent. The agent
stays its own capability; the operator is a second identity attached to it. When
you create an agent you either:

* reuse an operator your organization already owns and has claimed, or
* name a new operator, which is created together with the agent.

An operator Apostra mapped to your organization is not yours to reuse until you
claim it. Claim it first, then create the agent under it.

## After you create an agent

Test it in the [sandbox](/v2/features/sandbox). A seller can also use the
published [Test a Sales Agent skill](https://api.apostra.com/skills/test-sales-agent/SKILL.md).
Every agent in a Developer account goes through certification; the
[Agents](/v2/concepts/agents) page describes the certification state each agent
shows.


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