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

# Accounts and agents

> AdCP accounts and agents: the four entities in every transaction (brand, account, operator, agent), account-id namespaces, buyer-declared accounts, and billing configuration.

AdCP distinguishes four entities in every billable operation:

| Entity       | Question                            | How identified                                                                                                                                    |
| ------------ | ----------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Brand**    | Whose products are advertised?      | Brand reference: `domain` + optional `brand_id` and commercial-identity `countries[]` ([brand.json](/dist/docs/3.0.23/brand-protocol/brand-json)) |
| **Account**  | Who gets billed? What rates apply?  | [Account reference](#account-references)                                                                                                          |
| **Operator** | Who operates on the brand's behalf? | Domain (e.g., `pinnacle-media.com`)                                                                                                               |
| **Agent**    | What software is placing the buy?   | Authenticated session                                                                                                                             |

**Brand** — The advertiser whose products or services are promoted. Identified by a `brand` reference (`domain` + optional `brand_id` and ISO country `countries[]`), resolved via `/.well-known/brand.json`. Countries distinguish commercial advertiser identities without becoming delivery targeting.

**Account** — A billing relationship between a buyer and seller. Determines rate card, payment terms, credit limit, and who receives invoices. Every billable operation requires an account reference — a seller/storefront-assigned `account_id` when the seller or upstream platform owns the canonical account namespace, or an advertiser natural key (`brand`, `operator`, optional `operator_unit`, `currency`, `sandbox`) for buyer-declared accounts.

**Operator** — The entity driving buys — an agency trading desk, the brand's internal team, or another entity acting on behalf of the advertiser. Identified by domain and verifiable via [authorized operators](#authorized-operators) in `brand.json`.

**Agent** — The software placing buys and managing campaigns. Authenticates with the seller and may operate on behalf of multiple operators and brands.

See [Accounts Protocol overview](/dist/docs/3.0.23/accounts/overview) for the full commercial model and [sync\_accounts](/dist/docs/3.0.23/accounts/tasks/sync_accounts) for the task reference.

## What sellers declare

Sellers configure the `account` section of [`get_adcp_capabilities`](/dist/docs/3.0.23/protocol/get_adcp_capabilities#account):

**1. Which billing models do you support?** (`supported_billing`)

The buyer must pass one of these values as `billing` in every `sync_accounts` entry. The seller either accepts or rejects.

| Billing      | Who is invoiced                          | Use case                                                                                          |
| ------------ | ---------------------------------------- | ------------------------------------------------------------------------------------------------- |
| `operator`   | Operator (agency or brand buying direct) | Operator buying on their own terms                                                                |
| `agent`      | Agent                                    | Agent consolidates billing across brands                                                          |
| `advertiser` | Advertiser directly                      | Operator places orders but advertiser pays (common on social platforms and in DACH B2B workflows) |

This is an account-level invoiced-party choice. It does not select a payment rail, clearing intermediary, or settlement route for an individual media buy; AdCP payment and settlement remain out of protocol.

**2. Which account currency models do you support?** (`supported_account_currency_modes`)

Sellers implementing AdCP 3.2 advertiser-account provisioning advertise one or both values. The field remains optional in the shared 3.x wire schema so existing 3.0 and 3.1 responses continue to validate; absence means the older seller's currency model is not discoverable and does not imply support for either mode.

| Mode            | Provisioning behavior                                                                             |
| --------------- | ------------------------------------------------------------------------------------------------- |
| `fixed`         | Include one immutable ISO 4217 `currency`; it participates in the advertiser account natural key. |
| `per_media_buy` | Omit account `currency`; select currency on each proposal or media buy.                           |

When both are present, the buyer selects the model by including or omitting `currency`.

**3. Do you require operator-level auth?** (`require_operator_auth`)

This field determines the authentication model and the account reference shape:

When `false` (default) — **buyer-declared accounts**: the seller trusts the agent. The agent authenticates once and declares accounts via `sync_accounts`. On subsequent requests, the buyer passes the natural key (`brand` + `operator`) and the seller resolves internally.

When `true` — **account-id namespaces**: each operator must authenticate with the seller directly. The agent obtains a credential per operator — via OAuth using the seller's `authorization_endpoint`, or via API key out-of-band. Subsequent requests pass a seller-assigned `account_id`. If a credential may access more than one account, the seller MUST expose `list_accounts` and the buyer MUST resolve an explicit account before the first account-scoped request. If a credential is bound to exactly one account, the seller SHOULD expose `list_accounts` returning that singleton; a seller MAY omit `list_accounts` only when it supplies the same explicit account ID through another declared path or out-of-band onboarding.

For sandbox, the path follows the account namespace: account-id namespaces use pre-existing test accounts from `list_accounts` or out-of-band setup; buyer-declared accounts use `sync_accounts` with `sandbox: true` and reference by natural key.

Sellers can also declare `account_financials: true` to expose account-level financial data (spend, credit, invoices) via [`get_account_financials`](/dist/docs/3.0.23/accounts/tasks/get_account_financials). This only applies to operator-billed accounts.

**Example capabilities:**

```json theme={null}
{
  "account": {
    "require_operator_auth": false,
    "supported_billing": ["operator", "agent"],
    "supported_account_currency_modes": ["fixed", "per_media_buy"]
  }
}
```

Sellers that support `advertiser` billing declare it explicitly:

```json theme={null}
{
  "account": {
    "require_operator_auth": false,
    "supported_billing": ["operator", "agent", "advertiser"],
    "supported_account_currency_modes": ["fixed", "per_media_buy"]
  }
}
```

These fields combine into common patterns.

## Seller patterns

Which kind of platform are you buying from? That determines the account setup pattern.

| Platform type                              | Account pattern                       | `require_operator_auth` | `supported_billing`                       |
| ------------------------------------------ | ------------------------------------- | ----------------------- | ----------------------------------------- |
| [Social / walled garden](#social-platform) | Upstream-managed account-id namespace | `true`                  | `["operator"]`                            |
| [Direct publisher](#direct-publisher)      | Buyer-declared accounts               | `false`                 | `["operator"]` or `["operator", "agent"]` |
| [DSP / programmatic](#dsp--programmatic)   | Buyer-declared accounts               | `false`                 | `["agent"]`                               |

### Social platform

The operator already has an account on the platform — an ad account, a business manager, a self-serve dashboard. The upstream platform owns the canonical account namespace accessible to that credential. The agent obtains the operator's credentials (via OAuth or API key), opens a per-operator session, resolves an explicit account through `list_accounts`, and uses the returned `account_id` values. The platform bills the operator directly.

**Capabilities:**

```json theme={null}
{
  "account": {
    "require_operator_auth": true,
    "supported_billing": ["operator"],
    "supported_account_currency_modes": ["fixed"],
    "authorization_endpoint": "https://seller.example.com/oauth/authorize"
  }
}
```

**Buyer workflow:**

1. Call `get_adcp_capabilities` — see `require_operator_auth: true` and `authorization_endpoint`
2. For each operator:
   a. Obtain operator's credential (OAuth via `authorization_endpoint`, or API key out-of-band)
   b. Open a new session with the operator's credential
   c. Call `list_accounts` to discover accounts visible to that credential
3. Human or policy selects the correct account from the list
4. Call `get_products` / `create_media_buy` with the operator's session and `{ "account_id": "..." }`

**list\_accounts response:**

```json theme={null}
{
  "accounts": [{
    "account_id": "acc_spark_social_001",
    "name": "Spark paid social",
    "brand": { "domain": "nova-brands.com", "brand_id": "spark" },
    "operator": "pinnacle-media.com",
    "status": "active",
    "billing": "operator",
    "account_scope": "operator_brand"
  }]
}
```

Subsequent calls use the discovered ID:

```json theme={null}
{
  "account": { "account_id": "acc_spark_social_001" }
}
```

**Key point:** The operator's credential — not the agent's — authorizes all calls in that session. The buyer does not declare or create accounts through AdCP in the 3.0.x account-id model; `list_accounts` mirrors the upstream namespace. If the seller exposes `sync_accounts`, it is only for settings updates against an existing `account_id`, not natural-key provisioning, unless a future explicit capability declares account-id provisioning.

### Direct publisher

The publisher trusts the agent but bills the operator directly. The agent sets up accounts via `sync_accounts` — no per-operator login needed. Accounts may require human approval (credit checks, legal agreements) before becoming active.

Many publishers also accept agent billing (`supported_billing: ["operator", "agent"]`). The buyer chooses per account — operators with a direct relationship use `billing: "operator"`, everything else uses `billing: "agent"`. If the seller doesn't support the requested billing for a particular account, it rejects the request and the agent re-submits with a different model.

**Capabilities:**

```json theme={null}
{
  "account": {
    "supported_billing": ["operator", "agent"],
    "supported_account_currency_modes": ["fixed", "per_media_buy"]
  }
}
```

**Buyer workflow:**

1. Call `get_adcp_capabilities` — see `require_operator_auth` absent (defaults to `false`)
2. Call `sync_accounts` for each brand/operator pair
3. Wait for account status `active` — may require human to complete credit/legal at `setup.url`
4. Call `get_products` with `account` reference
5. Call `create_media_buy` with `account` reference

**sync\_accounts request — brand buying direct:**

```json theme={null}
{
  "accounts": [{
    "brand": { "domain": "acme-corp.com" },
    "operator": "acme-corp.com",
    "billing": "operator"
  }]
}
```

Seller acknowledges the request but requires setup before provisioning:

```json theme={null}
{
  "accounts": [{
    "brand": { "domain": "acme-corp.com" },
    "operator": "acme-corp.com",
    "action": "created",
    "status": "pending_approval",
    "billing": "operator",
    "account_scope": "brand",
    "setup": {
      "url": "https://seller.example.com/advertiser-onboard",
      "message": "Complete advertiser registration and credit application"
    }
  }]
}
```

The seller has acknowledged the relationship `(brand: "acme-corp.com", operator: "acme-corp.com", billing: "operator")`, but the account is pending review before it becomes active. A human at Acme Corp completes the setup at the URL. To check progress, the agent either:

* Re-calls `sync_accounts` with the same natural key — the seller returns the updated status
* Receives a webhook notification if `push_notification_config` was provided in the request

**Key point:** `pending_approval` is the normal path. Every buyer needs a direct relationship with the seller.

**Billing rejection — operator billing not available:**

The seller supports operator billing in general, but may not support it for every operator. Here, the agent requests operator billing for an operator without a direct relationship:

```json theme={null}
{
  "accounts": [{
    "brand": { "domain": "acme-corp.com" },
    "operator": "acme-corp.com",
    "billing": "operator"
  }]
}
```

Seller rejects the request because this operator has no direct billing relationship:

```json theme={null}
{
  "accounts": [{
    "brand": { "domain": "acme-corp.com" },
    "operator": "acme-corp.com",
    "action": "failed",
    "status": "rejected",
    "errors": [{
      "code": "BILLING_NOT_SUPPORTED",
      "message": "Operator billing is not available for this account. Re-submit with billing: \"agent\"."
    }]
  }]
}
```

The agent re-submits with `billing: "agent"` or informs the buyer that operator billing is not available with this seller. Billing is never silently remapped.

### DSP / programmatic

All billing flows through the agent. The agent has a standing relationship with the platform and consolidates billing across all brands and operators. Accounts are created instantly — no human approval needed.

**Capabilities:**

```json theme={null}
{
  "account": {
    "supported_billing": ["agent"],
    "supported_account_currency_modes": ["per_media_buy"]
  }
}
```

**Buyer workflow:**

1. Call `get_adcp_capabilities` — see `supported_billing: ["agent"]`
2. Call `sync_accounts` for each brand/operator pair with `billing: "agent"`
3. Accounts are active immediately — no human approval needed
4. Call `get_products` / `create_media_buy` with `account` reference

**sync\_accounts request:**

```json theme={null}
{
  "accounts": [{
    "brand": { "domain": "nova-brands.com", "brand_id": "spark" },
    "operator": "pinnacle-media.com",
    "billing": "agent"
  }]
}
```

Account active immediately:

```json theme={null}
{
  "accounts": [{
    "brand": { "domain": "nova-brands.com", "brand_id": "spark" },
    "operator": "pinnacle-media.com",
    "action": "created",
    "status": "active",
    "billing": "agent",
    "account_scope": "operator_brand"
  }]
}
```

**Key point:** The agent receives a single consolidated invoice. Per-brand accounts give reporting granularity but billing is centralized.

## Authorized operators

Brands declare who can represent them in `/.well-known/brand.json` via the `authorized_operators` field. Sellers SHOULD verify operators against this when processing `sync_accounts`.

```json theme={null}
{
  "house": {
    "domain": "nova-brands.com",
    "name": "Nova Brands"
  },
  "brands": [
    { "id": "spark", "names": [{"en": "Spark"}] },
    { "id": "glow", "names": [{"en": "Glow"}] }
  ],
  "authorized_operators": [
    {
      "domain": "pinnacle-media.com",
      "brands": ["spark", "glow"],
      "countries": ["US", "GB", "DE"]
    },
    {
      "domain": "summit-agency.jp",
      "brands": ["spark"],
      "countries": ["JP"]
    },
    {
      "domain": "nova-brands.com",
      "brands": ["*"]
    }
  ]
}
```

| Field       | Required | Description                                                      |
| ----------- | -------- | ---------------------------------------------------------------- |
| `domain`    | Yes      | Operator's domain                                                |
| `brands`    | Yes      | Brand IDs this operator can represent. `["*"]` means all brands. |
| `countries` | No       | ISO 3166-1 alpha-2 country codes. Omit for global authorization. |

### Verification flow

1. Resolve `{brand.domain}/.well-known/brand.json`
2. Check `authorized_operators` for matching `domain` with the brand in `brands`
3. If found → proceed (account may still need credit/legal approval)
4. If not found → reject the account (`action: "failed"`) or return `pending_approval` for manual review

Verification is a trust signal, not a gate. Finding the operator in `brand.json` lets the seller fast-track provisioning. If the operator isn't listed, the seller can still approve through its own review process.

**Self-authorization is implicit.** When the `operator` domain matches the brand's domain, the brand is operating directly — no listing in `authorized_operators` is needed.

`authorized_operators` models the interface between the brand and whoever operates on its behalf. It does not model internal agency hierarchies.

## Buyer-agent identity

`authorized_operators` tells the seller whether an operator is allowed to represent a brand. It doesn't tell the seller who the *agent* placing the call is, or what commercial relationship is on file with that agent. Those are different questions, and the seller checks both before provisioning.

Two layers run on every `sync_accounts` request:

| Layer                            | Question                                                              | Where it lives                                                                                                                                                                                                                                                                                                                                  |
| -------------------------------- | --------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Agent identity**               | Which buyer agent issued this request?                                | The seller's onboarding record, looked up by signed-request `agent_url` (when [request signing](/dist/docs/3.0.23/building/by-layer/L1/security#signed-requests-transport-layer) is in use) or by the bearer / API-key / OAuth credential the agent presented. Signature or credential establishes identity; authorization is a separate check. |
| **Brand-operator authorization** | Is the operator named in the request authorized to act for the brand? | `brand.json` `authorized_operators` (above). Verified whether the request is signed or not.                                                                                                                                                                                                                                                     |

Both layers MUST pass. A signed request from an onboarded agent for an unauthorized operator gets rejected on the brand-operator check; a request from an unrecognized agent for an authorized operator gets rejected on the identity check. Sellers that advertise [`request_signing.required_for`](/dist/docs/3.0.23/building/by-layer/L1/security#transport-scope) on `sync_accounts` reject unsigned traffic at the identity layer; sellers that don't advertise it MAY still require an established credential mapping before agent-billable values are accepted.

The brand-operator check runs against the seller's cached `brand.json` per [Operator revocation and caching](#operator-revocation-and-caching) — revocation is eventual. Sellers performing high-value or first-time-on-this-brand provisioning SHOULD bypass the cache to close the TOCTOU window.

**SDK naming for the brand-operator authorization Protocol.** SDKs that surface a typed Protocol for the brand-operator check (for adopters to plug their own resolver into) SHOULD name it after the file consulted: `BrandAuthorizationResolver` (or equivalent in idiomatic casing). The file is `brand.json/authorized_operators` — the brand-side declaration of who may represent the brand. SDKs SHOULD NOT name this Protocol after `adagents.json`, which is publisher-side / data-provider-side and models a different relationship (which sales agents may sell that publisher's inventory). Naming the buyer-side resolver `AdagentsResolver` confuses the two surfaces and locks adopters into the wrong mental model. This is a spec-side recommendation; SDK conventions track upstream.

**The agent's commercial state is offline.** Whether a buyer agent is *passthrough-only* (no payments relationship — only the operator can be invoiced) or *agent-billable* (the agent can be invoiced directly) is recorded in the seller's onboarding system, the same way operator account creation is. Provisioning that record — contract, KYC, payment terms, billing entity capture — is out of scope for AdCP. What's in scope is two on-wire consequences:

1. **Runtime billing gate.** A passthrough-only agent that submits `billing: "agent"` or `billing: "advertiser"` is rejected with `BILLING_NOT_PERMITTED_FOR_AGENT` and an `error.details.suggested_billing` of `operator`. See [Billing and Account Setup](/dist/docs/3.0.23/building/by-layer/L3/error-handling#billing-and-account-setup) for the recovery contract.
2. **Per-agent defaults.** Sellers MAY pre-fill `payment_terms`, `billing_entity`, rate-card linkage, and credit limit from the buyer agent's onboarding record when provisioning new accounts under that agent. Per-account values on the `sync_accounts` request always take precedence over per-agent defaults — the buyer can override per row. The per-agent layer is a recommended implementation pattern (it mirrors how SSPs maintain `buyer_id` / `seat_id` rows for OpenRTB DSPs); smaller publishers MAY collapse to seller-wide defaults until they have receivables ops that distinguish per-agent terms.

## Account references

Every account-scoped operation accepts an `account` object instead of a flat `account_id` string. The seller's `require_operator_auth` capability determines the auth model and reference shape; tool exposure distinguishes upstream-managed `account_id` namespaces from seller-defined IDs supplied out-of-band.

<Note>
  Sellers that support caller-scope introspection attach an optional `authorization` object to each per-account entry in [`sync_accounts`](/dist/docs/3.0.23/accounts/tasks/sync_accounts) and [`list_accounts`](/dist/docs/3.0.23/accounts/tasks/list_accounts) responses — listing the tasks and request fields this caller is allowed to use on the account, plus any standard named scope (e.g., `attestation_verifier`). See [Caller authorization](/dist/docs/3.0.23/accounts/overview#caller-authorization) for the full shape and semantics.
</Note>

### Account-id namespaces (`require_operator_auth: true`)

Accounts are managed outside of AdCP. The advertiser creates an account on the seller's platform, grants the operator permission to manage it, and the buyer passes a seller-assigned `account_id`. The agent is not involved in account creation or billing setup — those are handled between the advertiser, operator, and seller directly.

**Typical sellers:** Social platforms, self-serve ad platforms — anywhere the advertiser already has an account.

**Upstream-managed workflow:**

1. Advertiser creates an account on the seller's platform (out-of-band)
2. Advertiser grants the operator permission to manage the account (out-of-band)
3. Agent calls `list_accounts` to discover available accounts
4. Human selects the correct account from the list
5. Agent passes `{ "account_id": "acc_acme_001" }` on every request (`get_products`, `create_media_buy`, etc.)

`list_accounts` is mandatory when the authenticated credential may access more than one account because the upstream owns the namespace. When the credential is bound to exactly one account, sellers SHOULD still expose `list_accounts` returning that singleton so SDKs can auto-select it and send explicit `{ "account_id": "..." }` on required-account calls. `sync_accounts` provisioning is out of scope for account-id namespaces in 3.0.x unless a future explicit capability declares it; if `sync_accounts` is exposed today, it is settings-update mode for an existing `account_id`.

**Seller-defined workflow:**

Some sellers use `account_id` without exposing an account discovery surface. In that pattern, the seller gives the buyer an account ID during onboarding or configuration, and the buyer passes that ID on account-scoped calls. Absence of `list_accounts` means there is no protocol namespace to discover; it does not mean the buyer should try to provision by natural key.

### Buyer-declared accounts (`require_operator_auth: false`)

The agent manages the buying relationship. It calls `sync_accounts` to tell the seller who's advertising, who's operating on the brand's behalf, and who's paying. The seller provisions accounts and responds with status — the account IDs are a byproduct of the declaration, not something the buyer needs to know upfront.

Buyer-declared-account sellers SHOULD also expose `list_accounts` as the recovery read for stateless buyers. Replaying `sync_accounts` is not a cold-start recovery mechanism when the buyer has lost the advertiser natural keys required to compose that replay. `list_accounts` returns those acknowledged natural-key fields so they round-trip into later calls; it does not make the seller-issued `account_id` mandatory.

**Typical sellers:** Traditional publishers, retail media networks, DSPs — anywhere the buying relationship is established programmatically.

`sync_accounts` is the declaration tool. Each entry is a set of flags that tells the seller what the buyer needs:

| Flag                                                   | What it tells the seller                                                                                                                                                                                                            |
| ------------------------------------------------------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `brand` (`domain` + optional `brand_id`/`countries[]`) | Which commercial advertiser entity is advertising; countries do not target delivery                                                                                                                                                 |
| `operator`                                             | Who operates on the brand's behalf (agency, trading desk, or the brand itself)                                                                                                                                                      |
| `operator_unit`                                        | Optional operator-owned business unit, seat, or platform account; stable `id` plus mutable display `name`                                                                                                                           |
| `currency`                                             | Optional immutable account currency when the seller's advertiser object is currency-bound                                                                                                                                           |
| `billing`                                              | Who gets the invoice — `operator`, `agent`, or `advertiser`                                                                                                                                                                         |
| `billing_entity`                                       | Structured business entity details for the party responsible for payment — legal name, VAT ID, tax ID, address, contacts, and bank details. Used for formal B2B invoicing. Bank details are write-only (never echoed in responses). |
| `payment_terms`                                        | Payment terms for this account (`net_15`, `net_30`, `net_45`, `net_60`, `net_90`, `prepay`). The seller must accept these terms or reject the account — terms are never silently remapped.                                          |
| `sandbox`                                              | Whether this is a sandbox (test) account — no real spend. Only used with buyer-declared accounts; account-id namespace sandboxes are pre-existing and discovered through `list_accounts` or supplied out-of-band.                   |

Every combination of flags that might require the seller to do something different — bill a different entity, set up a different rate card, create a sandbox — is a distinct declaration.

### Billing entity and invoice recipient

For markets that require structured invoicing data (e.g., EU B2B transactions requiring VAT IDs), the `billing_entity` on an account provides the default business entity details for whoever `billing` points to. This includes legal name, tax identifiers, postal address, billing contact, and bank details.

On individual media buys, an `invoice_recipient` can override the account default — useful when a specific campaign should be billed to a different party. When `invoice_recipient` differs from the account default and the account has `governance_agents`, the seller MUST include it in the `check_governance` request so the governance agent can approve or reject the billing redirect.

**Workflow:**

1. Agent calls `sync_accounts` with one or more declarations
2. Seller provisions or links accounts for each, responds with status:
   * `active` — ready to use
   * `pending_approval` — seller reviewing (human may need to visit `setup.url`)
   * `rejected` — seller declined the request
3. For subsequent requests, pass the account reference:
   * **Buyer-declared accounts** (`require_operator_auth: false`): pass the natural key `{ "brand": { "domain": "acme-corp.com" }, "operator": "pinnacle-media.com" }`
   * **Account-id namespaces** (`require_operator_auth: true`): pass `{ "account_id": "acc_acme_001" }` (discover via `list_accounts` for upstream-managed namespaces, or receive out-of-band for seller-defined namespaces)
   * **Sandbox (buyer-declared)**: pass the natural key with `sandbox: true` (declared via `sync_accounts`)
   * **Sandbox (account-id namespace)**: pass `{ "account_id": "test_acc_001" }` (pre-existing test account, discovered via `list_accounts` or supplied out-of-band)
4. When anything changes (billing model, new brand, new operator), call `sync_accounts` again
5. After a cold start, call `list_accounts` to recover previously acknowledged relationships when the seller exposes the recommended read surface

The agent may be directly responsible for billing when `billing` is `"agent"`. When `billing` is `"operator"` or `"advertiser"`, the agent facilitates but is not the invoiced party. The seller may require human approval before activating accounts.

### Natural key semantics

The tuple `(brand, operator, operator_unit.id, currency, sandbox)` identifies the advertiser object in the seller system. The nested `brand` carries `domain`, optional `brand_id`, and optional ISO country `countries[]`; these countries qualify commercial identity and never target delivery. `operator_unit` identifies the operator's own business unit, agency seat, or buying-platform account. Its stable `id` participates in identity, while its optional `name` is display metadata and may change without creating a new account. `currency` participates only when the seller's advertiser object is locked to one currency. Omit it when currency is selected per media buy.

This separates two account namespaces that must not be conflated: `operator_unit.id` is assigned by the buyer-side operator, while `account_id` is assigned by the AdCP seller/storefront. Both may be opaque values, but they identify different objects and are not interchangeable.

See [sync\_accounts task reference](/dist/docs/3.0.23/accounts/tasks/sync_accounts) for the full request/response schema.

### Account status

| Status             | Meaning                     | Next step                                                              |
| ------------------ | --------------------------- | ---------------------------------------------------------------------- |
| `active`           | Ready to use                | Place buys on this account                                             |
| `pending_approval` | Seller reviewing            | Human may need to visit `setup.url`. Poll `list_accounts` for updates. |
| `rejected`         | Seller declined the request | Review rejection reason, adjust and re-sync, or contact seller         |
| `payment_required` | Credit limit reached        | Add funds or route spend to other accounts                             |
| `suspended`        | Was active, now paused      | Contact seller                                                         |
| `closed`           | Was active, now terminated  | —                                                                      |

### Account scope

The agent requests accounts by natural key — `(brand, operator)`. The seller decides what granularity to assign. The `account_scope` field in the response tells the agent how the seller resolved the request:

| Scope            | Meaning                                                        | Example                                                                                                        |
| ---------------- | -------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------- |
| `operator`       | One account for all brands under this operator                 | Agent sends (Pinnacle Media, Acme) and (Pinnacle Media, Nova) — seller maps both to the Pinnacle Media account |
| `brand`          | One account for this brand regardless of operator              | Agent sends (Acme, Pinnacle Media) and (Acme, Summit Agency) — seller maps both to the Acme account            |
| `operator_brand` | Dedicated account for this operator+brand pair                 | Agent sends (Pinnacle Media, Acme) — seller creates a specific Acme-via-Pinnacle account                       |
| `agent`          | Agent-scoped account with no brand- or operator-specific split | Agent sends any brand — seller maps the request to the standing agent-scoped account                           |

The agent does not choose the scope — the seller assigns it based on its own account policy. An agent requesting `(brand: {domain: "acme-corp.com"}, operator: "pinnacle-media.com")` might receive an operator-scoped account, a brand-scoped account, or a dedicated operator\_brand account depending on the seller.

When multiple natural keys resolve to the same scope, the `account_scope` explains why.

For buyer-declared accounts (`require_operator_auth: false`), use the complete natural key (`brand` + `operator` + optional `operator_unit`, `currency`, and `sandbox`) on subsequent requests. A seller may also return an `account_id` from `sync_accounts` as its internal handle, but the seller MUST continue accepting the natural-key `AccountRef` for every account provisioned this way and MUST return its natural-key fields from `list_accounts`. For account-id namespaces (`require_operator_auth: true`), discover seller/storefront account IDs via `list_accounts` for upstream-managed namespaces, or receive them out-of-band for seller-defined namespaces — including sandbox test accounts.

## Error codes

| Code                     | When returned                                    | Resolution                                      |
| ------------------------ | ------------------------------------------------ | ----------------------------------------------- |
| `ACCOUNT_REQUIRED`       | Multiple accounts; seller can't determine which  | Pass `account_id` in the account reference      |
| `ACCOUNT_NOT_FOUND`      | `account_id` doesn't exist or agent lacks access | Check account reference, re-run `sync_accounts` |
| `ACCOUNT_SETUP_REQUIRED` | Natural key resolved but account needs setup     | Check `details.setup` for URL/message           |
| `ACCOUNT_AMBIGUOUS`      | Natural key resolves to multiple accounts        | Pass `account_id` or more specific natural key  |
| `PAYMENT_REQUIRED`       | Credit limit reached or funds depleted           | Add funds, route to another account             |
| `ACCOUNT_SUSPENDED`      | Account not in good standing                     | Contact seller                                  |
| `BRAND_REQUIRED`         | Billable operation without brand reference       | Include `brand` in request                      |

When the seller returns `ACCOUNT_REQUIRED`, it includes the available accounts:

```json theme={null}
{
  "errors": [{
    "code": "ACCOUNT_REQUIRED",
    "message": "Multiple accounts available. Please specify account_id in the account reference.",
    "details": {
      "available_accounts": [
        { "account_id": "acc_acme_001", "name": "Acme Corp" },
        { "account_id": "acc_pinnacle", "name": "Pinnacle Media" }
      ]
    }
  }]
}
```

## Design notes

### sync\_accounts and seller record systems

When an agent declares `(brand: {domain: "acme-corp.com"}, operator: "pinnacle-media.com")`, the seller looks up or creates records in its own system — CRM, OMS, ad server, or billing platform.

`sync_accounts` is the buyer-side interface to the seller's record system. The seller may:

* Map the natural key to an existing account and return `status: "active"`
* Create a new record and return it immediately (`status: "active"`)
* Create a placeholder pending human review (`status: "pending_approval"`)
* Decline the request entirely (`status: "rejected"`)

`list_accounts` returns all records the seller has mapped for this agent — including pending and rejected entries. The agent uses `list_accounts` to see the full state of its portfolio with this seller, not just active accounts.

### Accounts and insertion orders

An account represents a standing relationship — who gets billed, what rates apply, what credit is available. It is not a campaign or an insertion order.

Insertion orders and campaign flights are modeled as media buys via `create_media_buy`. The account determines *billing terms*; the media buy determines *what runs and when*. A single account can have many media buys over its lifetime.

### Operator revocation and caching

If a brand removes an operator from `authorized_operators`, existing active accounts are not automatically deactivated. Revocation is eventual, not immediate — similar to how `ads.txt` changes propagate on the supply side.

Sellers SHOULD respect standard HTTP caching headers on `brand.json` and re-validate periodically. A reasonable cache TTL is 24 hours.

### Brand identity for SMBs

Domain-based identity via `/.well-known/brand.json` works for organizations of any size — it's a static JSON file that can be hosted on any web server.

For organizations that cannot host files on their domain, the `authoritative_location` field in `brand.json` allows the house domain to redirect to a hosted location:

```json theme={null}
{
  "house": {
    "domain": "local-bakery.com"
  },
  "authoritative_location": "https://registry.agenticadvertising.org/brands/local-bakery.com"
}
```