Migrating signals

AdCP 3.0 rc.1 makes three changes to the Signals Protocol: delivery target flattening, structured pricing options, and usage reporting simplification.

Deliver-to flattening

The nested deliver_to object in get_signals requests is replaced by two top-level fields.

beta.3	rc.1	Notes
`deliver_to.destinations`	`destinations`	Moved to top level
`deliver_to.countries`	`countries`	Moved to top level

beta.3:

test=false

{
  "signal_spec": "in-market auto intenders",
  "deliver_to": {
    "destinations": [
      { "agent_url": "https://dsp.example.com", "seat_id": "seat_123" }
    ],
    "countries": ["US", "CA"]
  }
}

rc.1:

test=false

{
  "signal_spec": "in-market auto intenders",
  "destinations": [
    { "agent_url": "https://dsp.example.com", "seat_id": "seat_123" }
  ],
  "countries": ["US", "CA"]
}

Pricing options

The legacy pricing object (with a single cpm field) is replaced by a pricing_options array. Each option is a discriminated union on model.

beta.3	rc.1	Notes
`pricing: { cpm: 2.50 }`	`pricing_options[]`	Array of pricing model objects
Implicit pricing selection	`pricing_option_id` on `activate_signal`	Explicit buyer commitment
No idempotency	`idempotency_key` on `report_usage`	Prevents duplicate billing

Three pricing models

CPM — Fixed cost per thousand impressions:

{
  "$schema": "https://adcontextprotocol.org/schemas/v3/core/signal-pricing-option.json",
  "pricing_option_id": "po_auto_cpm",
  "model": "cpm",
  "cpm": 2.50,
  "currency": "USD"
}

Percent of media — Percentage of media spend, with optional CPM cap:

{
  "$schema": "https://adcontextprotocol.org/schemas/v3/core/signal-pricing-option.json",
  "pricing_option_id": "po_auto_pom",
  "model": "percent_of_media",
  "percent": 15,
  "max_cpm": 5.00,
  "currency": "USD"
}

Flat fee — Fixed charge per reporting period (monthly licensed segments):

{
  "$schema": "https://adcontextprotocol.org/schemas/v3/core/signal-pricing-option.json",
  "pricing_option_id": "po_auto_flat",
  "model": "flat_fee",
  "amount": 10000.00,
  "period": "monthly",
  "currency": "USD"
}

Activation with pricing

When activating a signal, pass the selected pricing_option_id:

test=false

{
  "signal_agent_segment_id": "luxury_auto_intenders",
  "destinations": [
    { "type": "agent", "agent_url": "https://dsp.example.com", "account": { "account_id": "acct_pinnacle" } }
  ],
  "pricing_option_id": "po_auto_cpm"
}

Usage reporting

report_usage adds idempotency_key and removes the kind and operator_id fields.

beta.3	rc.1	Notes
`kind` field	Removed	Usage records are self-describing via `signal_agent_segment_id` or `standards_id`
`operator_id` field	Removed	Account reference provides operator identity
No idempotency	`idempotency_key`	Client-generated UUID prevents duplicate billing on retries

rc.1 usage report:

{
  "$schema": "https://adcontextprotocol.org/schemas/v3/account/report-usage-request.json",
  "idempotency_key": "550e8400-e29b-41d4-a716-446655440000",
  "reporting_period": {
    "start": "2025-03-01T00:00:00Z",
    "end": "2025-03-31T23:59:59Z"
  },
  "usage": [
    {
      "account": { "account_id": "acct_pinnacle_signals" },
      "signal_agent_segment_id": "luxury_auto_intenders",
      "pricing_option_id": "po_auto_cpm",
      "impressions": 4200000,
      "media_spend": 21000.00,
      "vendor_cost": 2100.00,
      "currency": "USD"
    }
  ]
}

The pricing_option_id in the usage record must match the one passed at activation, allowing the vendor to verify the correct rate was applied.

Migration steps

Flatten deliver_to

Move deliver_to.destinations and deliver_to.countries to top-level fields in get_signals requests.

Parse pricing_options array

Update signal response parsing to read pricing_options (array) instead of pricing (object). Switch on model field to determine the pricing type.

Select pricing at activation

When calling activate_signal, pass the selected pricing_option_id from the signal’s pricing_options array.

Add idempotency_key to report_usage

Generate a unique key (UUID) for each report_usage call. Retries with the same key are idempotent.

Remove kind and operator_id

Remove kind and operator_id from usage records. Usage type is determined by the presence of signal_agent_segment_id (signals) or standards_id (governance).

Track pricing_option_id through lifecycle

Store the pricing_option_id at activation time and pass it in report_usage records so the vendor can verify billing.

Validate against schemas

Run requests against get-signals-request.json, activate-signal-request.json, and report-usage-request.json schemas.

Signals Protocol

Full reference for signal discovery, activation, usage reporting, and pricing models.

Related: Pricing | Optimization goals | AdCP 3.0 overview

​Migrating signals

​Deliver-to flattening

​Pricing options

​Three pricing models

​Activation with pricing

​Usage reporting

​Migration steps

Signals Protocol

Migrating signals

Deliver-to flattening

Pricing options

Three pricing models

Activation with pricing

Usage reporting

Migration steps