> ## 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.

# decline_proposals

> Terminally decline one or more immutable proposals.

`decline_proposals` records that the buyer evaluated one or more proposals and will not pursue them. The operation is terminal: a seller must reject later [`refine_proposals`](/dist/docs/3.0.23/media-buy/task-reference/refine_proposals) or new logical [`create_media_buy`](/dist/docs/3.0.23/media-buy/task-reference/create_media_buy) attempts for a declined proposal with [`INVALID_STATE`](/dist/docs/3.0.23/building/verification/compliance-catalog#error-code-invalid-state). Exact retries of an earlier successful call still follow the shared idempotency replay contract. A proposal that was already executed cannot subsequently be declined and returns `unable`.

**Request schema:** [`/schemas/3.0.23/media-buy/decline-proposals-request.json`](https://adcontextprotocol.org/schemas/3.0.23/media-buy/decline-proposals-request.json)

```json theme={null}
{
  "idempotency_key": "550e8400-e29b-41d4-a716-446655441004",
  "declines": [
    {
      "proposal_id": "proposal_123",
      "reason": "inventory_fit",
      "detail": "The available placement mix does not fit this campaign."
    }
  ],
  "opportunity": {
    "opportunity_id": "opp_spring_launch_2027",
    "status": "closed",
    "close_reason": "not_pursued"
  }
}
```

Each result has an explicit `declined` or `unable` outcome and preserves request order. Retrying with the same idempotency key replays the original response. Declining the same proposal again under a new key also returns `declined` while preserving the first recorded reason and detail, making the terminal state semantically idempotent.

When `opportunity` is present, every proposal must belong to its `opportunity_id`. Proposal outcomes are independent, but the opportunity update is applied only if every result is `declined`; any `unable` result leaves the opportunity unchanged.

The request does not carry `proposal_version`. Each `proposal_id` identifies one immutable commercial snapshot; [`refine_proposals`](/dist/docs/3.0.23/media-buy/task-reference/refine_proposals) mints a new ID whenever terms change.