发送 RCS 消息

直接发送会绕过所有短信回退逻辑。如果收件人的设备或运营商不支持 RCS，则不会传送消息。对于大多数用例，建议使用基于池的发送，因为它可以自动回退短信，无需支付额外费用。

如果收件人的设备或运营商不支持 RCS，则不会传送消息。未尝试回退短信。仅当你想要 RCS-or-nothing传送或在 AWS 最终用户消息之外管理短信回退时，才使用此模式。

复制以下提示并将其粘贴到您的 AI 代理或编码助手中：

## RCS Messaging Assistant Prompt

Help me send RCS messages using AWS End User Messaging SMS with the
`pinpoint-sms-voice-v2` service. Show me exact CLI commands and Python/boto3
examples. Ask me for my details before generating any commands.

**Important rules for generating commands:**
- The API is `send-text-message` — the same command used for SMS. There is
  NO separate RCS send API.
- There is NO `describe-messages` API. Do not generate it.
- The boto3 method is `send_text_message` on the
  `pinpoint-sms-voice-v2` client.
- Use the term "testing" — NOT "sandbox".

**Prerequisites:** I have an existing RCS agent (created via the setup process)
and a verified test device.

### Pattern 1: Direct RCS sending (simplest, good for testing)

Send directly through my RCS Agent ARN. RCS-only delivery, no SMS fallback.
If the recipient's device doesn't support RCS, the message is not delivered.

CLI: `send-text-message --destination-phone-number <E.164>
--origination-identity <agent-arn> --message-body "<text>"
--message-type <TRANSACTIONAL|PROMOTIONAL>`

Returns `MessageId`.

### Pattern 2: Pool-based sending (recommended for production)

Send through a phone pool containing my RCS agent (and optionally SMS phone
numbers for fallback). The service tries RCS first, then falls back to SMS
asynchronously if no RCS signal within 25 seconds. This is NOT synchronous
fallback — the SMS is sent as a separate attempt after the timeout.

To set up a pool:
- `create-pool --origination-identity <rcs-agent-id> --message-type TRANSACTIONAL` → returns `PoolId`
- Optionally add SMS numbers: `associate-origination-identity --pool-id <id>
  --origination-identity <phone-number-id>`

CLI: `send-text-message --destination-phone-number <E.164>
--origination-identity <pool-id> --message-body "<text>"
--message-type <TRANSACTIONAL|PROMOTIONAL>`

### Pattern 3: Account-level sending

Send without specifying `--origination-identity`. The service auto-selects
the best identity from the account.

CLI: `send-text-message --destination-phone-number <E.164>
--message-body "<text>" --message-type <TRANSACTIONAL|PROMOTIONAL>`

**Compliance warning:** If the account has multiple RCS agents, SMS numbers,
or different use cases, the service picks an identity automatically — which
may not be the intended one. Use pool-based or direct sending for explicit
control over which identity is used.

### Delivery verification

- For testing: check the test device directly — the message appears from
  the branded RCS agent.
- For production: configure event destinations BEFORE sending using
  `create-event-destination` (SNS, CloudWatch Logs, or Firehose). Event
  destinations do not retroactively capture events for already-sent messages.
- CloudWatch metrics in `AWS/SMSVoice` namespace provide aggregate delivery
  statistics.

### Behavioral notes

- Sticky sending: the service remembers the last successful identity per
  destination number for 25 hours.
- Pool-based sending is recommended for production because it provides
  automatic SMS fallback.
- All three patterns use the same `send-text-message` API — the only
  difference is what you pass (or don't pass) as `--origination-identity`.

---

**Before generating commands, ask me for:**
- Which sending pattern I want to use (direct, pool-based, or account-level)
- My RCS Agent ARN
- My pool ID (if using pool-based sending)
- Destination phone number in E.164 format
- Message type (TRANSACTIONAL or PROMOTIONAL)
- Message text