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

# Glossary

> The words the Blujay API docs use, each defined once.

| Term | Meaning |
| - | - |
| **Workspace** | Your Blujay account. An API key belongs to one workspace and can see everything in it. |
| **Phone number** | A Blujay number your workspace messages from. It has a plan, a live `send_status`, and on Dedicated and AI Agent plans, `limits`, `queue` and `health_status`. |
| **Plan** | Free Plan, Dedicated or AI Agent. Decides who a number can message and which features it can use. See [Plans](/plans.md). |
| **Shared number** | The Free Plan number, shared with other Free Plan workspaces. `access_type: "shared"`. |
| **Dedicated number** | A number that is yours alone. `access_type: "dedicated"`. Both Dedicated and AI Agent numbers are dedicated numbers. |
| **Contact** | A person saved in your workspace, with a phone number and optionally an email, name, tags, stage and assigned team member. |
| **Verified contact** | On the Free Plan, a person who texted your shared number first and was verified in Blujay. Only verified contacts can be messaged. |
| **New contact** | Someone a phone number has never texted before. The daily new-contact limit counts these. People who text you first never count. |
| **Recipient** | Who a message goes to: the `to` addresses on a send. |
| **Participant** | A person in a group chat. Your own numbers in the group are listed separately, in the chat's `phone_numbers`. |
| **Active chat** | A chat Blujay still treats as current. Typing, read receipts, replies and effects need an active chat; otherwise they return `UNSUPPORTED_CHAT_OPERATION`. See [Group chats](/messaging/group-chats.md). |
| **Established iMessage group** | A group chat whose first message has gone out over iMessage. Rename, add, remove, replies and effects need one. See [Group chats](/messaging/group-chats.md). |
| **Sender** | On an inbound group message, the participant who wrote it (`sender` object). |
| **Chat** | A conversation on one of your numbers. `direct` with one person, or `group` with several. A chat has one `chat_id` for its whole life. |
| **Direct chat** | A chat between one of your numbers and one person. |
| **Group chat** | A chat between one of your numbers and two or more people. iMessage groups support rename, add and remove; see [Group chats](/messaging/group-chats.md). |
| **Message** | One message in a chat, inbound or outbound, with a `status`. |
| **Part** | What a message contains: `text`, `link`, `media` or `vcard`. A message is a list of parts in order. |
| **Attachment** | A file you uploaded once, referenced by `attachment_id`, or a file someone sent you. |
| **Contact card** | A vCard you saved in Blujay and can send as a native contact card. Not the same as your number's own Name & Photo, which the API doesn't manage today. |
| **Service** | How a message travels: `iMessage`, `RCS` or `SMS`. Webhook payloads use lowercase. |
| **Auto** | Leaving out `preferred_service`. Blujay picks iMessage when the person can receive it, otherwise RCS or SMS. |
| **Degradation** | Something Blujay could not deliver because the message went out as RCS or SMS, for example an effect. Listed in `degradations`. |
| **Capability check** | `POST /v1/capability/evaluate_service`: whether a number can receive iMessage, RCS or SMS. |
| **Reply** | A text or a tapback from the contact. Replies lift the pre-reply rules and restart the 6-text count. Calls never count. |
| **Pre-reply rules** | The rules on sends before a contact replies: no links, no attachments, 300 characters. See [Sending rules](/messaging/sending-rules.md). |
| **Opt-out** | A record that a phone number or email must not be messaged. Sends return `RECIPIENT_SUPPRESSED`. |
| **Idempotency key** | The `Idempotency-Key` header that makes a retried write safe. See [Idempotency](/idempotency.md). |
| **Trace ID** | `trace_id` in every response body and the `X-Trace-ID` header. Identifies one request. Include it when you contact support. |
| **Webhook subscription** | An HTTPS address where Blujay sends events, with the event types and phone numbers you chose. |
| **Event** | One thing that happened, delivered to a subscription with an `event_id`. |
| **Webhook version** | The date-named payload shape a subscription is pinned to. See [Versions](/webhooks/versions.md). |
| **Workflow** | An automation built in Blujay. The API can enroll a contact in one. |

## Next steps

> **[Key concepts](/key-concepts.md)**
>
> How the resources fit together.

> **[Plans](/plans.md)**
>
> What each plan can do.


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