# Add a tab to a live whiteboard

> Page: https://docs.plotwork.dev/api/post-v1-boards-board-tabs. Index of every page: https://docs.plotwork.dev/llms.txt

A new tab with the source given, or an empty diagram of a kind (an empty flow when neither is given), after another tab or last.

`POST /v1/boards/{board}/tabs`

## TL;DR

| Question | Answer |
|---|---|
| What does it do? | Add a tab to a live whiteboard. |
| What does it take? | A JSON body of type [`AgentAddBoardTabBody`](https://docs.plotwork.dev/api/schemas.md#agentaddboardtabbody). |
| What does it return? | Status 201 with a body of type [`AgentBoardWriteResult`](https://docs.plotwork.dev/api/schemas.md#agentboardwriteresult). |
| What can go wrong? | `400` the body is not valid; `401` the API key is missing or not valid; `403` the account's plan does not include the REST API (plan.rest_not_included), the key is a person's own or a person's own agent (boards.org_key_required), a trusted publisher (boards.publisher_not_allowed), an organisation key without the boards scope (key.scope_missing), boards are not on for the organisation (boards.not_enabled), or the caller may look but not change the board (boards.forbidden); `404` no such board or tab, or the board is not open to the caller: the cases look alike; `409` the tab changed since baseVersion and the edit no longer applies (diagram.version_conflict, with details.currentVersion and each operation's result), the board has as many tabs as it may (boards.tab_limit), or the organisation is on legal hold; `413` the source is longer than a tab may be (boards.source_too_long), or the board holds as much as it may (boards.storage_full); `422` the result has errors (diagram.invalid, the diagnostics in details), an edit did not apply to the current version (boards.operation_failed, details.results), or it holds something that looks like a secret and the organisation blocks them (boards.secret_blocked); `429` too many requests, or a daily limit is spent; `503` live whiteboards are not set up on this server. Every failure uses the one error envelope. |

## What it does

A new tab with the source given, or an empty diagram of a kind (an empty flow when neither is given), after another tab or last. The REST twin of add_board_tab.

## Path parameters

| Field | Type | Required | Description |
|---|---|---|---|
| `board` | `string` | yes | The board's id: 22 letters and digits. |

## Request body

The body has the type [`AgentAddBoardTabBody`](https://docs.plotwork.dev/api/schemas.md#agentaddboardtabbody).

| Field | Type | Required | Description |
|---|---|---|---|
| `name` | `string` | yes | at least 1 character; at most 60 characters. |
| `kind` | `string` | no | With no source: start an empty diagram of this kind, such as sequence. Left out, an empty flow. pattern `^[a-z][a-z0-9]{0,23}$`. |
| `source` | `string` | no | Diagram source; the first line is the header, such as flow "Title" (draw_diagram lists every kind). at least 1 character; at most 50000 characters. |
| `after` | `string \| null` | no | Put it after this tab; null for first, left out for last. at least 12 characters; at most 12 characters; pattern `^[0-9A-Za-z]+$`. |

## Responses

| Status | Meaning | Body |
|---|---|---|
| 201 | The new tab. | [`AgentBoardWriteResult`](https://docs.plotwork.dev/api/schemas.md#agentboardwriteresult) |
| 400 | The body is not valid. | [`ErrorResponse`](https://docs.plotwork.dev/api/schemas.md#errorresponse) |
| 401 | The API key is missing or not valid. | [`ErrorResponse`](https://docs.plotwork.dev/api/schemas.md#errorresponse) |
| 403 | The account's plan does not include the REST API (plan.rest_not_included), the key is a person's own or a person's own agent (boards.org_key_required), a trusted publisher (boards.publisher_not_allowed), an organisation key without the boards scope (key.scope_missing), boards are not on for the organisation (boards.not_enabled), or the caller may look but not change the board (boards.forbidden). | [`ErrorResponse`](https://docs.plotwork.dev/api/schemas.md#errorresponse) |
| 404 | No such board or tab, or the board is not open to the caller: the cases look alike. | [`ErrorResponse`](https://docs.plotwork.dev/api/schemas.md#errorresponse) |
| 409 | The tab changed since baseVersion and the edit no longer applies (diagram.version_conflict, with details.currentVersion and each operation's result), the board has as many tabs as it may (boards.tab_limit), or the organisation is on legal hold. | [`ErrorResponse`](https://docs.plotwork.dev/api/schemas.md#errorresponse) |
| 413 | The source is longer than a tab may be (boards.source_too_long), or the board holds as much as it may (boards.storage_full). | [`ErrorResponse`](https://docs.plotwork.dev/api/schemas.md#errorresponse) |
| 422 | The result has errors (diagram.invalid, the diagnostics in details), an edit did not apply to the current version (boards.operation_failed, details.results), or it holds something that looks like a secret and the organisation blocks them (boards.secret_blocked). | [`ErrorResponse`](https://docs.plotwork.dev/api/schemas.md#errorresponse) |
| 429 | Too many requests, or a daily limit is spent. | [`ErrorResponse`](https://docs.plotwork.dev/api/schemas.md#errorresponse) |
| 503 | Live whiteboards are not set up on this server. | [`ErrorResponse`](https://docs.plotwork.dev/api/schemas.md#errorresponse) |

## Response body

A 201 answer has the type [`AgentBoardWriteResult`](https://docs.plotwork.dev/api/schemas.md#agentboardwriteresult).

| Field | Type | Required | Description |
|---|---|---|---|
| `changed` | `boolean` | yes | False when the write changed nothing; nothing was stored. |
| `version` | `integer` | yes | The tab's version now: the baseVersion of the next edit. |
| `tab` | `any` | yes |  |
| `tab.id` | `string` | yes | at least 12 characters; at most 12 characters; pattern `^[0-9A-Za-z]+$`. |
| `tab.name` | `string` | yes |  |
| `tab.kind` | `string` | yes |  |
| `tab.position` | `number` | yes |  |
| `tab.version` | `integer` | yes | Send it as baseVersion with the next edit, and as sinceVersion to learn what changed after it. |
| `tab.updatedAt` | `integer` | yes |  |
| `tab.updatedBy` | `string` | yes |  |
| `results` | `object[]` | yes |  |
| `results[].op` | `string` | yes |  |
| `results[].applied` | `boolean` | yes |  |
| `results[].lines` | `integer[]` | yes |  |
| `results[].message` | `string` | yes |  |
| `results[].hint` | `string \| null` | yes |  |
| `changes` | `object[]` | yes |  |
| `changes[].change` | `string` | yes |  |
| `changes[].subject` | `string` | yes |  |
| `changes[].name` | `string` | yes |  |
| `changes[].line` | `integer \| null` | yes |  |
| `changes[].detail` | `string` | yes |  |
| `warnings` | `Diagnostic[]` | yes |  |
| `warnings[].code` | `"E100" \| "E101" \| "E110" \| "E111" \| "E120" \| "E121" \| "E123" \| "E124" \| "E125" \| "E130" \| "E131" \| "E132" \| "E133" \| "E134" \| "E135" \| "E136" \| "E137" \| "E138" \| "E139" \| "E140" \| "W200" \| "W201" \| "W202" \| "W203" \| "W204" \| "W205" \| "W206" \| "W207" \| "W208" \| "W500" \| "W600" \| "W601" \| "W700" \| "W701" \| "W702" \| "W703" \| "W704" \| "W705" \| "W706" \| "W707" \| "W708" \| "W709" \| "W710" \| "M100" \| "M101" \| "M102" \| "M103" \| "M104" \| "M110" \| "M200" \| "M201" \| "M202" \| "M203" \| "M204" \| "M205" \| "M206" \| "M207" \| "M208" \| "M209" \| "M210" \| "M211" \| "M212" \| "M213" \| "M214" \| "M215" \| "M216" \| "M217" \| "M218" \| "E300" \| "E301" \| "E302" \| "E303" \| "E304" \| "W300" \| "W301" \| "W302" \| "W303" \| "M120" \| "M220" \| "M221" \| "M222" \| "E340" \| "E341" \| "E342" \| "E343" \| "E344" \| "E345" \| "W320" \| "W321" \| "W322" \| "W323" \| "M240" \| "M241" \| "M242" \| "E360" \| "E361" \| "E362" \| "E363" \| "E364" \| "E365" \| "E366" \| "E367" \| "W330" \| "W331" \| "W332" \| "W333" \| "W334" \| "M250" \| "M251" \| "E400" \| "E401" \| "E402" \| "E403" \| "W350" \| "W351" \| "W352" \| "W353" \| "M270" \| "M271" \| "E420" \| "E421" \| "E422" \| "E423" \| "E424" \| "W360" \| "W361" \| "W362" \| "W363" \| "W364" \| "M180" \| "M280" \| "M281" \| "M282" \| "E320" \| "E321" \| "E322" \| "E323" \| "E324" \| "E325" \| "E326" \| "E327" \| "E328" \| "E329" \| "E330" \| "W310" \| "W311" \| "W312" \| "W313" \| "W314" \| "M130" \| "M131" \| "M132" \| "M230" \| "M231" \| "M232" \| "M233" \| "M234" \| "M235" \| "M236" \| "M237" \| "M238" \| "E380" \| "E381" \| "E382" \| "E383" \| "W340" \| "W341" \| "W342" \| "W343" \| "M260" \| "I100" \| "I101" \| "I102" \| "I103" \| "I104" \| "I105" \| "I200" \| "I201" \| "I202" \| "I203" \| "I204" \| "I206" \| "R100" \| "R101" \| "R200" \| "R201" \| "R202" \| "R203" \| "R204" \| "R205" \| "R206" \| "R207" \| "S100" \| "S200" \| "S101" \| "S102" \| "S103" \| "S104" \| "S201" \| "S202" \| "S203" \| "S204"` | yes | Stable code to branch on; E-codes are errors, W-codes are warnings. |
| `warnings[].severity` | `"error" \| "warning"` | yes | Errors stop rendering; warnings never do. |
| `warnings[].message` | `string` | yes | What is wrong, in one sentence. |
| `warnings[].line` | `integer` | yes | 1-based line in the submitted source. minimum 1. |
| `warnings[].column` | `integer` | yes | 1-based column in that line. minimum 1. |
| `warnings[].length` | `integer` | yes | Number of characters the problem covers. minimum 1. |
| `warnings[].hint` | `string \| null` | yes | A concrete suggestion for fixing it, or null. |
| `secrets` | `object` | yes |  |
| `secrets.count` | `integer` | yes |  |
| `secrets.kinds` | `string[]` | yes |  |

## See also

| Doc | Why |
|---|---|
| [API reference](https://docs.plotwork.dev/api/reference.md) | Every endpoint, and the error envelope |
| [Schemas](https://docs.plotwork.dev/api/schemas.md) | Every request and response type |
| [Tool reference](https://docs.plotwork.dev/mcp/tools.md) | The operations as callable tools |