> ## Documentation Index > Fetch the complete documentation index at: https://howto.paigeme.dev/llms.txt > Use this file to discover all available pages before exploring further. # Upload the sample file a media header needs > Meta will not review an IMAGE, VIDEO or DOCUMENT header without an EXAMPLE of the media it will carry, so a media-header template cannot be created until you have one of these handles. Upload the sample here, then put the returned `handle` into the header component as `example.header_handle: [""]` when you call `POST /v1/templates`. Creating a media header without it is `400`, not a Meta error. **Two transports, pick one.** - JSON `{ "format": "DOCUMENT", "source_url": "https://..." }` — Paige downloads it. Only public http(s) URLs: private, loopback and link-local addresses are refused and redirects are re-checked at every hop. Add `filename` / `mime` to override what the remote server declares. - JSON `{ "format": "IMAGE", "data": "", "filename": "...", "mime": "..." }` — inline bytes, capped at **5 MB decoded**, lower than the per-format ceilings because the body is buffered whole in memory. A `data:` URI prefix is accepted and stripped. **Size and type are per FORMAT.** IMAGE takes `image/jpeg` or `image/png` up to 5 MB; VIDEO takes `video/mp4` or `video/3gpp` up to 16 MB; DOCUMENT takes PDF, Word, Excel, PowerPoint or plain text up to 100 MB. Oversize is `413 file_too_large` and a type WhatsApp will not take is `415`. **The declared mime type is not trusted.** The bytes are checked against their own signature, and a file whose contents disagree with its `mime` is `415` — sending a video as `image/png` to slip past the image size cap does not work. **A handle is not a media id.** `media_id` from `POST /v1/media` addresses a file Meta can SEND and is useless as a `header_handle`; the reverse is also true. The handle is short-lived and single-purpose: get one, create the template with it, and do not store it. **Uploads are metered by BYTES as well as by request count**, against the same per-key budget `POST /v1/media` charges. A burst of large samples can therefore return `429 rate_limited` even while you are inside the request-per-minute budget — retry after the window. A `source_url` download is also aborted mid-stream once it passes that budget, so a sample bigger than a whole minute of it can never be fetched. **Required scope:** `templates:manage` ## OpenAPI ````yaml /api-reference/openapi.json post /v1/templates/header-sample openapi: 3.1.0 info: title: Paige API version: 1.0.0 description: >- The Paige public REST API (`/v1`). Build WhatsApp automations against your Paige project: send messages, manage templates, read conversations, tag contacts, assemble broadcasts, edit bot code + flows, and register signed webhooks. ## Authentication Every `/v1` request authenticates with a project API key: `Authorization: Bearer pk_live_…`. Mint and scope keys in **Settings → API keys**. A key carries its own project context, so `/v1` paths never include a project id. ## Scopes Each endpoint requires one or more scopes (see each operation, and the `x-required-scopes` extension). Grant a key only the scopes it needs. A key missing a required scope gets `403 insufficient_scope`. ## Response envelope Success: `{ "success": true, "data": … }`. Error: `{ "success": false, "error": { "code", "message" }, "request_id" }`. Some errors add `error.details` with structured extras (e.g. `quota_exceeded` carries `limit` + `resetAt`) — read it defensively, its keys depend on the code. The `request_id` is also returned as the `X-Request-Id` header on every response. ## Rate limits & quota Requests are throttled per key (`RateLimit-*` headers; exceed → `429 rate_limited`). WhatsApp sends also draw down a daily quota (exceed → `429 quota_exceeded`). Both carry `Retry-After`. ## Idempotency Send an `Idempotency-Key` header on `POST /v1/messages` to make retries safe — a completed key replays the stored response and never re-sends. ## Webhook signatures Outbound webhook deliveries carry `X-Paige-Signature: t=,v1=`. Verify with the reference `verifyPaigeSignature` helper (constant-time HMAC over `"."`, 300s tolerance). contact: name: Paige url: https://paigeme.dev servers: - url: https://api.paigeme.dev description: Production security: - ApiKeyAuth: [] tags: - name: Meta description: Smoke / diagnostics. - name: Messages description: Send messages and read delivery status + media. - name: Conversations description: List conversations, read messages, set state. - name: Contacts description: Read contact messages; update names, tags, attributes. - name: Templates description: WhatsApp message template CRUD. - name: Broadcasts description: Segments + broadcast assembly (always pending_approval). - name: Build description: Read/edit bot code, deploy, read/generate/update flows. - name: Tables description: >- Read and write the project's own database tables. Paige platform tables are denied, and an update or delete must always be filtered. - name: Media description: >- Upload, list, retrieve and delete the project's media assets. The slug an upload returns is what the bot sends by. - name: Webhooks description: Register signed outbound webhooks. paths: /v1/templates/header-sample: post: tags: - Templates summary: Upload the sample file a media header needs description: >- Meta will not review an IMAGE, VIDEO or DOCUMENT header without an EXAMPLE of the media it will carry, so a media-header template cannot be created until you have one of these handles. Upload the sample here, then put the returned `handle` into the header component as `example.header_handle: [""]` when you call `POST /v1/templates`. Creating a media header without it is `400`, not a Meta error. **Two transports, pick one.** - JSON `{ "format": "DOCUMENT", "source_url": "https://..." }` — Paige downloads it. Only public http(s) URLs: private, loopback and link-local addresses are refused and redirects are re-checked at every hop. Add `filename` / `mime` to override what the remote server declares. - JSON `{ "format": "IMAGE", "data": "", "filename": "...", "mime": "..." }` — inline bytes, capped at **5 MB decoded**, lower than the per-format ceilings because the body is buffered whole in memory. A `data:` URI prefix is accepted and stripped. **Size and type are per FORMAT.** IMAGE takes `image/jpeg` or `image/png` up to 5 MB; VIDEO takes `video/mp4` or `video/3gpp` up to 16 MB; DOCUMENT takes PDF, Word, Excel, PowerPoint or plain text up to 100 MB. Oversize is `413 file_too_large` and a type WhatsApp will not take is `415`. **The declared mime type is not trusted.** The bytes are checked against their own signature, and a file whose contents disagree with its `mime` is `415` — sending a video as `image/png` to slip past the image size cap does not work. **A handle is not a media id.** `media_id` from `POST /v1/media` addresses a file Meta can SEND and is useless as a `header_handle`; the reverse is also true. The handle is short-lived and single-purpose: get one, create the template with it, and do not store it. **Uploads are metered by BYTES as well as by request count**, against the same per-key budget `POST /v1/media` charges. A burst of large samples can therefore return `429 rate_limited` even while you are inside the request-per-minute budget — retry after the window. A `source_url` download is also aborted mid-stream once it passes that budget, so a sample bigger than a whole minute of it can never be fetched. **Required scope:** `templates:manage` operationId: uploadTemplateHeaderSample parameters: - schema: type: string description: >- Target project id, for an MCP OAuth bearer (`mcp_at_…`) attached to more than one project — get ids from `GET /v1/projects`. Matched case-insensitively. Omit it and a READ falls back to the connection's default project; a **mutation** (any non-GET) on a connection with 2+ projects is rejected with `400 project_required` — a write is never defaulted to a guessed project. A connection with exactly one project never needs the header. Scopes are checked against the SELECTED project only, never a union across the connection. For a `pk_` API key the header selects nothing — one key is one project's context — but it IS validated: omit it and the key's own project is used, send it and it must name that project, otherwise the call is rejected with `403 project_not_attached` (a blank value is `400 invalid_project_header`, as above). required: false name: X-Paige-Project in: header requestBody: required: true content: application/json: schema: anyOf: - type: object properties: format: type: string enum: - IMAGE - VIDEO - DOCUMENT description: >- The header format this sample is for. IMAGE takes JPEG/PNG up to 5 MB, VIDEO takes MP4/3GP up to 16 MB, DOCUMENT takes PDF/Office/plain text up to 100 MB. The declared type is checked against the file own magic bytes, so a mislabelled file is refused here rather than forwarded to Meta. source_url: type: string format: uri description: >- Public http(s) URL Paige downloads the sample from. Private, loopback and link-local addresses are refused and redirects are re-checked at every hop. The download is aborted mid-stream at the smaller of this format ceiling and the API key remaining per-minute upload byte budget, so a sample larger than that budget can never be fetched. filename: type: string minLength: 1 maxLength: 255 description: Overrides the filename derived from the URL. mime: type: string minLength: 1 maxLength: 255 description: >- Overrides the Content-Type the remote server declares. Use it when the host serves the file as application/octet-stream. required: - format - source_url additionalProperties: false - type: object properties: format: type: string enum: - IMAGE - VIDEO - DOCUMENT description: >- The header format this sample is for. IMAGE takes JPEG/PNG up to 5 MB, VIDEO takes MP4/3GP up to 16 MB, DOCUMENT takes PDF/Office/plain text up to 100 MB. The declared type is checked against the file own magic bytes, so a mislabelled file is refused here rather than forwarded to Meta. data: type: string minLength: 1 description: >- The sample bytes, base64-encoded. Plain base64 or a data: URI. Capped at 5 MB DECODED, lower than the per-format ceilings because the whole body is buffered in memory. Use source_url for anything larger. filename: type: string minLength: 1 maxLength: 255 description: Original filename, including its extension. mime: type: string minLength: 1 maxLength: 255 description: >- The sample mime type, e.g. image/png. Must be one WhatsApp accepts for this header format. required: - format - data - filename - mime additionalProperties: false responses: '201': description: Success. content: application/json: schema: type: object properties: success: type: boolean enum: - true data: type: object properties: handle: type: string description: >- Meta's opaque upload handle. Goes straight into the HEADER component as `example.header_handle: [handle]`. format: type: string description: >- IMAGE | VIDEO | DOCUMENT — the format the sample was validated against. filename: type: string mime_type: type: string description: >- The mime type Paige verified against the bytes, not necessarily the one you declared. size: type: number description: Decoded size in bytes. required: - handle - format - filename - mime_type - size required: - success - data '400': description: >- Validation / bad request (e.g. `invalid_request`, `invalid_cursor`, `invalid_template` for a Meta 4xx rejection of a template payload, which carries Meta's own detail as the message; note `outside_24h_window` is 409, not 400). Also `invalid_project_header` (any credential: `X-Paige-Project` was sent but blank) and, for multi-project MCP bearers, `project_required` (a mutation, or a read with no default, and no `X-Paige-Project`). content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '401': description: >- Missing or invalid API key (`api_key_required` / `invalid_api_key` / `invalid_token` for a revoked or expired OAuth bearer). content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '403': description: >- Key lacks the required scope, project inactive, or a write targets a platform-protected file (`insufficient_scope` / `project_inactive` / `subscription_inactive` / `protected_file`). Also `project_not_attached` (the `X-Paige-Project` project is not one this credential may act on — not attached to the MCP connection, or not the `pk_` key's own project; identical response whether or not it exists) and, for MCP bearers, `no_project_access` (the connection has no projects attached). content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '404': description: Resource not found (`not_found` / `*_not_found`). content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '413': description: Error. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '415': description: Error. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '429': description: >- Rate limit (`rate_limited`) or daily send quota (`quota_exceeded`) exceeded. Carries `RateLimit-*` + `Retry-After` headers. headers: RateLimit-Limit: description: Requests permitted in the current window. schema: type: integer RateLimit-Remaining: description: Requests remaining in the current window. schema: type: integer RateLimit-Reset: description: Seconds until the window resets. schema: type: integer Retry-After: description: Seconds to wait before retrying. schema: type: integer content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '500': description: Unexpected server error (`server_error`). content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '502': description: >- Upstream failure — a Meta credentials rejection (`meta_auth_error`) or a failed/truncated agent run on the build + flow endpoints (`build_failed`). content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' security: - ApiKeyAuth: [] components: schemas: ErrorResponse: type: object properties: success: type: boolean enum: - false error: $ref: '#/components/schemas/ApiError' request_id: type: string description: Per-request id, also returned as the X-Request-Id header. required: - success - error - request_id ApiError: type: object properties: code: type: string description: Stable, machine-readable error code. example: invalid_request message: type: string description: Human-readable message (safe to surface). example: Invalid request body details: type: object properties: {} description: >- Structured extras for codes that carry them — the keys depend on `code`. `quota_exceeded` carries `limit` + `resetAt`; most errors omit this field entirely. required: - code - message securitySchemes: ApiKeyAuth: type: http scheme: bearer bearerFormat: API key description: >- Project API key issued in Settings → API keys. Send it as `Authorization: Bearer pk_live_…`. ````