Add a block.

POST /v1/pages/{page_id}/blocks

scope: pages:writeCreator & Pro plansquota cost: 1send an Idempotency-Key

Append ONE block to the page DRAFT, preserving every existing block byte-for-byte. Optionally wire an uploaded file (public_path from List files) into IMAGE/FILE/CAROUSEL/PRODUCT blocks. Requires expected_updated_at.

Requires scope: pages:write. Plan entitlement: public_api (Creator and Pro).

Consequential operation — send an Idempotency-Key header.

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Try it

Request.

curl "https://app.getbioflow.com/v1/pages/PAGE_ID/blocks" \
  -X POST \
  -H "Authorization: Bearer bf_live_YOUR_KEY" \
  -H "Idempotency-Key: a-unique-id-per-attempt" \
  -H "Content-Type: application/json" \
  -d '{
    "expected_updated_at": "string",
    "kind": "string",
    "data": {},
    "file_url": "string",
    "file_name": "string"
  }'

Parameters

Path & query parameters.

Parameters accepted by addBlock
Name	In	Type	Required	Description
`page_id`	path	string	yes	Page ID from List pages

Request body

JSON body (application/json).

Request-body fields for addBlock
Field	Type	Required	Description
`expected_updated_at`	string	yes	Concurrency stamp: the draft.updated_at you last read. A mismatch is refused with 409 stale_snapshot — re-read the page and retry.
`kind`	string	yes	Block kind, e.g. LINK
`data`	object	no	—
`file_url`	string	no	public_path of a workspace file from List files
`file_name`	string	no	—

Response

201 — The page with the new block.

Fields of the 201 response for addBlock
Field	Type	Description
`id`	string	—
`title`	string	—
`description`	string	—
`slug`	string	—
`status`	DRAFT \| PUBLISHED \| ARCHIVED	—
`locale`	string	—
`public_url`	string \| null	Live URL when routed; null for unrouted drafts
`theme`	object	—
`draft`	object	—
`published`	object	—

Every response also carries X-Request-Id plus the IETF draft-11 RateLimit / RateLimit-Policy headers.

Errors

What can go wrong here.

Problem codes this operation can return
Code	Status	Meaning
`invalid_request`	400	The request body or parameters failed validation
`invalid_api_key`	401	Missing, malformed, unknown, disabled, or expired API key
`insufficient_scope`	403	The API key was not granted the required scope
`feature_not_enabled`	403	The workspace plan does not include public API access
`test_key_read_only`	403	Test-mode keys are restricted to read operations
`rate_limited`	429	Per-key rate limit exceeded
`quota_exhausted`	429	Monthly API quota exhausted
`internal_error`	500	Something went wrong on our side

All errors are RFC 9457 application/problem+json — branch on code, quote request_id to support. Full registry on the API docs hub; interactive playground in the API reference.