Slack unofficial API: download a Slack invoice PDF
About
Developers looking for a Slack API to download a Slack invoice PDF usually find there is none they can use: Slack's API has no billing or invoice endpoint. This script fills that gap. It works like an API endpoint — one call with typed arguments, a JSON response — but runs through a real browser, yours or a hosted one, so it needs no Slack developer account, API key or app review.
Input
billId optionalA bill ID from slack.com/list_invoices, used only when pdfUrl is not given. Combined with workspaceDomain to build the URL.
pdfUrl optionalThe statement's download URL as returned by slack.com/list_invoices (https://<workspace>.slack.com/admin/billing/<billId>/pdf). Preferred over billId.
workspaceDomain optionalWorkspace host to target when using billId, e.g. acme.slack.com. Defaults to my.slack.com (primary workspace). Ignored when pdfUrl is given.
Output
filename requiredThe real suggested filename, taken from the file's Content-Disposition (e.g. Slack-Statement-SBIE-10873175.pdf). Falls back to Slack-<billId>.<ext> if Slack sends no Content-Disposition.
pdf_base64 requiredThe file bytes, base64-encoded. Decode and write it yourself — the script is sandboxed and cannot write to disk.
size_bytes optionalByte length of the decoded file.
content_type optionalThe file's own MIME type. Normally application/pdf; Slack answers application/zip for a bundled statement, in which case pdf_base64 holds zip bytes and filename ends in .zip.
FAQ
Get Slack channel messages
Read a channel's message history by name (e.g. 'social' or '#social') or id (C…). Newest first; pass cursor to paginate, oldest/latest (unix ts) to bound the range. Authors are resolved to display names. Requires login.
Slack unofficial API: list your Slack invoices and billing statements
An unofficial Slack API for billing invoices. List Slack billing statements from the workspace's admin billing history. Returns workspace, total and invoices (date, statement, billId, amount, status, description, pdfUrl) — metadata only. Feed a row's pdfUrl (or billId) to slack.com/download_invoice to fetch that statement's PDF. Requires a workspace billing admin; defaults to the primary workspace, or pass workspaceDomain (e.g. acme.slack.com).
Search Slack messages
Full-text search across the workspace's messages, supporting Slack's modifiers (from:@user, in:#channel, before:/after:date, "exact phrase"). One page per call. Requires login.