Stannp

Print and post letters and postcards through the Stannp Direct Mail API, with UK address validation built in. Agents trigger real mail off a record and price the campaign before committing to it.

20 actions Basic auth available

Stannp website ↗ Platform Documentation ↗ Capability data verified 2026-08-02

A quarterly audience export lands from the CRM as a spreadsheet

Import Recipients loads the file into a new group with column mapping and duplicate handling

Validate Address checks each row against postal records and marks the ones that cannot be matched

Create Campaign and Get Campaign Cost return the full breakdown, separating valid, invalid and international per-piece rates

Get Campaign Sample renders a proof PDF and the agent forwards it immediately, because the link expires after 30 minutes

The campaign owner approves the spend and the send date; only then does the agent call Book Campaign

What This Integration Enables

Stannp is the connector in this part of the catalogue that already thinks the way an operations team thinks. Its campaign flow is a ladder with the expensive rung deliberately placed at the top: Create Campaign costs nothing, Get Campaign Cost prices it, Get Campaign Sample proofs it, and Book Campaign is the single call that charges the run and puts paper into production. Most direct mail APIs make sending the frictionless default. Stannp made reviewing the default and sending the decision.

FlowRunner agents climb that ladder and stop at the top. Alongside campaigns, the connector covers single transactional pieces with Create Postcard and Create Letter, ready-made documents with Post PDF Letter, the recipient address book with groups and CSV import, and UK address validation returning the Postcode Address File delivery point suffix and UDPRN. Accounts exist in one region only, either Europe and the UK or the US and Canada, and postcard sizes follow the region, so the flow is built against one postal system rather than pretending geography does not exist.

Without FlowRunner

Spend known after the fact The true cost of a run appears on the invoice rather than before the decision

Undeliverables paid for Addresses that postal records cannot match are printed and posted anyway

Proof reviewed by whoever is free The sample is checked informally with no record of who signed it off

With FlowRunner

Priced before committing The cost breakdown is read while the campaign is still free to abandon

Address quality made visible Validation counts sit next to the spend so the wasted portion is a number, not a guess

One recorded approval The person who approved the run and the send date are captured with the decision

Use Case Scenarios

A priced and proofed quarterly campaign

A quarterly audience lands as an export from HubSpot or a Google Sheets tab. The agent creates a group, calls Import Recipients with a column mapping so unmapped columns become custom merge fields, and runs Validate Address across the rows. List Groups reports the validation counts. It then calls Create Campaign against a template from List Templates, reads Get Campaign Cost, and generates a sample. Because the sample link is only live for 30 minutes, the flow forwards it the moment it is generated rather than attaching it to a digest that goes out overnight. On approval, Book Campaign commits the run for the chosen send date.

Transactional statements straight from a generated PDF

An upstream system already produces finished, addressed documents such as statements or invoices. Post PDF Letter takes those documents as they are and reads the delivery address off the page rather than taking a recipient object, which means the flow does not re-key an address that the document generator has already resolved. Sends carrying sensitive data are marked transactional. The agent polls Get Letter for production status, cost and the hosted PDF of the finished piece, and writes the tracking reference back onto the source record in Xero or the billing system that produced it.

A single postcard triggered by an account event, with an escape hatch

A support save, a renewal, or a milestone in the CRM triggers one postcard through Create Postcard, using a saved template and the account's merge fields. Test Mode returns a sample PDF without printing, posting or charging, so the flow is proven end to end before it ever costs anything. If the wrong record fires the flow, Cancel Mail Piece stops the item before it goes to print, and the agent surfaces that window to a person immediately rather than discovering the mistake in the following month's reconciliation. Items already in production cannot be cancelled, so the alert is worth nothing if it arrives late, which is why it is sent as soon as the order is accepted.

Human-in-Loop Highlight

The gate is on Book Campaign, and what makes it specific is what Get Campaign Cost actually returns. The breakdown separates per-piece rates for valid, invalid and international recipients, which means the agent can tell a person not only what the run costs but how much of it is being spent on addresses that postal records could not match. So the approval request reads: "Campaign Q3-WINBACK, 1,412 recipients, send date 12 August. 1,338 validated, 61 unmatched, 13 international. Total 1,043.60 GBP including VAT, of which 44.53 GBP is going to the 61 addresses Stannp could not verify. The proof is attached and its link expires in 26 minutes. Book it, book it without the unmatched rows, or hold?" That is a decision a marketing owner can make in ten seconds and would never have been given the data to make otherwise. Book Campaign is the point at which the entire run is charged and physical mail is produced, so it is the only sensible place to put a person. Everything below it on the ladder is free, and FlowRunner uses all of it.

Agent processes routinely

Detects exception requiring judgment

Clear match Continues automatically

Ambiguous Routes to human via preferred channel

Human decides

Agent resumes with decision

Agent Capabilities

20 actions

Single Mail Pieces

Create Postcard Prints and posts a single postcard to one recipient, using either a saved template or supplied front and back artwork. Test Mode returns a sample PDF without anything being printed, posted or charged. The response includes a hosted PDF proof of the finished piece.
Create Letter Prints and posts a mail-merged letter to one recipient from a saved template or an uploaded document. Test Mode returns a sample PDF without anything being printed, posted or charged.
Post PDF Letter Posts a ready-made PDF as a letter, reading the delivery address straight off the document rather than taking a recipient object. Used when another system already produces finished, addressed documents. Sends carrying sensitive data are marked transactional.
Get Postcard Retrieves a postcard by ID with its production status, cost, tracking reference and a hosted PDF of the finished piece. Used to follow an item from receipt through printing to delivery.
Get Letter Retrieves a letter by ID with its production status, cost, tracking reference and a hosted PDF of the finished piece.
Cancel Mail Piece Cancels a postcard or letter before it goes to print, stopping it being produced and charged. Items already in production cannot be cancelled, so this is a short window rather than an undo.

Addresses and Recipients

Validate Address Checks an address against postal records and returns a normalised version with delivery point data. For UK addresses this includes the Postcode Address File delivery point suffix and UDPRN. Used before sending to avoid paying to post undeliverable mail.
Create Recipient Adds a recipient to a group in the address book, with control over how duplicates are detected and handled. Extra fields supplied become custom merge fields available to templates.
List Recipients Retrieves recipients from the address book, optionally limited to one group, using offset and limit paging. The response is a bare array, so the end of the list is reached when fewer rows come back than were asked for.
Delete Recipient Removes a recipient from the address book so they are excluded from future campaigns. Used to honour opt-out and suppression requests.
Import Recipients Imports a CSV or spreadsheet into a group in one call, with column mapping and duplicate handling. Unmapped columns can become custom merge fields or be skipped.
List Groups Retrieves the recipient groups on the account with their validation counts and import progress. Group IDs from here are what the recipient and campaign operations expect.
Create Group Creates an empty group to import or add recipients into. Groups are the audience unit a campaign mails to.

Campaigns

Create Campaign Creates a bulk campaign that will post one piece to every selected recipient in a group. Creating a campaign does not send or charge anything, which is what makes the review steps below it possible.
Get Campaign Cost Returns a full cost breakdown before booking, including per-piece rates for valid, invalid and international recipients plus delivery charges, net, VAT and total. Called before Book Campaign so a flow never commits to an unexpected spend.
Get Campaign Sample Generates a proof PDF of a campaign so artwork and merge fields can be reviewed before committing. Stannp hosts the PDF and the link is only valid for 30 minutes, so it is forwarded promptly.
Book Campaign Commits a campaign for production on a chosen send date. This is the point at which the whole run is charged and physical mail is produced.
List Campaigns Retrieves the campaigns on the account with their type, status and recipient validation summary. Used to find a campaign ID or to check whether a run has been booked and dispatched.

Account

List Templates Retrieves the saved artwork templates with their size, page count and duplex setting. Template IDs from here are what the postcard, letter and campaign operations expect.
Get Balance Returns the remaining credit on the account. Checked before a large campaign so a run does not stall partway through for lack of funds.

Frequently Asked Questions

What can FlowRunner do with Stannp?

FlowRunner agents can run Create Postcard, Create Letter, and Post PDF Letter in Stannp, plus 17 more actions.

Does connecting Stannp to FlowRunner require OAuth?

No. Stannp connects to FlowRunner with basic authentication (a username and password), no OAuth flow required.

Can Stannp trigger a FlowRunner workflow automatically?

Stannp doesn't currently expose triggers in FlowRunner. It connects as an action step inside workflows started by another trigger.

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