Stannp website screenshot

Stannp

Stannp is a direct mail platform that enables businesses to send physical postcards and letters programmatically via a REST API. The platform lets developers create campaigns, upload recipient lists, trigger individual mail pieces in real time, and track print and delivery status through webhooks and event endpoints. Authentication uses API key-based HTTP Basic Auth over HTTPS, and the API follows a simple JSON response envelope with success/data or success/error fields. Stannp serves businesses across the UK, US, and Canada with per-item pricing for letters and postcards at scale, and supports no-code integrations through Zapier and Make as well as official SDKs for PHP, Go, and C#.

Stannp publishes 7 APIs on the APIs.io network, including Account API, Campaigns API, Events API, and 4 more. Tagged areas include Direct Mail, Postcards, Letters, Print, and Physical Mail.

The Stannp catalog on APIs.io includes 1 JSON-LD context and 1 Spectral governance ruleset.

Stannp’s developer surface includes authentication, documentation, engineering blog, pricing, and 10 more developer resources.

🌐 Visit website 📡 Source on GitHub
54.7/100 developing ▬ flat Agent 42/100 agent ready Full breakdown ↓
scored 2026-08-05 · rubric v0.9.1
AccessFreemiumSelf serve⚡ Free to try
7 APIs
Direct MailPostcardsLettersPrintPhysical MailMarketing AutomationCampaigns

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-08-05 · rubric v0.9.1
Composite quality — 54.7/100 · developing
Contract Quality 19.6 / 25
Developer Ergonomics 4.3 / 20
Commercial Clarity 11.6 / 20
Operational Transparency 4.8 / 13
Governance 7.0 / 12
Discoverability 7.4 / 10
Agent readiness — 42/100 · agent ready
Machine-Readable Contract 18 / 18
Agentic Access Contract 10 / 10
MCP Server 0 / 12
Machine-Readable Auth 10 / 10
Idempotency 9 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 7 / 7
Rate-Limit Signaling 7 / 7
Typed Event Surface 0 / 6
Agent Skills 0 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3
A2A Agent Card 0 / 8
Dry-Run / Simulate Mode 0 / 4
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/stannp: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 7

Individual APIs this provider publishes, each with its own machine-readable definition.

Stannp Account API

Account balance and user information

Stannp Campaigns API

Manage batch direct mail campaigns

Stannp Events API

Record recipient engagement and conversion events

Stannp Groups API

Manage recipient groups

Stannp Letters API

Create, post, retrieve, and cancel letter mailpieces

Stannp Postcards API

Create, retrieve, and cancel postcard mailpieces

Stannp Recipients API

Manage individual recipients and bulk imports

Scroll for all 7

Pricing Plans 1

Published pricing tiers and plan structures.

Stannp Plans Pricing

5 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Stannp Rate Limits

4 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

Stannp Finops

FINOPS

Semantic Vocabularies 1

JSON-LD contexts and semantic vocabularies used across these APIs.

Stannp Context

45 classes · 9 properties

JSON-LD

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Stannp API Rules

5 rules · 4 warnings 1 info

SPECTRAL

JSON Schema 3

Standalone JSON Schema definitions for this provider's data models.

Campaign

8 properties

JSON SCHEMA

Mailpiece

8 properties

JSON SCHEMA

Recipient

22 properties

JSON SCHEMA

Examples 3

Example request and response payloads for these APIs.

Create Postcard Request

8 fields

EXAMPLE

Create Postcard Response

2 fields

EXAMPLE

Webhook Payload

5 fields

EXAMPLE

Security Posture 3

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Stannp Authentication

http · 1 scheme

SECURITY

Stannp Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Stannp Trust Center

trust center published

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Stannp Agentic Access

32 operations · 23 acting

32 operations · 23 acting

AGENTIC

Resources

Documentation 1

Reference material describing how the API behaves

Documentation
Documentation

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess
AgenticAccess

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrganization
GitHubOrganization

Access & Security 3

Authentication, authorization, and security posture

TrustCenter
TrustCenter
 DomainSecurity
DomainSecurity
 Authentication
Authentication

Operate 1

Status, limits, changes, and where to get help

RateLimits
RateLimits

Commercial 3

Pricing, plans, and the legal terms of use

Pricing
Pricing
 Plans
Plans
 FinOps
FinOps

Company 3

The organization behind the API

Website
Website
 LinkedIn
LinkedIn
 Blog
Blog

Other 1

Properties that don't map to a standard resource type

X
X

Source (apis.yml)

apis.yml Raw ↑ 
aid: stannp
name: Stannp
description: 'Stannp is a direct mail platform that enables businesses to send physical postcards and letters programmatically
  via a REST API. The platform lets developers create campaigns, upload recipient lists, trigger individual mail pieces in
  real time, and track print and delivery status through webhooks and event endpoints. Authentication uses API key-based HTTP
  Basic Auth over HTTPS, and the API follows a simple JSON response envelope with success/data or success/error fields. Stannp
  serves businesses across the UK, US, and Canada with per-item pricing for letters and postcards at scale, and supports no-code
  integrations through Zapier and Make as well as official SDKs for PHP, Go, and C#.

  '
type: Index
accessModel:
  pricing: freemium
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  label: Freemium · Self-serve signup
  confidence: high
  source:
  - plans
  - authentication
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/stannp.png
tags:
- Direct Mail
- Postcards
- Letters
- Print
- Physical Mail
- Marketing Automation
- Campaigns
url: https://raw.githubusercontent.com/api-evangelist/stannp/refs/heads/main/apis.yml
created: '2026-06-12'
modified: '2026-06-12'
specificationVersion: '0.19'
apis:
- aid: stannp:stannp-account-api
  name: Stannp Account API
  description: Account balance and user information
  humanURL: https://www.stannp.com/us/direct-mail-api
  baseURL: https://api-eu1.stannp.com/v1/
  tags:
  - Account
  properties:
  - type: OpenAPI
    url: openapi/stannp-account-api-openapi.yml
  - type: Documentation
    url: https://www.stannp.com/us/direct-mail-api/guide
  - type: JSONSchema
    url: json-schema/recipient.json
  - type: JSONSchema
    url: json-schema/mailpiece.json
  - type: JSONSchema
    url: json-schema/campaign.json
  - type: Vocabulary
    url: vocabulary/stannp-vocabulary.yml
  - type: JSONLDContext
    url: json-ld/stannp-context.jsonld
- aid: stannp:stannp-campaigns-api
  name: Stannp Campaigns API
  description: Manage batch direct mail campaigns
  humanURL: https://www.stannp.com/us/direct-mail-api
  baseURL: https://api-eu1.stannp.com/v1/
  tags:
  - Campaigns
  properties:
  - type: OpenAPI
    url: openapi/stannp-campaigns-api-openapi.yml
  - type: Documentation
    url: https://www.stannp.com/us/direct-mail-api/guide
  - type: JSONSchema
    url: json-schema/recipient.json
  - type: JSONSchema
    url: json-schema/mailpiece.json
  - type: JSONSchema
    url: json-schema/campaign.json
  - type: Vocabulary
    url: vocabulary/stannp-vocabulary.yml
  - type: JSONLDContext
    url: json-ld/stannp-context.jsonld
- aid: stannp:stannp-events-api
  name: Stannp Events API
  description: Record recipient engagement and conversion events
  humanURL: https://www.stannp.com/us/direct-mail-api
  baseURL: https://api-eu1.stannp.com/v1/
  tags:
  - Events
  properties:
  - type: OpenAPI
    url: openapi/stannp-events-api-openapi.yml
  - type: Documentation
    url: https://www.stannp.com/us/direct-mail-api/guide
  - type: JSONSchema
    url: json-schema/recipient.json
  - type: JSONSchema
    url: json-schema/mailpiece.json
  - type: JSONSchema
    url: json-schema/campaign.json
  - type: Vocabulary
    url: vocabulary/stannp-vocabulary.yml
  - type: JSONLDContext
    url: json-ld/stannp-context.jsonld
- aid: stannp:stannp-groups-api
  name: Stannp Groups API
  description: Manage recipient groups
  humanURL: https://www.stannp.com/us/direct-mail-api
  baseURL: https://api-eu1.stannp.com/v1/
  tags:
  - Groups
  properties:
  - type: OpenAPI
    url: openapi/stannp-groups-api-openapi.yml
  - type: Documentation
    url: https://www.stannp.com/us/direct-mail-api/guide
  - type: JSONSchema
    url: json-schema/recipient.json
  - type: JSONSchema
    url: json-schema/mailpiece.json
  - type: JSONSchema
    url: json-schema/campaign.json
  - type: Vocabulary
    url: vocabulary/stannp-vocabulary.yml
  - type: JSONLDContext
    url: json-ld/stannp-context.jsonld
- aid: stannp:stannp-letters-api
  name: Stannp Letters API
  description: Create, post, retrieve, and cancel letter mailpieces
  humanURL: https://www.stannp.com/us/direct-mail-api
  baseURL: https://api-eu1.stannp.com/v1/
  tags:
  - Letters
  properties:
  - type: OpenAPI
    url: openapi/stannp-letters-api-openapi.yml
  - type: Documentation
    url: https://www.stannp.com/us/direct-mail-api/guide
  - type: JSONSchema
    url: json-schema/recipient.json
  - type: JSONSchema
    url: json-schema/mailpiece.json
  - type: JSONSchema
    url: json-schema/campaign.json
  - type: Vocabulary
    url: vocabulary/stannp-vocabulary.yml
  - type: JSONLDContext
    url: json-ld/stannp-context.jsonld
- aid: stannp:stannp-postcards-api
  name: Stannp Postcards API
  description: Create, retrieve, and cancel postcard mailpieces
  humanURL: https://www.stannp.com/us/direct-mail-api
  baseURL: https://api-eu1.stannp.com/v1/
  tags:
  - Postcards
  properties:
  - type: OpenAPI
    url: openapi/stannp-postcards-api-openapi.yml
  - type: Documentation
    url: https://www.stannp.com/us/direct-mail-api/guide
  - type: JSONSchema
    url: json-schema/recipient.json
  - type: JSONSchema
    url: json-schema/mailpiece.json
  - type: JSONSchema
    url: json-schema/campaign.json
  - type: Vocabulary
    url: vocabulary/stannp-vocabulary.yml
  - type: JSONLDContext
    url: json-ld/stannp-context.jsonld
- aid: stannp:stannp-recipients-api
  name: Stannp Recipients API
  description: Manage individual recipients and bulk imports
  humanURL: https://www.stannp.com/us/direct-mail-api
  baseURL: https://api-eu1.stannp.com/v1/
  tags:
  - Recipients
  properties:
  - type: OpenAPI
    url: openapi/stannp-recipients-api-openapi.yml
  - type: Documentation
    url: https://www.stannp.com/us/direct-mail-api/guide
  - type: JSONSchema
    url: json-schema/recipient.json
  - type: JSONSchema
    url: json-schema/mailpiece.json
  - type: JSONSchema
    url: json-schema/campaign.json
  - type: Vocabulary
    url: vocabulary/stannp-vocabulary.yml
  - type: JSONLDContext
    url: json-ld/stannp-context.jsonld
common:
- type: AgenticAccess
  url: agentic-access/stannp-agentic-access.yml
- type: TrustCenter
  url: security/stannp-trust-center.yml
- type: DomainSecurity
  url: security/stannp-domain-security.yml
- type: Authentication
  url: authentication/stannp-authentication.yml
- type: Website
  url: https://www.stannp.com
- type: Documentation
  url: https://www.stannp.com/us/direct-mail-api/guide
- type: GitHubOrganization
  url: https://github.com/Stannp
- type: LinkedIn
  url: https://www.linkedin.com/company/stannp-com-postcard-bulk-mailer
- type: X
  url: https://twitter.com/stannpdm
- type: Blog
  url: https://go.stannp.com/blogs
- type: Pricing
  url: https://www.stannp.com/us/pricing-tiers
- type: Plans
  url: plans/stannp-plans-pricing.yml
- type: RateLimits
  url: rate-limits/stannp-rate-limits.yml
- type: FinOps
  url: finops/stannp-finops.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com