PostGrid website screenshot

PostGrid

PostGrid is a physical mail automation platform that provides REST APIs for sending printed letters, postcards, checks, and self-mailers at scale. It offers a Print & Mail API that enables developers to programmatically trigger and manage direct mail campaigns with full personalization and tracking support. PostGrid also provides US & Canada Address Verification and International Address Verification APIs covering 245+ countries for real-time autocomplete, standardization, geocoding, and bulk batch verification. The platform supports both test and live API environments, integrates natively with Salesforce, HubSpot, Zapier, and Marketo, and handles postage, printing, and delivery end-to-end.

PostGrid is listed with 3 APIs on the APIs.io network, including Print & Mail API, and 2 more. Tagged areas include Direct Mail, Print & Mail, Address Verification, Address Validation, and Postcards.

The PostGrid catalog on APIs.io includes 1 JSON-LD context.

PostGrid’s developer surface includes documentation, engineering blog, changelog, pricing, support, and 10 more developer resources.

24.9/100 emerging ▬ flat Agent 27/100 agent aware Heartbeat 32/100 slowing saas Full breakdown ↓
scored 2026-11-13 · rubric v0.28.0 · Show this score on your site →
AccessFreemiumFree trial
3 APIs 1 MCP Servers
Direct MailPrint & MailAddress VerificationAddress ValidationPostcardsLettersChecksPhysical MailMail AutomationAddress AutocompleteGeocoding

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-11-13 · rubric v0.28.0
Regulatory Posture applies to this provider. Its tags matched the Horizontal (data, software, accessibility, platform) regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.
Create-or-Update Ergonomics could not be measured. We hold no machine-readable contract for this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero: never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and several others — scorable at all.
The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.
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Agent readiness — checks not met, largest first (exact, from this profile):
  • Agentic Access Contract +10 pts — agentic_access artifact present (x-agentic-access), graded by author Ask about this →
  • Machine-Readable Auth +10 pts — a served openid-configuration/oauth-authorization-server carrying `issuer` (served), else the securitySchemes class in the provider OpenAPIs — bound (mutualTLS, DPoP, Signature) > negotiable (oauth2 authorizationCode/clientCredentials, openIdConnect) > bearer (http bearer, apiKey) Ask about this →
  • Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented) Ask about this →
  • Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes Ask about this →
  • A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0 Ask about this →
  • Registration Without a Human +6 pts — a `registration_endpoint` in the served RFC 8414 / OIDC discovery document Ask about this →
8 more unmet checks in the Agent Readiness table above.
Kin Score — facets with the most composite points still available (weight × headroom):
Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.
Not sure how this applies to your stack? Ask about any one item. Kin Lane reads every question, looks at your profile and your situation, and replies with what a fix would take — scoped to that one area, priced up front, yours whether you ship it or not. Ask a question →
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or email info@apis.io
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from the provider profile at artifacts.apis.io/postgrid/apis.yml: open an issue on github.com/api-evangelist/postgrid to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Markets this provider is in provisional

The Kin Score Market layer reads a provider inside its market: its position, and how deep its integrations go. Depth is only comparable within a position. Provisional and unweighted: not part of the Kin Score or agent readiness.

MarketPositionDepthRegistered MCP serverDeclares compatibility
Stripe App Marketplace and Partner Ecosystem (builders on Stripe) builds-on 22.2 - -

Registered MCP server and declares compatibility are report only — not weighted. Undeclared means we found nothing we can read, so there is no number: we never infer integrations.

Standards implemented 3

Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.

measured — observed by APIs.io (verified)
measured — observed by APIs.io (verified)
measured — observed by APIs.io (published)

APIs 3

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

PostGrid Print & Mail API

A REST API for programmatically sending letters, postcards, checks, and self-mailers. Handles printing, postage, and delivery with support for templates, contacts, tracking, web...

PostGrid US & Canada Address Verification API

A REST API for real-time address autocomplete, verification, and standardization for US and Canadian addresses. Supports CASS-certified validation, geocoding (latitude/longitude...

PostGrid International Address Verification API

A REST API for verifying, standardizing, and autocompleting addresses across 245+ countries worldwide. Supports real-time lookups and bulk verification workflows. Authenticated ...

MCP Servers 1

Model Context Protocol servers that expose these APIs to AI agents.

PostGrid MCP Server

Remote MCP server at mcp.postgrid.com over HTTP.

MCP SERVER

PostGrid API pricing

Not yet checked against PostGrid's own pricing page. Compiled by API Evangelist on 2026-06-12; confirm before you rely on a figure. A free plan or tier is listed.

PlanPrice
Print & Mail Starter freemium Free · $1.019 per per piece
Print & Mail Enterprise enterprise —
Address Verification Essential (US & CA) paid $18.0 / month · $16.2 / month
Address Verification Business (US & CA) paid $40.0 / month · $36.0 / month
Address Verification Growth (US & CA) paid $200.0 / month · $180.0 / month
Address Verification Enterprise (US & CA) enterprise —
International Address Verification Essential paid $20.0 / month · $18.0 / month
International Address Verification Business paid $45.0 / month · $40.5 / month

All 13 plans, limits and sources →

Rate limits

Compiled by API Evangelist, not yet checked against PostGrid's documentation. Rate-limit details →

Pricing Plans 1

Published pricing tiers and plan structures.

PostGrid Plans Pricing

13 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

PostGrid Rate Limits

3 limits

RATE LIMITS

Service Levels 1

Uptime the provider promises or reports, as SLA4OAI. Read from its own pages; APIs.io runs no monitors.

FinOps 1

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

Semantic Vocabularies 1

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

Postgrid Context

8 classes · 0 properties

JSON-LD

Security Posture 1

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

PostGrid Domain Security

TLSv1.3 · DMARC

SECURITY

Resources

Documentation 1

Reference material describing how the API behaves

Build 1

SDKs, sample code, and the tooling you integrate with

Access & Security 1

Authentication, authorization, and security posture

Operate 4

Status, limits, changes, and where to get help

Commercial 3

Pricing, plans, and the legal terms of use

Company 3

The organization behind the API

Other 2

Properties that don't map to a standard resource type

Source (apis.yml)

apis.yml Raw ↑
aid: postgrid
name: PostGrid
description: PostGrid is a physical mail automation platform that provides REST APIs for sending printed letters, postcards,
  checks, and self-mailers at scale. It offers a Print & Mail API that enables developers to programmatically trigger and
  manage direct mail campaigns with full personalization and tracking support. PostGrid also provides US & Canada Address
  Verification and International Address Verification APIs covering 245+ countries for real-time autocomplete, standardization,
  geocoding, and bulk batch verification. The platform supports both test and live API environments, integrates natively with
  Salesforce, HubSpot, Zapier, and Marketo, and handles postage, printing, and delivery end-to-end.
type: Index
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: false
  label: Hosted service · you call their endpoint
  confidence: medium
  source:
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: freemium
  onboarding: unknown
  trial: true
  try_now: false
  public: false
  label: Freemium (free trial)
  confidence: low
  source:
  - plans
  - security
  generated: '2026-11-13'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/postgrid.png
x-docs-platform: postman
x-docs-platform-confidence: medium
x-docs-platform-checked: 2026-10-04
tags:
- Direct Mail
- Print & Mail
- Address Verification
- Address Validation
- Postcards
- Letters
- Checks
- Physical Mail
- Mail Automation
- Address Autocomplete
- Geocoding
url: https://raw.githubusercontent.com/api-evangelist/postgrid/refs/heads/main/apis.yml
created: '2026-06-12'
modified: '2026-06-12'
specificationVersion: '0.23'
apis:
- aid: postgrid:print-mail-api
  name: PostGrid Print & Mail API
  description: A REST API for programmatically sending letters, postcards, checks, and self-mailers. Handles printing, postage,
    and delivery with support for templates, contacts, tracking, webhooks, and both test and live modes. Authenticated via
    x-api-key header.
  humanURL: https://docs.postgrid.com/
  baseURL: https://api.postgrid.com
  tags:
  - Direct Mail
  - Letters
  - Postcards
  - Checks
  - Self-Mailers
  - Print
  - Mail Automation
  properties:
  - type: Documentation
    url: https://docs.postgrid.com/
  - type: OpenAPI
    url: https://postgrid.readme.io/llms.txt
  - type: PythonSDK
    url: https://github.com/postgrid/postgrid-python
  - type: NodeSDK
    url: https://github.com/postgrid/postgrid-node
  - type: Examples
    url: https://github.com/postgrid/postgrid-examples
- aid: postgrid:address-verification-api
  name: PostGrid US & Canada Address Verification API
  description: A REST API for real-time address autocomplete, verification, and standardization for US and Canadian addresses.
    Supports CASS-certified validation, geocoding (latitude/longitude), freeform address parsing, and batch verification for
    large-scale processing. Authenticated via x-api-key header with a default rate limit of 5 requests per second.
  humanURL: https://avdocs.postgrid.com/
  baseURL: https://api.postgrid.com/addver
  tags:
  - Address Verification
  - Address Validation
  - Address Autocomplete
  - CASS
  - Geocoding
  - US
  - Canada
  properties:
  - type: Documentation
    url: https://avdocs.postgrid.com/
- aid: postgrid:international-address-verification-api
  name: PostGrid International Address Verification API
  description: A REST API for verifying, standardizing, and autocompleting addresses across 245+ countries worldwide. Supports
    real-time lookups and bulk verification workflows. Authenticated via x-api-key header.
  humanURL: https://intdocs.postgrid.com/
  baseURL: https://api.postgrid.com/addver
  tags:
  - Address Verification
  - Address Validation
  - International
  - Global
  - Address Autocomplete
  properties:
  - type: Documentation
    url: https://intdocs.postgrid.com/
common:
- type: DomainSecurity
  url: security/postgrid-domain-security.yml
- type: Website
  url: https://www.postgrid.com/
- type: Documentation
  url: https://docs.postgrid.com/
- type: Developers
  url: https://www.postgrid.com/developers/
- type: GitHubOrganization
  url: https://github.com/postgrid
- type: LinkedIn
  url: https://www.linkedin.com/company/postgrid
- type: X
  url: https://x.com/postgridinc
- type: Blog
  url: https://www.postgrid.com/blog/
- type: ChangeLog
  url: https://www.postgrid.com/updates-and-releases/
- type: Pricing
  url: https://www.postgrid.com/pricing/
- type: StatusPage
  url: https://status.postgrid.com/
- type: Support
  url: https://www.postgrid.com/help-support/
- type: Plans
  url: plans/postgrid-plans-pricing.yml
- type: RateLimits
  url: rate-limits/postgrid-rate-limits.yml
- type: FinOps
  url: finops/postgrid-finops.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

PostGrid API — frequently asked questions

Does PostGrid have an API?

Yes. APIs.io lists 3 APIs from PostGrid, including PostGrid Print & Mail API, PostGrid US & Canada Address Verification API and PostGrid International Address Verification API.

Is there an OpenAPI specification for the PostGrid API?

Yes. APIs.io indexes 1 OpenAPI specification for PostGrid, each linked for download from this page.

How much does the PostGrid API cost?

APIs.io lists 13 pricing plans for PostGrid, with each plan's price, limits and inclusions under Pricing on this page.

Does PostGrid have an MCP server?

Yes. APIs.io lists 1 MCP server for PostGrid: Remote MCP server at mcp.postgrid.com over HTTP.

Is the PostGrid API ready for AI agents?

PostGrid has a Kin Score of 24.9 out of 100 (emerging) and an Agent Readiness score of 27.1 (agent-aware), scored by API Evangelist on 2026-11-13.

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