flatin.pt

Portuguese property-tax APIs providing keyless access to IMI rates for all 308 municipalities and IMT/stamp duty purchase-cost calculations, sourced from official Autoridade Tributária tables. flatin.pt serves the same numbers as a REST API with an OpenAPI schema, a remote MCP server exposing four agent tools, an llms.txt for agent discovery, and a CC BY 4.0 open CSV dataset — no key and no sign-up.

flatin.pt publishes 1 API on the APIs.io network: Public API. Tagged areas include Real Estate, Property Tax, Tax, IMI, and IMT.

The flatin.pt catalog on APIs.io includes 1 Spectral governance ruleset.

flatin.pt’s developer surface includes documentation, getting-started guide, API reference, pricing, changelog, support, and 22 more developer resources.

🌐 Visit website 📡 Source on GitHub
59.4/100 strong ▬ flat Agent 32/100 agent ready Front door AI 2/6 trace saas Full breakdown ↓
scored 2026-10-04 · rubric v0.23.0
1 published contract 1 MCP Servers
Real EstateProperty TaxTaxIMIIMTStamp DutyPortugalOpen DataGovernment DataFiscal DataMCPAI Agents

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-10-04 · rubric v0.23.0
Composite quality — 59.4/100 · strong
Contract Quality 8.8 / 19
Developer Ergonomics 9.6 / 15
Access Clarity 7.9 / 15
Operational Transparency 6.4 / 10
Contract Governance 4.8 / 9
Discoverability 5.6 / 8
Regulatory Posture 4.6 / 15
Create-or-Update Ergonomics 0.0 / 10
Agent readiness — 32/100 · agent ready
Machine-Readable Contract 18 / 18
Agentic Access Contract 0 / 10
Documented Reversibility 0 / 6
MCP Server 12 / 12
Machine-Readable Auth 10 / 10
Idempotency 9 / 9
Stable Error Semantics 8 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 7 / 7
Typed Event Surface 0 / 6
Agent Skills 5 / 5
Well-Known Catalog 4 / 4
Consent & Bot Identity 0 / 3
A2A Agent Card 0 / 8
Dry-Run / Simulate Mode 0 / 4
Delegated User Identity 0 / 6
Protected Resource Metadata 0 / 5
Registration Without a Human 0 / 6
Agentic Commerce Well-Known Document 0 / 5
Regulatory Posture applies to this provider. Its tags matched the Government & Public Sector 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 applies to this provider. This API accepts writes, so it carries 10 points of the composite. It is scored from the published contracts themselves: whether a caller can create-or-update in one call, whether the write accepts a key the caller already holds, and whether the response says which branch ran. Without that, every write needs a search-and-branch in front of it, and the first time that check is skipped a duplicate record is created. Scored against the observed mean rather than raw — a provider at the catalog average is unchanged by this facet, not penalised by it.
The six quality facets above are damped to 75 points between them, because the conditional facet above carries the other 25. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 75% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.
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 github.com/api-evangelist/flatin-pt: open an issue to ask a question, or submit a pull request to add artifacts. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

APIs 1

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

flatin.pt Public API

Keyless public endpoints: IMI rates and IMT calculation.

MCP Servers 1

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

flatin.pt Property Taxes MCP

Remote Model Context Protocol server for Portuguese property taxes — IMT/stamp duty on a purchase and IMI rates for all 308 municipalities. Keyless, stateless Streamable HTTP.

MCP SERVER

Pricing Plans 1

Published pricing tiers and plan structures.

Flatin Pt Plans Pricing

1 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Flatin Pt Rate Limits

2 limits

RATE LIMITS

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

flatin.pt API Rules

9 rules · 3 errors 4 warnings 2 info

SPECTRAL

Security Posture 3

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

Flatin Pt Authentication

1 scheme

SECURITY

Flatin Pt Domain Security

TLSv1.3 · DMARC

SECURITY

Flatin Pt Vulnerability Disclosure

security.txt · contact published

SECURITY

Resources

Get Started 2

Portal, sign-up, and the first successful call

DeveloperPortal
DeveloperPortal
 GettingStarted
GettingStarted

Documentation 2

Reference material describing how the API behaves

Documentation
Documentation
 APIReference
APIReference

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

AgentSkill
AgentSkill
 WellKnown
WellKnown
 LLMsTxt
LLMsTxt
 MCPServer
MCPServer

Design & Contract 1

Pagination, idempotency, versioning, errors, and events

SpectralRules
SpectralRules

Build 4

SDKs, sample code, and the tooling you integrate with

SDKs
SDKs
 Packages
Packages
 GitHubOrganization
GitHubOrganization
 GitHubRepository
GitHubRepository

Access & Security 4

Authentication, authorization, and security posture

Security
Security
 SecurityTxt
SecurityTxt
 VulnerabilityDisclosure
VulnerabilityDisclosure
 DomainSecurity
DomainSecurity

Operate 4

Status, limits, changes, and where to get help

RateLimits
RateLimits
 StatusPage
StatusPage
 ChangeLog
ChangeLog
 Support
Support

Commercial 4

Pricing, plans, and the legal terms of use

Pricing
Pricing
 TermsOfService
TermsOfService
 PrivacyPolicy
PrivacyPolicy
 License
License

Company 1

The organization behind the API

Website
Website

Other 2

Properties that don't map to a standard resource type

Overlay
Overlay
 APICatalog
APICatalog

Source (apis.yml)

apis.yml Raw ↑ 
name: flatin.pt
description: Portuguese property-tax APIs providing keyless access to IMI rates for all 308 municipalities and IMT/stamp duty
  purchase-cost calculations, sourced from official Autoridade Tributária tables. flatin.pt serves the same numbers as a REST
  API with an OpenAPI schema, a remote MCP server exposing four agent tools, an llms.txt for agent discovery, and a CC BY
  4.0 open CSV dataset — no key and no sign-up.
deliveryModel:
  model: saas
  license_evidence:
    not_product:
    - flatinpt/mcp
  open_source: unknown
  commercial: true
  callable_host: false
  label: Hosted service · you call their endpoint
  confidence: low
  source:
  - pricing
  - repository-not-product
  generated: '2026-09-25'
  method: derived
image: https://flatin.pt/assets/brand/raster/icon-256.png
url: https://raw.githubusercontent.com/api-evangelist/flatin-pt/refs/heads/main/apis.yml
created: '2026-09-16'
modified: '2026-09-16'
specificationVersion: '0.21'
tags:
- Real Estate
- Property Tax
- Tax
- IMI
- IMT
- Stamp Duty
- Portugal
- Open Data
- Government Data
- Fiscal Data
- MCP
- AI Agents
tags_raw:
- Real Estate
- Property Tax
- Taxes
- IMI
- IMT
- Stamp Duty
- Portugal
- Open Data
- Government Data
- Fiscal Data
- MCP
- AI Agents
- Real-Estate
apis:
- aid: flatin-pt:flatin-pt-public-api
  name: flatin.pt Public API
  description: 'Keyless public endpoints: IMI rates and IMT calculation.'
  humanURL: https://flatin.pt/en/tools/api-and-data/
  baseURL: https://flatin.pt/api/v1
  tags:
  - Public
  tags_raw:
  - public
  properties:
  - type: OpenAPI
    url: openapi/flatin-pt-public-api-openapi.yml
  - type: ToolCrosswalk
    url: mcp/flatin-pt-tool-crosswalk.yml
  - type: LLMsTxt
    url: llms/flatin-pt-llms.txt
  - type: Authentication
    url: authentication/flatin-pt-authentication.yml
  - type: Conventions
    url: conventions/flatin-pt-conventions.yml
  - type: Idempotency
    url: conventions/flatin-pt-conventions.yml
  - type: ErrorCatalog
    url: errors/flatin-pt-problem-types.yml
  - type: DataModel
    url: data-model/flatin-pt-data-model.yml
  - type: Conformance
    url: conformance/flatin-pt-conformance.yml
  - type: RateLimits
    url: rate-limits/flatin-pt-rate-limits.yml
  - type: Plans
    url: plans/flatin-pt-plans-pricing.yml
  - type: ChangeLog
    url: changelog/flatin-pt-changelog.yml
  - type: Lifecycle
    url: lifecycle/flatin-pt-lifecycle.yml
  - type: Dataset
    url: https://flatin.pt/api/v1/imi/rates.csv
  - type: Documentation
    url: https://flatin.pt/en/tools/api-and-data/
maintainers:
- FN: HOLY CHAOS, UNIPESSOAL LDA (flatin.pt)
  email: info@flatin.pt
  url: https://flatin.pt/en/
generated:
  by: apis.io/add
  model: claude-opus-4-8
  confidence: 97
  at: '2026-09-16T11:39:19.753Z'
common:
- type: Overlay
  url: overlays/flatin-pt-openapi-overlay.yaml
- type: AgentSkill
  url: skills/_index.yml
- type: Website
  url: https://flatin.pt/en/
- type: DeveloperPortal
  url: https://flatin.pt/en/tools/api-and-data/
- type: Documentation
  url: https://flatin.pt/en/tools/api-and-data/
- type: GettingStarted
  url: https://flatin.pt/en/tools/api-and-data/#rest
- type: APIReference
  url: https://flatin.pt/api/openapi.json
- type: Pricing
  url: https://flatin.pt/api/plans.json
- type: RateLimits
  url: rate-limits/flatin-pt-rate-limits.yml
- type: StatusPage
  url: https://flatin.pt/status/
- type: ChangeLog
  url: changelog/flatin-pt-changelog.yml
- type: TermsOfService
  url: https://flatin.pt/en/legal/termos-utilizacao/
- type: PrivacyPolicy
  url: https://flatin.pt/en/legal/privacidade/
- type: Security
  url: security/flatin-pt-vulnerability-disclosure.yml
- type: SecurityTxt
  url: well-known/flatin-pt-security.txt
- type: VulnerabilityDisclosure
  url: security/flatin-pt-vulnerability-disclosure.yml
- type: DomainSecurity
  url: security/flatin-pt-domain-security.yml
- type: WellKnown
  url: well-known/flatin-pt-well-known.yml
- type: APICatalog
  url: well-known/flatin-pt-api-catalog.json
- type: SpectralRules
  url: rules/flatin-pt-spectral.yaml
- type: LLMsTxt
  url: llms/flatin-pt-llms.txt
- type: MCPServer
  url: mcp/flatin-pt-mcp.yml
- type: SDKs
  url: packages/flatin-pt-packages.yml
- type: Packages
  url: packages/flatin-pt-packages.yml
- type: License
  url: https://creativecommons.org/licenses/by/4.0/
- type: GitHubOrganization
  url: https://github.com/flatinpt
- type: GitHubRepository
  url: https://github.com/flatinpt/mcp
- type: Support
  url: mailto:info@flatin.pt
x-enrichment:
  date: '2026-09-16'
  status: enriched
  artifacts_added: 26
  pass: local-v3

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