stackin-io

Stackin provides a Brazilian fiscal API platform that enables developers to issue electronic invoices (NF-e) and service invoices (NFS-e) via a simple REST interface. The service handles document generation, tax calculation, and submission to government tax authorities, offering both sandbox (free) and production environments with dashboards for tracking. It aims to simplify compliance for SaaS, e‑commerce, and ERP solutions in Brazil.

stackin-io is listed with 1 API on the APIs.io network. Tagged areas include Finance, Tax, Brazil, Invoicing, and SaaS.

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

stackin-io’s developer surface includes sandbox, authentication, getting-started guide, documentation, pricing, support, signup flow, and 25 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

61.9/100 strong Agent 48/100 agent ready Full breakdown ↓
scored 2026-10-31 · rubric v0.25.0 · Show this score on your site →

1 API 1 MCP Servers 1 Agent Skills

Finance Tax Brazil InvoicingSaaS

Kin Score

Kin Score How this is scored →
scored 2026-10-31 · rubric v0.25.0

Composite quality — 61.9/100 · strong

Contract Quality 10.0 / 21

Developer Ergonomics 10.4 / 17

Access Clarity 12.4 / 17

Operational Transparency 3.7 / 11

Contract Governance 8.1 / 10

Discoverability 5.5 / 9

Regulatory Posture 5.1 / 15

Agent readiness — 48/100 · 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 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 6 / 6

Protected Resource Metadata 5 / 5

Registration Without a Human 6 / 6

Agentic Commerce Well-Known Document 0 / 5

Pagination 5 / 5

Distinct Operations 3 / 3

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
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Request/Response Examples +7 pts — share of operations carrying request/response examples; else an Examples / Code Samples link
Typed Event Surface +6 pts — AsyncAPI document, OR webhooks/callbacks objects in the as-published OpenAPI, OR common[].type includes Webhooks
Documented Reversibility +6 pts — a reversal operation in the contract, graded up when a window is documented too
Agentic Commerce Well-Known Document +5 pts — a parsing /.well-known/ucp.json or acp.json declaring a version and at least one service — `self` when its endpoints are on the provider's own domain, `platform` when they are on a vendor's

3 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Contract Quality scores 46.9 — up to +13.3 composite points
Operational Transparency scores 33.7 — up to +8.6 composite points
Developer Ergonomics scores 61.2 — up to +7.8 composite points

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.

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/stackin-io/apis.yml: open an issue on github.com/api-evangelist/stackin-io 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 →

APIs 1

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

stackin-io API

stackin-io API as documented publicly: 2 operations. Contract generated from the documentation by API Evangelist (2026-10-31); not the provider's own document.

MCP Servers 1

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

stackin-io MCP Server

Remote MCP server at mcp.stackin.io.

MCP SERVER

Agent Skills 1

Packaged agent skills for driving this provider's APIs from an AI assistant.

invoice

AGENT SKILL

Pricing Plans 1

Published pricing tiers and plan structures.

Stackin Io Plans Pricing

4 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Stackin Io Rate Limits

5 limits

RATE LIMITS

Semantic Vocabularies 1

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

Stackin Io Context

1 classes · 4 properties

JSON-LD

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

stackin-io API Rules

11 rules · 9 errors 1 warnings 1 info

SPECTRAL

JSON Schema 1

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

PostStackinRequest

4 properties

JSON SCHEMA

Security Posture 2

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

Stackin Io Authentication

1 scheme

SECURITY

Stackin Io Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Scopes 1

OAuth scopes governing access to this provider's APIs.

Stackin Io Scopes

OAuth 2.0 · no documented scopes

0 scopes

SCOPES

Resources

Get Started 4

Portal, sign-up, and the first successful call

Sandbox

Sandbox

GettingStarted

GettingStarted

SignUp

SignUp

Login

Documentation 1

Reference material describing how the API behaves

Documentation

Documentation

Agent Surfaces 3

MCP servers, agent skills, and machine-readable catalogs

AgentSkill

AgentSkill

MCPServer

MCPServer

WellKnown

WellKnown

Design & Contract 8

Pagination, idempotency, versioning, errors, and events

Spectral

JSONLD

Vocabulary

DataModel

Idempotency

Conventions

ErrorCatalog

Conformance

Scroll for all 8

Build 4

SDKs, sample code, and the tooling you integrate with

ToolCrosswalk

ToolCrosswalk

SDKs

SDKs

Packages

Packages

GitHubOrganization

GitHubOrganization

Access & Security 2

Authentication, authorization, and security posture

Authentication

Authentication

DomainSecurity

DomainSecurity

Operate 2

Status, limits, changes, and where to get help

RateLimits

RateLimits

Support

Support

Commercial 4

Pricing, plans, and the legal terms of use

Plans

Pricing

TermsOfService

PrivacyPolicy

Company 2

The organization behind the API

Website

Website

Blog

Blog

Other 2

Properties that don't map to a standard resource type

Hosts

Hosts

Vendors

Vendors

Source (apis.yml)

aid: stackin-io
name: stackin-io
description: Stackin provides a Brazilian fiscal API platform that enables developers to issue electronic invoices (NF-e)
  and service invoices (NFS-e) via a simple REST interface. The service handles document generation, tax calculation, and
  submission to government tax authorities, offering both sandbox (free) and production environments with dashboards for tracking.
  It aims to simplify compliance for SaaS, e‑commerce, and ERP solutions in Brazil.
url: https://artifacts.apis.io/stackin-io/apis.yml
x-type: company
x-source: harvest:mcp-registry
x-tier: profiled
x-tier-reason: enrichment pass 2026-10-31 (modular-v1; was harvest)
image: https://app.stackin.io/logo.svg
specificationVersion: '0.20'
created: '2026-10-31'
modified: '2026-10-31'
tags:
- Finance
- Tax
- Brazil
- Invoicing
- SaaS
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: RateLimits
  url: rate-limits/stackin-io-rate-limits.yml
- type: Plans
  url: plans/stackin-io-plans-pricing.yml
- type: Spectral
  url: rules/stackin-io-rules.yml
- type: JSONLD
  url: json-ld/stackin-io-context.jsonld
- type: Vocabulary
  url: vocabulary/stackin-io-vocabulary.yml
- type: AgentSkill
  url: skills/_index.yml
- type: DataModel
  url: data-model/stackin-io-data-model.yml
- type: Idempotency
  url: conventions/stackin-io-conventions.yml
- type: Conventions
  url: conventions/stackin-io-conventions.yml
- type: Sandbox
  url: sandbox/stackin-io-sandbox.yml
- type: Authentication
  url: authentication/stackin-io-authentication.yml
- type: ErrorCatalog
  url: errors/stackin-io-problem-types.yml
- type: Conformance
  url: conformance/stackin-io-conformance.yml
- type: ToolCrosswalk
  url: mcp/stackin-io-tool-crosswalk.yml
- type: MCPServer
  url: mcp/stackin-io-mcp.yml
- type: WellKnown
  url: well-known/stackin-io-well-known.yml
- type: Hosts
  url: hosts/stackin-io-hosts.yml
- type: Vendors
  url: vendors/stackin-io-vendors.yml
- type: SDKs
  url: packages/stackin-io-packages.yml
- type: Packages
  url: packages/stackin-io-packages.yml
- type: GettingStarted
  url: https://docs.stackin.io/blog/quickstart
- type: DomainSecurity
  url: security/stackin-io-domain-security.yml
- type: Website
  url: https://stackin.io/
- type: Documentation
  url: https://docs.stackin.io
- type: Pricing
  url: https://app.stackin.io/pricing
- type: TermsOfService
  url: https://app.stackin.io/terms
- type: PrivacyPolicy
  url: https://app.stackin.io/privacy
- type: Support
  url: https://wa.me/554888135243
- type: SignUp
  url: https://app.stackin.io/signup
- type: Login
  url: https://app.stackin.io/login
- type: Blog
  url: https://docs.stackin.io/blog
- type: GitHubOrganization
  url: https://github.com/stackin-io
apis:
- aid: stackin-io:stackin-io-api
  name: stackin-io API
  description: 'stackin-io API as documented publicly: 2 operations. Contract generated from the documentation by API Evangelist
    (2026-10-31); not the provider''s own document.'
  humanURL: https://docs.stackin.io/api
  baseURL: https://mcp.stackin.io
  properties:
  - type: OpenAPI
    url: openapi/_ae-authored/stackin-io-openapi-generated.yml
    x-provenance: generated
  - type: JSONSchema
    url: json-schema/stackin-io-post-stackin-request-schema.json
x-coverage:
  state: unreadable
  reason: no-machine-readable-spec
  method: derived
  generated: '2026-10-31'
  generator: derive-coverage.py (pre-flight evidence)
  detail: the company publishes developer documentation but serves no machine-readable contract from it
  evidence:
  - url: https://docs.stackin.io/mcp
    status: null
  - url: https://stackin.io/
    status: 200
x-enrichment:
  date: '2026-10-31'
  status: enriched
  artifacts_added: 30
  pass: modular-v1
  engine: identity=oss,contract=oss,surfaces=oss,docs=oss,regulatory=oss

stackin-io API — frequently asked questions

Does stackin-io have an API?

Yes. APIs.io lists 1 API from stackin-io, including stackin-io API.

Is there an OpenAPI specification for the stackin-io API?

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

How do I authenticate with the stackin-io API?

stackin-io documents its authentication (1 scheme). The details are profiled on APIs.io as Stackin Io Authentication.

How much does the stackin-io API cost?

APIs.io lists 4 pricing plans for stackin-io, with each plan's price, limits and inclusions under Pricing Plans on this page.

Does stackin-io have an MCP server?

Yes. APIs.io lists 1 MCP server for stackin-io: Remote MCP server at mcp.stackin.io.

Is the stackin-io API ready for AI agents?

stackin-io has a Kin Score of 61.9 out of 100 (strong) and an Agent Readiness score of 47.8 (agent-ready), scored by API Evangelist on 2026-10-31.

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