name: Tvarka ATK API
description: A single REST API estate for Lithuanian eID authentication and qualified electronic signing (QES). The ATK API
  reads the Lithuanian identity card itself - physical smart-card reader or NFC phone tap - through one request, polling,
  webhook and metering model, and adds standalone validation, timestamping and long-term-validation (LTV)/archive trust services;
  contract 1.4.0 withdrew the short-lived Smart-ID and Mobile-ID passthrough, so the ATK surface is deliberately card-only.
  Hosted remote-method ceremonies moved to the separate Tvarka Sign API (sign-api.tvarka.pro), an orchestration contract with
  RFC 9457 problem details and a live, anonymously introspectable MCP server at /mcp. eIDAS-aligned and EU-resident, operated
  from Lithuania by Advokato M. Kiskio kontora INVENT and Socialiniai algoritmai, UAB, and priced per successful operation
  with no subscription or minimum.
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: true
  label: Hosted service · you call their endpoint
  confidence: high
  source:
  - openapi
  - pricing
  generated: '2026-08-28'
  method: derived
image: https://tvarka.pro/static/img/tvarka-logo-closer.53b2d1b2a9b0.svg
url: https://atk.tvarka.pro/apis.json
created: '2026-08-02'
modified: '2026-08-31'
specificationVersion: '0.23'
tags:
- Authentication
- Digital Signature
- eIDAS
- QES
- Lithuania
- OpenAPI
- eID
- Smart-ID
- Mobile-ID
- NFC
- Timestamping
- LTV
- Webhook
- Identity
- Trust Services
- GDPR
tags_raw:
- Authentication
- Digital Signature
- eIDAS
- QES
- Lithuania
- OpenAPI
- eID
- Smart-ID
- Mobile-ID
- NFC
- Timestamping
- LTV
- Webhooks
- Identity
- Trust Services
- GDPR
apis:
- aid: tvarka-atk-api:tvarka-atk-api-auth-api
  name: Tvarka ATK API Auth API
  description: The eID authentication ceremony (`/v1/auth/*`).
  humanURL: https://atk.tvarka.pro/docs/
  baseURL: https://atk.tvarka.pro/v1
  tags:
  - Authentication
  tags_raw:
  - Auth
  properties:
  - type: OpenAPI
    url: openapi/tvarka-atk-api-auth-api-openapi.yml
  - type: PostmanCollection
    url: https://atk.tvarka.pro/postman/auth.json
  - type: PostmanCollection
    url: https://atk.tvarka.pro/postman/sign.json
  - type: Documentation
    url: https://atk.tvarka.pro/docs/
  - type: APIsJSON
    url: https://atk.tvarka.pro/apis.json
- aid: tvarka-atk-api:tvarka-atk-api-erasure-api
  name: Tvarka ATK API Erasure API
  description: The Erasure API from Tvarka ATK API — 3 operation(s) for erasure.
  humanURL: https://atk.tvarka.pro/docs/
  baseURL: https://atk.tvarka.pro/v1
  tags:
  - Erasure
  properties:
  - type: OpenAPI
    url: openapi/tvarka-atk-api-erasure-api-openapi.yml
  - type: PostmanCollection
    url: https://atk.tvarka.pro/postman/auth.json
  - type: PostmanCollection
    url: https://atk.tvarka.pro/postman/sign.json
  - type: Documentation
    url: https://atk.tvarka.pro/docs/
  - type: APIsJSON
    url: https://atk.tvarka.pro/apis.json
- aid: tvarka-atk-api:tvarka-atk-api-ltv-api
  name: Tvarka ATK API LTV API
  description: Post-signature timestamp and long-term-validation upgrades.
  humanURL: https://atk.tvarka.pro/docs/
  baseURL: https://atk.tvarka.pro/v1
  tags:
  - LTV
  properties:
  - type: OpenAPI
    url: openapi/tvarka-atk-api-ltv-api-openapi.yml
  - type: PostmanCollection
    url: https://atk.tvarka.pro/postman/auth.json
  - type: PostmanCollection
    url: https://atk.tvarka.pro/postman/sign.json
  - type: Documentation
    url: https://atk.tvarka.pro/docs/
  - type: APIsJSON
    url: https://atk.tvarka.pro/apis.json
- aid: tvarka-atk-api:tvarka-atk-api-pairing-api
  name: Tvarka ATK API Pairing API
  description: NFC remote pairing - complete a request by tapping a card on a different device.
  humanURL: https://atk.tvarka.pro/docs/
  baseURL: https://atk.tvarka.pro/v1
  tags:
  - Pairing
  properties:
  - type: OpenAPI
    url: openapi/tvarka-atk-api-pairing-api-openapi.yml
  - type: PostmanCollection
    url: https://atk.tvarka.pro/postman/auth.json
  - type: PostmanCollection
    url: https://atk.tvarka.pro/postman/sign.json
  - type: Documentation
    url: https://atk.tvarka.pro/docs/
  - type: APIsJSON
    url: https://atk.tvarka.pro/apis.json
- aid: tvarka-atk-api:tvarka-atk-api-sign-api
  name: Tvarka ATK API Sign API
  description: The QES signing ceremony (`/v1/sign/*`).
  humanURL: https://atk.tvarka.pro/docs/
  baseURL: https://atk.tvarka.pro/v1
  tags:
  - Sign
  properties:
  - type: OpenAPI
    url: openapi/tvarka-atk-api-sign-api-openapi.yml
  - type: PostmanCollection
    url: https://atk.tvarka.pro/postman/auth.json
  - type: PostmanCollection
    url: https://atk.tvarka.pro/postman/sign.json
  - type: Documentation
    url: https://atk.tvarka.pro/docs/
  - type: APIsJSON
    url: https://atk.tvarka.pro/apis.json
- aid: tvarka-atk-api:tvarka-atk-api-tvarka-atk-api-api
  name: Tvarka ATK API Tvarka ATK API API
  description: The Tvarka ATK API API from Tvarka ATK API — 0 operation(s) for tvarka atk api.
  humanURL: https://atk.tvarka.pro/docs/
  baseURL: https://atk.tvarka.pro/v1
  tags:
  - Tvarka ATK API
  properties:
  - type: PostmanCollection
    url: https://atk.tvarka.pro/postman/auth.json
  - type: PostmanCollection
    url: https://atk.tvarka.pro/postman/sign.json
  - type: Documentation
    url: https://atk.tvarka.pro/docs/
  - type: APIsJSON
    url: https://atk.tvarka.pro/apis.json
- aid: tvarka-atk-api:tvarka-atk-api-tvarka-atk-qes-signing-api-paid-tier-addendum-api
  name: Tvarka ATK API Tvarka ATK QES Signing API (paid Tier Addendum) API
  description: The Tvarka ATK QES Signing API (paid Tier Addendum) API from Tvarka ATK API — 0 operation(s) for tvarka atk
    qes signing api (paid tier addendum).
  humanURL: https://atk.tvarka.pro/docs/
  baseURL: https://atk.tvarka.pro/v1
  tags: []
  tags_raw:
  - Tvarka ATK QES Signing API (paid Tier Addendum)
  properties:
  - type: PostmanCollection
    url: https://atk.tvarka.pro/postman/auth.json
  - type: PostmanCollection
    url: https://atk.tvarka.pro/postman/sign.json
  - type: Documentation
    url: https://atk.tvarka.pro/docs/
  - type: APIsJSON
    url: https://atk.tvarka.pro/apis.json
- aid: tvarka-atk-api:tvarka-atk-api-validation-api
  name: Tvarka ATK API Validation API
  description: Standalone advisory validation of signed artifacts.
  humanURL: https://atk.tvarka.pro/docs/
  baseURL: https://atk.tvarka.pro/v1
  tags:
  - Validation
  properties:
  - type: OpenAPI
    url: openapi/tvarka-atk-api-validation-api-openapi.yml
  - type: PostmanCollection
    url: https://atk.tvarka.pro/postman/auth.json
  - type: PostmanCollection
    url: https://atk.tvarka.pro/postman/sign.json
  - type: Documentation
    url: https://atk.tvarka.pro/docs/
  - type: APIsJSON
    url: https://atk.tvarka.pro/apis.json
- aid: tvarka-atk-api:tvarka-atk-api-well-known-api
  name: Tvarka ATK API Well Known API
  description: Keys for verifying the optional `assertion` JWT.
  humanURL: https://atk.tvarka.pro/docs/
  baseURL: https://atk.tvarka.pro/v1
  tags:
  - .well Known
  tags_raw:
  - Well-known
  properties:
  - type: OpenAPI
    url: openapi/tvarka-atk-api-well-known-api-openapi.yml
  - type: PostmanCollection
    url: https://atk.tvarka.pro/postman/auth.json
  - type: PostmanCollection
    url: https://atk.tvarka.pro/postman/sign.json
  - type: Documentation
    url: https://atk.tvarka.pro/docs/
  - type: APIsJSON
    url: https://atk.tvarka.pro/apis.json
- aid: tvarka-atk-api:tvarka-sign-api
  name: Tvarka Sign API
  description: 'Machine channel for Tvarka Sign: post a document and a list of signers and Tvarka runs its ordinary qualified
    signing ceremony for each of them on the hosted page or in the Tvarka Sign mobile app (LT ATK over NFC, Smart-ID, Mobile-ID).
    Nothing in the API signs anything - a signature is always a human act with the signer''s own eID - so every operation
    is about getting a document in front of the right person and learning what they did. Orchestration sibling of the card-level
    ATK API; RFC 9457 problem details, HMAC-signed webhooks, and a hosted MCP server.'
  version: 1.2.1
  created: '2026-08-31'
  modified: '2026-08-31'
  baseURL: https://sign-api.tvarka.pro
  humanURL: https://sign-api.tvarka.pro/docs
  tags:
  - Digital Signature
  - QES
  - eIDAS
  - Lithuania
  - OpenAPI
  - MCP
  - Webhook
  - Identity
  tags_raw:
  - Digital Signature
  - QES
  - eIDAS
  - Lithuania
  - OpenAPI
  - MCP
  - Webhooks
  - Identity
  properties:
  - type: OpenAPI
    url: openapi/tvarka-sign-api-openapi.yml
  - type: OpenAPI
    name: Provider-hosted contract
    url: https://sign-api.tvarka.pro/openapi.json
    mediaType: application/vnd.oai.openapi+json;version=3.1
  - type: Documentation
    url: https://sign-api.tvarka.pro/docs
  - type: APIReference
    url: https://sign-api.tvarka.pro/docs
  - type: MCPServer
    url: mcp/tvarka-sign-api-mcp.yml
  - type: ToolCrosswalk
    url: mcp/tvarka-sign-api-tool-crosswalk.yml
  - type: LLMsTxt
    url: llms/tvarka-sign-api-llms.txt
  - type: Authentication
    url: authentication/tvarka-sign-api-authentication.yml
  - type: ErrorCatalog
    url: errors/tvarka-sign-api-problem-types.yml
  - type: Webhooks
    url: asyncapi/tvarka-sign-api-webhooks.yml
  - type: Sandbox
    url: sandbox/tvarka-sign-api-sandbox.yml
  - type: Conventions
    url: conventions/tvarka-sign-api-conventions.yml
  - type: Overlay
    url: overlays/tvarka-sign-api-openapi-overlay.yaml
  - type: DataModel
    url: data-model/tvarka-sign-api-data-model.yml
  - type: RateLimits
    url: rate-limits/tvarka-sign-api-rate-limits.yml
  - type: AgentSkill
    url: skills/tvarka-sign-api-request-signatures.md
maintainers:
- FN: Tvarka API team
  email: info@tvarka.pro
  organizationName: Tvarka
  url: https://atk.tvarka.pro/docs/
generated:
  by: apis.io/add
  model: claude-opus-4-8
  confidence: 95
  at: '2026-08-02T22:54:13.353Z'
x-enrichment:
  date: '2026-08-31'
  status: enriched
  artifacts_added: 17
  pass: local-v1
common:
- type: AgenticAccess
  url: agentic-access/tvarka-agentic-access.yml
- type: DomainSecurity
  url: security/tvarka-atk-api-domain-security.yml
- type: Authentication
  url: authentication/tvarka-atk-api-authentication.yml
- type: DeveloperPortal
  url: https://atk.tvarka.pro/docs/
- type: Documentation
  url: https://atk.tvarka.pro/docs/
- type: APIReference
  url: https://atk.tvarka.pro/docs/api/
- type: GettingStarted
  url: https://atk.tvarka.pro/docs/quickstart/
- type: Support
  url: https://tvarka.pro/kontaktai/
- type: SignUp
  url: https://atk.tvarka.pro/docs/access/
- type: Pricing
  url: https://atk.tvarka.pro/docs/pricing/
- type: TermsOfService
  url: https://tvarka.pro/salygos/
- type: PrivacyPolicy
  url: https://tvarka.pro/privatumas/
- type: Postman
  name: Authentication collection
  url: https://atk.tvarka.pro/postman/auth.json
- type: Postman
  name: Signing and services collection
  url: https://atk.tvarka.pro/postman/sign.json
- type: Packages
  url: packages/tvarka-atk-api-packages.yml
- type: SDKs
  url: packages/tvarka-atk-api-packages.yml
- type: WellKnown
  url: well-known/tvarka-atk-api-well-known.yml
- type: LLMsTxt
  url: llms/tvarka-atk-api-llms.txt
- type: MCPServer
  url: mcp/tvarka-sign-api-mcp.yml
- type: Overlay
  url: overlays/tvarka-atk-api-openapi-overlay.yaml
- type: Conformance
  url: conformance/tvarka-atk-api-conformance.yml
- type: Compliance
  url: https://tvarka.pro/saugumas/
- type: ErrorCatalog
  url: errors/tvarka-atk-api-problem-types.yml
- type: Lifecycle
  url: lifecycle/tvarka-atk-api-lifecycle.yml
- type: StatusPage
  url: https://atk.tvarka.pro/status/
- type: Deprecation
  url: https://atk.tvarka.pro/docs/lifecycle/
- type: ChangeLog
  url: changelog/tvarka-atk-api-changelog.yml
- type: Security
  url: https://tvarka.pro/saugumas/
- type: VulnerabilityDisclosure
  url: security/tvarka-atk-api-vulnerability-disclosure.yml
- type: Sandbox
  url: sandbox/tvarka-atk-api-sandbox.yml
- type: Conventions
  url: conventions/tvarka-atk-api-conventions.yml
- type: Idempotency
  url: conventions/tvarka-atk-api-conventions.yml
- type: Webhooks
  url: asyncapi/tvarka-atk-api-webhooks.yml
- type: DataModel
  url: data-model/tvarka-atk-api-data-model.yml
- type: Examples
  url: examples/tvarka-atk-api-examples.yml
- type: RateLimits
  url: rate-limits/tvarka-atk-api-rate-limits.yml
- type: Plans
  url: plans/tvarka-atk-api-plans.yml
- type: AgentSkill
  url: skills/_index.yml
- type: Arazzo
  name: Authenticate a person with a Lithuanian eID card
  url: arazzo/tvarka-atk-api-authenticate-eid-card.yml
- type: Arazzo
  name: Sign a PDF with a qualified electronic signature
  url: arazzo/tvarka-atk-api-sign-pades-document.yml
- type: Arazzo
  name: Validate, timestamp and archive an existing signed document
  url: arazzo/tvarka-atk-api-timestamp-and-archive.yml
- type: ToolCrosswalk
  url: mcp/tvarka-sign-api-tool-crosswalk.yml
- type: SecurityTxt
  url: well-known/tvarka-security.txt
- type: APIsJSON
  url: https://atk.tvarka.pro/apis.json
- type: LLMsTxt
  name: Tvarka Sign API (provider-published)
  url: llms/tvarka-sign-api-llms.txt
- type: Webhooks
  name: Tvarka Sign API signing events
  url: asyncapi/tvarka-sign-api-webhooks.yml
- type: ErrorCatalog
  name: Tvarka Sign API RFC 9457 problem types
  url: errors/tvarka-sign-api-problem-types.yml
- type: Sandbox
  name: Tvarka Sign API sandbox
  url: sandbox/tvarka-sign-api-sandbox.yml
- type: Conventions
  name: Tvarka Sign API conventions
  url: conventions/tvarka-sign-api-conventions.yml
- type: Authentication
  name: Tvarka Sign API authentication
  url: authentication/tvarka-sign-api-authentication.yml
- type: HelpCenter
  url: https://tvarka.pro/pagalba/
- type: Overlay
  name: Tvarka Sign API overlay
  url: overlays/tvarka-sign-api-openapi-overlay.yaml
- type: DataModel
  name: Tvarka Sign API data model
  url: data-model/tvarka-sign-api-data-model.yml
- type: RateLimits
  name: Tvarka Sign API rate limits
  url: rate-limits/tvarka-sign-api-rate-limits.yml
type: Index
position: Producing
access: 3rd-Party