Dropbox Sign (HelloSign)

Dropbox Sign (formerly HelloSign) is an eSignature platform whose v3 REST API lets developers send documents for legally binding electronic signature, build reusable templates, embed signing directly in their own apps, run bulk send jobs, and manage accounts, teams, and API apps. The API exposes 73 operations across 12 product areas (Signature Request, Template, Bulk Send, Embedded, Account, Team, Report, Fax, Fax Line, Unclaimed Draft, API App, OAuth), with API-key and OAuth 2.0 authentication, 23 webhook event types, official SDKs in six languages, and a published hosted documentation MCP server. HelloSign was a Y Combinator company (S11), acquired by Dropbox in 2019 and rebranded to Dropbox Sign in 2022; the API base host remains api.hellosign.com.

Dropbox Sign (HelloSign) publishes 13 API contracts indexed on the APIs.io network, including Account API, Api App API, Bulk Send Job API, and 10 more. Tagged areas include Company, E-Signature, Documents, Digital Agreements, and Signature Workflow.

The Dropbox Sign (HelloSign) catalog on APIs.io includes 2 event-driven AsyncAPI specifications.

Dropbox Sign (HelloSign)’s developer surface includes engineering blog, authentication, sandbox, changelog, documentation, API reference, getting-started guide, and 35 more developer resources.

🌐 Visit website 📡 Source on GitHub

60.2/100 strong ▬ flat Agent 45/100 agent ready saas Full breakdown ↓
scored 2026-10-17 · rubric v0.24.0

2 published contracts 1 MCP Servers

Company E-Signature DocumentsDigital AgreementsSignature WorkflowEmbedded Signing Compliance

What this lets a business do 1

Business capabilities this provider's published APIs can perform, derived from its own contracts. Browse all capabilities →

Developer Platform & API Ecosystem Management

BC-4270

API App

POST /api_app GET /api_app/{client_id}

Kin Score

Kin Score How this is scored →
scored 2026-10-17 · rubric v0.24.0

Composite quality — 60.2/100 · strong

Contract Quality 11.0 / 19

Developer Ergonomics 10.1 / 15

Access Clarity 9.1 / 15

Operational Transparency 4.9 / 10

Contract Governance 1.6 / 9

Discoverability 5.6 / 8

Regulatory Posture 6.8 / 15

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 45/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 6 / 6

MCP Server 12 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 7 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 6 / 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 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 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 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/hellosign: 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 →

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.

Market	Position	Depth	Registered MCP server	Declares compatibility
Legal and E-Signature	long-tail	2.5 (thin)	-	-

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.

APIs 13

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

Dropbox Sign (HelloSign) Account API

{'$ref': './markdown/en/tags/account-tag-description.md'}

Dropbox Sign (HelloSign) Api App API

{'$ref': './markdown/en/tags/api-app-tag-description.md'}

Dropbox Sign (HelloSign) Bulk Send Job API

{'$ref': './markdown/en/tags/bulk-send-job-tag-description.md'}

Dropbox Sign (HelloSign) Embedded API

{'$ref': './markdown/en/tags/embedded-tag-description.md'}

Dropbox Sign (HelloSign) Fax API

The Fax API from Dropbox Sign (HelloSign) — 4 operation(s) for fax.

Dropbox Sign (HelloSign) Fax Line API

{'$ref': './markdown/en/tags/fax-lines-tag-description.md'}

Dropbox Sign (HelloSign) Report API

{'$ref': './markdown/en/tags/report-tag-description.md'}

Dropbox Sign (HelloSign) Signature Request API

{'$ref': './markdown/en/tags/signature-request-tag-description.md'}

Dropbox Sign (HelloSign) Team API

{'$ref': './markdown/en/tags/team-tag-description.md'}

Dropbox Sign (HelloSign) Template API

{'$ref': './markdown/en/tags/template-tag-description.md'}

Dropbox Sign (HelloSign) Unclaimed Draft API

{'$ref': './markdown/en/tags/unclaimed-draft-tag-description.md'}

Dropbox Sign (HelloSign) Callbacks and Events API

The Callbacks and Events API from Dropbox Sign (HelloSign) — 0 operation(s) for callbacks and events.

Dropbox Sign (HelloSign) O Auth API

{'$ref': './markdown/en/tags/oauth-tag-description.md'}

Scroll for all 13

Postman Collections 12

Ready-to-run Postman collections for exercising this provider's APIs.

Dropbox Sign Account API

POSTMAN

Dropbox Sign Account Api App API

POSTMAN

Dropbox Sign Account Bulk Send Job API

POSTMAN

Dropbox Sign Account Embedded API

POSTMAN

Dropbox Sign Account Fax API

POSTMAN

Dropbox Sign Account Fax Line API

POSTMAN

Dropbox Sign Account OAuth API

POSTMAN

Dropbox Sign Account Report API

POSTMAN

Dropbox Sign Account Signature Request API

POSTMAN

Dropbox Sign Account Team API

POSTMAN

Dropbox Sign Account Template API

POSTMAN

Dropbox Sign Account Unclaimed Draft API

POSTMAN

Scroll for all 12

Open Collections 13

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

API Collection

OPEN COLLECTION

Dropbox Sign Account API

OPEN COLLECTION

Dropbox Sign Account Api App API

OPEN COLLECTION

Dropbox Sign Account Bulk Send Job API

OPEN COLLECTION

Dropbox Sign Account Embedded API

OPEN COLLECTION

Dropbox Sign Account Fax API

OPEN COLLECTION

Dropbox Sign Account Fax Line API

OPEN COLLECTION

Dropbox Sign Account OAuth API

OPEN COLLECTION

Dropbox Sign Account Report API

OPEN COLLECTION

Dropbox Sign Account Signature Request API

OPEN COLLECTION

Dropbox Sign Account Team API

OPEN COLLECTION

Dropbox Sign Account Template API

OPEN COLLECTION

Dropbox Sign Account Unclaimed Draft API

OPEN COLLECTION

Scroll for all 13

MCP Servers 1

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

Dropbox Sign (HelloSign) MCP Server

Official hosted MCP server published by Dropbox Sign (formerly HelloSign) for AI client integration (Claude Code, Cursor, etc.), advertised in the docs llms.txt. Serves the Drop...

MCP SERVER

Event Specifications 2

AsyncAPI definitions for this provider's event-driven and streaming APIs.

Dropbox Sign Events and Callbacks

AsyncAPI description of the Dropbox Sign (formerly HelloSign) outbound event / callback surface. Dropbox Sign delivers event notifications by issuing HTTP POST requests to a sub...

ASYNCAPI

Hellosign Events Webhooks

ASYNCAPI

OpenAPI Overlays 1

Overlays applied on top of this provider's contracts. Each card says who wrote it: a document the provider publishes, or one API Evangelist derived or generated.

Hellosign Openapi Overlay

2 actions · update · hellosign-openapi-original.yaml

UNRECORDED

Security Posture 4

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

Hellosign Authentication

http · 2 schemes

SECURITY

Hellosign Domain Security

TLSv1.3 · DMARC

SECURITY

Hellosign Vulnerability Disclosure

Intigriti · security.txt · contact published

SECURITY

Hellosign Trust Center

HIPAA, ISO 9001, SOC (CPA/AICPA attestation), Skyhigh Enterprise-Ready

SECURITY

Scopes 1

OAuth scopes governing access to this provider's APIs.

Hellosign Scopes

7 scopes

SCOPES

Agentic Access 1

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

Hellosign Agentic Access

73 operations · 46 acting

AGENTIC

Resources

Get Started 4

Portal, sign-up, and the first successful call

Sandbox

DeveloperPortal

GettingStarted

SignUp

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 5

MCP servers, agent skills, and machine-readable catalogs

LlmsText

AgenticAccess

MCPServer

LLMsTxt

AgentSkill

Design & Contract 7

Pagination, idempotency, versioning, errors, and events

ErrorCatalog

Conventions

Lifecycle

Conformance

Webhooks

Components

DataModel

Scroll for all 7

Build 4

SDKs, sample code, and the tooling you integrate with

PostmanWorkspace

PostmanWorkspace

Packages

Packages

SDKs

SDKs

GitHubOrganization

GitHubOrganization

Access & Security 7

Authentication, authorization, and security posture

DomainSecurity

Authentication

OAuthScopes

Compliance

TrustCenter

VulnerabilityDisclosure

VulnerabilityDisclosure

Security

Security

Scroll for all 7

Operate 4

Status, limits, changes, and where to get help

StatusPage

Deprecation

ChangeLog

Support

Commercial 3

Pricing, plans, and the legal terms of use

Pricing

Pricing

TermsOfService

TermsOfService

PrivacyPolicy

PrivacyPolicy

Company 3

The organization behind the API

LinkedIn

Blog

Blog

Website

Website

Other 3

Properties that don't map to a standard resource type

CapabilityMap

CapabilityMap

ParentCompany

ParentCompany

Overlay

Overlay

Source (apis.yml)

aid: hellosign
name: Dropbox Sign (HelloSign)
description: Dropbox Sign (formerly HelloSign) is an eSignature platform whose v3 REST API lets developers send documents
  for legally binding electronic signature, build reusable templates, embed signing directly in their own apps, run bulk send
  jobs, and manage accounts, teams, and API apps. The API exposes 73 operations across 12 product areas (Signature Request,
  Template, Bulk Send, Embedded, Account, Team, Report, Fax, Fax Line, Unclaimed Draft, API App, OAuth), with API-key and
  OAuth 2.0 authentication, 23 webhook event types, official SDKs in six languages, and a published hosted documentation MCP
  server. HelloSign was a Y Combinator company (S11), acquired by Dropbox in 2019 and rebranded to Dropbox Sign in 2022; the
  API base host remains api.hellosign.com.
url: https://raw.githubusercontent.com/api-evangelist/hellosign/refs/heads/main/apis.yml
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
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  source:
  - authentication
  - scopes
  - security
  - sandbox
  generated: '2026-09-03'
  method: derived
image: https://github.com/hellosign.png
x-type: company
x-source: vc-portfolio
x-backed-by:
- y-combinator
x-tier: enriched
x-tier-reason: real-api-enriched
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-09-16'
x-docs-platform: fern
x-docs-platform-confidence: medium
x-docs-platform-checked: 2026-10-03
tags:
- Company
- E-Signature
- Documents
- Digital Agreements
- Signature Workflow
- Embedded Signing
- Compliance
tags_raw:
- Company
- eSignature
- Electronic Signatures
- Documents
- Digital Agreements
- Signature Workflow
- Embedded Signing
- Compliance
- Electronic Signature
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
apis:
- aid: hellosign:hellosign-account-api
  name: Dropbox Sign (HelloSign) Account API
  description: '{''$ref'': ''./markdown/en/tags/account-tag-description.md''}'
  humanURL: https://developers.hellosign.com/
  baseURL: https://api.hellosign.com/v3
  tags:
  - Account
  properties:
  - type: OpenAPI
    url: openapi/hellosign-account-api-openapi.yml
- aid: hellosign:hellosign-api-app-api
  name: Dropbox Sign (HelloSign) Api App API
  description: '{''$ref'': ''./markdown/en/tags/api-app-tag-description.md''}'
  humanURL: https://developers.hellosign.com/
  baseURL: https://api.hellosign.com/v3
  tags:
  - API App
  tags_raw:
  - Api App
  properties:
  - type: OpenAPI
    url: openapi/hellosign-api-app-api-openapi.yml
- aid: hellosign:hellosign-bulk-send-job-api
  name: Dropbox Sign (HelloSign) Bulk Send Job API
  description: '{''$ref'': ''./markdown/en/tags/bulk-send-job-tag-description.md''}'
  humanURL: https://developers.hellosign.com/
  baseURL: https://api.hellosign.com/v3
  tags:
  - Bulk Send Job
  properties:
  - type: OpenAPI
    url: openapi/hellosign-bulk-send-job-api-openapi.yml
- aid: hellosign:hellosign-embedded-api
  name: Dropbox Sign (HelloSign) Embedded API
  description: '{''$ref'': ''./markdown/en/tags/embedded-tag-description.md''}'
  humanURL: https://developers.hellosign.com/
  baseURL: https://api.hellosign.com/v3
  tags:
  - Embedded
  properties:
  - type: OpenAPI
    url: openapi/hellosign-embedded-api-openapi.yml
- aid: hellosign:hellosign-fax-api
  name: Dropbox Sign (HelloSign) Fax API
  description: The Fax API from Dropbox Sign (HelloSign) — 4 operation(s) for fax.
  humanURL: https://developers.hellosign.com/
  baseURL: https://api.hellosign.com/v3
  tags:
  - Fax
  properties:
  - type: OpenAPI
    url: openapi/hellosign-fax-api-openapi.yml
- aid: hellosign:hellosign-fax-line-api
  name: Dropbox Sign (HelloSign) Fax Line API
  description: '{''$ref'': ''./markdown/en/tags/fax-lines-tag-description.md''}'
  humanURL: https://developers.hellosign.com/
  baseURL: https://api.hellosign.com/v3
  tags:
  - Fax Line
  properties:
  - type: OpenAPI
    url: openapi/hellosign-fax-line-api-openapi.yml
- aid: hellosign:hellosign-report-api
  name: Dropbox Sign (HelloSign) Report API
  description: '{''$ref'': ''./markdown/en/tags/report-tag-description.md''}'
  humanURL: https://developers.hellosign.com/
  baseURL: https://api.hellosign.com/v3
  tags:
  - Report
  properties:
  - type: OpenAPI
    url: openapi/hellosign-report-api-openapi.yml
- aid: hellosign:hellosign-signature-request-api
  name: Dropbox Sign (HelloSign) Signature Request API
  description: '{''$ref'': ''./markdown/en/tags/signature-request-tag-description.md''}'
  humanURL: https://developers.hellosign.com/
  baseURL: https://api.hellosign.com/v3
  tags:
  - Signature Request
  properties:
  - type: OpenAPI
    url: openapi/hellosign-signature-request-api-openapi.yml
- aid: hellosign:hellosign-team-api
  name: Dropbox Sign (HelloSign) Team API
  description: '{''$ref'': ''./markdown/en/tags/team-tag-description.md''}'
  humanURL: https://developers.hellosign.com/
  baseURL: https://api.hellosign.com/v3
  tags:
  - Team
  properties:
  - type: OpenAPI
    url: openapi/hellosign-team-api-openapi.yml
- aid: hellosign:hellosign-template-api
  name: Dropbox Sign (HelloSign) Template API
  description: '{''$ref'': ''./markdown/en/tags/template-tag-description.md''}'
  humanURL: https://developers.hellosign.com/
  baseURL: https://api.hellosign.com/v3
  tags:
  - Templates
  tags_raw:
  - Template
  properties:
  - type: OpenAPI
    url: openapi/hellosign-template-api-openapi.yml
- aid: hellosign:hellosign-unclaimed-draft-api
  name: Dropbox Sign (HelloSign) Unclaimed Draft API
  description: '{''$ref'': ''./markdown/en/tags/unclaimed-draft-tag-description.md''}'
  humanURL: https://developers.hellosign.com/
  baseURL: https://api.hellosign.com/v3
  tags:
  - Unclaimed Draft
  properties:
  - type: OpenAPI
    url: openapi/hellosign-unclaimed-draft-api-openapi.yml
- aid: hellosign:hellosign-callbacks-and-events-api
  name: Dropbox Sign (HelloSign) Callbacks and Events API
  description: The Callbacks and Events API from Dropbox Sign (HelloSign) — 0 operation(s) for callbacks and events.
  humanURL: https://developers.hellosign.com/
  baseURL: https://api.hellosign.com/v3
  tags:
  - Callbacks and Events
  properties:
  - type: OpenAPI
    url: openapi/hellosign-callbacks-and-events-api-openapi.yml
  - type: AsyncAPI
    url: asyncapi/hellosign-events-asyncapi.yml
    x-moved-from: dropbox-sign (asyncapi/dropbox-sign-events-asyncapi.yml, consolidated 2026-10-14)
  - type: Documentation
    url: https://developers.hellosign.com/docs/events/overview/
- aid: hellosign:hellosign-oauth-api
  name: Dropbox Sign (HelloSign) O Auth API
  description: '{''$ref'': ''./markdown/en/tags/oauth-tag-description.md''}'
  humanURL: https://developers.hellosign.com/
  baseURL: https://api.hellosign.com/v3
  tags:
  - Authentication
  tags_raw:
  - OAuth
  properties:
  - type: OpenAPI
    url: openapi/hellosign-oauth-api-openapi.yml
common:
- type: LinkedIn
  url: https://www.linkedin.com/company/dropboxsign
  x-moved-from: dropbox-sign
- type: Blog
  url: https://sign.dropbox.com/blog
  x-moved-from: dropbox-sign
- type: LlmsText
  url: https://developers.hellosign.com/llms.txt
  x-moved-from: dropbox-sign
- type: CapabilityMap
  url: capabilities/hellosign-capability-edges.yml
  name: Dropbox Sign (HelloSign) Business Capability Map
- type: Website
  url: https://hellosign.com
- type: ParentCompany
  url: https://apis.io/providers/dropbox/
  name: Dropbox
  x-relationship: acquired
  x-evidence: HelloSign was a Y Combinator company (S11), acquired by Dropbox in 2019 and rebranded to Dropbox Sign in 2022;
    the API base host remains api.
- type: Overlay
  url: overlays/hellosign-openapi-overlay.yaml
- type: PostmanWorkspace
  url: https://www.postman.com/kinlaneapi/dropbox-sign-hellosign/overview
- type: AgenticAccess
  url: agentic-access/hellosign-agentic-access.yml
- type: DomainSecurity
  url: security/hellosign-domain-security.yml
- type: Authentication
  url: authentication/hellosign-authentication.yml
- type: OAuthScopes
  url: scopes/hellosign-scopes.yml
- type: MCPServer
  url: mcp/hellosign-mcp.yml
- type: LLMsTxt
  url: llms/hellosign-llms.txt
- type: Packages
  url: packages/hellosign-packages.yml
- type: SDKs
  url: packages/hellosign-packages.yml
- type: ErrorCatalog
  url: errors/hellosign-error-codes.yml
- type: Conventions
  url: conventions/hellosign-conventions.yml
- type: Lifecycle
  url: lifecycle/hellosign-lifecycle.yml
- type: StatusPage
  url: https://status.hellosign.com/
- type: Deprecation
  url: lifecycle/hellosign-lifecycle.yml
- type: Conformance
  url: conformance/hellosign-conformance.yml
- type: Compliance
  url: https://sign.dropbox.com/trust
- type: TrustCenter
  url: security/hellosign-trust-center.yml
- type: VulnerabilityDisclosure
  url: security/hellosign-vulnerability-disclosure.yml
- type: Security
  url: https://app.intigriti.com/programs/dropbox/dropbox-vdp
- type: Webhooks
  url: asyncapi/hellosign-events-webhooks.yml
- type: AgentSkill
  url: skills/_index.yml
- type: Sandbox
  url: sandbox/hellosign-sandbox.yml
- type: Components
  url: components/hellosign-components.yml
- type: DataModel
  url: data-model/hellosign-data-model.yml
- type: ChangeLog
  url: changelog/hellosign-changelog.yml
- type: DeveloperPortal
  url: https://developers.hellosign.com/
- type: Documentation
  url: https://developers.hellosign.com/docs/overview/
- type: APIReference
  url: https://developers.hellosign.com/api/reference/
- type: GettingStarted
  url: https://developers.hellosign.com/api/api-quickstart
- type: Support
  url: https://help.dropbox.com/sign
- type: GitHubOrganization
  url: https://github.com/hellosign
- type: Pricing
  url: https://sign.dropbox.com/products/api
- type: SignUp
  url: https://app.hellosign.com/account/signUp
- type: TermsOfService
  url: https://www.hellosign.com/terms
- type: PrivacyPolicy
  url: https://www.hellosign.com/privacy
x-enrichment:
  date: '2026-07-19'
  status: backfilled
  pass: local-v1
  note: backfilled from .gitignore signal + verified work evidence

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