Tessian

Tessian, now part of Proofpoint, is an AI-powered email security platform that protects against inbound threats (phishing and impersonation), accidental data loss, and deliberate data exfiltration across its Defender, Guardian, Enforcer, Architect, and Constructor modules. The Tessian API is a RESTful, JSON, read-oriented interface that exports security-event, anomaly, company-risk, user-monitoring, audit-log, and trigger data into SIEMs and other data-management tools. It authenticates with a static API token, paginates by checkpoint, and returns ISO 8601 UTC timestamps.

Tessian publishes 10 APIs on the APIs.io network, including Anomalies API, Audits API, Beta Endpoints API, and 7 more. Tagged areas include Company, Enterprise, Email Security, Cybersecurity, and Data Loss Prevention.

Tessian’s developer surface includes documentation, API reference, authentication, support, and 15 more developer resources.

🌐 Visit website 📡 Source on GitHub
36.7/100 thin ▬ flat Agent 65/100 agent native Full breakdown ↓
scored 2026-07-27 · rubric v0.5
AccessSelf serve
10 APIs 1 MCP Servers
CompanyEnterpriseEmail SecurityCybersecurityData Loss PreventionSIEMSecurityPhishing

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-07-27 · rubric v0.5
Composite quality — 36.7/100 · thin
Contract Quality 13.1 / 25
Developer Ergonomics 10.9 / 20
Commercial Clarity 2.1 / 20
Operational Transparency 0.7 / 13
Governance 0.0 / 12
Discoverability 10.0 / 10
Agent readiness — 65/100 · agent native
Machine-Readable Contract 18 / 18
Agentic Access Contract 15 / 15
MCP Server 12 / 12
Machine-Readable Auth 10 / 10
Idempotency 0 / 9
Stable Error Semantics 8 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 0 / 7
Typed Event Surface 0 / 6
Agent Skills 5 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/tessian: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 10

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

Tessian Anomalies API

Endpoints in this section detail anomalous user activity that has been detected by the system, where anomalous activity is defined as users sending unusual numbers of sensitive ...

Tessian Audits API

Endpoints in this section allow you to access audit information of usage and changes made to your Tessian Products.

Tessian Beta Endpoints API

The Beta Endpoints API from Tessian — 1 operation(s) for beta endpoints.

Tessian Deprecated API

**⚠️ These endpoints are marked as deprecated and will be going away soon.** You should look to migrate away from using the endpoints in this section as they are no longer maint...

Tessian Endpoints API

The Endpoints API from Tessian — 9 operation(s) for endpoints.

Tessian Events API

Endpoints in this section allow you to access security events from Tessian.

Tessian Groups API

Groups are named collections of email addresses; their members may be specified either by specific address, or by a wildcard including all addresses in an entire domain.

Tessian Monitoring API

Endpoints in this section provide ways to monitor information in Tessian.

Tessian Risk API

Endpoints in this section expose risk drivers, which are the underlying components for the Tessian combined Risk Score.

Tessian Triggers API

The Triggers API from Tessian — 1 operation(s) for triggers.

Scroll for all 10

MCP Servers 1

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

tessian-mcp.yml

MCP SERVER

Security Posture 2

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

Tessian Authentication

apiKey · 1 scheme

SECURITY

Tessian Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Agentic Access 1

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

Tessian Agentic Access

13 operations · 5 acting

13 operations · 5 acting

AGENTIC

Resources

Get Started 1

Portal, sign-up, and the first successful call

DeveloperPortal
DeveloperPortal

Documentation 2

Reference material describing how the API behaves

Documentation
Documentation
 APIReference
APIReference

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

MCPServer
MCPServer
 LLMsTxt
LLMsTxt
 AgentSkill
AgentSkill
 AgenticAccess
AgenticAccess

Design & Contract 5

Pagination, idempotency, versioning, errors, and events

Conventions
Conventions
 ErrorCatalog
ErrorCatalog
 Conformance
Conformance
 DataModel
DataModel
 Lifecycle
Lifecycle

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrganization
GitHubOrganization

Access & Security 2

Authentication, authorization, and security posture

Authentication
Authentication
 DomainSecurity
DomainSecurity

Operate 1

Status, limits, changes, and where to get help

Support
Support

Commercial 1

Pricing, plans, and the legal terms of use

TermsOfService
TermsOfService

Company 1

The organization behind the API

Website
Website

Other 1

Properties that don't map to a standard resource type

Overlay
Overlay

Source (apis.yml)

apis.yml Raw ↑ 
aid: tessian
accessModel:
  pricing: unknown
  onboarding: self-serve
  trial: false
  try_now: false
  public: false
  label: Self-serve signup
  confidence: medium
  source:
  - authentication
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/tessian.png
name: Tessian
description: Tessian, now part of Proofpoint, is an AI-powered email security platform that protects against inbound threats
  (phishing and impersonation), accidental data loss, and deliberate data exfiltration across its Defender, Guardian, Enforcer,
  Architect, and Constructor modules. The Tessian API is a RESTful, JSON, read-oriented interface that exports security-event,
  anomaly, company-risk, user-monitoring, audit-log, and trigger data into SIEMs and other data-management tools. It authenticates
  with a static API token, paginates by checkpoint, and returns ISO 8601 UTC timestamps.
url: https://raw.githubusercontent.com/api-evangelist/tessian/refs/heads/main/apis.yml
x-type: company
x-source: vc-portfolio
x-backed-by:
- accel
- balderton-capital
x-tier: stub
x-tier-reason: portfolio-lead
specificationVersion: '0.20'
created: '2026-07-17'
modified: '2026-07-21'
tags:
- Company
- Enterprise
- Email Security
- Cybersecurity
- Data Loss Prevention
- SIEM
- Security
- Phishing
apis:
- aid: tessian:tessian-anomalies-api
  name: Tessian Anomalies API
  description: Endpoints in this section detail anomalous user activity that has been detected by the system, where anomalous
    activity is defined as users sending unusual numbers of sensitive emails to unauthorized addresses compared to their normal
    behaviour.
  humanURL: https://developer.tessian.com/documentation/api/index.html
  baseURL: https://your-domain.tessian-platform.com
  tags:
  - Anomalies
  properties:
  - type: OpenAPI
    url: openapi/tessian-anomalies-api-openapi.yml
  - type: Documentation
    url: https://developer.tessian.com/documentation/api/index.html
  - type: APIReference
    url: https://developer.tessian.com/documentation/api/index.html
- aid: tessian:tessian-audits-api
  name: Tessian Audits API
  description: Endpoints in this section allow you to access audit information of usage and changes made to your Tessian Products.
  humanURL: https://developer.tessian.com/documentation/api/index.html
  baseURL: https://your-domain.tessian-platform.com
  tags:
  - Audits
  properties:
  - type: OpenAPI
    url: openapi/tessian-audits-api-openapi.yml
  - type: Documentation
    url: https://developer.tessian.com/documentation/api/index.html
  - type: APIReference
    url: https://developer.tessian.com/documentation/api/index.html
- aid: tessian:tessian-beta-endpoints-api
  name: Tessian Beta Endpoints API
  description: The Beta Endpoints API from Tessian — 1 operation(s) for beta endpoints.
  humanURL: https://developer.tessian.com/documentation/api/index.html
  baseURL: https://your-domain.tessian-platform.com
  tags:
  - Beta Endpoints
  properties:
  - type: OpenAPI
    url: openapi/tessian-beta-endpoints-api-openapi.yml
  - type: Documentation
    url: https://developer.tessian.com/documentation/api/index.html
  - type: APIReference
    url: https://developer.tessian.com/documentation/api/index.html
- aid: tessian:tessian-deprecated-api
  name: Tessian Deprecated API
  description: '**⚠️ These endpoints are marked as deprecated and will be going away soon.**


    You should look to migrate away from using the endpoints in this section as they are no longer maintained. Timelines for
    removal, and migration guides are available against each endpoint.'
  humanURL: https://developer.tessian.com/documentation/api/index.html
  baseURL: https://your-domain.tessian-platform.com
  tags:
  - Deprecated
  properties:
  - type: OpenAPI
    url: openapi/tessian-deprecated-api-openapi.yml
  - type: Documentation
    url: https://developer.tessian.com/documentation/api/index.html
  - type: APIReference
    url: https://developer.tessian.com/documentation/api/index.html
- aid: tessian:tessian-endpoints-api
  name: Tessian Endpoints API
  description: The Endpoints API from Tessian — 9 operation(s) for endpoints.
  humanURL: https://developer.tessian.com/documentation/api/index.html
  baseURL: https://your-domain.tessian-platform.com
  tags:
  - Endpoints
  properties:
  - type: OpenAPI
    url: openapi/tessian-endpoints-api-openapi.yml
  - type: Documentation
    url: https://developer.tessian.com/documentation/api/index.html
  - type: APIReference
    url: https://developer.tessian.com/documentation/api/index.html
- aid: tessian:tessian-events-api
  name: Tessian Events API
  description: Endpoints in this section allow you to access security events from Tessian.
  humanURL: https://developer.tessian.com/documentation/api/index.html
  baseURL: https://your-domain.tessian-platform.com
  tags:
  - Events
  properties:
  - type: OpenAPI
    url: openapi/tessian-events-api-openapi.yml
  - type: Documentation
    url: https://developer.tessian.com/documentation/api/index.html
  - type: APIReference
    url: https://developer.tessian.com/documentation/api/index.html
- aid: tessian:tessian-groups-api
  name: Tessian Groups API
  description: Groups are named collections of email addresses; their members may be specified either by specific address,
    or by a wildcard including all addresses in an entire domain.
  humanURL: https://developer.tessian.com/documentation/api/index.html
  baseURL: https://your-domain.tessian-platform.com
  tags:
  - Groups
  properties:
  - type: OpenAPI
    url: openapi/tessian-groups-api-openapi.yml
  - type: Documentation
    url: https://developer.tessian.com/documentation/api/index.html
  - type: APIReference
    url: https://developer.tessian.com/documentation/api/index.html
- aid: tessian:tessian-monitoring-api
  name: Tessian Monitoring API
  description: Endpoints in this section provide ways to monitor information in Tessian.
  humanURL: https://developer.tessian.com/documentation/api/index.html
  baseURL: https://your-domain.tessian-platform.com
  tags:
  - Monitoring
  properties:
  - type: OpenAPI
    url: openapi/tessian-monitoring-api-openapi.yml
  - type: Documentation
    url: https://developer.tessian.com/documentation/api/index.html
  - type: APIReference
    url: https://developer.tessian.com/documentation/api/index.html
- aid: tessian:tessian-risk-api
  name: Tessian Risk API
  description: Endpoints in this section expose risk drivers, which are the underlying components for the Tessian combined
    Risk Score.
  humanURL: https://developer.tessian.com/documentation/api/index.html
  baseURL: https://your-domain.tessian-platform.com
  tags:
  - Risk
  properties:
  - type: OpenAPI
    url: openapi/tessian-risk-api-openapi.yml
  - type: Documentation
    url: https://developer.tessian.com/documentation/api/index.html
  - type: APIReference
    url: https://developer.tessian.com/documentation/api/index.html
- aid: tessian:tessian-triggers-api
  name: Tessian Triggers API
  description: The Triggers API from Tessian — 1 operation(s) for triggers.
  humanURL: https://developer.tessian.com/documentation/api/index.html
  baseURL: https://your-domain.tessian-platform.com
  tags:
  - Triggers
  properties:
  - type: OpenAPI
    url: openapi/tessian-triggers-api-openapi.yml
  - type: Documentation
    url: https://developer.tessian.com/documentation/api/index.html
  - type: APIReference
    url: https://developer.tessian.com/documentation/api/index.html
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: DeveloperPortal
  url: https://developer.tessian.com/
- type: Documentation
  url: https://developer.tessian.com/documentation/api/index.html
- type: APIReference
  url: https://developer.tessian.com/documentation/api/index.html
- type: Authentication
  url: authentication/tessian-authentication.yml
- type: Conventions
  url: conventions/tessian-conventions.yml
- type: ErrorCatalog
  url: errors/tessian-problem-types.yml
- type: Conformance
  url: conformance/tessian-conformance.yml
- type: DataModel
  url: data-model/tessian-data-model.yml
- type: Lifecycle
  url: lifecycle/tessian-lifecycle.yml
- type: MCPServer
  url: mcp/tessian-mcp.yml
- type: LLMsTxt
  url: llms/tessian-llms.txt
- type: Overlay
  url: overlays/tessian-openapi-overlay.yaml
- type: AgentSkill
  url: skills/_index.yml
- type: AgenticAccess
  url: agentic-access/tessian-agentic-access.yml
- type: DomainSecurity
  url: security/tessian-domain-security.yml
- type: GitHubOrganization
  url: https://github.com/tessian
- type: TermsOfService
  url: https://www.proofpoint.com/us/legal/api-terms-of-use
- type: Support
  url: mailto:support@tessian.com
- type: Website
  url: https://www.tessian.com
x-enrichment:
  date: '2026-07-21'
  status: enriched
  artifacts_added: 14
  pass: local-v1