API Security Testing Services
Assess the controls behind web, mobile and partner integrations. SignX's in-house team supports REST, GraphQL and SOAP API testing, with identities, roles, workflows, environments and safety limits defined for each engagement.
- Clarify risk across business-critical integrations
- Help engineers prioritize confirmed API weaknesses
- Support launch, partner and customer security reviews
For teams whose products depend on connected services
The assessment is intended for product and engineering teams that need a defined review of APIs serving users, partners or internal systems. SignX supports remote security assessments for international clients, subject to technical feasibility and agreed engagement scope.
SaaS platforms
Teams exposing internal, partner or public APIs across role-aware or tenant-aware products.
Mobile backends
Products whose critical identity, data and transaction controls depend on backend services.
Connected ecosystems
Businesses adding third-party integrations or new REST, GraphQL or SOAP API consumers.
Release readiness
Engineering teams preparing a material API release or responding to a customer security review.
API findings connected to business-critical workflows
A defined assessment gives product and engineering teams a clearer view of API risk while keeping coverage tied to named interfaces and approved test data.
Trust-boundary clarity
Show where identities, roles, objects and services cross the interfaces selected for review.
Actionable evidence
Give engineers appropriately redacted technical context for confirmed findings.
Integration readiness
Inform release, partner-integration and customer-review decisions without treating testing as certification.
API testing protocols
SignX's in-house security team supports REST, GraphQL and SOAP testing. Every engagement names the exact versions, operations and test boundaries.
REST APIs
Testing of approved REST endpoints, authentication flows and business operations within the written scope.
GraphQL APIs
Testing of approved GraphQL operations and access boundaries within the agreed schema and environment.
SOAP APIs
Testing of approved SOAP services, operations and message handling within the agreed boundary.
Delivered by SignX's in-house security team
API assessment activities
These activities are available capabilities. Exact interfaces, roles, workflows and safety limits are selected in the written scope and quotation.
API authentication
Assessment of authentication controls for approved API consumers.
Token handling and lifecycle
Assessment of approved token issuance, use, expiry and related lifecycle behavior.
Object and function authorization
Assessment of object-level and function-level access controls.
Role and tenant separation
Assessment of approved role and tenant boundaries.
Data exposure
Assessment of unintended data exposure through approved interfaces.
Business workflows
Assessment of documented API business workflows within permitted test actions.
Available activities are selected in the written scope and quotation
Controls that cannot be understood from an endpoint list alone
The final scope determines what is tested. These areas show the kinds of API risk an authorized, system-specific engagement may examine.
Object authorization
Access to records or resources across users, roles or tenant boundaries.
Function authorization
Administrative or privileged operations exposed to the wrong identity or consumer.
Authentication and tokens
Credential, token lifecycle and session behavior across approved authentication flows.
Data and properties
Excessive data exposure or unsafe handling of client-controlled object properties.
Rate-control safeguards
Rate-control behavior only when explicitly authorized and protected by agreed availability safeguards; load, stress and denial-of-service testing are excluded.
Role and tenant separation
Access boundaries between approved roles, consumers and tenants.
Interfaces, identities and trust boundaries defined in writing
REST, GraphQL and SOAP are supported. Environments, base URLs, versions, operations, roles, tenant boundaries and permitted test data are agreed before testing. Webhooks, asynchronous interfaces and source-code review are not included. Browser and mobile clients require their own scope.
Interfaces and versions
Approved REST, GraphQL or SOAP interfaces, versions, operations and environments selected during scoping.
Identities and roles
Authentication methods, test credentials, consumer types and tenant or privilege boundaries supplied for review.
Business workflows
Documented sensitive actions and abuse cases that can be exercised safely with approved test data.
Explicit limitations
Excluded clients, dependencies, rate-sensitive operations, prohibited actions and untested trust relationships.
From interface inventory to engineering readout
A practical sequence keeps role coverage visible, protects sensitive evidence and separates confirmed findings from assumptions.
Inventory
Confirm interfaces, versions, consumers and trust boundaries.
Authorize access
Agree roles, credentials, test data and prohibited actions.
Exercise controls
Review authentication, token handling, authorization, data exposure and approved business flows.
Validate
Confirm suspected findings and protect sensitive evidence.
Report and read out
Prioritize findings and review remediation with engineers.
Agree retesting
Retesting arrangements, including scope, timing and any applicable fees, are agreed as part of the project quotation.
Standard assessment deliverables
Seven standard deliverables for each scoped assessment
Severity model: CVSS 4.0 + Business Context. CVSS v4.0 is applied to technical vulnerabilities when it is suitable and supported by the available evidence. Technical severity, affected assets and exploit conditions are recorded separately from business impact, asset criticality and remediation priority. When CVSS is unsuitable or the evidence is insufficient, the report uses a reasoned qualitative severity and clearly states its basis.
- Executive summary for business and technical stakeholders
- Documented assessment scope, exclusions, environments, dates and testing limitations
- Validated technical findings with appropriately redacted supporting evidence
- Severity ratings and business-risk prioritization using the approved CVSS 4.0 + Business Context model where applicable
- Actionable remediation recommendations
- Technical assessment report and client readout session
- Retesting arrangements documented according to the project's agreed scope and quotation
Questions before an API assessment
The answers keep client interfaces, test modes and coverage boundaries explicit without implying certification or guaranteed security.
Which API protocols does SignX test?
SignX's in-house team supports REST, GraphQL and SOAP APIs. Webhooks, asynchronous interfaces and source-code review are not included in this service.
Does API testing include the web or mobile interface?
Not automatically. The API, web application and mobile application should have explicit boundaries so the included layers are clear.
Can rate-control behavior be assessed?
Only when it is explicitly authorized and availability safeguards are agreed. API security testing does not include load, stress or denial-of-service testing.
Will the assessment certify an API as secure?
No. The report describes findings within the agreed scope and time period. It is not a certification or a guarantee that no vulnerability exists.
Connect API findings to the products they support
Existing SignX software services remain the primary offer. These links provide engineering context without implying that assessment work is bundled.
Custom Software Development
Plan, build and evolve connected business applications.
Explore service02SaaS Application Development
Build role-aware SaaS products and operational platforms.
Explore service03Web Application Development
Develop custom web platforms, portals and connected systems.
Explore serviceDiscuss your API security assessment
Share the interfaces, environments, authentication methods and roles you need reviewed. We will use that information to prepare a written scope and quotation.