c/side website screenshot

c/side

c/side (cside) is a client-side security platform that detects script attacks, AI agents, account takeover, and fraud at the browser layer. It provides active runtime detection that watches what third-party scripts, users, and agents actually do as they execute in the live browser session, in real time, rather than relying on static scans or block-lists, and it automates PCI DSS 4.0.1 requirements 6.4.3 and 11.6.1 (validated by a VikingCloud QSA). cside deploys as a single JavaScript snippet with no proxy and no DNS changes, and was the first client-side security product with integrated AI analysis. The platform protects websites from malicious third-party scripts, e-skimming, Magecart, and supply chain attacks, and adds device fingerprinting (102+ signals), VPN/bot/AI-agent detection, chargeback evidence, and privacy monitoring for GDPR, CCPA, and HIPAA. Founded in 2024 and backed by Uncork Capital, cside integrates via a CLI, Next.js and Vite plugins, a manual script tag, and Salesforce Lightning, and sends security alerts through webhook, S3, and Jira/Linear notification endpoints. cside publishes an llms.txt, a public read-only MCP server, and a Trust Center covering SOC 2 Type II, PCI SAQ-D, and ISO 27001.

c/side is profiled on the APIs.io network. Tagged areas include Company, Security, Client-Side Security, Application Security, and Fraud Prevention.

The c/side catalog on APIs.io includes 1 event-driven AsyncAPI specification.

c/side’s developer surface includes documentation, getting-started guide, engineering blog, pricing, signup flow, CLI, changelog, and 21 more developer resources.

46.2/100 developing ▬ flat Agent 33/100 agent aware Full breakdown ↓
scored 2026-08-20 · rubric v0.12.0
0 APIs 1 MCP Servers
CompanySecurityClient-Side SecurityApplication SecurityFraud PreventionPCI DSS ComplianceDevice FingerprintingBot DetectionWeb SecurityScript Monitoring

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-08-20 · rubric v0.12.0
Composite quality — 46.2/100 · developing
Contract Quality 9.6 / 21
Developer Ergonomics 8.9 / 17
Access Clarity 6.3 / 17
Operational Transparency 5.8 / 11
Contract Governance 1.9 / 10
Discoverability 5.8 / 9
Regulatory Posture 6.1 / 15
Agent readiness — 33/100 · agent aware
Machine-Readable Contract 18 / 18
Agentic Access Contract 0 / 10
Documented Reversibility 0 / 6
MCP Server 12 / 12
Machine-Readable Auth 0 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 0 / 7
Typed Event Surface 6 / 6
Agent Skills 0 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 3 / 3
A2A Agent Card 0 / 8
Dry-Run / Simulate Mode 0 / 4
Regulatory Posture applies to this provider. Its tags matched the Payments 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.
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/.
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/c-side: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

MCP Servers 1

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

c/side MCP Server

cside operates a public, read-only remote MCP (Model Context Protocol) server at https://mcp.cside.com that exposes cside.com marketing-site and docs.cside.com documentation con...

MCP SERVER

Event Specifications 1

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

C Side Webhooks

ASYNCAPI

Security Posture 3

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

C Side Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

C Side Vulnerability Disclosure

security.txt · contact published

SECURITY

C Side Trust Center

SOC 2 Type II, PCI DSS (SAQ-D AOC), ISO 27001 (in progress), GDPR

SECURITY

Resources

Get Started 3

Portal, sign-up, and the first successful call

Documentation 1

Reference material describing how the API behaves

Agent Surfaces 3

MCP servers, agent skills, and machine-readable catalogs

Design & Contract 4

Pagination, idempotency, versioning, errors, and events

Build 4

SDKs, sample code, and the tooling you integrate with

Access & Security 6

Authentication, authorization, and security posture

Operate 3

Status, limits, changes, and where to get help

Commercial 2

Pricing, plans, and the legal terms of use

Company 2

The organization behind the API

Source (apis.yml)

apis.yml Raw ↑
aid: c-side
name: c/side
description: c/side (cside) is a client-side security platform that detects script attacks, AI agents, account takeover, and
  fraud at the browser layer. It provides active runtime detection that watches what third-party scripts, users, and agents
  actually do as they execute in the live browser session, in real time, rather than relying on static scans or block-lists,
  and it automates PCI DSS 4.0.1 requirements 6.4.3 and 11.6.1 (validated by a VikingCloud QSA). cside deploys as a single
  JavaScript snippet with no proxy and no DNS changes, and was the first client-side security product with integrated AI analysis.
  The platform protects websites from malicious third-party scripts, e-skimming, Magecart, and supply chain attacks, and adds
  device fingerprinting (102+ signals), VPN/bot/AI-agent detection, chargeback evidence, and privacy monitoring for GDPR,
  CCPA, and HIPAA. Founded in 2024 and backed by Uncork Capital, cside integrates via a CLI, Next.js and Vite plugins, a manual
  script tag, and Salesforce Lightning, and sends security alerts through webhook, S3, and Jira/Linear notification endpoints.
  cside publishes an llms.txt, a public read-only MCP server, and a Trust Center covering SOC 2 Type II, PCI SAQ-D, and ISO
  27001.
url: https://raw.githubusercontent.com/api-evangelist/c-side/refs/heads/main/apis.yml
x-type: company
x-source: vc-portfolio
x-backed-by:
- uncork-capital
x-tier: stub
x-tier-reason: portfolio-lead
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  source: []
  generated: '2026-07-22'
  method: derived
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-07-18'
image: https://og.cside.com/?title=cside%2C%20Client-Side%20Security%20%26%20Browser%20Fraud%20Prevention
tags:
- Company
- Security
- Client-Side Security
- Application Security
- Fraud Prevention
- PCI DSS Compliance
- Device Fingerprinting
- Bot Detection
- Web Security
- Script Monitoring
apis: []
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: Website
  url: https://cside.com
- type: DeveloperPortal
  url: https://docs.cside.com
- type: Documentation
  url: https://docs.cside.com
- type: GettingStarted
  url: https://docs.cside.com/quickstart
- type: Blog
  url: https://cside.com/blog
- type: Pricing
  url: https://cside.com/pricing
- type: SignUp
  url: https://dash.cside.com/auth/signup
- type: PrivacyPolicy
  url: https://cside.com/privacy-policy
- type: HelpCenter
  url: https://cside.com/faq
- type: GitHubOrganization
  url: https://github.com/client-side-dev
- type: MCPServer
  url: mcp/c-side-mcp.yml
- type: LLMsTxt
  url: llms/c-side-llms.txt
- type: Packages
  url: packages/c-side-packages.yml
- type: SDKs
  url: packages/c-side-packages.yml
- type: CLI
  url: cli/c-side-cli.yml
- type: Components
  url: components/c-side-components.yml
- type: WellKnown
  url: well-known/c-side-well-known.yml
- type: SecurityTxt
  url: well-known/c-side-security.txt
- type: Webhooks
  url: asyncapi/c-side-webhooks.yml
- type: ChangeLog
  url: changelog/c-side-changelog.yml
- type: Lifecycle
  url: lifecycle/c-side-lifecycle.yml
- type: StatusPage
  url: https://status.cside.com
- type: Conformance
  url: conformance/c-side-conformance.yml
- type: Compliance
  url: https://trust.cside.com
- type: TrustCenter
  url: security/c-side-trust-center.yml
- type: VulnerabilityDisclosure
  url: security/c-side-vulnerability-disclosure.yml
- type: Security
  url: https://cside.com/security
- type: DomainSecurity
  url: security/c-side-domain-security.yml
x-enrichment:
  date: '2026-07-19'
  status: backfilled
  pass: local-v1
  note: backfilled from .gitignore signal + verified work evidence