/azure-active-directory-b2c

name: azure-active-directory-b2c
description: Expert knowledge for Azure Active Directory B2C development including troubleshooting, best practices, decision making, architecture & design patterns, limits & quotas, security, configuration, integrations & coding patterns, and deployment. Use when building B2C user flows/custom policies, configuring IdPs/MFA, securing APIs, automating CI/CD, or monitoring with Sentinel, and other Azure Active Directory B2C related development tasks. Not for Azure Role-based access control (use azure-rbac), Azure Information Protection (use azure-information-protection), Azure Security (use azure-security), Azure Sentinel (use azure-sentinel).
compatibility: Requires network access. Uses mcp_microsoftdocs:microsoft_docs_fetch or fetch_webpage to retrieve documentation.
metadata:
  generated_at: "2026-08-09"
  generator: "docs2skills/1.0.0"

Azure Active Directory B2C Skill

This skill provides expert guidance for Azure Active Directory B2C. Covers troubleshooting, best practices, decision making, architecture & design patterns, limits & quotas, security, configuration, integrations & coding patterns, and deployment. It combines local quick-reference content with remote documentation fetching capabilities.

How to Use This Skill

> **IMPORTANT for Agent**: Use the **Category Index** below to locate relevant sections. For categories with line ranges (e.g., `L35-L120`), use `read_file` with the specified lines. For categories with file links (e.g., `[security.md](security.md)`), use `read_file` on the linked reference file

> **IMPORTANT for Agent**: If `metadata.generated_at` is more than 3 months old, suggest the user pull the latest version from the repository. If `mcp_microsoftdocs` tools are not available, suggest the user install it: [Installation Guide](https://github.com/MicrosoftDocs/mcp/blob/main/README.md)

This skill requires **network access** to fetch documentation content:

• **Preferred**: Use `mcp_microsoftdocs:microsoft_docs_fetch` with query string `from=learn-agent-skill`. Returns Markdown.
• **Fallback**: Use `fetch_webpage` with query string `from=learn-agent-skill&accept=text/markdown`. Returns Markdown.

Category Index

| Category | Lines | Description | |----------|-------|-------------| | Troubleshooting | L37-L43 | Diagnosing and fixing Azure AD B2C errors, debugging custom policies and user flows, and using Application Insights to trace and troubleshoot policy execution. | | Best Practices | L44-L52 | Best practices for configuring Azure AD B2C, designing user flows/custom policies, securing MFA and architecture, and detecting/mitigating credential and account attacks. | | Decision Making | L53-L60 | Guidance on planning Azure AD B2C usage: choosing app types, understanding MAU billing, regions/data residency, retirement impact, and selecting a user migration strategy. | | Architecture & Design Patterns | L61-L69 | Global Azure AD B2C customer identity architectures, comparing funnel- vs region-based designs, and step-by-step proof-of-concept implementations for each pattern | | Limits & Quotas | L70-L77 | Service limits, quotas, and restrictions for Azure AD B2C tenants, including directory size, token formats/constraints, and tenant creation and scaling limits. | | Security | L78-L94 | Security hardening for Azure AD B2C: MFA, Conditional Access, Identity Protection, CAPTCHA, TLS/ciphers, policy keys, admin/tenant access control, API security, and Sentinel-based monitoring. | | Configuration | L95-L209 | Configuring Azure AD B2C: custom policies, user flows, tokens, MFA, identity providers, claims/transformations, app/API registration, UI/localization, SSO, security, and advanced auth options. | | Integrations & Coding Patterns | L210-L322 | Patterns and step-by-step guides for integrating Azure AD B2C into apps, securing APIs, configuring IdPs/social logins, custom policies, fraud/risk tools, and routing logs/monitoring. | | Deployment | L323-L327 | Automating deployment of Azure AD B2C custom policies using CI/CD pipelines, including setup steps, YAML examples, and best practices for Azure Pipelines and GitHub Actions. |

Troubleshooting

| Topic | URL | |-------|-----| | Azure AD B2C error codes and troubleshooting reference | https://learn.microsoft.com/en-us/azure/active-directory-b2c/error-codes | | Troubleshoot Azure AD B2C custom policies and user flows | https://learn.microsoft.com/en-us/azure/active-directory-b2c/troubleshoot | | Troubleshoot Azure AD B2C custom policies with Application Insights | https://learn.microsoft.com/en-us/azure/active-directory-b2c/troubleshoot-with-application-insights |

Best Practices

| Topic | URL | |-------|-----| | Apply Azure AD B2C integration and configuration best practices | https://learn.microsoft.com/en-us/azure/active-directory-b2c/best-practices | | Developer guidance for Azure AD B2C user flows and custom policies | https://learn.microsoft.com/en-us/azure/active-directory-b2c/custom-policy-developer-notes | | Secure phone-based MFA in Azure AD B2C using monitoring and alerts | https://learn.microsoft.com/en-us/azure/active-directory-b2c/phone-based-mfa | | Apply security best practices to Azure AD B2C architecture | https://learn.microsoft.com/en-us/azure/active-directory-b2c/security-architecture | | Mitigate credential attacks in Azure AD B2C | https://learn.microsoft.com/en-us/azure/active-directory-b2c/threat-management |

Decision Making

| Topic | URL | |-------|-----| | Choose appropriate application types for Azure AD B2C | https://learn.microsoft.com/en-us/azure/active-directory-b2c/application-types | | Understand Azure AD B2C MAU billing and tier selection | https://learn.microsoft.com/en-us/azure/active-directory-b2c/billing | | Plan Azure AD B2C region availability and data residency | https://learn.microsoft.com/en-us/azure/active-directory-b2c/data-residency | | Choose a user migration approach to Azure AD B2C | https://learn.microsoft.com/