Microsoft Code Reference

---
name: microsoft-code-reference
description: "Look up Microsoft API references, find working code samples, and verify SDK code is correct. USE FOR: Azure SDK method verification, .NET/Python package lookups, code sample discovery, error troubleshooting, catching hallucinated methods and deprecated patterns. DO NOT USE FOR: conceptual documentation (use microsoft-docs), skill creation (use microsoft-skill-creator), Bicep/Terraform module lookups (use azure-bicep-patterns or terraform-patterns)."
compatibility: Works with Microsoft Learn MCP Server (https://learn.microsoft.com/api/mcp). Can also use the mslearn CLI as a fallback.
license: MIT
metadata:
  author: microsoftdocs
  version: "1.0"
  category: code-verification
---

# Microsoft Code Reference

Verify SDK code against official Microsoft documentation. Catches hallucinated
methods, wrong signatures, and deprecated patterns by querying live docs.

## Tools

| Need                    | Tool                           | Example                                                                 |
| ----------------------- | ------------------------------ | ----------------------------------------------------------------------- |
| API method/class lookup | `microsoft_docs_search`        | `"BlobClient UploadAsync Azure.Storage.Blobs"`                          |
| Working code sample     | `microsoft_code_sample_search` | `query: "upload blob managed identity", language: "python"`             |
| Full API reference      | `microsoft_docs_fetch`         | Fetch URL from `microsoft_docs_search` (for overloads, full signatures) |

## Finding Code Samples

Use `microsoft_code_sample_search` to get official, working examples:

```text
microsoft_code_sample_search(query: "upload file to blob storage", language: "csharp")
microsoft_code_sample_search(query: "authenticate with managed identity", language: "python")
microsoft_code_sample_search(query: "send message service bus", language: "javascript")
```

**When to use:**

- Before writing code — find a working pattern to follow
- After errors — compare your code against a known-good sample
- Unsure of initialization/setup — samples show complete context

## API Lookups

```text
# Verify method exists (include namespace for precision)
"BlobClient UploadAsync Azure.Storage.Blobs"
"GraphServiceClient Users Microsoft.Graph"

# Find class/interface
"DefaultAzureCredential class Azure.Identity"

# Find correct package
"Azure Blob Storage NuGet package"
"azure-storage-blob pip package"
```

Fetch full page when method has multiple overloads or you need complete parameter details.

## Error Troubleshooting

Use `microsoft_code_sample_search` to find working code samples and compare
with your implementation. For specific errors, use `microsoft_docs_search`
and `microsoft_docs_fetch`:

| Error Type         | Query                                          |
| ------------------ | ---------------------------------------------- |
| Method not found   | `"[ClassName] methods [Namespace]"`            |
| Type not found     | `"[TypeName] NuGet package namespace"`         |
| Wrong signature    | `"[ClassName] [MethodName] overloads"` → fetch |
| Deprecated warning | `"[OldType] migration v12"`                    |
| Auth failure       | `"DefaultAzureCredential troubleshooting"`     |
| 403 Forbidden      | `"[ServiceName] RBAC permissions"`             |

## When to Verify

Always verify when:

- Method name seems "too convenient" (`UploadFile` vs actual `Upload`)
- Mixing SDK versions (v11 `CloudBlobClient` vs v12 `BlobServiceClient`)
- Package name doesn't follow conventions (`Azure.*` for .NET, `azure-*` for Python)
- Using an API for the first time

## Validation Workflow

Before generating code using Microsoft SDKs, verify it's correct:

1. **Confirm method or package exists** — `microsoft_docs_search(query: "[ClassName] [MethodName] [Namespace]")`
2. **Fetch full details** (for overloads/complex params) — `microsoft_docs_fetch(url: "...")`
3. **Find working sample** — `microsoft_code_sample_search(query: "[task]", language: "[lang]")`

For simple lookups, step 1 alone may suffice. For complex API usage, complete all three steps.

## CLI Alternative

If the Learn MCP server is not available, use the `mslearn` CLI via Bash instead:

```bash
# Run directly (no install needed)
npx @microsoft/learn-cli search "BlobClient UploadAsync Azure.Storage.Blobs"

# Or install globally, then run
npm install -g @microsoft/learn-cli
mslearn search "BlobClient UploadAsync Azure.Storage.Blobs"
```

| MCP Tool                                                      | CLI Command                                |
| ------------------------------------------------------------- | ------------------------------------------ |
| `microsoft_docs_search(query: "...")`                         | `mslearn search "..."`                     |
| `microsoft_code_sample_search(query: "...", language: "...")` | `mslearn code-search "..." --language ...` |
| `microsoft_docs_fetch(url: "...")`                            | `mslearn fetch "..."`                      |

Pass `--json` to `search` or `code-search` to get raw JSON output for further processing.