Migrating Bond Interfaces

Microsoft.Bond.Interfaces to Bond.CSharp Migration

Overview

Migrate from the legacy Microsoft.Bond.Interfaces package to the unified Bond.CSharp SDK. Microsoft.Bond.Interfaces provided a subset of Bond types (interfaces and base classes) without the full runtime or compiler. Bond.CSharp is the consolidated package that bundles Bond.Core, Bond.IO, Bond.JSON, Bond.Reflection, and the gbc schema compiler, providing everything needed for Bond serialization on modern .NET.

Package Reference Changes

Old References (Remove)

<PackageReference Include="Microsoft.Bond.Interfaces" Version="*" />
<!-- Also remove if present — these are replaced by Bond.CSharp -->
<PackageReference Include="Microsoft.Bond" Version="*" />
<PackageReference Include="Microsoft.Bond.Core.CSharp" Version="*" />

New Reference (Add)

<!-- Unified package: includes runtime, IO, JSON, reflection, and gbc compiler -->
<PackageReference Include="Bond.CSharp" Version="{latest-stable}" />

Workflow

Migration Progress:
- [ ] Step 1: Detect Bond usage
- [ ] Step 2: Update package references
- [ ] Step 3: Regenerate schema code (if applicable)
- [ ] Step 4: Update namespace references
- [ ] Step 5: Handle API differences
- [ ] Step 6: Build and verify

Step 1: Detect Bond Usage

Scan the project for:

• using Bond; and using Bond.IO; statements
• using Microsoft.Bond; statements (old namespace)
• References to Bond types: IBonded<T>, Bonded<T>, BondDataType, schema-attributed structs
• .bond schema files in the project
• Generated _types.cs or _grpc.cs files from the gbc compiler

Step 2: Update Package References

Remove Microsoft.Bond.Interfaces, Microsoft.Bond, and Microsoft.Bond.Core.CSharp package references. Add Bond.CSharp in the project file.

Bond.CSharp includes MSBuild targets that automatically compile .bond schema files during build. If the project previously used a manual gbc invocation, the build-integrated compiler may replace it.

Step 3: Regenerate Schema Code (If Applicable)

If the project contains .bond schema files:

• Remove previously generated C# files (typically *_types.cs, *_grpc.cs)
• Ensure .bond files are included in the project (Bond.CSharp auto-discovers them)
• Build the project — Bond.CSharp runs gbc automatically and generates fresh code

If the project only consumes pre-generated Bond types without .bond files, skip this step.

Step 4: Update Namespace References

| Old Namespace | New Namespace |

|---------------|---------------|

| Microsoft.Bond | Bond |

| Microsoft.Bond.IO | Bond.IO |

| Microsoft.Bond.Tag | Bond.Tag |

Most types keep the same name — only the root namespace prefix changes from Microsoft.Bond to Bond.

Step 5: Handle API Differences

The core Bond types are largely the same, but some patterns differ:

| Old (Microsoft.Bond.Interfaces) | New (Bond.CSharp) | Notes |

|----------------------------------|-------------------|-------|

| IBonded<T> interface | IBonded<T> (same) | Interface is unchanged |

| Bonded<T> class | Bonded<T> (same) | Implementation is unchanged |

| Manual serializer setup | new Serializer<T>(protocol) | Use the typed serializer API |

| Custom protocol readers | CompactBinaryReader<T>, FastBinaryReader<T> | Concrete reader types from Bond.IO |

If the project used only the interfaces from Microsoft.Bond.Interfaces (e.g., IBonded<T>, BondDataType), the migration is primarily a namespace change.

Step 6: Build and Verify

• Build the project:

   dotnet build

• If .bond schemas are present, verify the generated code compiles correctly
• Run serialization round-trip tests — serialize and deserialize representative objects to confirm data fidelity
• Verify interoperability with existing Bond-serialized data stores or services

Troubleshooting

gbc Compiler Not Found

Bond.CSharp ships gbc as a build tool. If the build fails with a missing gbc error, ensure the Bond.CSharp package restored correctly. Run dotnet restore --force to refresh the package cache.

Schema Compilation Errors

If .bond schema files reference types from other schemas, ensure all dependent .bond files are in the project. The gbc compiler resolves imports relative to the project directory. Add <BondImportDirectory> in the project file to specify additional import paths:

<ItemGroup>
  <BondImportDirectory Include="path/to/shared/schemas" />
</ItemGroup>

Missing Types After Migration

If the project previously referenced only Microsoft.Bond.Interfaces for a subset of types, Bond.CSharp provides the full type set. Verify that using Bond; replaces using Microsoft.Bond; in all files.

Binary Compatibility

Bond's wire format is stable across versions. Data serialized with the old Microsoft.Bond packages is compatible with Bond.CSharp. No data migration is needed.