feat: refactor api surface for clarity

.config/dotnet-tools.json

@@ -16,6 +16,13 @@
         "dotnet-script"
       ],
       "rollForward": false
+    },
+    "docfx": {
+      "version": "2.78.5",
+      "commands": [
+        "docfx"
+      ],
+      "rollForward": false
     }
   }
 }

.vscode/flowthru.code-snippets

@@ -10,16 +10,16 @@
 		"scope": "csharp",
 		"prefix": "_pipeline",
 		"body": [
-			"using Flowthru.Pipelines;",
+			"using Flowthru.Flows;",
 			"using $1",
 			"",
 			"public static class ${RELATIVE_FILEPATH/.*?(\\w+).cs$/$1/}",
 			"{",
 			"  public static Pipeline Create(Catalog catalog)",
 			"  {",
-			"    return PipelineBuilder.CreatePipeline(pipeline =>",
+			"    return FlowBuilder.CreateFlow(pipeline =>",
 			"    {",
-			"      pipeline.AddNode(",
+			"      pipeline.AddStep(",
 			"        label: \"$2\",",
 			"        description: \"\"\"",
 			"          $3",
@@ -34,7 +34,7 @@
 		],
 		"description": "Creates a basic Flowthru pipeline structure."
 	},
-	"FlowthruNode": {
+	"FlowthruStep": {
 		"scope": "csharp",
 		"prefix": "_node",
 		"body": [

CONTRIBUTING.md

@@ -74,8 +74,8 @@ Flowthru handles these through an **effect type** called `FlowIO<T>`. If you're
 The key runtime guarantees:
 
 - **All I/O is lazy and explicit.** Side effects cannot be accidentally dropped or silently ignored.
-- **Errors are captured, never swallowed.** Node failures propagate to structured pipeline results. Silent `catch {}` blocks are a bug.
-- **Nodes are isolated.** A failing node halts execution and reports which node failed and why — partial silent failures are not possible.
+- **Errors are captured, never swallowed.** Step failures propagate to structured pipeline results. Silent `catch {}` blocks are a bug.
+- **Steps are isolated.** A failing node halts execution and reports which node failed and why — partial silent failures are not possible.
 
 ## Decision Rules for Contributors
 

Directory.Build.props

@@ -16,6 +16,11 @@
     <RestorePackagesWithLockFile>false</RestorePackagesWithLockFile>
   </PropertyGroup>
 
+  <!-- Generate XML documentation for src/ projects (consumed by DocFX) -->
+  <PropertyGroup Condition="$(MSBuildProjectDirectory.Contains('src'))">
+    <GenerateDocumentationFile>true</GenerateDocumentationFile>
+  </PropertyGroup>
+
   <!-- Centralized NuGet package configuration for all src/ projects -->
   <PropertyGroup Condition="$(MSBuildProjectDirectory.Contains('src'))">
     <Version>0.1.33</Version>

docs/CONTRIBUTING.md

@@ -27,7 +27,7 @@ Consider these examples:
 - **"How do I start writing my first pipeline?"** → This is someone learning. They need a tutorial.
 - **"How can I read data from a database instead of local files?"** → This is someone working with a specific need. They need a guide.
 - **"Why does Flowthru use so many types?"** → This is someone studying the framework's design. They need an explanation.
-- **"What parameters does `CatalogEntry` accept?"** → This is someone looking up technical details. They need reference documentation.
+- **"What parameters does `Item` accept?"** → This is someone looking up technical details. They need reference documentation.
 
 The same topic can yield different documentation depending on the question:
 
@@ -156,7 +156,7 @@ Let's say you want to document "catalog entries." Start by listing questions:
 - "How do I create my first catalog entry?" → Tutorial
 - "How do I configure a catalog entry for Parquet files?" → Guide
 - "Why are catalog entries properties rather than string keys?" → Explanation
-- "What methods are available on `ICatalogEntry<T>`?" → Reference
+- "What methods are available on `IItem<T>`?" → Reference
 
 Each question becomes a separate piece of documentation in its appropriate category. Together, they serve users at every stage of their journey with catalog entries.
 

docs/explanation/advanced/storage-composition.md

@@ -140,11 +140,11 @@ public class EFCoreStorageAdapter<T> : IStorageAdapter<IEnumerable<T>>
 
 ## Catalog-Level Constraint Narrowing
 
-After adapter creation, pipeline authors can further constrain catalog entries using `CatalogEntry<T>.Constrain()`:
+After adapter creation, pipeline authors can further constrain catalog entries using `Item<T>.Constrain()`:
 
 ```csharp
-public ICatalogEntry<IEnumerable<Company>> Companies => GetOrCreateEntry(() =>
-    CatalogEntries.Enumerable.Csv<Company>("companies", "data/companies.csv")
+public IItem<IEnumerable<Company>> Companies => GetOrCreateEntry(() =>
+    ItemFactory.Enumerable.Csv<Company>("companies", "data/companies.csv")
         .Constrain(traits => traits with { CanWrite = false })
 );
 ```
@@ -201,7 +201,7 @@ The trait system solves all three:
 
 - **Composable**: Eight independent boolean flags
 - **Queryable**: `adapter.Traits.CanWrite` checked before operation
-- **Fail-fast**: `CatalogEntry.Constrain()` validates at initialization
+- **Fail-fast**: `Item.Constrain()` validates at initialization
 
 The old interfaces remain as `[Obsolete]` for backward compatibility but have no effect on pipeline behavior.
 
@@ -211,9 +211,9 @@ The storage architecture is implemented in:
 
 - `src/core/Flowthru/Data/Capabilities/StorageTraits.cs` — the trait record
 - `src/core/Flowthru/Data/Storage/ComposedStorageAdapter.cs` — trait merging logic
-- `src/core/Flowthru/Data/CatalogEntry.cs` — `Constrain()` with ratchet validation
+- `src/core/Flowthru/Data/Item.cs` — `Constrain()` with ratchet validation
 - `src/core/Flowthru/Data/Storage/Medium/` — medium implementations with traits
 - `src/core/Flowthru/Data/Storage/Format/` — format serializers with traits
 
-Catalog entry factories (`CatalogEntries.Enumerable.Csv<T>(...)`) construct composed adapters with sensible defaults. Extension authors creating custom adapters should declare traits that accurately reflect their capabilities.
+Catalog entry factories (`ItemFactory.Enumerable.Csv<T>(...)`) construct composed adapters with sensible defaults. Extension authors creating custom adapters should declare traits that accurately reflect their capabilities.
 

docs/explanation/anatomy-of-a-pipeline.md

@@ -75,9 +75,9 @@ In this example:
 // Data/_01_Raw/Catalog.Raw.cs
 public partial class Catalog
 {
-  public ICatalogEntry<IEnumerable<IrisRawSchema>> IrisRaw =>
+  public IItem<IEnumerable<IrisRawSchema>> IrisRaw =>
     GetOrCreateEntry(() =>
-      CatalogEntries.Enumerable.Csv<IrisRawSchema>(
+      ItemFactory.Enumerable.Csv<IrisRawSchema>(
         label: "IrisRaw",
         filePath: $"{_basePath}/_01_Raw/Datasets/iris.csv"
       )
@@ -95,9 +95,9 @@ In this example:
 // Data/_04_Feature/Catalog.Feature.cs
 public partial class Catalog
 {
-  public ICatalogEntry<IEnumerable<IrisFeatureSchema>> IrisFeatures =>
+  public IItem<IEnumerable<IrisFeatureSchema>> IrisFeatures =>
     GetOrCreateEntry(() =>
-      CatalogEntries.Enumerable.Parquet<IrisFeatureSchema>(
+      ItemFactory.Enumerable.Parquet<IrisFeatureSchema>(
         label: "IrisFeatures",
         filePath: $"{_basePath}/_04_Feature/Datasets/iris_features.parquet"
       )
@@ -169,13 +169,13 @@ Pipelines are made up of **nodes** — transformation functions that are built t
 
 1. When writing a node, you don't need to worry about how it's connecting to other nodes — you just need to make sure it inputs the schema, and outputs  the schema
 
-### Nodes
+### Steps
 
-Nodes are simply functions. Easy! The **only** purpose of a node is to take in data that has one schema, and convert it to data that has another schema.
+Steps are simply functions. Easy! The **only** purpose of a node is to take in data that has one schema, and convert it to data that has another schema.
 
 ```csharp
-// Pipelines/DataEngineering/Nodes/SplitAndEncodeNode.cs
-public static class SplitAndEncodeNode
+// Pipelines/DataEngineering/Steps/SplitAndEncodeStep.cs
+public static class SplitAndEncodeStep
 {
   public static Func<
     IEnumerable<IrisRawSchema>, // Input Schema
@@ -194,8 +194,8 @@ public static class SplitAndEncodeNode
 
 Key points:
 
-- Nodes are a *contract*: that data for the node will **always** come in as the input schemas, and **always** come out as the output schemas.
-- Nodes can have any number of inputs, and any number of outputs — as long as they're defined in the input and output schemas, you're not limited to just one-in, one-out.
+- Steps are a *contract*: that data for the node will **always** come in as the input schemas, and **always** come out as the output schemas.
+- Steps can have any number of inputs, and any number of outputs — as long as they're defined in the input and output schemas, you're not limited to just one-in, one-out.
 
 
 ### Pipelines
@@ -214,11 +214,11 @@ public static class DataEngineeringPipeline
 {
   public static Pipeline Create(Catalog catalog, Params parameters)
   {
-    return PipelineBuilder.CreatePipeline(pipeline =>
+    return FlowBuilder.CreateFlow(pipeline =>
     {
-      pipeline.AddNode(
+      pipeline.AddStep(
         label: "SplitAndEncode", // Unique label for this node in the pipeline
-        transform: SplitAndEncodeNode.Create(),
+        transform: SplitAndEncodeStep.Create(),
         input: catalog.IrisRaw,
         output: catalog.IrisFeatures
       );
@@ -229,7 +229,7 @@ public static class DataEngineeringPipeline
 
 Key points:
 
-- **Nodes are never directly connected to each other**: Nodes always take in Catalog entries, and output Catalog entries — *never* directly to each other.
+- **Steps are never directly connected to each other**: Steps always take in Catalog entries, and output Catalog entries — *never* directly to each other.
 - **Order doesn't matter.** A node in the pipeline is **only** ever concerned about its input data and output data. Flowthru handles the order when you run the pipeline: as long as the data is available, or generated by another node, your pipeline will run.
 
 ## Entry Point
@@ -241,7 +241,7 @@ private static void ConfigureServices(IServiceCollection services, string basePa
 {
     services.AddFlowthru(flowthru =>
     {
-        flowthru.UseCatalog(_ => new Catalog(basePath: "Data")));
+        flowthru.RegisterCatalog(_ => new Catalog(basePath: "Data")));
 
         flowthru.RegisterPipeline<Catalog>(
             label: "DataEngineering",
@@ -256,4 +256,4 @@ private static void ConfigureServices(IServiceCollection services, string basePa
 }
 ```
 
-And that's it! This finishes the pipeline anatomy. At this point, you have Catalog entries, connected with Nodes in your Pipelines — everything you need to find new and creative ways to organize, analyze, and report on your data!
+And that's it! This finishes the pipeline anatomy. At this point, you have Catalog entries, connected with Steps in your Pipelines — everything you need to find new and creative ways to organize, analyze, and report on your data!

docs/guides/advanced/container-deployment.md

@@ -13,7 +13,7 @@ Deploy a Flowthru pipeline as a standalone container image for execution in envi
 A containerized pipeline replaces `FlowthruCli` with a minimal `Program.cs` that owns its own DI container. The key difference: no CLI argument parsing, no filesystem-based configuration.
 
 ```csharp
-using Flowthru.Pipelines;
+using Flowthru.Flows;
 using Flowthru.Services;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
@@ -26,7 +26,7 @@ services.AddLogging(logging =>
 services.AddFlowthru(flowthru =>
 {
     flowthru
-        .UseCatalog<MyCatalog>()
+        .RegisterCatalog<MyCatalog>()
         .RegisterPipeline<MyCatalog>("Ingest", catalog => IngestPipeline.Create(catalog))
         .RegisterPipeline<MyCatalog>("Transform", catalog => TransformPipeline.Create(catalog));
 
@@ -50,19 +50,19 @@ return result.Success ? 0 : 1;
 
 // --- helpers ---
 
-static PipelineSliceStrategy BuildSliceStrategy()
+static FlowSliceStrategy BuildSliceStrategy()
 {
     static HashSet<string>? ParseCsv(string? value) =>
         string.IsNullOrWhiteSpace(value) ? null : new(value.Split(',', StringSplitOptions.RemoveEmptyEntries));
 
-    return new PipelineSliceStrategy
+    return new FlowSliceStrategy
     {
         Pipelines  = ParseCsv(Environment.GetEnvironmentVariable("FLOWTHRU_PIPELINES")),
-        FromNodes  = ParseCsv(Environment.GetEnvironmentVariable("FLOWTHRU_FROM_NODES")),
-        ToNodes    = ParseCsv(Environment.GetEnvironmentVariable("FLOWTHRU_TO_NODES")),
+        FromSteps  = ParseCsv(Environment.GetEnvironmentVariable("FLOWTHRU_FROM_NODES")),
+        ToSteps    = ParseCsv(Environment.GetEnvironmentVariable("FLOWTHRU_TO_NODES")),
         FromData   = ParseCsv(Environment.GetEnvironmentVariable("FLOWTHRU_FROM_DATA")),
         ToData     = ParseCsv(Environment.GetEnvironmentVariable("FLOWTHRU_TO_DATA")),
-        OnlyNodes  = ParseCsv(Environment.GetEnvironmentVariable("FLOWTHRU_ONLY_NODES")),
+        OnlySteps  = ParseCsv(Environment.GetEnvironmentVariable("FLOWTHRU_ONLY_NODES")),
     };
 }
 ```
@@ -87,7 +87,7 @@ services.AddFlowthru(flowthru =>
 {
     // No UseConfiguration() call — the IConfiguration above is already registered
     flowthru
-        .UseCatalog<MyCatalog>()
+        .RegisterCatalog<MyCatalog>()
         .RegisterPipeline<MyCatalog>("Ingest", catalog => IngestPipeline.Create(catalog));
 });
 ```
@@ -152,7 +152,7 @@ docker run \
 
 ## Inspecting Results
 
-`ExecutePipelineAsync` returns a `PipelineResult` — a structured value object with `Success`, `ExecutionTime`, per-node `NodeResults` (including individual timing, I/O counts, and exceptions), and an optional top-level `Exception`. Serialize it to structured output for your runtime's observability:
+`ExecutePipelineAsync` returns a `FlowResult` — a structured value object with `Success`, `ExecutionTime`, per-node `StepResults` (including individual timing, I/O counts, and exceptions), and an optional top-level `Exception`. Serialize it to structured output for your runtime's observability:
 
 ```csharp
 var result = await flowthru.ExecutePipelineAsync(options, cancellationToken: cts.Token);
@@ -163,9 +163,9 @@ if (!result.Success)
         result.ExecutionTime.TotalSeconds,
         result.Exception?.Message);
 
-    foreach (var (name, node) in result.NodeResults.Where(n => !n.Value.Success))
+    foreach (var (name, node) in result.StepResults.Where(n => !n.Value.Success))
     {
-        logger.LogError("  Node {Node} failed: {Error}", name, node.Exception?.Message);
+        logger.LogError("  Step {Step} failed: {Error}", name, node.Exception?.Message);
     }
 }
 ```

docs/guides/advanced/metadata-providers.md

@@ -40,8 +40,8 @@ public class DashboardMetadataProvider : IMetadataProvider
     {
         var payload = new
         {
-            PipelineName = dag.PipelineName,
-            NodeCount = dag.Nodes.Count,
+            FlowName = dag.FlowName,
+            StepCount = dag.Steps.Count,
             EdgeCount = dag.Edges.Count,
             Timestamp = DateTime.UtcNow
         };
@@ -85,14 +85,14 @@ using Flowthru.Meta.Providers;
 
 services.AddFlowthru(flowthru =>
 {
-    flowthru.UseCatalog(_ => new MyCatalog());
-    flowthru.UsePipelines(_ => myPipelines);
+    flowthru.RegisterCatalog(_ => new MyCatalog());
+    flowthru.RegisterPipelines(_ => myPipelines);
 
     flowthru.ConfigureMetadata(meta =>
     {
         meta.AddProvider<JsonMetadataProvider, JsonMetadataProviderBuilder>(json => json
             .WithOutputDirectory("metadata")
-            .WithFilenameTemplate("dag-{PipelineName}-{Timestamp}")
+            .WithFilenameTemplate("dag-{FlowName}-{Timestamp}")
             .WithTimestamp("yyyyMMdd-HHmmss")
             .UseCompactFormat());
 
@@ -143,9 +143,9 @@ var singlePipelineDag = service.GetDagMetadata(pipelineName: "DataEngineering");
 
 // Get DAG with slicing applied
 var slicedDag = service.GetDagMetadata(
-    sliceStrategy: new PipelineSliceStrategy
+    sliceStrategy: new FlowSliceStrategy
     {
-        ToNodes = new HashSet<string> { "TransformNode" }
+        ToSteps = new HashSet<string> { "TransformStep" }
     }
 );
 ```
@@ -159,7 +159,7 @@ Useful for tooling, tests, or debugging pipeline structure before execution.
 ```csharp
 meta.AddProvider<JsonMetadataProvider, JsonMetadataProviderBuilder>(json => json
     .WithOutputDirectory("metadata")
-    .WithFilenameTemplate("dag-{PipelineName}-{Timestamp}")
+    .WithFilenameTemplate("dag-{FlowName}-{Timestamp}")
     .WithTimestamp("yyyyMMdd-HHmmss")
     .UseCompactFormat());
 ```
@@ -170,6 +170,6 @@ meta.AddProvider<JsonMetadataProvider, JsonMetadataProviderBuilder>(json => json
 meta.AddProvider<MermaidMetadataProvider, MermaidMetadataProviderBuilder>(mermaid => mermaid
     .WithOutputDirectory("metadata")
     .WithDirection(MermaidFlowchartDirection.LeftToRight)
-    .WithActiveNodeColor("#90EE90")
+    .WithActiveStepColor("#90EE90")
     .WithActiveDataColor("#ADD8E6"));
 ```