Blend AI Documentation

Every handle carries a data type. It’s how the editor knows which connections make sense — drag from an output and only compatible inputs accept the edge. A type describes what flows through a handle, not how many values; that’s a separate axis, covered in Lists & single values.

The types

Type	Carries
`text`	Strings — prompts, captions, model output.
`image`	An image file.
`video`	A video file.
`audio`	An audio file.
`file`	Any file, including the media types above.
`model`	A model selection. Keeping it distinct preserves model filtering and the model-picker control.
`collection`	A saved collection selection.
`any`	A flexible wildcard slot that adapts to whatever connects to it.
`tool-list`	A bundle of tools or sub-agents — only ever wired into an Agent’s tools input.

The distinctions are semantic, not cosmetic. An image is not a video is not audio; model and collection preserve their specialized selectors rather than degrading to plain text; and a tool-list isn’t content at all—it’s agent wiring.

Compatibility

When you drag an edge, the editor checks the source type against the target type:

Source	Target	Allowed?
`text`	`text` (same type)	✅ Exact match always connects.
anything	`any`	✅ `any` is a wildcard — except it never accepts `tool-list`.
`any`	anything	✅ `any` adapts to the target.
`image` / `video` / `audio`	`file`	✅ Media is a kind of file.
`model`	`model`	✅ Model selectors connect to model selectors.
`collection`	`collection`	✅ Collection selectors connect to collection selectors.
`tool-list`	`tool-list`	✅ The only valid use — strict on both sides.
`tool-list`	anything else	❌ Tools only plug into a tools input.
`text`	`image` (and other mismatched concrete types)	❌ Rejected.

Type answers what flows. How many values flow — a single value versus a list — is a different axis entirely, covered in Lists & single values.

Handles, edges & connections

How handles emit and receive data, and the rules that govern edges.

Lists & single values

The other axis — how many values move through a connection.

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Concepts

Workflow

Data types & compatibility

The types

Compatibility

Handles, edges & connections

Lists & single values

​The types

​Compatibility

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Handles, edges & connections

Lists & single values

The types

Compatibility

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