Context

A Context is the typed, serializable container that carries data between Tasks in a Workflow. One task writes a value; a downstream task reads it. The context is persisted with the execution, so it survives restarts and is available in the final result.

Mental model

• The context flows through the DAG: each task receives it, may mutate it, and returns it.
• It is persisted per execution — recovery restores it.
• The final context is returned on the execution result (final_context).

Interfaces

Rust

Context<T> is generic over the (serde-serializable) value type; most workflows use Context<serde_json::Value>:

use cloacina::Context;

let mut ctx = Context::new();
ctx.insert("raw", serde_json::json!([1, 2, 3]))?;
let raw = ctx.get("raw");          // Option<&Value>

Python

import cloaca

ctx = cloaca.Context({"job_id": "job_001"})
ctx.set("raw", [1, 2, 3])
raw = ctx.get("raw")

Key facts

• Serializable: values must be JSON-serializable; the context is stored in the database between task executions.
• Typed (Rust): Context<T> is generic; the common case is Context<serde_json::Value>.
• Initial + final: you pass an initial context to execute; the result exposes the final_context.

See also

• Task · Workflow · Runner
• Context management (design)