The agent session is not the unit of work.

A session is an execution context

Coding agents can now investigate a failure, change a codebase, run tests, and prepare a useful handoff. But the session that does this work is temporary by design. It can be compacted, interrupted, replaced by another model, or abandoned when the surrounding environment disappears.

That is not a defect in the agent. It is a category mistake in the system around it. A terminal session, chat thread, or harness run is an execution context. The business task is the durable commitment: why the work exists, who is responsible, what authority applies, what it is waiting for, and what outcome must be reviewed.

The durable object is the task

Consider an intermittent production failure. The first agent may gather logs and form a hypothesis. A person may answer a clarification. A second agent may make the change. A reviewer may reject the first result. The work has one continuing identity even though several sessions and people participate.

Treating every run as a new unit fragments the record. Decisions leak into prompts, discovered constraints live in transcripts, and responsibility becomes whatever the current session happens to remember. Treating the Task as the unit keeps the title, context, assignment, waiting conditions, discussions, results, and history attached to the thing the business actually understands.

The run explains how work was attempted. The Task explains what the business is doing.

Handoff must be a product behavior

A good handoff is not merely a summary generated at the end of a long conversation. It records what changed, what was verified, what remains uncertain, which decisions were made, and the next action. It is attributable to the Actor and run that produced it, and it remains next to the authoritative work.

This matters when an agent succeeds, but it matters even more when execution becomes uncertain. A lost worker connection does not prove that the external process stopped. A durable operational system should say what it knows, preserve the last meaningful report, prevent stale authority from continuing ordinary mutation, and return the uncertainty for human attention.

A better contract with agents

The useful contract is not ‘remember our entire conversation.’ It is: here is the bounded work, its current context, the instructions that govern it, the authority available for this attempt, and the place where progress and results must return.

Models and harnesses will keep changing. That should become an advantage instead of an organizational reset. When the operational record belongs to the business, a new agent can continue from durable Tasks, Notes, Decisions, Discussions, provenance, and handoffs rather than from archaeology inside a former vendor's transcript.