P06 — Multiple Agents / Same Repository

Problem

Two agents in one checkout create file, branch, dependency, and generated-artifact collisions.

Context

Independent tasks target the same repository at the same time. The workspace-root driver coordinates both Runs, while the canonical checkout remains an independently Git-managed repository under repos/.

Pattern

Give every Run its own worktree and branch. Coordinate through Intent; integrate Candidates through the repository policy.

Diagram

same repo
 ├─ Run A → branch A → Candidate A ┐
 └─ Run B → branch B → Candidate B ─┴→ validation / integration

Example

Run A addresses a bug while Run B upgrades dependencies. Neither edits the other’s files or branch:

ws run coder "Fix the authentication bug" --repo api --no-integrate &
ws run coder "Upgrade the dependency" --repo api --no-integrate &
wait

The driver inspects both Candidates and integrates them through the repository policy.

Trade-offs

Routine collisions drop sharply. Merge conflicts and semantic conflicts still exist and may be discovered only at integration.

Failure modes

Shared external services, shared ports, or generated artifacts still collide even when Git worktrees are separate.

Extension points

Pair worktree isolation with resource allocation and CI-based integration.

When not to use

Avoid concurrency when the tasks have a strict sequential dependency and parallelism has no benefit.