Last reviewed: 2026-05-14.

Who this is for

This guide is for maintainers who want more than one coding-agent attempt without losing control of the repository. It covers the context files that teach an agent how the repo works and the Git worktree pattern that keeps parallel attempts isolated.

The goal is not to run as many agents as possible. The goal is to make each attempt narrow, auditable, and easy to accept or reject.

Key takeaways

  • Context files are part of the product surface for coding agents.
  • Put priority order, architecture, required checks, and forbidden side effects in files the agent can read.
  • Use Git worktrees when two implementation attempts need separate branches.
  • Assign file ownership before parallel work starts.
  • Merge only after reviewing each diff and running the acceptance checks.
  • Do not parallelize tightly coupled product decisions just because the tooling allows it.

The repository context stack

A coding agent needs enough local truth to avoid guessing. The stack can be small:

FilePurposeWhat the agent should learn
AGENTS.md or equivalentNon-negotiable rulesRequired reading, forbidden commands, secret handling, handoff format.
README.mdFast architecture mapRuntime boundaries, main workflows, and where to look next.
docs/ROADMAP.mdCurrent directionAccepted phase gates and things that are intentionally out of scope.
docs/STATUS.mdGenerated readiness reportCurrent blockers, live state, queue counts, and capability coverage.
docs/SOP_EXECUTION_LOG.mdAcceptance historyWhat changed, which checks ran, and what remains unresolved.

The exact filenames may differ by tool. Anthropic documents project memory and instruction files for Claude Code, while OpenCode documents agent configuration in its own workflow. The durable principle is the same: make the repo teach the agent, then verify the agent’s work with commands.

What belongs in context files

Include operational facts that change agent behavior:

  • Current architecture and runtime boundaries.
  • Which files are generated and which files are hand-edited.
  • Secret-handling rules.
  • Required tests, lint checks, build checks, and smoke checks.
  • Branching, staging, committing, deploy, and PR expectations.
  • Stop conditions for paid actions, production writes, browser automation, domain changes, or destructive commands.
  • Known blockers and human inputs.

Leave out real secrets, huge stale logs, private customer data, and aspirational features that look like accepted work. An agent that reads a wish list as a roadmap will implement the wrong thing with great confidence.

Context validation prompt

Before editing, make the agent prove it has the context:

Read the repo instructions, README, roadmap, status report, and execution log.
Name the current runtime boundaries.
Name the files you would touch for this task.
Name the checks you will run.
Do not edit files yet.

If the answer misses a runtime boundary or proposes unrelated cleanup, fix the context or narrow the task. Do not reward a weak context read by giving the agent broader write access.

Parallel agents need ownership

Parallel work becomes dangerous when two agents believe they own the same file. Before delegation, define ownership:

Ownership itemExample
Branchcodex/content-quality-gate
Worktree directory../comet-satellite-content-quality
Write scopescripts/check_static_content_quality.py and docs only
Verificationpython3 scripts/check_sop_foundation.py and git diff --check
Merge ruleNo merge until diff and checks are reviewed

That ownership table is not bureaucracy. It is the cheapest way to avoid lost work, accidental reversions, and confusing Git state.

Git worktree pattern

Use git worktree when two agents need independent implementation attempts:

git worktree add ../agent-a -b codex/agent-a
git worktree add ../agent-b -b codex/agent-b

Then give each agent a separate target:

  • Agent A owns the content quality checker.
  • Agent B owns the documentation and status updates.
  • Agent C investigates a failing check without writing files.

Each worktree has its own working directory and branch while sharing repository objects. That is cleaner than cloning the repository repeatedly and safer than letting multiple agents write inside one checkout.

When not to parallelize

Do not split work when the next action depends on one result, when two changes touch the same schema, or when the hard part is product judgment. Parallel agents are useful for bounded implementation slices. They are less useful for deciding strategy, naming public APIs, or changing a shared content gate that every publishing path depends on.

If the change is cross-cutting, keep one agent responsible for the final integration. Otherwise each branch can be locally correct and globally incoherent.

Merge discipline

Run this before merging any agent worktree back:

git -C ../agent-a status --short
git -C ../agent-a diff --stat
git -C ../agent-a diff --check

Then inspect the changed files, run the acceptance checks, and copy the final summary into the PR or execution log. Delete a worktree only after the branch is integrated or intentionally abandoned:

git worktree remove ../agent-a

Do not use a worktree as a trash can for unresolved changes. If the branch is rejected, record why so the next agent does not rediscover the same failure mode.

Real failure modes

Failure modeWhat it looks likePrevention
Context driftThe agent follows old docs over fresh statusKeep source priority explicit and regenerate status after workflow changes.
Shared-file collisionTwo agents edit the same script or CSVAssign file ownership before spawning work.
Hidden generated outputA build changes tracked public files unexpectedlyName generated outputs and require git status --short.
Review overloadFive branches arrive with no test evidenceRequire each agent to report exact checks and changed files.
Stale demo contentA canary page bypasses queue, source, and review ledgersRequire static content quality gates before public builds.

The last row is now a standing rule for this project: public canaries must be quality-gated. A demo page that gets indexed is no longer just a demo.

Reader next step

Start with the setup and model-routing guide, then use this page to decide whether a second agent should run in a separate worktree. When the implementation is ready, finish with the test repair and PR workflow.

The core CTA target remains intentionally blocked until a human approves it. Do not invent a conversion URL just to make a dashboard look complete.

Sources checked