Agentic Planning For Cross Package Refactors Operational Checklist: practical systems guide

# Agentic Planning For Cross-Package Refactors: Operational Checklist

Cross-package refactors collapse under their own weight when you treat them as big-bang migrations. A function signature change that touches twelve packages becomes fourteen merge conflicts, three broken CI runs, and a staging environment that won't start. The problem isn't the refactor itself—it's that most teams plan these changes as if they're editing a single file, then wonder why the deployment turns into a three-day fire drill.

Agentic systems like Goatfied's plan-constrain-edit-validate loop change the failure mode. Instead of generating a 4,000-line diff that no one can review, you get a sequence of small, individually testable changes that cross package boundaries safely. But you still need operational discipline. Here's what actually works when you're changing interfaces used by half your codebase.

Write the constraint manifest first

Before any code changes, document what must remain true throughout the refactor. This isn't aspirational—these are compile-time and runtime gates that will block merges if violated.

For a cross-package API change, your constraint file might specify:

constraints:

  - type: no_breaking_changes_without_deprecation

    packages: ["@company/api-client", "@company/internal-sdk"]

  - type: test_coverage_threshold

    minimum: 85

    scope: changed_files

  - type: dependency_graph_acyclic

    root: "packages/"

When Goatfied's agent loop plans edits, these constraints become hard requirements. The planner knows it can't remove a method without first adding a deprecated wrapper. It won't propose changes that drop test coverage. You're trading flexibility for the ability to actually land the refactor.

The alternative—hoping reviewers catch breaking changes in a 200-file diff—doesn't scale past two packages.

Sequence the work by dependency order, not by package

Most engineers start with "let's update package A, then B, then C." This fails because package C imports A and B, so you're constantly rebasing. The dependency graph doesn't care about alphabetical order.

Calculate the topological sort of your affected packages. Start with leaf nodes (packages that depend on others but are not themselves dependencies). Work backwards toward your root packages.

# Example with npm workspaces

npx lerna ls --graph --scope "@company/*"

# Identify leaves, schedule them first

An agent-based system can generate this ordering automatically if you feed it dependency metadata. Goatfied's planner can read `package.json` files and prioritize edits that unblock downstream work. You still need to review the sequence—some "leaf" packages might be critical user-facing apps where you want extra validation before merge.

The operational win: each PR becomes mergeable as soon as its tests pass, because you're not waiting on upstream changes.

Commit to maximum diff size per PR

Hard limit: 300 lines of functional changes per pull request. More than that and review quality collapses. People start skimming. Bugs slip through.

For agentic workflows, this means breaking the plan into multiple execution passes. After the agent generates a 50-file refactor plan, partition it into chunks that each touch ≤3 packages and stay under the line limit.

Goatfied's approach: the agent proposes a plan with explicit breakpoints. You see "Phase 1: add new API methods to `core-utils` (estimated 120 LOC). Phase 2: migrate `auth-service` callers (estimated 280 LOC)." Each phase maps to one PR.

The review discipline this enforces is worth the coordination overhead. Small diffs get merged in hours, not days. Mistakes are cheap to roll back.

Gate merges on cross-package test execution

Your CI must run the full test suite for every downstream package that imports the changed code. Not just the package you edited—everything that transitively depends on it.

Standard CI config won't catch this automatically. You need workspace-aware test discovery:

# Example GitHub Actions step

- name: Run affected tests

  run: |

    npx nx affected:test --base=main --head=HEAD

For agentic systems, wire this into the validate step. After the agent proposes an edit, the validation pass should fail immediately if downstream tests break. Don't wait for CI.

Goatfied runs lint, type check, and affected tests before marking an edit complete. The agent sees failures and retries with a narrower change. This catches "I updated the interface but forgot a call site in package B" before you push.

Deploy to staging with selective package rollouts

Even after tests pass, deploy the refactored packages to staging one at a time. Don't update all twelve packages in a single deployment.

Use feature flags or canary deploys to route a small percentage of traffic through the new code paths. Monitor error rates, latency, and any domain-specific metrics (database query counts, cache hit rates, etc.).

For teams running Goatfied self-hosted, the agent audit log becomes valuable here. You can trace which specific AI-generated edits correspond to performance regressions. If staging latency spikes after deploying `@company/data-layer` v2.1.0, pull up the log to see exactly what changed and why the agent made that decision.

This is slower than a big-bang deploy, but you're optimizing for actually finishing the refactor instead of rolling it back on Friday night.

Keep a rollback runbook for each phase

Every PR in the refactor sequence needs a one-command rollback plan. Document it in the PR description before merge.

Example:

## Rollback

1. Revert to `@company/core-utils@1.4.2`

2. Redeploy `auth-service` and `api-gateway`

3. Clear Redis cache for keys matching `auth:token:*`

If something breaks in production, you don't want to be debugging which of eight PRs caused it. You want to revert the most recent phase, verify health, then investigate.

Goatfied's small-diff approach makes this tractable. Each PR is reversible because it changed a narrow slice of the system. Compare to a monolithic refactor PR where rollback means losing two weeks of other improvements that merged alongside it.

Related reading

• [Self-hosted AI coding assistants: a complete Goatfied deployment guide](/blog/self-hosted-ai-coding-assistants-goatfied-deployment-guide)
• [Deployment playbook #2: practical Goatfied tactics for shipping PRs](/blog/goatfied-deployment-playbook-2)