Migration Diary: Cutting Over to a Free AI Tier Without Breaking Your Loop

Migrating your AI-assisted development loop to a free tier is a measurement exercise, not a download-and-switch moment. You need a cutover plan, a rollback path, and an honest list of leftovers before you touch a single endpoint. This diary shows the structure I use when leaving one AI workflow for another, and it includes a ledger script you can run on day one.

Why I started keeping a migration diary

The trigger was billing fatigue, not feature envy. I was spending more time watching token counters than reviewing diffs, and every experiment with a paid assistant felt like a gamble with an opaque meter. I wanted a setup where the limits were visible enough to plan around, which is what pushed me toward open-source tooling with a free tier.

MonkeyCode fits that description: it is an open-source project with a free model tier and a free server option, and the current free tier includes 10 million tokens. Disclosure: This article was prepared as part of MonkeyCode's product outreach. I treat those numbers as a starting point for measurement, not as a permanent contract, because free tiers change terms without ceremony.

The cutover plan

A migration diary is only useful if the plan is boring and repeatable. Here is the six-step plan I use, and it works for any AI tool, not just MonkeyCode.

1. Inventory every AI workflow you actually run. List the real tasks: commit message generation, doc summarization, code review, refactoring suggestions, test writing. If you cannot name a workflow, you cannot measure it.

2. Classify each workflow by blast radius. A commit message that is slightly wrong costs you nothing. A code review that misses a security issue costs you an incident. Sort your list from lowest risk to highest risk before you migrate anything.

3. Measure a baseline before you move. Run your current tool for three days and record latency, token consumption, and how often you accept its output. This baseline is your rollback trigger, and it is the only honest way to know whether the new tier is actually better.

4. Move the low-risk workflows first. Start with summaries and commit messages, and keep the high-risk workflows on your old tool. This builds confidence in the new endpoint without exposing your review process to an unproven model.

5. Run both tools in parallel for one week. Do not cut over in a single afternoon. Every workflow you move should run side by side with the old one until you have enough samples to compare quality.

6. Cut over, log everything, and keep the rollback. When the ledger shows stable latency and acceptable output, you can switch. Keep the old tool configured for another week, because the first regression always shows up after you celebrate.

The migration ledger

A migration without a ledger is just a hope. This script records every workflow you cut over, along with latency and HTTP status, so you can spot regressions before they become habits. Save it as migration-ledger.sh and run it each time you exercise a migrated workflow.

#!/usr/bin/env bash
# migration-ledger.sh — record every workflow you cut over to the free tier
set -euo pipefail

ENDPOINT="${1:-YOUR_ENDPOINT_URL}"
WORKFLOW="${2:-unlabeled}"
LEDGER="migration-ledger.csv"

if [[ ! -f "$LEDGER" ]]; then
  echo "timestamp,workflow,latency_ms,http_code,notes" > "$LEDGER"
fi

start=$(date +%s%N)
code=$(curl -s -o /tmp/mc-response.json -w "%{http_code}" -X POST "$ENDPOINT" -H "Content-Type: application/json" -d '{"messages":[{"role":"user","content":"ping"}]}')
end=$(date +%s%N)
latency=$(( (end - start) / 1000000 ))

echo "$(date -Iseconds),$WORKFLOW,$latency,$code,${3:-}" >> "$LEDGER"
tail -n 1 "$LEDGER"

Run it once per workflow, and you will build a migration history you can actually inspect.

./migration-ledger.sh https://your-endpoint.example/v1/chat commit-messages "moved from old tool"
./migration-ledger.sh https://your-endpoint.example/v1/chat doc-summaries "baseline week"

After a week, a short awk command turns the ledger into a readable trend line.

awk -F, 'NR>1 {print $1, $3, $4}' migration-ledger.csv | column -t

The leftovers

Every migration leaves something behind, and you should decide what stays before you start. Three things consistently survive my cutovers, and they should survive yours too.

Code review stays on the strong model with a human gate. The current debate about AI reviewers being untested applies directly to migrations. A free tier is fine for drafting review comments, but the final pass belongs to a human who can reject a confident wrong suggestion.

Long-running batch jobs stay off the free tier. If a job burns tokens for hours, it will eat your free quota in one afternoon. Metered experiments belong on the free tier; production batch processing belongs somewhere with a predictable bill.

The free server option is for experiments, not production. A free server is a great place to test a deployment, run a demo, or reproduce a bug. It is not a hosting strategy for customer-facing workloads, because you have no SLA and no guarantee of permanence.

Who should not use this approach

If your team handles regulated data or needs a contractual uptime guarantee, do not run production workloads on a free tier. If your workflow cannot tolerate variable latency, measure the free endpoint for a full week before you trust it. And if you cannot afford to lose access to the tool on short notice, keep a paid fallback configured.

Free tiers are a measurement budget, not a commitment. The terms change, the quotas move, and the model behind the endpoint can be swapped without warning. Check the current documentation before you rely on any specific number.

The takeaway

Start with the ledger, not with the endpoint. Inventory your workflows, classify them by risk, and migrate the boring ones first. The numbers in this article reflect the offering as of late August 2026, and free tiers move without warning, so check the project docs before you rely on any quota. If you want a place to run that experiment, MonkeyCode's free tier — currently 10 million tokens plus a free server option — is a reasonable starting point.