agent loop detected: rewriting wrangler.toml and wrangler.jsonc in alternating passes, every version broken

TL;DR

Pick one config format and delete the other. wrangler reads wrangler.toml OR wrangler.jsonc, and having both (or an agent that keeps converting between them) guarantees confusion about which file is authoritative. Commit to toml or jsonc, remove the other file entirely, and fix the single remaining config in place.

agent loop detected: rewriting wrangler.toml and wrangler.jsonc in alternating passes, every version broken

1. Stop the loop. List the config files in the project root:

for f in wrangler.toml wrangler.jsonc; do test -f "$f" && echo "$f exists"; done

Expected: you see which files exist. If both exist, that is the core problem.

2. Choose one format. Prefer wrangler.toml (the long-standing default, most examples and docs use it) unless the project already standardized on jsonc.

Expected: a decision recorded in the run log, not revisited next pass.

3. Delete the losing file and make sure nothing references it:

rm wrangler.jsonc

(or rm wrangler.toml if you chose jsonc). Then grep scripts and docs for mentions of the deleted filename.

Expected: exactly one config file remains. Wrangler's file discovery is now unambiguous.

4. Validate the surviving config without deploying:

wrangler deploy --dry-run

Expected: the parsed config prints with no errors. Fix parse errors in place; do not convert formats to fix them.

5. From here, every fix edits the one file. If a future pass proposes "convert to the other format", reject it: format conversion is never the fix for a config content error.

Expected: consecutive passes all touch the same file, and errors change because content changes, not because the format changed.

Use this when

• Passes alternate between writing wrangler.toml and wrangler.jsonc.
• Both files exist in the repo and disagree.
• The agent "fixes" a config error by converting formats instead of fixing the content.

Not for this skill when

• Only one config file exists and it has a content error. Fix the content; this skill is about format oscillation.
• A human deliberately migrated formats once. One migration is fine; the loop is the problem.
• The error is about a missing config file entirely. Create one (toml) rather than choosing between two.

Variant phrasings

• agent keeps converting wrangler.toml to jsonc
• two wrangler config files conflicting
• wrangler.jsonc vs wrangler.toml loop
• autonomous agent rewriting config format every pass

Why it happens

Wrangler supports two config formats, and an agent that hits a parse error in one may "fix" it by rewriting everything in the other format, introducing new syntax errors (JSON trailing commas, TOML quoting, comment styles) that the next pass "fixes" by converting back. Each conversion is a fresh chance to mangle the content, and the agent never actually addresses the original bad key or value. One authoritative file removes the oscillation surface entirely.

Edge cases

• Some monorepo setups have a wrangler.toml per worker package. The rule is one config per worker root, not one per repo; make sure the agent is not deleting sibling workers' configs.
• wrangler.jsonc allows comments; wrangler.toml uses # comments. Agents converting between them often drop comments carrying important notes. Preserve any human comments when you pick the winner.
• CI may reference the config filename explicitly (e.g. --config wrangler.jsonc). Update those references when you delete a file, or the pipeline breaks the next run.
• If the agent insists both are needed, show it wrangler's startup banner: it names the single config file it loaded. That is the authoritative one.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_7vOFtrbn9UD-u6C9cVGVcA