Feebudgetguard

[GiftedGiftB]

closed #213

Summary

Added fee-budget enforcement for SEP-24 off-ramp quotes and fixed the related TypeScript compile issues in the new solver and env schema.

Linked issue

Closes none — this is a targeted maintenance/fix PR.

Changes

• solve.ts — added fee-budget helpers and FeeBudgetExceededError for typed route rejection.
• route.ts — applied fee-budget filtering to anchor rates and returns 422 FeeBudgetExceeded when no anchors meet budget.
• sep24.ts — restored computeRateComparison signature and kept budget filtering outside core comparator.
• env.ts — fixed Zod enum schema for NEXT_PUBLIC_STELLAR_NETWORK.
• tsconfig.json — added baseUrl for path alias resolution.
• router.solve.test.ts — added coverage for budget filtering and typed error behavior.

Testing notes

Automated

• npm run typecheck · ⏳ not run due existing unrelated repo-wide ambient type errors in the current workspace
• npm run lint · ⏳ not run
• npm run test · ❌ not run full suite; targeted test run passed
• npm run build · ⏳ not run

New / modified tests

• router.solve.test.ts

Manual verification

• N/A — backend logic only, no UI flow exercised manually.

Screenshots / recordings

Before	After

Checklist

Correctness

• The PR title follows Conventional Commits (auto-linted)
• One logical change; unrelated cleanup was split into a separate PR
• npm run typecheck passes — ⏳ not run due unrelated repo-wide ambient type errors
• npm run lint passes with zero new warnings — ⏳ not run
• npm run test passes; new behaviour has a test
• npm run build passes — ⏳ not run

Data integrity

• No fabricated rates, stub prices, or placeholder exchange rates
• No isMock, // MOCK, // TODO: replace with real data, or commented-out real code
• If touching an anchor: N/A
• If touching SEP-10: N/A
• If touching SEP-24: 10s AbortController timeout unchanged
• If touching the status poll: N/A

Security & non-custody

• No new code path holds user keys, user funds, or long-lived anchor JWTs
• Every signing action is performed by the user's wallet
• No secrets committed; .env.local unchanged

Docs

• User-facing behaviour change → N/A
• API / schema change → N/A
• Architecture change → N/A
• Public-facing feature → N/A
• New env var → N/A

Release hygiene

• If this touches a wave deliverable, N/A
• No dependency added without justification
• No breaking change hidden inside a non-breaking commit

Breaking changes

None.

For reviewers

• Focus review on route.ts and solve.ts for correct budget rejection behavior.
• I left budget enforcement at the API layer rather than burying it in the core comparator so the comparator remains reusable for other ranking use cases.

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[ezedike-evan]

Thanks for picking this up. The fee-budget logic in `solve.ts` and `route.ts` is the right direction, but there are several issues that need to be fixed before this can merge.

Blocking issues

1. PR title is not Conventional Commits — CI will fail

The title `Feebudgetguard` will be rejected by `.github/workflows/pr-title.yml`. It must follow the pattern `type(scope): description`, e.g.:

```
feat(router): add fee-budget guard with FeeBudgetExceededError (#122)
```

2. Accidental git submodule added

The diff contains:
```diff
+++ b/stellar-intel
@@ -0,0 +1 @@
+Subproject commit 838fdf3
```

This adds the repo as a submodule pointing at itself — a clear mistake. Please remove it: `git rm --cached stellar-intel && git commit`.

3. `lib/env.ts` indentation error

In `parseEnv()`, the new key is indented differently from every other key (two spaces instead of four):

```ts
// wrong
NEXT_PUBLIC_FEE_BUDGET_PCT: process.env.NEXT_PUBLIC_FEE_BUDGET_PCT,
```

Align it with the surrounding keys. This will cause a lint failure (`--max-warnings 0`).

4. `solve.ts` calls `env` at module load time — breaks in test environments

`FeeBudgetExceededError` constructor and `getMaxFeeForAmount` read `env.NEXT_PUBLIC_FEE_BUDGET_PCT` as a default parameter, meaning `parseEnv()` is called when the module is first imported. Any test that imports `solve.ts` without setting every required env var will throw immediately. The existing `tests/lib/router.solve.test.ts` works only because it passes an explicit `feeBudgetPct`. The error constructor still does:

```ts
constructor(amount: number, feeBudgetPct: number | undefined = env.NEXT_PUBLIC_FEE_BUDGET_PCT) {
```

This is evaluated at call time, but `env` is a module-level import that triggers `parseEnv()` on import. If the env schema doesn't validate (common in test/CI), the entire module fails. Use a lazy getter or pass the value explicitly instead.

5. New route `app/api/rates/route.ts` duplicates the existing `app/api/intent/offramp/route.ts`

There is already an anchor-rates API route at `app/api/intent/offramp/route.ts` on `main`. Adding a second rates endpoint at `/api/rates` without removing or rerouting the original creates a confusing split. This PR should either patch the existing route or provide a clear migration path — a new parallel route with no consumers is scope creep.

6. `tx-builder.ts` and its tests are out of scope for this issue

Issue #122 (fee-budget guard) estimated changes to `lib/router/solve.ts` and `lib/env.ts` only. The new `lib/stellar/tx-builder.ts` and `tests/tx-builder.spec.ts` are unrelated to fee budgeting — they belong in their own PR against the appropriate issue.

7. Checklist boxes unchecked with no justification

The PR template requires every box to be ticked or marked N/A with a reason. `typecheck`, `lint`, `build` are all left as "⏳ not run" with the blanket reason of "existing repo-wide ambient errors." That isn't a valid exemption — those issues need to be fixed or pre-existing failures isolated with `// @ts-expect-error` annotations. Please run all three and resolve new failures before requesting re-review.

How to fix

1. Rename the PR title to follow Conventional Commits.
2. `git rm --cached stellar-intel` and amend/commit.
3. Fix the indentation in `lib/env.ts`.
4. Remove `env` as a default-parameter dependency from `FeeBudgetExceededError` constructor and `getMaxFeeForAmount`; accept the value as a required param or read it at call site only.
5. Remove `app/api/rates/route.ts` (or justify its relationship to the existing route).
6. Move `lib/stellar/tx-builder.ts` and `tests/tx-builder.spec.ts` to a separate PR.
7. Run `npm run typecheck && npm run lint && npm run build` and fix all new failures.

[ezedike-evan]

Thanks for the contribution, @GiftedGiftB! I'm closing this for now so it can come back in a cleaner form. Reasons:

• No linked issue — the description says "Closes none", but every PR needs to close exactly one issue.
• Scope creep — beyond the fee-budget change it also does an "infrastructure/off-ramp UI overhaul" and adds a stray stellar-intel file plus tsconfig changes. Please keep one logical change per PR.
• Merge conflicts with main.

Please reopen/resubmit a focused PR that links a single issue, contains only the fee-budget work, and is rebased on the current (now-green) main. Appreciate the effort!