How to check route quality before swapping USDC to WETH

Swapping USDC to WETH looks like a one-click action, but the price you see in a wallet quote is not always the price you keep. Before you commit, you can run a read-only route check that models how much a given route would quietly leak — to MEV, slippage, and gas — and compares it against supported alternatives at the same trade size. This walkthrough shows how to do that for a USDC → WETH swap, how to read the result, and how to keep a record of the call.

What "route quality" means

Route quality is the execution-adjusted quality of a swap, not its headline price. Two routes can show a nearly identical quote and still hand you very different outcomes once MEV, slippage, and gas are accounted for. A route check scores the dimensions that quietly erode execution and turns them into one comparable number.

For a supported route, the check models:

• MEV exposure — how exposed the route is to sandwich and frontrun activity, expressed in plain basis points.
• Expected route leak — the modeled gap between the mid quote and the price a route would realistically clear at your notional, in bps and in USD.
• Slippage versus the mid quote, kept separate from the swap fee and from gas.
• Gas efficiency and liquidity depth — the quality terms that make a route cheaper and deeper.

Those combine into a single 0–100 Routescore and an A–F grade. The sign convention is explicit: risk penalties (MEV, slippage) are subtracted and quality terms (gas efficiency, liquidity depth) are added, so a higher Routescore always means a better execution-adjusted route. The number is modeled and point-in-time — a comparison input, not a quote and not a prediction that any specific trade will or will not be attacked. Some risks sit deliberately outside the score and are surfaced separately on the artifact: oracle, bridge, and smart-contract risk are named, not folded into a price-execution number.

Run the check on USDC → WETH

Start with the public sample report at /reports/usdc-weth-10k — a worked USDC → WETH example at a $10k notional that renders the full artifact with no signup and no wallet connection, so you can see the shape of the output before running your own.

When you are ready to run your own numbers:

You now have a grade, an expected-leak band, and at least one alternative to compare against.

Read the grade, the expected-leak band, and the alternatives

The grade summarizes modeled route quality; the expected-leak figure is what that grade implies in dollars at your notional. Read it in three passes:

• The grade (A–F). A high grade means the modeled risk penalties are low relative to the quality terms for that route, at that size, right now. A low grade is a reason to look harder, not a verdict.
• The expected-leak band. Leak is shown as a range, not a single hard figure, because slippage at a point in time is a range — depth, routing, and timing all move it. For a deep USDC → WETH pool a small trade sits near the tight end of the band; a larger notional pushes toward the wide end as depth thins and price impact grows. Watch where your size lands inside the band rather than fixating on the midpoint.
• The alternatives. When a supported route carries a lower modeled leak than the canonical Uniswap V3 baseline, it is surfaced as a lower-leak route for the same pair. Routescore shows you that comparison and the caveats and lets you decide — it compares routes, it does not pick one for you and it never sends a transaction.

Move the trade-size slider and watch the band shift: a route that grades cleanly at $1k can grade very differently at $100k. That movement is the point — it tells you how sensitive this particular USDC → WETH swap is to the size you are about to commit.

Decide, then keep a record

The route check is the pre-decision step, not the trade. When you act, you confirm the live quote and your slippage tolerance in your own venue, with your own settings. Routescore stays read-only and non-custodial throughout — it never holds, moves, routes, or executes the swap.

The check is worth more when it leaves a trail:

• Save the scenario and you get a decision record that captures the route, notional, modeled leak band, model and feature versions, source freshness, caveats, and confidence state — the full basis for the number, not just the number. It is hash-recorded and tamper-evident: edit a field after the fact and the recomputed hash no longer matches.
• Attach an outcome label later, once you know how the swap actually cleared. That label lands as a new append-only state, so the call and the result sit side by side.
• Review the record to see whether the modeled band held at that size. Run a check, save the record, review the outcome — that loop is the part that compounds, turning one route check into calibration evidence over time.

For USDC → WETH specifically, this is where a habit pays off: it is one of the most-traded pairs in DeFi, so a saved record of why you chose a route at a given size is reusable context the next time you run the same swap.

Where to go next

• Run your own check on the route check.
• Learn what it covers on the DeFi route checker.
• Inspect a worked example in the USDC → WETH sample report.
• Read how the score is built in the methodology.