Your tokens.
Your strike.

Kest is a Solana covered-call protocol. Writers lock tokens and offer buyers the right to buy them at a fixed strike for a premium in SOL. Use the desk to model a position and the devnet ledger to follow actual trades.

What you can use today

The private desk runs in the browser. It offers four sample markets, an interactive payoff chart, and editable drafts saved on your device. Saving a draft moves no funds. On the same page, Live from the chain reads finalized devnet activity. Verify it yourself links each protocol account and sample transaction to Solana Explorer.

What happens when a call is filled

A writer locks the token quantity. A buyer pays a premium for the right to buy those tokens at a fixed strike. The recorded devnet buyer exercised before expiry. If the buyer exercises, the writer delivers the tokens and receives the strike payment. If the option expires unexercised, the writer recovers the tokens. The writer keeps the premium in both cases.

Edition dated 14 November 2026. Examples use the sample desk. On-chain observations use finalized Solana devnet receipts. The proof directory includes the addresses and signatures.

Model a position you can check by hand. This example uses the JUP sample market and a custom premium.

1. Open a JUP call. Choose Markets, then Write on the JUP row. Its reference price is 0.0031 SOL per JUP. Opening from the home-page Write a call button instead selects wSOL and carries over the home-page strike slider.
2. Enter your terms. Set Collateral quantity to 100, leave Strike above reference spot at +15%, select 7 days, and enter 0.05 in Total premium (SOL). Entering the premium last overrides the estimate.
3. Read the chart. Leave Price at expiry at 135% of spot. The marker should read 0.4065 SOL. The strike is 0.003565 SOL per JUP. Drag the price below the strike to see the position value fall.
4. Save and reopen. Choose Save draft. In My drafts, select Edit to reopen the same terms, then Update draft to keep a change. Delete removes the selected draft from this browser. Closing the form discards unsaved edits.

Reading the two lines

The solid line shows the value of the collateral plus the premium, assuming exercise above the strike. The dashed line shows the value of holding the same tokens. Where the solid line becomes horizontal, the writer has reached the maximum gross position value for those terms. The marker shows the selected scenario.

Why an apparently unchanged result can be correct

In this example, moving the price from 135% to 200% of spot leaves the solid line at 0.4065 SOL. The buyer can acquire all 100 JUP at the fixed strike, so additional appreciation above it accrues to the buyer. Below the strike, the writer still bears the token price risk.

Each market starts with a fixed SOL-denominated reference price. Defaults model collateral worth approximately 1 SOL, making the four rows easy to compare.

¹ Total sample premium on the default collateral at the default strike and term. Different rows have different terms. Premium rate ↓ ranks the fixture rates directly, without annualizing. These figures are illustrative, and the broader SPL-token vision exceeds the four samples available here.

Inputs and units

Switching the underlying resets the quantity, strike, tenor, expiry and premium to the new market’s defaults. wSOL is a wrapped form of SOL. Because the desk quotes in SOL, its wSOL price slider is a mechanical illustration of the chart, rather than a realistic forecast of large wSOL/SOL moves.

The simulator first suggests a premium from a fixed market preset. It then values the writer’s position at the expiry price you select.

Premium estimate

Let Q be token quantity, S₀ reference spot in SOL per token, s the selected strike uplift as a decimal, and D the selected term in days. The preset supplies its premium rate r₀, strike uplift s₀, and term D₀. For JUP these are 0.045, 0.15, and 30.

P = Q × S₀ × r₀ × √(D / D₀) × (1 + s₀) / (1 + s)

Doubling quantity doubles the estimate. A longer tenor increases it with the square root of time. A higher strike lowers it if all else is equal. For 100 JUP, +15%, and 7 days, the rule suggests about 0.00673849 SOL. The walkthrough overrides this with 0.05 SOL. This heuristic uses no order book, implied volatility, or live pricing data.

Value at expiry

Let K be strike in SOL per token, S_T the token price at expiry, and P the total premium. Values below assume exercise above strike and exclude fees.

K = S₀ × (1 + s)
Writer value = Q × min(S_T, K) + P
Hold value = Q × S_T
Buyer profit or loss = Q × max(S_T − K, 0) − P

The chart displays gross writer value. To measure profit against the reference position, subtract Q × S₀. A writer with a different acquisition cost should use that cost for personal profit or loss. The premium offsets only part of a decline. At a zero token price the modeled writer value is P.

The writer’s gross cap is Q × K + P. Relative to buying the collateral at S₀, the writer’s break-even price on the uncapped branch is S₀ − P/Q when that price is nonnegative. The buyer breaks even at K + P/Q. The hold-only line overtakes the covered-call line above that same price.

Follow one 100-JUP draft through six expiry prices. The writer keeps the premium in every scenario, while the buyer recovers its cost only once the token price rises far enough above the strike.

Reference spot is 0.0031 SOL per JUP. A +15% strike gives 0.003565 SOL per JUP. The collateral starts at 0.31 SOL and the buyer pays a total 0.05 SOL premium. Exercising costs 0.3565 SOL for all 100 JUP.

¹ Percentage of the reference spot. All monetary columns are in SOL. ² Writer P/L uses 0.31 SOL as starting collateral value and excludes fees. Exactly at the strike, either exercise choice has the same gross value.

At 135%, the buyer can pay 0.3565 SOL for tokens worth 0.4185 SOL. The difference is 0.062 SOL. After the 0.05 SOL premium, the buyer gains 0.012 SOL. The writer gains 0.0965 SOL against the starting position, while simply holding would have gained 0.1085 SOL.

A buyer pays a premium to acquire a call. Exercising requires a second SOL payment for the tokens. Each payment generated a protocol fee in the recorded trade.

Follow the 0.0028 SOL of fees

Rates above describe these two devnet transactions. Premium volume is the gross premium on filled calls. The writer’s take can differ after fees. The simulator shows gross values and excludes fees.

How to verify a burn

Follow the reserve’s activity. A completed buyback should link its SOL spend to the KEST received and the SPL burn instruction in the same successful transaction. The burn amount is measured in KEST base units. The first recorded reserve transactions funded the reserve and burned zero KEST.

The devnet history contains a write, a purchase, an exercise and a second write. Explorer links under On-chain proof let you follow each instruction.

When can the buyer exercise?

The devnet buyer exercised before the recorded expiry. The desk chart uses the token price at expiry to compare outcomes. Its slider cannot exercise a position or tell you the final eligible slot.

What fully collateralized means

The writer commits the full number of tokens promised to the buyer. That covers delivery even if the price rises. It leaves the writer exposed to a decline in the token and limits the upside once the strike is reached. The buyer still needs the strike payment to exercise.

The desk models whole positions. Partial fills, transfer of an exercise right, and cancellation of a filled call are outside the simulator.

Live from the chain reads finalized accounts from Solana devnet. The proof directory links the executable program, configuration, staking pool, buyback reserve, token mint, vaults and reference transactions.

Read the six counters

Verify a payment yourself

1. Choose the right network. Open On-chain proof and select the exercise receipt. Explorer should say Devnet and show a successful transaction.
2. Follow both legs. Expand the Kest instructions and inner transfers. Check the mint and token movement, the SOL payment, and the fee destinations. Open ClaimRewards to see the SOL actually claimed.
3. Check freshness. Read the finalized slot and timestamp next to the counters. A saved snapshot stays dated if a new reading cannot be verified.

Identify tokens by mint address. A supported-mint policy must account for transfer fees, freeze authority and transfer hooks before promising delivery for a new asset.

Kest displays quantities in token units and prices in SOL per token. Keeping these units separate makes it easier to read the composer and verify a settlement.

A call is in the money when the expiry price exceeds the strike. The premium is a sunk cost for the buyer at exercise time. A buyer can rationally exercise an in-the-money call and still lose money overall if its exercise value is smaller than the premium.

The desk ships as static HTML, CSS and JavaScript with bundled fonts and a logo. The working simulator requires no API key, RPC endpoint, wallet, database or package installation.

Run the desk locally

Extract the UI archive and open a terminal in the folder containing index.html. Run python3 -m http.server 8000 and visit http://localhost:8000/. In the hosted source checkout the same files are under dist/. Using localhost gives drafts a consistent browser origin.

Connecting a trading UI

The read-only panel uses public devnet RPC with no API key. To submit trades, integrate a version-matched instruction schema, supported mints and decimals, then simulate and confirm each transaction. A wallet would sign write actions. RPC provides account reads and transaction status. A market-discovery service, quote source or price oracle is conditional on the chosen trading and settlement design.

Replace hard-coded samples with clearly identified market data. Display an explicit mint and cluster, the collateral and SOL flows the user will sign, and a confirmed receipt. Treat a pending or timed-out submission as unresolved and reconcile the on-chain option state before enabling a retry.

The current desk keeps an array of drafts in localStorage under kest:drafts:1. Each record is specific to the browser profile and site origin. There is no account sync or on-chain order ID.

Common questions

Why did the premium stop moving? Editing it manually fixes its value. Reopening a saved draft also fixes the saved premium. Changing the underlying or starting a fresh call restores automatic estimation for that selection.

Why did the expiry date change? Choosing a new term recalculates from the current browser time. Reopening an existing draft preserves its saved expiry. An old draft can show a past date because it is a saved simulation.

Where did my draft go? Use the same browser, profile and site address. The hosted desk and localhost have separate storage. Clearing site data or ending a private browsing session can erase drafts. A storage error is reported if the browser rejects a save.

Why is there no transaction link? Save draft writes locally. There is no wallet signature, collateral transfer or premium payment to look up. Delete removes only the browser record.

Why can’t I save? Enter a supported token, a finite quantity of at least 0.000001 and a finite nonnegative premium. If those fields validate but saving fails, check that the browser allows storage for the site.

Use these acceptance checks before enabling wallet transactions. The linked devnet receipts demonstrate individual actions. They do not cover all failure cases.

Decisions still needed

Publish the exact expiry boundary, reclaim conditions, mint admission criteria, staking eligibility, fee configuration controls, buyback execution permissions and upgrade policy for the release users will sign against.

Implementation record

The on-page proof directory identifies the devnet program, account and vault addresses, transaction signatures, and snapshot slot. Verify the corresponding deployment and interface separately before using another cluster.