justi.fun and pump.fun
Rules, fees and API side by side.
pump.fun made one-click Solana launches normal. Both are good places to launch. This page lists the differences that matter when you build a product on top. pump.fun facts come from its public docs and SDK; rates there change over time, so check pump.fun/docs/fees for the current numbers.
Side by side
| justi.fun | pump.fun | |
|---|---|---|
| Curve program | Meteora Dynamic Bonding Curve | pump.fun's own bonding curve program |
| After graduation | Meteora DAMM v2, 100% of LP locked | PumpSwap, pump.fun's own AMM |
| Trading fee | Chosen by the creator per coin: 0.625% to 3.7879% total, every part listed (creator, holders, platform, Meteora) | Set by pump.fun for every coin; see their fee page |
| Holder rewards | Optional per coin: 0.5% of volume paid to holders in SOL every 10 minutes | Not a launch setting |
| Opening trades | 5 second window: fee starts at 50% and steps down; the extra buys back and burns | Normal fee from the first trade |
| Create transaction | Built by the server, sent privately through Jito | Built and sent by the creator's client |
| Dev buy | Capped at 15% of supply | Set by the creator |
| Copies | Exact copies (same ticker, name, image, website and X) refused for 24 hours | Not checked at launch |
| Supply and authorities | 1B fixed, no mint or freeze authority, metadata locked | 1B fixed, no mint or freeze authority |
| Hosted REST API | Yes: launch, quote, swap, submit, data, OpenAPI 3.1 spec | Third-party services offer hosted APIs |
| SDK | @justifun/sdk: full flow (build, sign, submit, confirm) | @pump-fun/pump-sdk: open-source instruction builders |
| Webhooks and streams | Signed webhooks, WebSocket channels, SSE | Available from third-party data providers |
| AI agents | @justifun/mcp MCP server and llms.txt | See pump.fun's docs |
When justi fits
- You want launches inside your own app without running Solana transaction code: one REST call builds it, your user signs.
- Your users care about the opening seconds: the window makes early bundles pay into burns.
- You want a coin to pay its holders, or its creator, at a rate you choose and can show.
- You want webhooks and a typed SDK from day one.
Your app can support both. Use each venue's own tools for its coins, and tag justi coins with the configs on the Protocol page.