Rent-Free Solana Programs

The Light SDK pays rent-exemption for PDAs, token accounts, and mints. Program logic stays mostly untouched.

| Rent cost (per account) | Solana / SPL | Light SDK | | :---------------------- | :------------------ | :------------------- | | Token account | ~2,000,000 lamports | ~11,000 lamports | | Avg. DeFi pool | ~$2 | ~$0.02 |

Workflow

Clarify intent
- Recommend plan mode, if it's not activated
- Use AskUserQuestion to resolve blind spots
- All questions must be resolved before execution
Identify references and skills
- Match task to domain references below
- Locate relevant documentation and examples
Write plan file (YAML task format)
- Use AskUserQuestion for anything unclear — never guess or assume
- Identify blockers: permissions, dependencies, unknowns
- Plan must be complete before execution begins
Execute
- Use Task tool with subagents for parallel research
- Subagents load skills via Skill tool
- Track progress with TodoWrite
When stuck: spawn subagent with Read, Glob, Grep, DeepWiki MCP access and load skills/ask-mcp

Domain References

| Audience | Reference | | -------- | --------- | | Anchor pattern | references/anchor.md | | Pinocchio pattern | references/pinocchio.md | | Client SDK (LightProgramInterface) | references/client-sdk.md | | Testing | references/testing.md | | CPI instructions | references/instructions.md | | FAQ | references/faq.md | | Router integration | references/router.md |

When to use which

| Criteria | Anchor | Pinocchio | |----------|--------|-----------| | Framework | anchor-lang 0.31, #[light_program] macro | pinocchio 0.9, LightProgramPinocchio derive | | State struct | Option<CompressionInfo> + LightAccount derive | CompressionInfo (non-optional) + bytemuck::Pod + Zeroable + #[repr(C)] | | Account creation | #[light_account(init, ...)] attribute or CreateTokenAccountCpi | CreateTokenAccountCpi, CreateMints batch pattern | | Compress/decompress handlers | Auto-generated by #[light_program] macro | Route ProgramAccounts::COMPRESS_ACCOUNTS_IDEMPOTENT etc. in entrypoint | | Program ID constant | Not needed (macro derives it) | pub const ID: Pubkey = pubkey_array!(...) + LIGHT_CPI_SIGNER required | | Dependencies | light-sdk, light-sdk-macros, light-token, light-anchor-spl | light-account-pinocchio, light-token-pinocchio, bytemuck |

DeFi integration

For DeFi programs (AMMs, lending, vaults): the Anchor and Pinocchio patterns above apply directly. DeFi-specific references:

| Task | Reference | |------|-----------| | Router/aggregator integration (cold account loading) | references/router.md | | LightProgramInterface trait (client SDK for routers) | references/client-sdk.md |

Hot vs Cold Model

After extended inactivity (multiple epochs without writes), accounts auto-compress to cold state. Programs only interact with hot accounts. Clients load cold accounts back on-chain via create_load_instructions.

| | Hot (active) | Cold (inactive) | |---|---|---| | Storage | On-chain | Compressed | | Latency | Normal | +0-200ms | | Tx size | Normal | +100-2400 bytes | | CU | Normal | +15k-400k CU | | Program code | No change | No change |

The hot path has zero overhead.

External References

| Resource | Link | |----------|------| | Anchor AMM reference | cp-swap-reference | | Pinocchio swap reference | pinocchio-swap | | Anchor counter (rent-free PDA) | basic-macros/counter | | Pinocchio counter (zero-copy PDA) | pinocchio/counter |

SDK references

| Package | Link | |---------|------| | light-sdk | docs.rs | | light-sdk-macros | docs.rs | | light-sdk-pinocchio | docs.rs | | light-token | docs.rs | | light-token-pinocchio | docs.rs | | light-account-pinocchio | docs.rs | | light-token-client | docs.rs | | light-client | docs.rs | | light-program-test | docs.rs |

Security

This skill does not pull, store, or transmit external secrets. It provides code patterns, documentation references, and development guidance only.

No credentials consumed. The skill requires no API keys, private keys, or signing secrets. env: [] is declared explicitly.
User-provided configuration. RPC endpoints, wallet keypairs, and authentication tokens (Privy, wallet adapters) are configured in the user's own application code — the skill only demonstrates how to use them.
Install source. npx skills add Lightprotocol/skills installs from the public GitHub repository (Lightprotocol/skills). Verify the source before running.
Subagent scope. This skill may spawn read-only subagents that use Read, Glob, and Grep to search the local repository. Restrict the working directory to your project.
Audited protocol. Light Protocol smart contracts are independently audited. Reports are published at github.com/Lightprotocol/light-protocol/tree/main/audits.