pico-zkapp-template

Minimal Fibonacci-on-Pico example.

Prerequisites

Install the Pico CLI:

cargo +nightly-2025-08-04 install \
  --git https://github.com/brevis-network/pico \
  --tag v2.0.0 \
  pico-cli

Install the Pico guest toolchain (one time):

cargo pico install

Quick start

Create a project and build the guest ELF:

cargo pico new --template basic my-app
cd my-app/app && cargo pico build

Prove:

cd ../prover
VK_VERIFICATION=false cargo run --release

Expected output:

Public value n: 100, a: 3314859971, b: 2425370821

VK_VERIFICATION=false is needed while running stock shapes against a freshly-built guest ELF on this release.

AOT mode (experimental)

Opt-in path that drives the snapshot-main thread with the AOT emulator (SnapshotMainMode::Aot) instead of the interpreter. AOT chunks are generated from your own guest ELF, so the flow has one extra prep step you re-run whenever app/src/*.rs changes.

One-time setup

Install the AOT codegen binary:

cargo +nightly-2025-08-04 install \
  --git https://github.com/brevis-network/pico \
  --tag v2.0.0 \
  pico-aot-codegen

Every time the guest changes

Rebuild the guest ELF, regenerate AOT chunks against it, then prove:

cd app && cargo pico build
cd ..

PICO_AOT_RUNTIME_SPEC='git = "https://github.com/brevis-network/pico", tag = "v2.0.0"' \
  generate_crates app/elf/riscv64im-pico-zkvm-elf ./aot-generated

cd prover
VK_VERIFICATION=false cargo run --release --features aot -- --aot

PICO_AOT_RUNTIME_SPEC tells the codegen tool to emit pico-aot-runtime as a git dep in the generated chunk Cargo.tomls, so aot-generated/ can live at the template root without a local pico checkout.

Expected: the console prints aot enabled: default_snapshot_main_mode = Aot followed by the same Public value n: 100, ... line as the default path.

Notes on AOT mode

• aot-generated/ is specific to your current guest ELF. If app/src/*.rs changes, re-run cargo pico build and generate_crates; otherwise the chunks' PC ranges will no longer match and AOT will silently fall back to the interpreter.
• aot-generated/ is gitignored apart from a minimal bootstrap stub. Never commit the regenerated contents.
• At larger inputs the AOT path panics at vm/src/emulator/riscv/memory.rs:1013. Tracked upstream. Does not fire at n = 100.

Layout notes

• app/elf/riscv64im-pico-zkvm-elf is the default guest ELF, produced by cargo pico build inside app/.
• app/elf/riscv32im-pico-zkvm-elf is the historical rv32 ELF, kept for reference. The current Pico VM cannot execute it.