This was last tested with bb 1.1.3, and nargo 1.0.0-beta.8
To install these versions:

bbup -v 1.1.3
noirup -v 1.0.0-beta.8

You only need to compile the circuits, and run prove.ts:

bash compile.sh
npm start

in bb 0.84, the verification key's length is 128.
when updating to 1.1.3, the verification key's length is 112.

Make sure to input the appropriate value in HONK_VK_SIZE in ./recurse/src/main.nr

If you don't like my prove.ts script and want to run things with the CLI using bb, here's some help

First build and prove the circuits that are going to be "recursed".

The proof needs to be in a specific format (an array of 32 bytes field elements).
bb has an option to do it automatically: --output_format

cd circuit_1 && mkdir proof

# compile the circuit and executes it
nargo execute

# generate proof
bb prove -v -s ultra_honk -b "./target/circuit_1.json" -w "./target/circuit_1.gz" -o ./proof --output_format bytes_and_fields --honk_recursion 1 --recursive --init_kzg_accumulator

# generate VK
bb write_vk -v -s ultra_honk -b "./target/circuit_1.json" -o ./proof --output_format bytes_and_fields --honk_recursion 1 --init_kzg_accumulator

bb verify -s ultra_honk -k ./proof/vk -p ./proof/proof -i ./proof/public_inputs

In the proof directory, the files that are important for us:

• proof_fields.json -> should be an array of 456 values + the number of public inputs
• vk_fields.json -> should be an array of 128 values

The first value in the proof_fields array should be the public input.
You need to remove it from the array!
If there are multiple public inputs, then remove all of them.

In the end, proof_fields's length must be 456.

You'll actually need to copy the public inputs to the recursive circuit

circuit_1 example
In our circuit_1, we have 2 public inputs:

• b = 4
• c = 12

So we'll remove the first 2 values which should be:

• 0x0000000000000000000000000000000000000000000000000000000000000004
• 0x000000000000000000000000000000000000000000000000000000000000000c

• Copy proof and VK to recurse/Prover.toml
• Adapt the number of public inputs in the recurse circuit: public_inputs: [Field; 2],
• Copy public inputs to recurse/Prover.toml

It seems like key_hash should be 0x0000000000000000000000000000000000000000000000000000000000000000 for now. Maybe that will change in the future

cd recurse
mkdir proof

nargo execute

bb prove -v -b "./target/recurse.json" -w "./target/recurse.gz" -o ./proof --recursive
bb write_vk -v -b "./target/recurse.json" -o ./proof --honk_recursion 1
bb verify -k ./proof/vk -p ./proof/proof -i ./proof/public_inputs