JAM Service Playground

JAM Service Playground

This is a minimal playground to write JAM Services in C.

Details

You have access to the C Service SDK and a musl standard library with picoalloc. A few Linux syscalls are emulated to give the impression that the program is running on a Linux system, when in fact; it is running on the PVM interpreter of the GrayMatter JAM client (currently closed source).

The complete flow looks like this:

• C code: The user types in the code.
• Rest API: User pressed the 'Run' button.
• Backend server: API server receives the code.
• C compiler: Server calls the Clang C compiler to create a RISC-V object file.
• polkatool link: Create a '.jam' service file that is conformant to the Gray Paper.
• GrayMatter PVM Interpreter: Use the PVM interpreter of GM to execute the entry point.
• API reply: Synchronously send the execution result back to the client as JSON reply.

Keyboard Shortcuts

• Ctrl + Enter: Run code

Future

We plan to make it possible to call other entry points next to Accumulate here and also pass arguments to them. It will so be possible to see the post-execution stats like remaining gas and similar.