Forth on ESP32

ESPIDFORTH

ESP32forth ported to ESP-IDF via PlatformIO — no Arduino layer — running on ESP32, S3, C3 and C6. Extracted from Project MAG*Net's Hive AI prototype so every consumer shares one versioned core.

Source on GitHub Read launch story

What it is

A Forth interpreter running natively on ESP-IDF — built with PlatformIO, with no Arduino layer underneath it. Boot a board and you get a versioned banner with build info and memory stats, then an ok> prompt:

ok> : square dup * ;
ok> 7 square .
49

Where it came from

ESPIDFORTH began as Phase 2 of the Project MAG*Net Hive AI prototype. In August 2026 we lifted it into a standalone repository with its full history preserved, so that MAG*Net hive nodes and every other consumer share one versioned core instead of drifting copies — the usual fate of an interpreter living inside somebody’s application tree.

Targets

Target Status
ESP32-S3 Builds — primary target (M5Stack Dial, 8MB PSRAM)
ESP32-C3 Builds, tested on hardware — RISC-V, USB-serial-JTAG console
ESP32-C6 Builds — RISC-V
ESP32 Builds — classic Xtensa

What it implements

The core ANS Forth word set: arithmetic, the full stack vocabulary, comparison and logic, memory (! @ c! c@ here allot), defining words (: ;, variable, constant), and control flow including if/else/then, do/loop/+loop, and the begin/until/while/repeat family.

Test suites are compiled in by default and stripped by a build flag — the C3 release build is 178 KB, against 184 KB with tests included.

Status

Active. Today the engine is a stub implementing that core word set; the full ESP32forth v7.0.8.0 engine is preserved in third_party/ and replaces the stub once its Arduino dependencies are fully stripped. Source on github.com/IoTone/ESPIDFORTH.