Edict
<a href="https://glama.ai/mcp/servers/Sowiedu/Edict"><img width="380" height="200" src="https://glama.ai/mcp/servers/Sowiedu/Edict/badge" /></a>
A programming language designed for AI agents. No parser. No syntax. Agents produce AST directly as JSON.
Edict is a statically-typed, effect-tracked programming language where the canonical program format is a JSON AST. It's purpose-built so AI agents can write, verify, and execute programs through a structured pipeline — no text parsing, no human-readable syntax, no ambiguity.
Agent (LLM)
│ produces JSON AST via MCP tool call
↓
Schema Validator ─── invalid? → StructuredError → Agent retries
↓
Name Resolver ────── undefined? → StructuredError + candidates → Agent retries
↓
Type Checker ─────── mismatch? → StructuredError + expected type → Agent retries
↓
Effect Checker ───── violation? → StructuredError + propagation chain → Agent retries
↓
Contract Verifier ── unproven? → StructuredError + counterexample → Agent retries
(Z3/SMT) ↓
Code Generator (pure-JS WASM encoder) → WASM → ExecuteFeatures
- JSON AST — Programs are JSON objects, not text files. No lexer, no parser.
- Structured errors — Every error is a typed JSON object with enough context for an agent to self-repair.
- Type system —
Int,Float,String,Bool,Array<T>,Option<T>,Result<T,E>, records, enums, refinement types. - Effect tracking — Functions declare
pure,reads,writes,io,fails. The compiler verifies consistency. - Contract verification — Pre/post conditions verified at compile time by Z3 (via SMT). Failing contracts return concrete counterexamples.
- WASM compilation — Verified programs compile to WebAssembly via a pure-JS encoder and run in Node.js.
- MCP interface — All tools exposed via Model Context Protocol for direct agent integration.
- Schema migration — ASTs from older schema versions are auto-migrated. No breakage when the language evolves.
Execution Model
Edict compiles to WebAssembly and runs in a sandboxed VM. This is a deliberate security decision — not a limitation:
- No ambient authority — compiled WASM cannot access the filesystem, network, or OS unless the host explicitly provides those capabilities via the pluggable
EdictHostAdapterinterface - Compile-time capability declaration — the effect system (
io,reads,writes,fails) lets the host inspect what a program requires before running it - Runtime enforcement —
RunLimitscontrols execution timeout, memory ceiling, and filesystem sandboxing - Defense-in-depth — agent-generated code that runs immediately needs stronger isolation than human-reviewed code. The effect system + WASM sandbox + host adapter pattern provides exactly that
Host capabilities available through adapters: filesystem (sandboxed), HTTP, crypto (SHA-256, MD5, HMAC), environment variables, CLI arguments. New capabilities are added by extending EdictHostAdapter.
Quick Start
For AI Agents (MCP)
The fastest way to use Edict is through the MCP server — it exposes the entire compiler pipeline as tool calls:
npx edict-lang # start MCP server (stdio transport, no install needed)Or install locally:
npm install edict-lang
npx edict-lang # start MCP serverTwo calls to get started: edict_schema (learn the AST format) → edict_check (submit a program). See MCP Tools for the full tool list.
For Development
npm install
npm test # 2675 tests across 136 files
npm run mcp # start MCP server (stdio transport)Docker
Run the Edict MCP server in a container — no local Node.js required:
# stdio transport (default — for local MCP clients)
docker run -i ghcr.io/sowiedu/edict
# HTTP transport (for remote/networked MCP clients)
docker run -p 3000:3000 -e EDICT_TRANSPORT=http ghcr.io/sowiedu/edictSupported platforms: linux/amd64, linux/arm64.
Browser
Run the Edict compiler entirely in the browser — no server required:
| Bundle | Size | Phases | Use case |
|---|---|---|---|
edict-lang/browser | 318 KB | 1–3 (validate, resolve, typecheck, effects, lint, patch) | Lightweight checking |
edict-lang/browser-full | ~14 MB | 1–5 (+ WASM codegen, Z3 contracts, WASM execution) | Full compile & run |
import { compileBrowser, runBrowserDirect } from 'edict-lang/browser-full';
const result = compileBrowser(astJson);
if (result.ok) {
const run = await runBrowserDirect(result.wasm);
console.log(run.output); // "Hello, World!"
}Note: ESM modules require HTTP serving. Use
npx serve .or any static server —file://won't work.
See examples/browser/index.html for a working example.
QuickJS (Sandboxed Environments)
The Edict compiler also runs inside QuickJS WASM — useful for sandboxed runtimes, edge workers, or embedding in other WASM applications:
| Bundle | Size | Phases | Slowdown vs Node.js |
|---|---|---|---|
dist/edict-quickjs-check.js | 373 KB | 1–3 (validate, resolve, typecheck, effects) | ~3.7x |
dist/edict-quickjs-full.js | 932 KB | 1–5 (check + WASM compile) | ~3.7x |
import { EdictQuickJS } from "edict-lang/quickjs";
const edict = await EdictQuickJS.createFull(); // phases 1-5
const result = edict.compile(ast);
if (result.ok) {
console.log(result.wasm); // Uint8Array of valid WASM
}
edict.dispose();Note:
quickjs-emscriptenis an optional peer dependency — install it alongsideedict-langto useEdictQuickJS. For fs-free environments, passbundleSourcedirectly instead of loading from disk.
See docs/quickjs-feasibility-report.md for full benchmarks and recommendations.
MCP Tools
| Tool | Description |
|---|---|
edict_schema | Returns the full AST JSON Schema — the spec for how to write programs |
edict_version | Returns compiler version and capability info |
edict_examples | Returns 41 example programs as JSON ASTs (includes schema snippet) |
edict_validate | Validates AST structure (field names, types, node kinds) |
edict_check | Full pipeline: validate → resolve names → type check → effect check → verify contracts |
edict_compile | Compiles a checked AST to WASM (returns base64-encoded binary) |
edict_run | Executes a compiled WASM binary, returns output and exit code |
edict_patch | Applies targeted AST patches by nodeId and re-checks |
edict_errors | Returns machine-readable catalog of all error types |
edict_lint | Runs non-blocking quality analysis and returns warnings |
edict_debug | Execution tracing and crash diagnostics |
edict_compose | Combines composable program fragments into a module |
edict_explain | Explains AST nodes, errors, or compiler behavior |
edict_export | Packages a program as a UASF portable skill |
edict_import_skill | Imports and executes a UASF skill package |
edict_generate_tests | Generates tests from Z3-verified contracts |
edict_replay | Records and replays deterministic execution traces |
edict_deploy | Compiles and deploys an Edict program to edge runtimes (Cloudflare Workers) |
edict_invoke | Invokes a deployed Edict WASM service via HTTP |
edict_invoke_skill | Invokes a UASF skill package directly |
edict_package | Packages a compiled program as a deployable skill bundle |
edict_support | Returns diagnostics and environment info for troubleshooting |
MCP Resources
| URI | Description |
|---|---|
edict://schema | The full AST JSON Schema |
edict://schema/minimal | Minimal schema variant for token-efficient bootstrap |
edict://examples | All example programs |
edict://errors | Machine-readable error catalog |
edict://schema/patch | JSON Schema for the AST patch protocol |
edict://guide | Agent bootstrap guide for MCP-first onboarding |
edict://support | Diagnostics and environment info |
Example Program
A "Hello, World!" in Edict's JSON AST:
{
"kind": "module",
"id": "mod-hello-001",
"name": "hello",
"imports": [],
"definitions": [
{
"kind": "fn",
"id": "fn-main-001",
"name": "main",
"params": [],
"effects": ["io"],
"returnType": { "kind": "basic", "name": "Int" },
"contracts": [],
"body": [
{
"kind": "call",
"id": "call-print-001",
"fn": { "kind": "ident", "id": "ident-print-001", "name": "print" },
"args": [
{ "kind": "literal", "id": "lit-msg-001", "value": "Hello, World!" }
]
},
{ "kind": "literal", "id": "lit-ret-001", "value": 0 }
]
}
]
}The Agent Loop
The core design: an agent submits an AST → the compiler validates it → if wrong, returns a StructuredError with enough context for the agent to self-repair → the agent fixes it → resubmits.
// 1. Agent reads the schema to learn the AST format
const schema = edict_schema();
// 2. Agent writes a program (may contain errors)
const program = agentWritesProgram(schema);
// 3. Compile — returns structured errors or WASM
const result = edict_compile(program);
if (!result.ok) {
// 4. Agent reads errors and fixes the program
// Errors include: nodeId, expected type, candidates, counterexamples
const fixed = agentFixesProgram(program, result.errors);
// 5. Resubmit
return edict_compile(fixed);
}
// 6. Run the WASM
const output = edict_run(result.wasm);Architecture
src/
├── ast/ # TypeScript interfaces for every AST node
├── validator/ # Schema validation (structural correctness)
├── resolver/ # Name resolution (scope-aware, with Levenshtein suggestions)
├── checker/ # Type checking (bidirectional, with unit types)
├── effects/ # Effect checking (call-graph propagation)
├── contracts/ # Contract verification (Z3/SMT integration)
├── codegen/ # WASM code generation (pure-JS encoder)
│ ├── codegen.ts # IR → WASM module orchestration
│ ├── compile-ir-expr.ts # IR expression compilation
│ ├── compile-ir-*.ts # Specialized IR compilers (calls, data, match, scalars)
│ ├── runner.ts # WASM execution (Node.js WebAssembly API)
│ ├── host-adapter.ts # EdictHostAdapter interface + platform adapters
│ ├── closures.ts # Closure capture and compilation
│ ├── hof-generators.ts # Higher-order function WASM generators
│ ├── wasm-encoder.ts # Pure-JS WASM binary encoder (replaced binaryen)
│ ├── wasm-interpreter.ts # Pure-JS WASM interpreter (no WebAssembly API needed)
│ ├── recording-adapter.ts # Execution recording for replay
│ ├── replay-adapter.ts # Deterministic replay from recorded traces
│ └── string-table.ts # String interning for WASM memory
├── ir/ # Mid-level IR (lowering, optimization)
├── builtins/ # Builtin registry and domain-specific builtins
├── compact/ # Compact AST format (token-efficient for agents)
├── compose/ # Composable program fragments
├── deploy/ # Edge deployment scaffolding (Cloudflare Workers)
├── incremental/ # Incremental checking (dependency graph + diff)
├── lint/ # Non-blocking quality warnings
├── patch/ # Surgical AST patching by nodeId
├── migration/ # Schema version migration (auto-upgrade older AS
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