sno code — Synoema Mode

Deep language integration for .sno projects

When Does Synoema Mode Activate?

The agent detects project type on startup. Synoema mode activates automatically when:

sno.toml is present in the project root, or
≥50% of source files have a .sno extension

If both .sno files and other languages are present, the agent enters Mixed mode — Synoema tools remain active alongside general-purpose tools.

# Force Synoema mode regardless of detection
sno code --project-type synoema

# Check what the agent detects
sno code config detect

The status line (printed to stderr on startup) shows the resolved project type:

sno-code 0.1.0 | synoema | default | anthropic/claude-sonnet-4-6 | ask

Type-Aware Tools

In Synoema mode, the agent has access to language-specific tools that understand the type system, contracts, and module structure:

Typecheck before commit

The agent can run sno check to validate edits before suggesting them. Errors come back as structured diagnostics with LSP-compatible ranges, so the agent can self-correct:

# The agent uses this internally:
sno check file.sno
sno --errors json check file.sno   # LSP-compatible JSON output

Contract verification

Synoema supports requires/ensures contracts on functions. The agent verifies that edits preserve contracts:

# Inspect contracts
sno doc --contracts rule_pump.sno

# Verify with timeout
sno verify file.sno

Code generation

The JIT compiler (Cranelift) and WASM backend are available as agent tools for testing generated code:

sno jit file.sno          # JIT-compile and run
sno wasm file.sno         # Compile to WebAssembly
sno build --native file.sno -o binary   # AOT compile

Formatting

The agent auto-formats generated code with the deterministic sno fmt formatter:

sno fmt file.sno           # Format in-place
sno fmt src/ --check       # CI dry-run

MCP Integration

The Synoema MCP server (synoema-mcp) provides structured tools that the agent can invoke for deep codebase operations:

MCP Tool	Description
`typecheck`	Run `sno check` and return structured diagnostics
`eval_expr`	Evaluate a Synoema expression and return the result
`doc_query`	Query the language reference for type signatures and semantics
`get_context`	Get surrounding context for a symbol or location
`get_context_for_edit`	Get context optimized for making edits at a location
`search_corpus`	RAG vector search over the Synoema knowledge base

Setup

# Install MCP server
sno mcp-install

# Configure for Claude Desktop or Cursor
sno setup claude --binary
sno setup cursor --binary

# Verify
sno doctor

See MCP & RAG documentation for the full tool reference.

RAG Retrieval

The agent can search a pre-built vector index of the Synoema language documentation, stdlib, and idioms. This provides accurate, up-to-date knowledge about language features.

Install the RAG pack

sno rag install
sno rag status

The pack includes an ONNX embedding model and a pre-built vector index. Updates are checked automatically.

How it works

When the agent encounters a Synoema-related question, it routes the query through the Embed role (configurable model — e.g., ollama/bge-m3) to find relevant documentation chunks. Results are injected into the agent’s context for the current turn.

Custom indexes

# Build a custom index from your own sources
sno build-index \
  --sources corpus.jsonl,docs/,skills/ \
  --output ~/.sno/index/custom \
  --model ~/.sno/models/embed/current \
  --chunk-strategy auto \
  --batch-size 64

SNO.md Overlay

In addition to AGENTS.md (loaded for all project types), Synoema mode loads SNO.md files that provide language-specific context:

repo/SNO.md              # Repository-wide Synoema context
repo/src/SNO.md          # Subsystem-specific overlay
repo/src/core/SNO.md     # Module-specific overlay

SNO.md files are loaded after AGENTS.md and are injected with # Synoema-specific overlay: <path> headers. Use them for:

Type system conventions specific to your project
Contract patterns and verification rules
Module dependency guidelines
IoT rule compilation requirements

Inline Fix Agent

sno fix is a lightweight ReAct agent that automatically fixes type errors and diagnostics in a single file:

sno fix broken.sno                    # Fix type errors
sno fix broken.sno --max-turns 5      # Limit iterations
sno fix broken.sno --dry-run          # Preview diff without writing
sno fix broken.sno --with-rag         # Use RAG for context
sno fix broken.sno --with-rag --top-k 8

Unlike the full sno code agent, sno fix is focused on a single file and exits when all diagnostics are resolved or the turn limit is reached.

Synoema-Aware Skills

Skills are reusable task templates. In Synoema mode, the bundled skill library includes language-specific workflows:

# List available skills
sno skill list

# Install a custom skill
sno skill install ./my-skill/SKILL.md

Skills can specify tool allowlists, preferred models, and detailed instructions. They are injected into the agent’s context as an XML <skills> block.

Mixed Mode

When a project contains both .sno files and files in other languages, the agent enters Mixed mode. This is common for projects that use Synoema for domain logic alongside Rust, Python, or TypeScript for infrastructure.

In Mixed mode:

All Synoema tools remain available (sno check, contracts, MCP, RAG)
General-purpose tools are also active (file editing, shell commands)
The agent can reason across language boundaries

# Force Mixed mode
sno code --project-type mixed