eggcalc

CLI calculator accepting natural language and unit conversion. Standard library only.

Install with pip install eggcalc and run it like calc 2 meters plus 2ft. It is spacing-tolerant and normalizes operator-adjacent spacing before parsing, including unit forms like 30 km / h in mph, 5 in in cm, and spaced unit products like 5 N m or 5 m s.

Written in pure Python with no external dependencies, it can be used as a CLI tool, a Python library, or an MCP server for AI agents.

Features

• Natural Language Input: "five plus three times two" → 11
• Unit Conversions: "30m + 100ft" → 60.48 m
• Complex Numbers: "sqrt(-1)" → 1j
• Safe Evaluation: AST-based parsing, no eval(), blocks dangerous operations
• MCP Server: deterministic text, JSON, validation, math, path, manifest, patch, repo, network, encoding, and temporal tools for AI agents
• Pure Python: Standard library only, no dependencies

Requirements

• Python 3.11 or higher (3.10 is no longer supported)
• Operating systems: Linux, macOS, Windows
• All tools and features are fully available on every supported runtime — no reduced capability set
• Compatibility evidence: primary CI runs the full gate on Ubuntu / Python 3.11; a recurring compatibility workflow covers Windows / Python 3.11, macOS / Python 3.11, and Ubuntu / Python 3.14 (path-filtered on push/PR plus a weekly schedule)

Installation

pip install eggcalc

Or from source:

git clone https://github.com/eggstack/eggcalc.git && cd eggcalc
pip install -e .

Or run directly without installing:

python -m eggcalc "five plus two"

CLI Usage

calc "five plus two"                    # 7
calc "(twenty + five) * 3"              # 75
calc "30m + 100ft"                      # 60.48 m
calc "sin of 3.14159"                   # 2.653e-06
calc "5 times avogadro"                 # 3.011e+24
calc -e "5 + 3"                         # 8 (quiet mode)
calc -i                                 # Interactive REPL
calc --mcp                              # MCP server mode

CLI Options

See docs/cli.md for the full option reference (including --usage, --verbose, -s/--show, --mcp-profile, and --mcp-schema-detail).

Python API

from eggcalc import evaluate_raw, evaluate

# Full pipeline (natural language, spaces, units)
result = evaluate_raw("five plus three")    # 8
result = evaluate_raw("30m + 100ft")        # 60.48 m

# Fast path (pre-normalized expressions only; skips the full pipeline)
result = evaluate("5+3")                     # 8

Caret (^) semantics differ between the two paths:

• evaluate() treats ^ as bitwise XOR (Python AST semantics).
• evaluate_raw() and CLI normalize ^ as exponentiation (rewritten to ** before parsing). Use xor/bitxor word forms for bitwise XOR through the full pipeline.

See docs/api.md for the full API reference including EggCalcApp, evaluate_cached(), evaluate_async(), evaluate_with_timeout(), trace_normalization(), custom constants/functions, and performance benchmarks.

To inspect how an expression is normalized without evaluating it:

from eggcalc import trace_normalization

trace = trace_normalization("five plus three")
# trace["normalized"] == "5+3"; trace["steps"] lists material rewrites per stage

or from the CLI: calc --explain "five plus three" (add --json for machine-readable output).

Evaluator built-ins preserve their dimensional contracts only while their canonical evaluator callables are active. Replacing a built-in name uses the generic dimensionless custom-callable rules. Canonical round() accepts round(number), round(number, ndigits), or the equivalent ndigits= form; omitted precision returns an int, while explicit precision returns a float. Timeout evaluation rejects added, deleted, or overridden callables before starting a worker process.

MCP Server

eggcalc runs as an MCP server exposing deterministic tools across 21 categories (math, text, json, validation, regex, list, path, identifier, shell, markdown, config, version, toml, cargo, unicode, manifest, patch, repo, network, encoding, temporal). All results are deterministic — same input always produces the same output.

Protocol version: Dual-era MCP over stdio — finalized 2026-07-28 stateless requests (per-request params._meta envelope, server/discover bootstrap, no handshake) plus legacy 2025-11-25 / 2024-11-05 handshake sessions (initialize before tools; pre-init tool requests are rejected). Successful tools/call results on both eras carry typed structuredContent (equal to the text envelope's result) alongside backward-compatible text; all tools advertise read-only/closed-world annotations and share one concise server instruction text. See docs/mcp.md for protocol details and lifecycle requirements.

calc --mcp

Programmatic multi-instance usage: Each McpServer instance owns its own McpServerConfig, ToolRegistry, ToolExecutor, evaluator, and session set. Multiple servers in one process are fully isolated. See docs/mcp.md for embedding examples.

Agent exposure: agent_core is an opt-in 10-tool experimental surface with deterministic specialist discovery via ToolRegistry.search_tools() plus tools/list(names=[...]) — see docs/mcp.md. Held-out cross-model evaluation shows that its current selection quality is below the full compact baseline, and the corrective pass did not promote an expanded candidate without per-case rollout evidence. full remains the default and practical general-agent recommendation. Exposure costs and the evidence live in the closure report and corrective reports (agent_core/compact ≈ 11.7 KB vs full/full ≈ 118.4 KB).

See docs/tool_inventory.md for the complete generated tool inventory. See docs/mcp.md for protocol usage, configuration, profiles, schema detail, and selected tool examples.

Runtime Capabilities

Query runtime capabilities (Python version, platform, feature detection, eggcalc version, supported protocol modes) from the CLI or Python API:

calc --capabilities          # JSON output
python -c "from eggcalc import detect_capabilities; print(detect_capabilities().to_json(indent=2))"

The MCP server's initialize response also includes a runtime key with capability information.

Supported Operations

Arithmetic: +, -, *, /, ** · Bitwise: &, |, ^, ~, <<, >> · Bases: 0x hex, 0b binary, 0o octal · Complex: 3+4i, 5j · Percentage: 50% = 0.5

Functions: trig (sin, cos, tan), hyperbolic, math (sqrt, log, exp), combinatorics (perm, comb, gcd, lcm), prime (isprime, primefactors), statistics (mean, median, std), random, memory registers, variables, and more. See docs/functions.md.

Units: length, time, data, data_rate, mass, volume, pressure, energy, power, force, voltage, current, angle, speed, area, frequency, temperature. Supports metric prefixes and imperial units. See docs/units.md.

Number words: zero through quintillion, fractions (half, quarter, thousandth, etc.).

Constants: pi, e, tau, i, avogadro, c, planck, boltzmann, gas constant, and more.

Custom Configuration

Create eggcalc_config.py to add custom constants, functions, and units:

CUSTOM_CONSTANTS = {"myconst": 42}
CUSTOM_FUNCTIONS = {"mysquare": lambda x, y: x**2 + y**2}
CUSTOM_UNITS = {"m": {"nm": 1e-9}}
CUSTOM_ALIASES = {"meter": "m", "meters": "m"}

Development

.venv/bin/python -m pytest tests/ -v     # Run tests
ruff check eggcalc tests                  # Lint
black eggcalc tests                       # Format
mypy eggcalc --ignore-missing-imports     # Type check
mypy --strict --follow-imports=silent --ignore-missing-imports tests/typing/consumer.py    # Strict consumer API check
make check                                # All checks (lint, format, typecheck, docs, test)
python build_single.py                    # Build single-file distribution

Security

eggcalc uses AST-based parsing (no eval()) with built-in DoS protection:

The MCP server adds additional resource bounds: request/output byte limits, per-tool timeouts, bounded thread pools, and pre-bounded inputs for all 83 tools. See docs/mcp.md and docs/mcp_resource_limits.md for details.

eggcalc_config.py is Python code loaded from the current working directory — only run eggcalc in directories you trust. Library APIs do not load config by default; set EGGCALC_LOAD_CONFIG=1 to enable. CLI loads config by default. Disable config loading with EGGCALC_NO_CONFIG=1.

License

MIT License