spreadsheet-kit MCP

agent-spreadsheet

agent-spreadsheet is the tool interaction service for agent-based spreadsheet usage.

It gives agents a safe, inspectable, token-efficient way to read, analyze, mutate, verify, and operationalize Excel workbooks without falling back to brittle UI automation.

If you want an agent to work with spreadsheets like a real system instead of a screenshot puppet, this is the stack.

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What this project is

agent-spreadsheet ships a unified spreadsheet interaction layer across three surfaces:

The WASM build (agent-spreadsheet-wasm) is the SDK's local runtime, not a separate product surface: JS and TypeScript code targets one object model and the execution substrate (server vs embedded engine) is a configuration choice.

In 0.16 these surfaces share the resident Rust document/evaluator runtime and 32-operation registry. Explicit native sessions automatically start a private journal-backed host. SDK/WASM and genuine just-bash sessions retain their history in memory; XLSX export saves a document snapshot, not a restartable session journal. Warm edit/recalculate/read loops avoid XLSX serialization and repeated evaluator ingestion. See runtime guarantees and limits and the SDK/just-bash examples.

Supported workbook modes:

• .xlsx / .xlsm — read + write
• .xls / .xlsb — discovery/read-oriented workflows only

Powered by Formualizer

Default in-process calculation uses [Formualizer](https://github.com/PSU3D0/formualizer) — a permissively licensed (MIT/Apache-2.0) spreadsheet engine written in Rust: formula parsing, dependency-graph recalculation, 400+ Excel functions, dynamic arrays, and deterministic evaluation built for agents. No Excel COM or headless LibreOffice is required. Optional LibreOffice integration remains available, but Formualizer is the release-critical backend.

That native engine is why this project can offer what most spreadsheet tooling for agents cannot: recalculate the actual workbook, trace which cells changed and why, and prove it — not just read cached values or push blind edits.

Embedding spreadsheet logic in your own product rather than driving workbooks as an agent? Use Formualizer directly (Rust, Python, JS/WASM).

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Why agents use agent-spreadsheet

Built for tool use, not just humans

• deterministic JSON contracts
• schema and example discovery from the CLI itself
• explicit pagination and compact output modes
• machine-readable warnings and error envelopes

Safe mutation, not blind mutation

• dry-run first workflows
• stateless output modes and overwrite safety
• event-sourced session editing
• verification surfaces for proving downstream outcomes
• structural impact analysis before risky workbook changes

Spreadsheet-aware, not generic file editing

• region detection
• table and footer-aware append helpers
• template row / row band cloning
• formula-specific replace and diagnostics
• named range CRUD
• recalculation + diff + proof flows

Good agent ergonomics

• nested command groups with legacy alias compatibility
• token-efficient reads
• exact-cell inspection and layout inspection
• workflow helpers for the repetitive parts agents usually get wrong

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What is new / what makes this stack different

The current surface is much stronger than a plain “read some cells” tool. Major capabilities now include:

• `asp` as the primary CLI with agent-spreadsheet preserved as a compatibility alias
• grouped verification via asp verify proof and asp verify diff
• preview-first workflow helpers for:
• write append
• write clone-template-row
• write clone-row-band
• formula-safe batch workflows with parse-policy diagnostics
• cell/layout/export/import inspection surfaces
• named range management (write name define|update|delete)
• formula-only replacement (write formulas replace)
• event-sourced session editing with log, branch, undo/redo, fork, apply, and materialize
• SheetPort manifest lifecycle + execution for contract-driven spreadsheet automation

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Install

Shell installer

curl -fsSL https://raw.githubusercontent.com/PSU3D0/agent-spreadsheet/main/install.sh | sh

The installer downloads a prebuilt CLI to ~/.local/bin and creates the asp command. Pin a release with ASP_VERSION=0.16.0, set ASP_INSTALL_DIR to choose another destination, or pass --mcp to install the MCP server too:

curl -fsSL https://raw.githubusercontent.com/PSU3D0/agent-spreadsheet/main/install.sh | sh -s -- --mcp

npm

npm i -g agent-spreadsheet

This installs both asp (the primary command) and agent-spreadsheet (the compatibility alias) from a prebuilt native binary. No Rust toolchain is required.

cargo-binstall

cargo binstall agent-spreadsheet

This installs the prebuilt CLI in seconds.

Cargo

cargo install agent-spreadsheet --features recalc --bin asp --bin agent-spreadsheet

This builds the CLI from source. Formualizer (the native Rust recalc engine) is included by default.

mise

mise use -g "ubi:PSU3D0/agent-spreadsheet[exe=asp]"

Homebrew

brew install psu3d0/tap/agent-spreadsheet

MCP server

cargo install agent-spreadsheet-mcp

Docker

# Read-only / slim

docker pull ghcr.io/psu3d0/agent-spreadsheet-mcp:latest

Write + recalc + screenshots

docker pull ghcr.io/psu3d0/agent-spreadsheet-mcp:latest-full

JavaScript SDK

npm i agent-spreadsheet-sdk

Prebuilt binaries

Download raw binaries and archives from GitHub Releases.

Published native assets include:

• Linux x86_64
• Linux arm64
• macOS x86_64
• macOS arm64
• Windows native binaries are not shipped for 0.16; native release validation targets Linux and macOS

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Start here: the core workflows

1) Orient the workbook before reading cells

# What sheets are here?

asp read sheets data.xlsx

What regions/tables/parameter blocks does this sheet contain?

asp read overview data.xlsx "Model"

What named items are available?

asp read names data.xlsx

Read a structured region as a table

asp read table data.xlsx --sheet "Model"

2) Inspect exactly what an agent needs

# Raw values for exact ranges

asp read values data.xlsx Model A1:C20

Detail-view for targeted cells (value / formula / cached / style triage)

asp read cells data.xlsx Model B2 D10:F12

Layout-aware rendering for a bounded range

asp read layout data.xlsx Model --range A1:H30 --render both

Export a bounded range to csv or grid json

asp read export data.xlsx Model A1:H30 --format csv --output model.csv

3) Do a safe stateless edit → recalc → proof → diff loop

asp workbook copy data.xlsx /tmp/draft.xlsx

asp write cells /tmp/draft.xlsx Inputs "B2=500" "C2==B2*1.1" asp workbook recalculate /tmp/draft.xlsx asp verify proof data.xlsx /tmp/draft.xlsx --targets Summary!B2,Summary!B3 --named-ranges asp verify diff data.xlsx /tmp/draft.xlsx --details --limit 50

A representative label-mode lookup:

asp analyze find-value data.xlsx "Net Income" --mode label --label-direction below

4) Preview structural risk before mutating the workbook

asp analyze ref-impact data.xlsx --ops @structure_ops.json --show-formula-delta

This is intentionally read-only. It surfaces shifted spans, absolute-reference warnings, token counts, and optional before/after formula samples.

5) Use workflow helpers instead of reinventing row logic

# Stateless batch writes

asp write batch transform data.xlsx --ops @ops.json --dry-run asp write batch style data.xlsx --ops @style_ops.json --dry-run

Append rows into a detected region or table, respecting footer rows when present

asp write append data.xlsx --sheet Revenue --table-name RevenueTable --from-csv rows.csv --header --dry-run

Clone one template row with preview-first planning

asp write clone-template-row data.xlsx --sheet Inputs --source-row 8 --after 8 --count 3 --dry-run

Clone a contiguous row band repeatedly

asp write clone-row-band data.xlsx --sheet Forecast --source-rows 12:16 --after 16 --repeat 4 --dry-run

6) Use a stateful session when the edit story gets complex

asp session start --base data.xlsx --workspace .

asp session op --session --ops @edit.json --workspace . asp session apply --session --workspace . asp session materialize --session --output result.xlsx --workspace .

And when you need proper history and branching:

asp session log --session <id> --workspace .

asp session fork --session scenario-a --workspace . asp session undo --session --workspace . asp session redo --session --workspace . asp session checkout --session --workspace .

7) Turn workbook interfaces into contracts with SheetPort

# Discover candidate ports from workbook structure

asp sheetport manifest candidates model.xlsx

Validate or normalize a manifest

asp sheetport manifest validate manifest.yaml asp sheetport manifest normalize manifest.yaml

Bind-check a workbook against a manifest

asp sheetport bind-check model.xlsx manifest.yaml

Execute the manifest with JSON inputs

asp sheetport run model.xlsx manifest.yaml --inputs @inputs.json

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CLI overview

The primary CLI is `asp`.

agent-spreadsheet remains available as a compatibility alias, so both of these are valid:

asp read sheets data.xlsx

agent-spreadsheet read sheets data.xlsx

Preferred command groups

• asp read ...
• asp analyze ...
• asp write ...
• asp workbook ...
• asp verify ...
• asp session ...
• asp sheetport ...

Legacy aliases

Legacy flat commands are still normalized to the new nested surface where practical. That makes migration easier for older prompts, docs, and automation.

Discoverability built into the CLI

When an agent is unsure of payload shape, it can ask the tool directly:

asp operations                  # CLI-supported runtime subset

asp registry --all # complete host-independent registry + schemas asp schema read_cells asp example read_cells asp schema write batch transform asp example write batch transform asp schema session op transform.write_matrix asp example session op transform.write_matrix

Canonical machine calls use the same registry and dispatcher as other surfaces. asp schema and asp example project the native adapter contract: resource_id and, for verification, baseline_resource_id are omitted from required JSON becau