What is tigerfs CLAUDE.md?

Project instructions for TigerFS, a FUSE filesystem that lets users access PostgreSQL database tables, rows, and columns as folders and files through normal Unix commands.

Use them when developing TigerFS, investigating filesystem behavior, changing database operations, or running its Go unit and integration tests.

They explain how the database-to-filesystem mapping works and list the required build, formatting, checking, and testing commands.

How timescale/tigerfs configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to timescale/tigerfs. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/timescale/tigerfs/main/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/timescale/tigerfs

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/timescale/tigerfs/claude-md/github.svg)](https://agentmods.dev/instructions/timescale/tigerfs/claude-md)

Your own site

<a href="https://agentmods.dev/instructions/timescale/tigerfs/claude-md"><img src="https://agentmods.dev/badge/instructions/timescale/tigerfs/claude-md/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/timescale/tigerfs/claude-md"><img src="https://agentmods.dev/badge/instructions/timescale/tigerfs/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 3,227 This file is loaded in full into every session.

When invoked 3,227 The same file — it is already loaded in full.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.03227	$0.03227
Opus 5.5	$0.01291	$0.01291
Sonnet 5.5	$0.00645	$0.00645
Haiku 4.5	$0.00323	$0.00323

Measured 2mo ago against content hash 8bbba29800b2, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

tigerfs CLAUDE.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

CLAUDE.md · 264 lines

How it starts

The opening of the file, as written. The whole thing — 264 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CLAUDE.md

Guidance for Claude Code when working with this repository.

Project Overview

TigerFS is a FUSE-based filesystem that exposes PostgreSQL databases as mountable directories. Users interact with tables, rows, and columns using Unix tools (ls, cat, grep, rm) instead of SQL.

Primary Goal: Enable Claude Code to explore and manipulate database data using Read/Glob/Grep operations.

Full specification: See docs/spec.md for complete technical details including filesystem structure, data formats, SQL patterns, and error codes.

Development Commands

# Build
go build -o bin/tigerfs ./cmd/tigerfs

# Test
go test ./...                    # All tests
go test -race ./...              # With race detection
go test -run TestName ./path     # Specific test

# Synth app tests
go test ./internal/tigerfs/fs/synth/...                                      # Unit (synth package)
go test -run "^TestSynth_" ./internal/tigerfs/fs/... ./test/integration/...  # Unit (synth_ops) + integration

# Before committing (required)
go fmt ./... && go vet ./... && go test ./... && go mod tidy

Architecture

Code Style

This is primarily a Go codebase. Follow Go idioms: error handling with explicit returns, table-driven tests, and gofmt formatting.

Key Packages

Package	Purpose
`cmd/tigerfs/`	Entry point with signal handling
`internal/tigerfs/cmd/`	Cobra commands (pure functional builders)
`internal/tigerfs/fs/`	Shared filesystem logic (path parsing, operations, stat cache)
`internal/tigerfs/fuse/`	Linux FUSE adapter
`internal/tigerfs/nfs/`	macOS NFS adapter
`internal/tigerfs/db/`	PostgreSQL client and queries
`internal/tigerfs/backend/`	Cloud backend resolution (Tiger, Ghost, postgres://)
`internal/tigerfs/mount/`	Mount registry for tracking active mounts
`internal/tigerfs/config/`	Viper-based configuration
`internal/tigerfs/logging/`	Zap structured logging
`internal/tigerfs/format/`	Data serialization (TSV, CSV, JSON)

Read the full file on GitHub · 264 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

2mo ago First seen · 264 lines · 3,227 tokens per session scan A 8bbba29800b2

Subscribe to this mod's changes

tigerfs CLAUDE.md is an instructions file published in the GitHub repository timescale/tigerfs (723 stars, last pushed 3d ago), licensed MIT. It adds 3,227 tokens to every session, about $0.0129 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Databases PostgreSQL

tigerfs CLAUDE.md next to 6 instructions from other repositories
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tigerfs: Instructions file for Claude Code