Show HN: Aict – Unix coreutils that output XML/JSON, built for AI agents

A new open-source project called Aict reimplements 33 Unix coreutils to output structured XML or JSON instead of plain text, reducing token waste and parsing errors for AI agents. The tools, including ls, grep, and cat, provide labeled fields, absolute paths, and Unix timestamps, and can be used via command line or an MCP server for AI assistants like Claude.

Unix coreutils with XML/JSON output — built for AI agents, not humans. Install install · Quick start quick-start · All tools tools · MCP server mcp-server · Claude Code claude-code-integration · Token cost token-cost · Benchmarks benchmarks · Contributing /synseqack/aict/blob/master/CONTRIBUTING.md AI agents run ls , grep , and cat and get back human-readable plaintext . Then they spend tokens parsing column positions, guessing field widths, and handling inconsistent formats. This is fragile and wasteful. -rw-r--r-- 1 user staff 2048 Apr 6 10:00 main.go ← which column is size? -rw-r--r-- 1 user staff 1024 Apr 6 10:00 utils.go ← what's the language? drwxr-xr-x 5 user staff 160 Apr 6 10:00 internal ← is this a directory? aict reimplements 33 Unix tools with structured output the agent can read directly — no parsing required. bash $ aict ls src/ <ls timestamp="1746123456" total entries="3" <file name="main.go" path="src/main.go" absolute="/project/src/main.go" size bytes="2048" size human="2.0K" language="go" mime="text/x-go" binary="false" executable="false" modified="1746120000" modified ago s="3456"/ <file name="utils.go" path="src/utils.go" absolute="/project/src/utils.go" size bytes="1024" size human="1.0K" language="go" mime="text/x-go" binary="false" executable="false" modified="1746120000" modified ago s="3456"/ <directory name="internal" path="src/internal" modified="1746120000"/ </ls Every field is labeled. Paths are always absolute. Timestamps are Unix integers. Language and MIME type are detected automatically — zero parsing needed. brew tap synseqack/aict brew install aict This installs aict plus shell completions for bash and zsh. The MCP server is built in: aict mcp . go install github.com/synseqack/aict@latest git clone https://github.com/synseqack/aict cd aict go build -o aict . Verify install: aict --help should list all available tools. Default: XML output best for AI agents aict ls src/ aict grep "func" . -r aict cat main.go aict diff old.go new.go JSON output aict ls src/ --json Plain text same as the original Unix tools aict ls src/ --plain Enable XML globally for all aict calls export AICT XML=1 33 tools across 6 categories. Every tool supports --xml default , --json , and --plain . | Category | Tools | |---|---| File inspection | cat head tail file stat wc | Search & compare | ls find grep diff | Path utilities | realpath basename dirname pwd | Text processing | sort uniq cut tr sed awk | Data & archives | jq tar | System & environment | env system ps df du checksums md5sum sha1sum sha256sum | Additional: git status, diff, log, ls-files, blame · completions bash/zsh/fish · doctor self-diagnostic All tools follow the same conventions: | Field | Convention | |---|---| | Paths | Always absolute absolute attr | | Timestamps | Unix epoch integers + ago s companion | | Sizes | Bytes size bytes + human-readable size human | | Booleans | "true" / "false" strings | | Errors | <error code="" msg=""/ elements — never stderr | | Empty results | Valid XML with zero counts, never an error | aict mcp exposes all tools as callable MCP functions via stdio transport. AI assistants call them natively — no shell wrapping needed. The MCP server is a subcommand of the main binary. Configure Claude Desktop ~/.config/claude/claude desktop config.json : { "mcpServers": { "aict": { "command": "aict", "args": "mcp" } } } If aict is not in PATH, use its full path: { "mcpServers": { "aict": { "command": "/usr/local/bin/aict", "args": "mcp" } } } Add to ~/.claude.json : { "mcpServers": { "aict": { "command": "aict", "args": "mcp" } } } Once connected, Claude Code can call ls , grep , diff , and all other tools as native functions with typed arguments and structured JSON results. Honest numbers first: aict output costs 1.1–7.8× more tokens per task than terse GNU output measured with tiktoken o200k base . What those tokens buy: fewer round-trips and zero parsing ambiguity. Where plaintext needs 2–4 chained calls ls then file for languages, find then stat per hit , aict answers in one. | Task | GNU | aict | Tokens GNU → aict | |---|---|---|---| | List dir with size/type/language | 2 calls | 1 call | 246 → 820 · 3.3× | | Read file + line count + type | 3 calls | 1 call | 173 → 274 · 1.6× | Find .go files with size/mtime | 4 calls | 1 call | 47 → 367 · 7.8× | | Grep with file/line/context | 1 call | 1 call | 141 → 326 · 2.3× | | Diff with change types | 1 call | 1 call | 167 → 192 · 1.2× | Every extra plaintext call is a full agent turn — model inference, tool-call overhead, and intermediate output all land in the context window anyway, none of which the token counts above include. And in this very benchmark, file 1 misidentified a Go source file as "C source"; aict labeled it go . In a live agent eval opencode, same task 3× per toolchain , the aict-equipped agent generated ~46% fewer output tokens median 265 vs 487 and was correct 3/3 — the GNU-equipped agent shipped a flawed report in the run where it trusted file 1 's language detection. See benchmarks/TOKENS.md /synseqack/aict/blob/master/benchmarks/TOKENS.md for both methodologies; reproduce with go run ./cmd/tokenbench .Use --plain when you only need raw content. aict trades some speed for semantic richness language detection, MIME typing, absolute paths . The overhead is intentional. Startup cost is ~3.6 ms per invocation. | Tool | GNU | --plain | --xml | Notes | |---|---|---|---|---| diff 1000 lines | 0.9 ms | 1.9 ms · 2.1× | 2.1 ms · 2.4× | ✅ Myers O ND | wc 100k lines | 6.1 ms | 16 ms · 2.6× | 17 ms · 2.7× | ✅ | awk 10k lines | 4.1 ms | 12 ms · 2.9× | 11 ms · 2.6× | ✅ | sed 10k lines | 3.3 ms | 14 ms · 4.2× | 16 ms · 4.9× | ✅ | find deep tree | 1.9 ms | 13 ms · 6.8× | 15 ms · 8.0× | ✅ | ls 1000 files | 4.0 ms | 51 ms · 12.9× | 70 ms · 17.7× | MIME+lang detection per file | cat 100k lines | 1.4 ms | 24 ms · 16.4× | 31 ms · 21.6× | line-by-line scan + encoding detect | grep 100k lines | 1.3 ms | 119 ms · 88× | 130 ms · 96× | Go regexp vs GNU SIMD | Medians from 5 runs on Linux/amd64. See benchmarks/ /synseqack/aict/blob/master/benchmarks for methodology and make bench to reproduce.Use --plain to skip enrichment when you only need raw content. Why XML and not JSON by default? XML attributes are denser in a context window. <file size="1024" lang="go"/ is shorter than {"size":1024,"lang":"go"} . Use --json if you prefer JSON — the structure is identical. Why not pipe GNU tools to jq? ls , cat , stat , find , diff , and wc don't output JSON. jq can't help with them. aict provides structured output for the entire toolchain, not just grep. aict also ships its own jq for querying JSON files with path expressions. How does this compare to ripgrep? ripgrep is much faster for pure search. aict grep adds language detection, MIME type, and a consistent output format shared with every other tool. Use ripgrep for speed-critical search; use aict when the agent needs structured context. How does this compare to eza / lsd? eza and lsd are better ls for humans — great colors and formatting. aict outputs data structures, not formatted tables. They're solving different problems. Does it work on Windows? ls , cat , stat , wc , find , diff , grep , head , tail , sort , uniq , cut , tr , sed , awk , jq , tar , checksums , df , and path utilities work on Windows. system is Linux/macOS; ps is Linux-only it reads /proc . Unsupported platforms get a structured <error element, never a crash. Is this safe to run in a sandboxed environment? Yes. aict is strictly read-only. No network requests MIME detection uses the Go stdlib, not HTTP . No telemetry. No data collection. It only reads paths you explicitly pass to it. How many dependencies does it have? One: the official MCP Go SDK https://github.com/modelcontextprotocol/go-sdk , used only by the aict mcp subcommand. All 33 tools and every internal package are pure Go standard library — enforced as a hard constraint in AGENTS.md /synseqack/aict/blob/master/AGENTS.md . Bug reports, feature requests, and PRs are welcome. See CONTRIBUTING.md /synseqack/aict/blob/master/CONTRIBUTING.md for guidelines, code style, and the tool implementation pattern. Issues tagged good first issue https://github.com/synseqack/aict/issues?q=label%3A%22good+first+issue%22 are a good place to start. MIT /synseqack/aict/blob/master/LICENSE — built entirely by AI tools, for AI tools.