agent-tool-shared-cli 0.1.2

Shared chassis for agent-ready CLIs: the exit-code contract, JSON/table/markdown/CSV output with field projection, and keyring-backed credentials.

agent-tool-shared-cli

The shared chassis for the agent-tool-<x>-cli family — agent-ready command-line tools that an LLM can drive with no prior knowledge of them.

Consumers: agent-tool-openproject-cli, agent-tool-drone-cli (in progress).

This repo also holds BLUEPRINT.md — the engineering standard the whole family is built to. Read that first if you are standing up a new tool.

pip install agent-tool-shared-cli

What's in it

This package is deliberately small. It holds the agent contract and the pure utilities that implement it — the things that must be identical across every tool, because an agent learns the contract once and applies it everywhere.

Module	What
agentcli.errors	The exit-code taxonomy (0/1/3/4/5/6/7/130) + DryRun
agentcli.output	Emitter: json/table/markdown/csv, --fields projection, NDJSON streaming
agentcli.credentials	Keyring storage with a 0600 fallback and an env override
agentcli.appspec	AppSpec — the two strings that make all of the above tool-specific

from agentcli import AppSpec, Credentials, Emitter, OutputFormat, NotFoundError

SPEC = AppSpec(name="drone-cli", env_prefix="DRONECLI")

SPEC.config_dir()            # ~/.config/drone-cli  (or $DRONECLI_CONFIG_DIR)
SPEC.env("TOKEN")            # "DRONECLI_TOKEN"

Credentials(SPEC).get_token("default")     # env > keyring > 0600 file
Emitter(OutputFormat.json, fields=["id", "status"]).emit(rows)
raise NotFoundError("no such build")       # -> exit 5, JSON on stderr

The exit-code contract

Published API. You may leave a code unallocated, or repurpose one deliberately. You may never renumber one — agents branch on these, and they are documented in three places per tool (README, the in-binary guide, and the Claude skill).

Code	Meaning
0	success (including a successful --dry-run)
1	generic error
2	reserved for Click/Typer usage errors — never allocate
3	config error
4	auth error (401/403)
5	not found (404)
6	conflict (409 / optimistic locking)
7	validation error (422) — see fieldErrors
8+	per-tool, and only for a condition you have observed
130	SIGINT

What is deliberately NOT here

client.py, serialize.py, resolve.py and the domain commands stay in each tool. They look shareable and are not:

OpenProject stops paginating on an authoritative total — "never stop on a short page". Drone has no total, and a short page is the terminator. The rule that inverts between tool #1 and tool #2 is exactly the rule you must not hoist.

Auth schemes, retry matrices and error-body shapes are the same story. Pulling them in would make this a framework with a config object per tool, which is how shared-code projects die.

Share the contract, not the transport.

Contributing

You need nothing but Python:

pip install -e '.[test]'
pytest                       # 74 tests, no network, no services

Changes here affect every downstream CLI. Two rules:

1. Never renumber an exit code, and never change an output shape without treating it as a breaking change — downstream agents depend on both.
2. Don't add a module because two tools happen to share it today. Wait until a third does, and until you can state the rule it obeys. tests/test_contract.py is the tripwire: if a change makes you edit it, stop and think.

License

MIT