agent-readable (Python + TypeScript)

Two sibling libraries, one philosophy: before coding against an unfamiliar API, inspect it at runtime to get the live public surface and any author-supplied behavioral rules — instead of guessing from stale training data.

	Python	TypeScript / JS
Library	agent-readable	agent-readable-ts
Install	pip install agent-readable	npm install agent-readable-ts
One-off, no install	uvx agent-readable <target>	npx agent-readable-ts <target>
Inspect function	agent_help(target)	agentHelp(target)
Author notes method	__agent_notes__() classmethod	agentNotes() method
Custom output method	__agent_help__()	agentHelper()
Protocol / mixin	AgentReadable, AgentReadableMixin	AgentHelper, AgentNoter interfaces

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When to activate

Call the inspect function before writing code against an API where guessing could plausibly be wrong — concretely, when:

• The target is project-local or third-party code you don't already know cold.
• It's stateful, version-sensitive, poorly documented, has lifecycle or ordering constraints, or exposes several similar entrypoints that are easy to confuse.
• You're adding or changing a public API meant for reuse by humans or agents.
• The user mentions agent_help, agentHelp, __agent_notes__, agentNotes, or the agent-readable / agent-readable-ts library.

When not to activate

Skip it for trivial builtins (len, dict, console.log), stdlib usage you know cold, routine calls into familiar libraries (a basic requests.get, a fs.readFile), and pure algorithmic code with no external API. Reserve it for APIs where getting usage wrong is plausible.

Language gate: this skill is for Python and TypeScript/JavaScript only. Do not apply it when working in other languages.

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Safety: imports and side effects

agent_help() / agentHelp() must import or require the target module — and import-time code runs. It may open connections, touch files, read env vars, or do heavy init. So:

• Run only in a trusted project environment.
• Don't blindly import untrusted, expensive, or destructive modules just to get help.
• If import is unsafe, read source/tests/type hints instead.

The output reflects the object as installed here, now. If code will run elsewhere (prod, CI), verify the package version there — the inspected API may differ.

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Python — Job 1: Consume

from agent_readable import agent_help

print(agent_help(SomeClass))      # class — constructor, public API, notes
print(agent_help(some_instance))  # instance — dispatches to its class
print(agent_help(some_module))    # module — docstring + public functions/classes/constants
print(agent_help(some_func))      # function or method — signature + docstring

From a shell — zero-install one-off (uv fetches and caches the CLI):

uvx agent-readable sqlite3:Connection
uvx agent-readable pathlib
uvx agent-readable json:dumps
uvx --with requests agent-readable requests:Session   # third-party target

pip-series equivalent: pipx run --spec agent-readable agent-readable <target>.

These one-off environments cannot import the project's own code — for project-local classes use the installed CLI (or python -c) from the project environment:

agent-readable my_package.temperature:CalibratedSensor
python -m agent_readable sqlite3:Connection

Reading the output

Section	Source	How to treat it
## Signature / ## Constructor	live introspection	Ground truth for the current call shape
## Public API	live introspection	Authoritative for which names exist
## Purpose, per-method summaries	docstrings	As accurate as the author's docstrings
## Agent usage rules	library boilerplate	Generic guardrails; don't invent behavior
## Notes from class <X>	__agent_notes__()	Behavioral guidance, if supplied and maintained

Attribute values are live too: public class attributes and module constants are listed with their current value (safe repr for exact primitives — a custom __repr__ is never executed), enums list their members, and module docs include C builtins — so agent_help(math) shows sin and pi, not just pure-Python code.

If a note contradicts a visible signature, trust the signature. Among multiple ## Notes from class sections, the leaf class wins.

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Python — Job 2: Author

Preference order: good docstrings → focused __agent_notes__() → (rarely) __agent_help__()

Docstrings first

agent_help() reads docstrings directly: the class docstring becomes ## Purpose, each method's first paragraph its ## Public API summary.

__agent_notes__() — cross-method rules only

Add a classmethod for rules that span methods:

class Sensor:
    """Reads a value from a hardware sensor."""

    def __init__(self, pin: int, *, unit: str = "C"): ...
    def calibrate(self, offset: float): ...
    def read(self) -> float: ...

    @classmethod
    def __agent_notes__(cls) -> str:
        return """
## Do
- Call `calibrate()` once during setup, before the first `read()`.

## Do not
- Do not call `read()` before `calibrate()` on first use.
"""

Belongs here: lifecycle/ordering, preconditions, cleanup, sync vs async, streaming vs non-streaming, do/don't lists.

Doesn't belong here: per-method behavior (→ that method's docstring), duplicated docstring content.

Only add __agent_notes__ when signatures + docstrings leave room for misuse. If the API is straightforward, skip them — they add maintenance burden.

Notes accumulate across the MRO (leaf wins on conflict). Don't call super() — collection is automatic. AgentReadableMixin only adds IDE hints; it's not required. A __agent_notes__() that raises is silently skipped — it won't break the document, but its rules won't be seen either; the contract test below calls the method directly and catches this.

Make notes verifiable

Anchor notes to real members and ship a contract test:

import re
from your_module import Sensor

def test_agent_notes_reference_real_members():
    for name in re.findall(r"`(\w+)\(\)`", Sensor.__agent_notes__()):
        assert hasattr(Sensor, name), f"note references missing member: {name}"

A rule worth writing down is usually worth asserting the behavior itself too (e.g. that read() raises before calibrate()).

Custom __agent_help__() — rarely

Replaces the auto-generated base document — but __agent_notes__() sections from the MRO are still appended after it. Use it for a curated base document while inherited notes keep flowing through; defining both is a supported combination. For full verbatim control of the entire output, don't define __agent_notes__() anywhere in the MRO — there is no other way to suppress notes. (On 0.2.x the notes were dropped with a warning when both were defined — mind the installed version when authoring shared code.)

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TypeScript — Job 1: Consume

import { agentHelp } from 'agent-readable-ts';

console.log(agentHelp(SomeClass));        // class constructor
console.log(agentHelp(someInstance));     // instance — dispatches to its class
console.log(agentHelp(someFn));           // function or arrow function
console.log(agentHelp(someObject));       // plain object

Install

npm install agent-readable-ts

Node 20.6+. typescript ships as a runtime dependency — the CLI uses it to parse .ts source for type signatures; the programmatic agentHelp() is plain runtime reflection and never invokes it.

CLI usage

# List all exports of a package
npx agent-readable-ts commander

# Document a specific export
npx agent-readable-ts commander:Command

# Node builtin
npx agent-readable-ts node:fs:ReadStream

# Local TypeScript file (Node 22.18+ loads .ts natively; older runtimes need a tsx loader)
npx agent-readable-ts ./src/widget.ts:Widget

# Package not installed anywhere: opt in to on-demand fetch
npx agent-readable-ts --install left-pad

pnpm users: pnpm dlx agent-readable-ts <target> works the same way.

The CLI mitigates TypeScript's runtime reflection limits by parsing .ts source directly or reading adjacent .d.ts declaration files for .js packages.

Packages installed in the current project resolve from its node_modules first — even in a one-off npx run — so project dependencies need no --install. For anything else the CLI refuses to fetch unless you pass --install, which runs npm install with --ignore-scripts into an isolated cache (~/.cache/agent-readable-ts, override with AGENT_READABLE_CACHE) — never into the project's node_modules. Cached packages load offline without needing --install again.

TypeScript runtime limitations

TypeScript has fundamental reflection constraints that Python doesn't:

• Type annotations and return types are unrecoverable from compiled JS — the CLI's source-parsing fills this gap.
• Parameter names fall back to arg0, arg1 when unavailable.
• Private TypeScript members detected via underscore prefix only (imperfect).
• JavaScript #private fields are completely unreflectable.
• Constructors and getters are not invoked during introspection.

When these constraints matter, prefer the CLI (npx agent-readable-ts) over the programmatic agentHelp() — the CLI can read the original .ts source.

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TypeScript — Job 2: Author

Preference order: good JSDoc → focused agentNotes() → (rarely) agentHelper()

JSDoc first

Document your public API with JSDoc. agentHelp() surfaces these alongside the method signatures.

agentNotes() — cross-method rules

Add an agentNotes() method for rules that span methods:

import { AgentNoter } from 'agent-readable-ts';

class DatabasePool implements AgentNoter {
    constructor(config: PoolConfig) { /* ... */ }
    acquire(): Promise<Connection> { /* ... */ }
    release(conn: Connection): void { /* ... */ }
    shutdown(): Promise<void> { /* ... */ }

    agentNotes(): string {
        return `
## Do
- Always call \`release(conn)\` after every \`acquire()\`, even on error.
- Call \`shutdown()\` during graceful application teardown.

## Do not
- Do not call \`acquire()\` after \`shutdown()\` — it throws.
- Do not share a \`Connection\` object across async tasks.
`;
    }
}

Notes accumulate across the inheritance chain in parent-to-child order — collection is automatic, like Python's MRO: implement agentNotes() on each class that has its own cross-method rules, and every class's section shows.

Belongs here: lifecycle/ordering, preconditions, cleanup, async/Promise constraints, do/don't lists.

Custom agentHelper() — rarely

Implements the AgentHelper interface and replaces the entire auto-generated output. Use only when you have a fully hand-crafted usage guide to ship verbatim.

Footgun: If both agentHelper() and agentNotes() are defined on the same class, agentHelper() wins and agentNotes() is dropped. The library emits a warning via setWarnOutput(), but warnings can be silenced or swallowed in agent shells. Treat "both defined" as a hard error. (Python differs: there, __agent_notes__ is always appended, even after custom __agent_help__.)

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The one rule

Before coding against an unfamiliar or risky Python or TypeScript API, call agent_help(target) (Python) or agentHelp(target) / the CLI (TypeScript): trust the signatures, sanity-check the notes, mind imports and version. When you author an API, make the notes verifiable so they fail loudly instead of lying quietly.