Naming

A tool’s name is what the API calls the endpoint, and Charter never changes it. Qualification belongs to whoever assembles tools into one namespace; these are the functions that do it, so every assembler uses one convention. Two APIs really do declare the same tool name — products_list exists in both Stripe and Shopify — so a surface holding both has to disambiguate them. See Tool names across packs for why the library does not qualify its own names, and why pack is not provider.

`qualified_names`

Every tool under <pack>__<tool>, keyed by the qualified name. This is what the three shipped adapters call, so a pack is named the same way inline, through LangChain, and over MCP. Qualified whatever else is loaded. A name is a property of the tool, not of its neighbours: qualifying only once a second pack appeared would rename every tool in the first the day someone added one, breaking saved prompts, allow-lists and logged traces in silence. MCP servers publish the same names whatever else is installed, and a host composes mcp__<server>__<tool> on top — charter-mcp names its server charter, so the result reads mcp__charter__gcalendar__events_list.

def qualified_names(tools: Iterable[Tool]) -> Dict[str, Tool]: ...

from charter import qualified_names
from charter.packs import gcalendar

qualified_names(gcalendar.TOOLS)
# {"gcalendar__events_insert": Tool(...), "gcalendar__events_list": Tool(...), ...}

Neither function qualifies only the colliding names. A surface where stripe__products_list sits beside a bare balance_retrieve makes the pack a substring of some names and not others, so any filter over it silently misses the unqualified half. Raises DeclarationError if a tool declares no pack, or if two tools qualify to the same name.

`qualified_name`

One tool’s qualified name.

def qualified_name(tool: Tool) -> str: ...

from charter import qualified_name
from charter.packs import stripe

qualified_name(stripe.products_list)   # "stripe__products_list"

Raises DeclarationError if the tool declares no pack. Falling back to the bare name would produce the half-qualified surface above, silently.

Routing a tool call back

MCP and LangChain resolve a tool call by name for you. The OpenAI APIs hand it back to you to execute, so you need the same mapping you published with — qualified_names is it.

import json

from charter import qualified_names
from charter.adapters.openai import to_openai_tools
from charter.packs import stripe

stripe.configure(api_key="sk_test_...")

tools = list(stripe.TOOLS)
by_name = qualified_names(tools)          # name -> Tool
definitions = to_openai_tools(tools)      # published under the same names

# what the model sends back, as OpenAI shapes it
name, arguments = "stripe__customers_list", '{"limit": 3}'

result = await by_name[name].ainvoke(json.loads(arguments))

Calling a Tool directly in Python never involves a name at all — tool.name stays events_list, and await gcalendar.events_list.ainvoke(...) is a Python reference. Qualification exists only where tools are published to a model.

Core

Schema

Authentication

Runtime

Operating

`qualified_names`

`qualified_name`

Routing a tool call back

​qualified_names

​qualified_name

​Routing a tool call back

`qualified_names`

`qualified_name`

Routing a tool call back