Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

[Unreleased] — Canonical Terminology Refactor

(See below for details — this will ship in a future version.)

[0.3.1] - 2026-02-26

Added

• Bundled type stubs: 255 connector .pyi stubs ship in the wheel — pip install fastn-ai gives full IDE autocomplete with zero extra setup
• Concurrent tool-schema fetching: fastn connector sync fetches tool schemas for all connectors in parallel (10 workers)
• __getattr__ fallback stubs: Connectors without tool schemas get a fallback stub so fastn.<connector>.<anything>() still works at runtime
• .gitattributes: Generated stubs collapse in GitHub PR diffs

Changed

• fastn connector sync is now the single command that does everything: fetch registry, fetch tool schemas, save snapshot, generate stubs
• fastn connector add now described as "fetch full tool schemas" (stubs already bundled)
• Removed _install_stubs_to_package() — stubs ship in the wheel, no runtime copy needed
• Removed generator/fetch_and_generate.py — merged into fastn connector sync
• Updated all docs and templates to use canonical fastn connector commands

Breaking Changes — Terminology

The SDK now uses the canonical Fastn architecture terminology:

Connectors provide tools. Flows compose tools. Agents run flows and tools with reasoning.

Concept	Old term (v0.3.0)	New term (canonical)
Service integration (Slack, Jira)	Tool	Connector
Callable function (send_message)	Action	Tool

Renamed Classes

• DynamicTool → DynamicConnector
• AsyncDynamicTool → AsyncDynamicConnector
• ToolNotFoundError → ConnectorNotFoundError (connector not in registry)
• ActionNotFoundError → ToolNotFoundError (tool not found in connector)

Renamed Methods

• fastn.tools.list() → fastn.connectors.list()
• fastn.tools.get(name) → fastn.connectors.get(name)
• fastn.get_actions(name) → fastn.get_tools(name)
• fastn.get_action(connector, tool) → fastn.get_tool(connector, tool)
• fastn.execute(action_id=...) → fastn.execute(tool=...)
• get_tools_for(..., tool=) → get_tools_for(..., connector=)

Renamed CLI Flags

• --tool → --connector (scope to a connector)
• --action → --tool (scope to a tool)

Renamed Files

• fastn/tool.py → fastn/connector.py
• tests/sdk/test_tool.py → tests/sdk/test_connector.py

Renamed Config Functions

• add_tool_to_manifest() → add_connector_to_manifest()
• remove_tool_from_manifest() → remove_connector_from_manifest()
• get_installed_tools() → get_installed_connectors()

Migration Guide

# Before (v0.3.0)
from fastn import ToolNotFoundError, ActionNotFoundError
tools = client.tools.list()
actions = client.get_actions("slack")
result = client.execute(action_id="send_message", params={...})
tools = client.get_tools_for("message", tool="slack", format="openai")

# After (canonical)
from fastn import ConnectorNotFoundError, ToolNotFoundError
connectors = client.connectors.list()
tools = client.get_tools("slack")
result = client.execute(tool="send_message", params={...})
tools = client.get_tools_for("message", connector="slack", format="openai")

[0.3.0] - 2026-02-21

Breaking Changes

• Terminology refactor: "Connector" is now "Tool", "Tool" (action) is now "Action" throughout the SDK
• Namespace restructure:
  • fastn.admin.connectors.list() → fastn.tools.list()
  • fastn.admin.connectors.get(name) → fastn.tools.get(name)
  • fastn.get_tools(connector_name) → fastn.get_actions(tool_name)
  • fastn.get_tool(connector_name, tool_name) → fastn.get_action(tool_name, action_name)
  • fastn.connections.initiate() → fastn.auth.connect()
  • fastn.connections.status() → fastn.auth.status()
  • fastn.configure_custom_auth() → fastn.auth.configure_custom()
  • get_tools_for(..., connector="slack") → get_tools_for(..., tool="slack")
• Exception renames:
  • ConnectorNotFoundError → ToolNotFoundError (with .tool_name attribute)
  • ToolNotFoundError → ActionNotFoundError (with .tool_name and .action_name attributes)
• File rename: fastn/connector.py → fastn/tool.py
  • DynamicConnector → DynamicTool
  • AsyncDynamicConnector → AsyncDynamicTool
• CLI option rename: fastn agent --connector → fastn agent --tool

Added

• fastn.auth.configure_custom(userinfo_url) — register custom auth provider via GraphQL updateResolverStep mutation
• Comprehensive documentation with terminology glossary, full feature examples (flows, auth, multi-tenant)
• Platform benefits documentation (performance, governance, security, observability)

Changed

• auth.configure_custom() now uses GraphQL updateResolverStep mutation instead of REST endpoint
• _ToolsAdmin.get() returns "actions" key instead of "tools" for consistency
• All user-facing CLI strings updated to use "tool" and "action" terminology
• All examples and documentation updated to match new API surface

[0.2.3] - 2026-02-20

Added

• get_tools_for() is now prompt-first: describe what you need in plain English and Fastn discovers the right tools
• get_tools_for() accepts connector= for direct registry lookup (single or list of connectors)
• get_tools_for() has a limit parameter (default 5) to control how many tools are returned
• "Platform Benefits" section in Python README documenting centralized gateway, monitoring, auth management

Changed

• Root README LLM section now shows complete working code with all variables defined
• Python README LLM section rewritten with prompt-first examples for all 4 LLM providers
• LLM agent example updated to use prompt-first tool discovery

[0.2.2] - 2026-02-20

Fixed

• Default tenant_id changed from "organization" to "" (empty) — backend handles defaults
• Updated tagline from "Pre-built tools" to accurate description of the integration platform

[0.2.1] - 2026-02-20

Changed

• Smart stub generation: only generates stubs for detected SDK languages (Python and/or TypeScript)
• Reorganized tests into tests/sdk/ and tests/cli/ for selective test runs
• Reorganized examples into examples/sdk/ and examples/cli/
• Added pytest markers (sdk, cli) and Makefile for development workflow
• Updated documentation with AI-friendly API reference and LLM provider examples

[0.2.0] - 2026-02-19

Added

• fastn agent command: AI-powered agentic tool execution with native function calling
  • OpenAI function-calling integration with automatic tool discovery
  • Prompt-based tool routing via getTools(prompt, limit) — sends only top-N tools to LLM
  • Configurable tool limit (--max-tools, default 5) to reduce hallucination
  • Benchmark summary table with token counts, cost estimation ($), and timing
  • Error recovery with consecutive error tracking (--max-errors, default 2)
  • Evaluation mode (--eval) — LLM judge assesses if agent called correct tools
  • Confirmation gates for tool calls (default on, -y to skip)
  • LLM diagnosis on persistent failures with debug context dump
  • Schema unwrapping for LLM consumption, re-wrapping for API execution
• fastn connector run command for direct tool execution from CLI
  • Interactive parameter prompting when no args provided
  • Inline parameters via --key value
  • Tenant ID as positional argument: fastn connector run slack send_message <tenant_id>
• --tenant option on fastn connector run and fastn agent for multi-tenant testing
• fastn connector ls --active to show only enabled tools in project and org
• Generic error detection (_detect_api_error) for diverse API response formats
  • Handles Slack, GitHub, Stripe, GraphQL, generic REST, HTTP status codes in body
  • Preserves original error messages for LLM diagnosis
• Interactive LLM provider setup (OpenAI, Anthropic, Gemini) on first fastn agent run
• Project selection during fastn login
• CLI split into cli/ package for maintainability

Changed

• Registry sync fetches from three scopes: project, organization, community
• fastn connector ls groups connectors by source category
• Tenant header corrected to x-fastn-space-tenantid
• Tool schemas unwrapped for LLM (flat params) and re-wrapped for API execution

Fixed

• Version alignment between pyproject.toml and init.py
• Error value preservation in API responses (Slack channel_not_found no longer overwritten)
• Agent summary table totals now include the final LLM response turn

[0.1.0] - 2025-02-19

Added

• FastnClient and AsyncFastnClient for sync and async workflows
• Dynamic connector proxy with attribute-based tool access (fastn.slack.send_message())
• Multi-connection support via connect() and per-call connection_id
• LLM agent integration:
  • get_tools_for(connector, format) — returns tools in OpenAI, Anthropic, Gemini, Bedrock, or raw format
  • execute(action_id, params) — execute tools by action ID with LLM-generated parameters
• AI-powered mode via run(prompt) for natural language tool discovery
• Control plane: admin.connectors.list(), admin.connectors.get(), get_tools(), get_tool()
• Schema-aware migrations with deprecation warnings for smooth upgrades
• OAuth device authorization flow (fastn login) with automatic token refresh
• CLI commands: init, login, logout, whoami, sync, add, remove, list, schema, version
• IDE autocomplete via generated .pyi type stubs
• Automatic retry with exponential backoff for transient failures
• Config file security (owner-only permissions)
• PEP 561 py.typed marker for type checker support
• 9 typed exceptions for granular error handling