API Docs · checklist.day

Machine-readable ground truth for libraries, SDKs, CLIs, APIs, and MCP servers. All endpoints return JSON.

Base URL: https://checklist.day v1

Authentication

Pass your API key in the request header. Not yet enforced — build against it now so your integration is ready when it goes live.

X-API-Key: your_api_key

Rate Limits

Not currently enforced. Planned limits:

unauthenticated100 req / hour

authenticated1,000 req / hour

Registry

GET /v1/registry

Paginated index

cursor number Last seen ID (default: 0)

limit number Page size, max 100 (default: 100)

language string python javascript

category string ai-ml database devops etc.

type string library api sdk cli

tag string verified reviewed draft stale

Response schema

cursor	number	Echo of the input cursor
next_cursor	number \| null	Pass as cursor for next page; null on last page
count	number	Number of entries in this page
docs	array	Registry entries
docs[].library	string	Unique slug identifier
docs[].type	string	`library` `sdk` `cli` `api`
docs[].categories	string[]	Ecosystem categories
docs[].description	string \| null	Short one-line description
docs[].language	string	`python` `javascript` `http`
docs[].status	string	`active` `maintenance` `deprecated` `abandoned` `renamed`
docs[].version	string \| null	Latest known version
docs[].install_tag	string \| null	`verified` `reviewed` `draft` `stale`
docs[].url	string	Canonical URL for the full entry

Example

{
  "cursor": 0,
  "next_cursor": 100,
  "count": 100,
  "docs": [
    {
      "library": "chromadb",
      "type": "library",
      "category": "vector-database",
      "description": "...",
      "language": "python",
      "status": "active",
      "version": "1.5.9",
      "install_tag": "verified",
      "url": "https://checklist.day/v1/registry/chromadb"
    }
  ]
}

GET /v1/registry/{library}

Full library doc

Response schema

library	string	Unique slug identifier
type	string	`library` `sdk` `cli` `api`
categories	string[]	Ecosystem categories
description	string \| null	Short one-line description
language	string	`python` `javascript` `http`
status	string	`active` `maintenance` `deprecated` `abandoned` `renamed`
version	string \| null	Latest known version
tags	string[]	Freeform tags
last_verified	string \| null	ISO date of last verification run
install	array	Install entries
install[].cmd	string	Full install command
install[].imports	string[]	Import statements paired with this command
homepage	string \| null	Project homepage (non-GitHub)
github	string \| null	GitHub repository URL
docs	string \| null	Documentation URL
changelog	string \| null	Changelog URL
pypi	string \| null	PyPI package URL
npm	string \| null	npm package URL
openapi_spec	string \| null	OpenAPI spec URL if available
status_page	string \| null	Service status page URL
smithery	string \| null	Smithery MCP listing URL
compatibility	object \| null	Compatibility summary; null if not yet tested
compatibility.summary.python_range	string	Python version range tested (e.g. `3.9–3.13`)
compatibility.summary.success_rate	number	% of environments where install succeeded
compatibility.summary.avg_install_s	number	Average install time in seconds
compatibility.summary.avg_import_s	number	Average import time in seconds
compatibility.summary.wheel_type	string	`wheel` or `sdist`
compatibility.url	string	URL to full compatibility matrix

Example

{
  "library": "chromadb",
  "type": "library",
  "category": "vector-database",
  "description": "...",
  "language": "python",
  "status": "active",
  "version": "1.5.9",
  "tags": ["vector-db"],
  "last_verified": "2026-05-13",
  "install": [
    { "cmd": "pip install chromadb", "imports": ["import chromadb"] },
    { "cmd": "pip install chromadb-client", "imports": [] }
  ],
  "homepage": "...", "github": "...", "docs": "...",
  "changelog": null, "pypi": "...", "npm": null,
  "openapi_spec": null, "status_page": null, "smithery": null,
  "compatibility": {
    "summary": {
      "python_range": "3.9–3.13",
      "success_rate": 100,
      "avg_install_s": 4.9,
      "avg_import_s": 1.8,
      "wheel_type": "wheel"
    },
    "url": "https://checklist.day/v1/registry/chromadb/compatibility"
  }
}

GET /v1/registry/{library}/install

Install + imports

Response schema

library	string	Unique slug identifier
install	array	Install entries
install[].cmd	string	Full install command
install[].imports	string[]	Import statements paired with this command

Example

{
  "library": "chromadb",
  "install": [
    {
      "cmd": "pip install chromadb",
      "imports": ["import chromadb"]
    }
  ]
}

GET /v1/registry/{library}/compatibility

Compatibility matrix

Response schema

library	string	Unique slug identifier
tag	string	Data quality signal for this entry
last_tested	string	ISO date of most recent test run
installed_version	string \| null	Resolved version installed during testing
pypi_latest	string \| null	Latest version on PyPI
is_stale	boolean	True if installed_version differs from pypi_latest
summary	object	Aggregated stats across all environments
summary.python_range	string	Python version range tested
summary.success_rate	number	% of environments where install succeeded
summary.avg_install_s	number	Average install time in seconds
summary.avg_import_s	number	Average import time in seconds
summary.wheel_type	string	`wheel` or `sdist`
results	array	Per-environment test results
results[].runtime	string	Docker image used for the test
results[].python_version	string	Python version (e.g. `3.11`)
results[].os_libc	string	OS and libc variant
results[].exit_code	number	0 = success, non-zero = failure
results[].wheel_type	string	`wheel` or `sdist`
results[].install_time_s	number \| null	Install duration in seconds
results[].import_time_s	number \| null	Import duration in seconds
results[].mem_mb	number \| null	Peak memory in MB
results[].disk_size	string \| null	Disk space used (e.g. `41M`)
results[].import_side_effects	string	`clean` or description of side effects
results[].failure_reason	string \| null	Error message if failed, null otherwise

Example

{
  "library": "chromadb",
  "tag": "verified",
  "last_tested": "2026-05-12",
  "installed_version": "1.5.9",
  "pypi_latest": "1.5.9",
  "is_stale": false,
  "summary": {
    "python_range": "3.9–3.13",
    "success_rate": 100,
    "avg_install_s": 4.9,
    "avg_import_s": 1.8,
    "wheel_type": "wheel"
  },
  "results": [
    {
      "runtime": "python:3.11-slim",
      "python_version": "3.11",
      "os_libc": "slim (glibc)",
      "exit_code": 0,
      "wheel_type": "wheel",
      "install_time_s": 4.9,
      "import_time_s": 1.79,
      "mem_mb": 36.9,
      "disk_size": "41M",
      "import_side_effects": "clean",
      "failure_reason": null
    }
  ]
}

MCP Registry

GET /v1/mcp

Paginated MCP server index

cursor number Last seen ID (default: 0)

limit number Page size, max 100 (default: 100)

category string developer-tools productivity data etc.

official boolean true to return only official servers

status string active deprecated

Response schema

cursor	number	Echo of the input cursor
next_cursor	number \| null	Pass as cursor for next page; null on last page
count	number	Number of entries in this page
servers	array	MCP server entries
servers[].slug	string	Source dedup key from mcpservers.org
servers[].path	string	Clean kebab-case path used in URLs
servers[].name	string	Display name
servers[].description	string \| null	Short description
servers[].category	string \| null	Category label
servers[].official	boolean	True if maintained by the tool's own team
servers[].stars	number \| null	GitHub stars
servers[].transport	string \| null	`stdio` `http` `sse`
servers[].tool_count	number \| null	Number of tools exposed
servers[].status	string	`active` `deprecated`
servers[].url	string	Canonical URL for the full entry

GET /v1/mcp/{path}

Full MCP server doc

Response schema

slug	string	Source dedup key
name	string	Display name
description	string \| null	Short description
category	string \| null	Category label
tags	string[]	Freeform tags
official	boolean	Maintained by the tool's own team
stars	number \| null	GitHub stars
transport	string \| null	`stdio` `http` `sse`
install	object \| null	Install instructions
tools	array \| null	List of tools with name + description
env_vars	array	Required environment variables
auth_type	string	`none` `api_key` `oauth`
github	string \| null	GitHub repository URL
homepage	string \| null	Project homepage
server_url	string \| null	Hosted server URL if remote
status	string	`active` `deprecated`
source	string \| null	Data source (e.g. `mcpservers.org`)
updated_at	string \| null	ISO date of last update

MCP Server

Connect any MCP-compatible client directly to the registry.

URLhttps://mcp.checklist.day/mcp

TransportStreamable HTTP

Authnone

Tools

`get_entry(library)`		Full registry doc for a single library
`search_registry(query)`		Keyword search across all registry entries
`search_checklists(query)`		Search operational checklists by topic or category