generated: '2026-07-20'
method: searched
source:
  - http://web.archive.org/web/20090810213933/http://blockchalk.com/developers
  - https://techcrunch.com/2010/05/27/blockchalk-1-million/
  - whois blockchalk.com
name: BlockChalk API lifecycle
status: retired
summary: >-
  BlockChalk was a location-based neighborhood messaging service launched in 2009 and funded
  in 2010. Its public read APIs are retired along with the product. The blockchalk.com domain
  registration is still active (registrar ERANET INTERNATIONAL LIMITED, expires 2028-07-20)
  but the delegated nameservers ns1/ns2.blockchalk.com do not resolve, so no BlockChalk host
  answers on the public internet.
versioning:
  scheme: path
  observed_versions:
    - version: unversioned
      paths:
        - /api/xml/chalk
        - /api/json/chalk
        - /rss/chalk
      evidence: Documented on the BlockChalk /developers page (archived 2009-08-10).
    - version: v0.6
      paths:
        - /api/v0.6/chalks/{latitude},{longitude}
      evidence: Captured 200 responses dated 2010-03 through 2010-09.
  stability_statement: >-
    BlockChalk published this warning on its own developer page: "these interfaces are early
    prototypes and are likely to change in the future." No stability or compatibility
    guarantee was ever offered.
deprecation:
  policy_published: false
  sunset_header: false
  deprecation_header: false
  notes: >-
    No RFC 8594 Sunset/Deprecation signaling and no published deprecation policy were found.
    The API went away with the company rather than through an announced deprecation.
sla:
  published: false
status_page:
  published: false
probes:
  date: '2026-07-20'
  results:
    - target: https://blockchalk.com/
      status: 000
      note: DNS resolution failure, no A record.
    - target: https://www.blockchalk.com/
      status: 000
      note: DNS resolution failure.
    - target: https://api.blockchalk.com/
      status: 000
      note: DNS resolution failure.
timeline:
  - date: '2009-07-20'
    event: blockchalk.com domain registered.
  - date: '2009-08'
    event: Public /developers page documents XML, JSON and RSS chalk interfaces.
  - date: '2010-01-08'
    event: TechCrunch covers the launch of BlockChalk as location-based sidewalk chalk.
  - date: '2010-05-27'
    event: BlockChalk announces $1M seed financing (Joshua Schachter, Battery Ventures, Founder Collective, Harrison Metal, Mitch Kapor and others).
  - date: '2010-09'
    event: Last captured 200 response from the /api/v0.6/chalks endpoint.
  - date: '2026-07-20'
    event: Domain registered but unresolvable; product and APIs confirmed retired.