Atex.Lexicon.Resolver (atex v0.9.1)

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Resolves published AT Protocol Lexicon schemas by NSID.

Implements the Lexicon publication and resolution specification, which uses DNS TXT records to locate the atproto repository that hosts a given NSID's schema, then fetches the record directly from the repository's PDS.

Per the specification, DNS resolution is not hierarchical: if the TXT record for the exact authority domain is not found, resolution fails immediately without traversing the DNS hierarchy.

Error returns

resolve/1 returns {:error, reason} on failure. Possible reasons:

  • :invalid_nsid - the given string is not a valid NSID.
  • :dns_resolution_failed - no valid did=<did> TXT record was found for the authority domain.
  • :did_resolution_failed - the DID from DNS could not be resolved to a DID document.
  • :no_pds_endpoint - the DID document does not contain a valid PDS service endpoint.
  • :record_not_found - the PDS has no lexicon record for the given NSID.
  • :invalid_record - the PDS returned a response that could not be interpreted as a lexicon record.
  • Any transport-level error from Req.

Summary

Functions

resolve(nsid)

Resolves the lexicon schema for the given NSID.

Functions

resolve(nsid)

@spec resolve(String.t()) ::
  {:ok, map()}
  | {:error,
     :invalid_nsid
     | :dns_resolution_failed
     | :did_resolution_failed
     | :no_pds_endpoint
     | :record_not_found
     | :invalid_record
     | any()}

Resolves the lexicon schema for the given NSID.

Performs DNS-based authority lookup followed by an atproto record fetch to retrieve the raw lexicon JSON map.

Parameters

  • nsid - A valid AT Protocol NSID string.

Examples

iex> Atex.Lexicon.Resolver.resolve("app.bsky.feed.post")
{:ok, %{"lexicon" => 1, "id" => "app.bsky.feed.post", "defs" => %{...}}}

iex> Atex.Lexicon.Resolver.resolve("not.valid!")
{:error, :invalid_nsid}