KOReader Anki plugin add card support

[mallomar]

Description:

AnkiConnect Android v1.15 returns malformed JSON when the KOReader Anki plugin attempts to add cards, but works correctly with Yomichan. This suggests an incompatibility with how AnkiConnect Android handles certain AnkiConnect API requests.

Environment:

• AnkiConnect Android version: 1.15
• AnkiDroid version: 2.22.3
• Android version: 15
• Device: Samsung Galaxy S23 FE
• KOReader version: 2025.08

Steps to Reproduce:

1. Install AnkiConnect Android v1.15
2. Configure KOReader Anki plugin to connect to http://localhost:8765
3. Set up a simple card profile (deck: "Vocabulary Builder", note type: "Basic (and reversed card)-31325")
4. Attempt to test the connection or add a card from KOReader

Expected Behavior:
KOReader should successfully add cards to AnkiDroid via AnkiConnect Android, similar to how Yomichan successfully adds cards.

Actual Behavior:
Connection test fails with malformed JSON error. The error occurs even with the simplest card template (no context field, just word and definition fields).

Error Log:

Failed to connect to 'http://127.0.0.1:8765':
com.google.gson.stream.MalformedJsonException: Use JsonReader.setLenient(true) to accept malformed JSON at line 1 column 14 path $
com.google.gson.JsonSyntaxException: com.google.gson.stream.MalformedJsonException: Use JsonReader.setLenient(true) to accept malformed JSON at line 1 column 14 path $
    at com.google.gson.JsonParser.parseReader(JsonParser.java:66)
    at com.google.gson.JsonParser.parseString(JsonParser.java:47)
    at com.kamwithk.ankiconnectandroid.routing.AnkiAPIRouting.findRouteHandleError(AnkiAPIRouting.java:106)
    at com.kamwithk.ankiconnectandroid.routing.APIHandler.chooseAPI(APIHandler.java:33)
    at com.kamwithk.ankiconnectandroid.routing.RouteHandler.getRouteHandler(RouteHandler.java:73)
    at fi.iki.elonen.router.RouterNanoHTTPD$DefaultStreamHandler.post(RouterNanoHTTPD.java:100)
    at fi.iki.elonen.router.RouterNanoHTTPD$UriResource.process(RouterNanoHTTPD.java:386)
    at fi.iki.elonen.router.RouterNanoHTTPD$UriRouter.process(RouterNanoHTTPD.java:596)
    at fi.iki.elonen.NanoHTTPD$HTTPSession.execute(NanoHTTPD.java:945)
    at fi.iki.elonen.NanoHTTPD$ClientHandler.run(NanoHTTPD.java:192)
    at java.lang.Thread.run(Thread.java:1119)
Caused by: com.google.gson.stream.MalformedJsonException: Use JsonReader.setLenient(true) to accept malformed JSON at line 1 column 14 path $
    at com.google.gson.stream.JsonReader.syntaxError(JsonReader.java:1597)
    at com.google.gson.stream.JsonReader.checkLenient(JsonReader.java:1404)
    at com.google.gson.stream.JsonReader.doPeek(JsonReader.java:542)
    at com.google.gson.stream.JsonReader.peek(JsonReader.java:425)
    at com.google.gson.JsonParser.parseReader(JsonParser.java:61)
    ... 11 more

Additional Context:

• Yomichan browser extension successfully adds cards to the same deck via AnkiConnect Android
• Both URLs tested (http://localhost:8765 and http://127.0.0.1:8765) produce the same error
• The "Vocabulary Builder" deck exists in AnkiDroid
• The note type "Basic (and reversed card)-31325" exists in AnkiDroid
• Error occurs with minimal card configuration (only word and definition fields, no context)

The KOReader Anki plugin developer noted that AnkiConnect Android should work since it implements the AnkiConnect API (see this comment). Since Yomichan works but KOReader doesn't, this suggests AnkiConnect Android may be handling certain API request formats differently.

Note: The error message suggests the JSON being parsed has an issue at "line 1 column 14 path $", which indicates the malformed JSON is in AnkiConnect Android's response to KOReader's request, not in KOReader's request itself.

[KamWithK]

I don't implement or test anything not actively used by Yomitan, it just wouldn't be reasonable/practical for me to have done so
Anything else is up to the community to contribute, so I'd recommend looking into this more and making a PR

[mallomar]

Hi @KamWithK, I've captured the actual HTTP traffic between KOReader and AnkiConnect Android. The issue is clear:

KOReader sends:

{"version":6,"action":"requestPermission"}

AnkiConnect Android responds with:

{
  "result": null,
  "error": "com.google.gson.stream.MalformedJsonException: Use JsonReader.setLenient(true) to accept malformed JSON at line 1 column 14 path $"
}

Column 14 is immediately after the 6 in "version":6.

The problem: AnkiConnect Android's JSON parser is rejecting the numeric value for the version field. According to the official AnkiConnect API documentation, the version field should be a number (integer), not a string. KOReader is sending the correct format per the spec.

The fix: AnkiConnect Android should accept version as a number type, not require it to be a string. The current strict type checking is incompatible with the official AnkiConnect API specification.

This is a simple type coercion issue - the Gson parser needs to be configured to accept numbers for the version field, or the data class should use a more flexible type that can handle both numbers and strings for backward compatibility.

[KamWithK]

Hi @KamWithK, I've captured the actual HTTP traffic between KOReader and AnkiConnect Android. The issue is clear:

KOReader sends:

{"version":6,"action":"requestPermission"}

AnkiConnect Android responds with:

{
"result": null,
"error": "com.google.gson.stream.MalformedJsonException: Use JsonReader.setLenient(true) to accept malformed JSON at line 1 column 14 path $"
}

Column 14 is immediately after the 6 in "version":6.

The problem: AnkiConnect Android's JSON parser is rejecting the numeric value for the version field. According to the official AnkiConnect API documentation, the version field should be a number (integer), not a string. KOReader is sending the correct format per the spec.

The fix: AnkiConnect Android should accept version as a number type, not require it to be a string. The current strict type checking is incompatible with the official AnkiConnect API specification.

This is a simple type coercion issue - the Gson parser needs to be configured to accept numbers for the version field, or the data class should use a more flexible type that can handle both numbers and strings for backward compatibility.

Create a PR for KOReader support and I'll happily review it and we can get it merged pretty soon, doesn't sound like it'll be more than a few lines to do this

[KamWithK]

Thank you for the PR @mallomar

[mallomar]

Thank you for the PR @mallomar

No problem! Please let me know if you'd like any changes.