Runtime crash: Jido.Browser.Error.InvalidError not JSON-encodable (jido_browser 2.0 + jido_ai)

[ortegacmanuel]

Problem

When running Goodwizard with updated deps (jido_browser ~> 2.0, jido_ai main), the agent crashes when the LLM invokes any browser tool that returns an error.

Error

(Protocol.UndefinedError) protocol Jason.Encoder not implemented for 
type Jido.Browser.Error.InvalidError (a struct)

Jason.Encoder protocol must always be explicitly implemented.

Stacktrace:
  (jason) Jason.encode!/2
  (jido_ai) Jido.AI.Turn.encode_tool_result_envelope/2
  (jido_ai) Jido.AI.Reasoning.ReAct.Strategy.append_tool_result_to_run_context/5
  (jido_ai) Jido.AI.Reasoning.ReAct.Strategy.apply_runtime_event/2
  (jido_ai) Jido.AI.Reasoning.ReAct.Strategy.process_worker_event/2

Cause

jido_ai's ReAct strategy calls Jido.AI.Turn.encode_tool_result_envelope/2 which tries to Jason.encode! tool results, including error structs. Jido.Browser.Error.InvalidError (from jido_browser 2.0) doesn't implement Jason.Encoder, so it crashes.

Impact

• Text-only Telegram chat works fine
• Any query where the LLM decides to use a browser tool (navigate, click, etc.) crashes the agent process
• The agent recovers (Telegram handler restarts), but the user sees "an unexpected error occurred"

Likely fix

Either:

1. jido_browser 2.0 needs @derive Jason.Encoder on all error structs (InvalidError, NavigationError, TimeoutError, etc.)
2. jido_ai's Turn.encode_tool_result_envelope needs to handle non-encodable structs gracefully (e.g., convert to %{error: inspect(struct)} before encoding)

Option 2 is more defensive — any tool could return a non-encodable struct.

Environment

• jido ~> 2.1 (hex)
• jido_ai main branch (commit 5601aa5)
• jido_browser ~> 2.0 (hex, v2.0.0)
• Elixir 1.18 / OTP 27
• Docker container

Related

This was discovered while resolving #23 (broken deps). The browser tools work in terms of compilation, but fail at runtime when errors occur.

[ortegacmanuel]

Additional finding: same crash on create_entity tool

The JSON encoding crash also occurs with Jido.Action.Error.InvalidInputError — not just browser errors. When the LLM calls create_entity with an entity type that has no schema (e.g., pets), the action returns InvalidInputError, and jido_ai's Turn.encode_tool_result_envelope tries to JSON-encode it → crash.

tool=create_entity event=stop status=error duration_ms=0
[signal.error] type=ai.react.worker.event 
  error=%Protocol.UndefinedError{
    protocol: Jason.Encoder, 
    value: %Jido.Action.Error.InvalidInputError{tool_name: "create_entity"}
  }

This means any tool error struct that doesn't implement Jason.Encoder will crash the agent. The fix in jido_ai's Turn.encode_tool_result_envelope should handle all non-encodable structs gracefully, not just browser errors.