# NousResearch/hermes-agent · MCP JSON error body message extraction fix

## Open now

- 1 issue, 2 PRs open on GitHub.
- #47867: MCP isError errors with nested JSON bodies are double-encoded, hiding actionable messages from the model
- PR #47871: fix(mcp): extract readable message from nested JSON isError bodies
- PR #47894: fix(mcp): extract message from JSON error bodies to prevent double-encoding

These members address a bug where MCP error responses with JSON bodies were being double-encoded, obscuring readable error messages. The work involves extracting human-readable messages from nested JSON error bodies.

## TL;DR

- 4 member(s): 1 open issue(s), 0 closed issue(s), 2 open PR(s), 0 merged PR(s), 1 PR(s) closed without merging.
- No fix has been merged to main; one or more PRs were attempted (see below).
- **Recommended:** review the prior/competing PR(s) below. A fix was attempted but not merged; your case may extend or revive that work.

## Maintainer resolution verdict

- Internal-tracker verdict over this cluster's issue members: `unresolved`. This is distinct from the fix status above. Weigh it yourself.

## How this cluster was grouped

- Link evidence (`STRUCTURAL_SPANNING`): every member is connected by structural evidence: shared changed files, or a closing/superseded reference.
- Pairwise link density `0.50`: the share of member pairs that carry a link, counting a structural link in full and a relevance-only link at 0.36. `1.00` means every pair is linked.

## Open related issues

- #47867: MCP isError errors with nested JSON bodies are double-encoded, hiding actionable messages from the model

## Prior & competing PRs

- **#47871: fix(mcp): extract readable message from nested JSON isError bodies**. open
  - maintainer direction: category `uncategorized`; implication `needs_llm`
  - files: `tests/tools/test_mcp_iserror_nested_json.py`, `tools/mcp_tool.py`
- **#47894: fix(mcp): extract message from JSON error bodies to prevent double-encoding**. open
  - maintainer direction: category `duplicate_of`; implication `duplicate`; refs `#47871`, `#47867`
  - files: `tools/mcp_tool.py`
- **#47956: fix(mcp): extract readable message from JSON error bodies (#47867)**. closed without merge
  - maintainer direction: category `duplicate_of`; implication `duplicate`; refs `#47871`, `#47867`, `#47894`

## Fix status

- No merged fix on record.
- Subsystem: `mcp`