Cairn

Tool-call parsing bugs in XML and nested JSON

NousResearch/hermes-agent · cluster 4543 · acp

Data as of

4 open items. Fix attempted, not merged.

The short answer

2open issues
2open PRs
7items grouped
Known?
Yes. 7 related items grouped here, 2 issues already closed.
Fix event
No fix has been merged to main. 1 PR closed without merging; see the attempts below.
Tracker
The maintainers' tracker marks this unresolved. That is separate from the fix event.
Still open
2 issues and 2 PRs.

Multiple bugs and fixes related to parsing tool calls that appear as inline XML tags or contain nested JSON, particularly affecting the Copilot ACP adapter. Issues include silent failures, regex fragility, and raw text passthrough.

Open issues2

  • Issue#22696BUG: tool_use parser fails intermittently when closing tag appears inside JSON strings
  • Issue#45139[Bug]: Tool execution fails silently with Copilot ACP --context long_context (Claude outputs <tool_use>)

Open PRs2

  • PR#23888fix(agent): replace fragile tool_call regex with brace-depth scanner for nested JSON
  • PR#45231fix(acp): parse <tool_use> XML tags from Copilot ACP long_context mode

1 PR closed without merging

From the close comments: other 1

  • #23508 Recover inline XML tool calls from chat-completion content · other → #22696, #23888
Closed issues · 2
  • Closed#4543[Bug]: Choosing GitHub Copilot ACP as a model provider breaks toolcalls
  • Closed#22688Bug: tool_use regex parser fails with nested JSON — blocks pass through as raw text
How this cluster was grouped
  • Link evidence (partly structural links): some members are connected by structural evidence (shared changed files, or a closing/superseded reference); the rest are joined by an automated relevance judgement over their text.
  • Members outside that structural core may belong to a different underlying problem.
  • Pairwise link density 0.19: the share of item 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.

Pick up a Lab task

Check whether a fix covers the open issues here, with your own agent. Bring back evidence for maintainers.

Open the Lab

At a glance

Subsystem
acp
Closed issues
2
Attempts
1 PR closed without merging

For your agent

The same facts, typed.

cluster/4543.json
cluster/4543.md