# Reported issues for Find Research Papers

Pod holds 5 of 5 GitHub reports that passed its relevance review. This can include external user reports, maintainer-confirmed bugs, and concrete feature gaps. Treat them as evidence to inspect, not a count of distinct defects.

Back to [Find Research Papers](/mcp/find-research-papers).

## Most discussed

### get_paper: three distinct upstream bugs visible in one day (429 no-backoff, arXiv→Crossref misrouting, connection-reset for CN users)

Sep 2 data, three real users (Brazil/claude-code 0.4.5, China/opencode 0.4.4, US/codex 0.4.5). 106 errors, all on `get_paper` except one. Three separate causes:

**1. [UPSTREAM] 429 with no backoff — 68 events, 23% of one user's get_paper calls.**
Message: `429 Client Error: Unknown Error for url: <url>`. A heavy user (300+ paper fetches in a session) gets throttled mid-session. Two problems: no exponential backoff/retry, and the message says "Unknown Error" so neither the model nor the human…

[Read the thread](https://github.com/surendranb/find-research-papers-mcp/issues/19) · 2026-09-02 · open · 1 comment

### Packaging regression: ModuleNotFoundError 'papers_mcp.sources' hits real user 13 times

**Data (Aug 31, live user):** The fleet's most engaged papers user (Brazil, claude-code, active four consecutive nights) is getting install-level failures on every call today:

- `ModuleNotFoundError: No module named 'papers_mcp.sources'` — 13 events
- `ModuleNotFoundError: No module named 'requests'` — 2 events

Their sessions on Aug 27–29 ran clean at 97–100% rows on 0.4.3. Today's calls fail at import, so this looks like a newly published build whose packaging omits the `papers_mcp.sources`…

[Read the thread](https://github.com/surendranb/find-research-papers-mcp/issues/17) · 2026-08-31 · closed · 1 comment

### id_type='unknown' and sources=['arXiv.'] are refused when both could be normalised — recognition over recall

**DATA** — two validation refusals seen in telemetry:

```
get_paper       unknown id_type 'unknown'. Use one of: auto, doi, arxiv, pmid, openalex, s2
search_papers   unknown source(s): arXiv.      (trailing period / capitalisation)
search_papers   unknown source(s): fake_xyz. Known: arxiv, openalex, crossref, semanticscholar, pubmed
```

The `arXiv.` variant was seen 41 times in 7 days from one install. The
`fake_xyz` case is correct behaviour — that install's harness is literally
named…

[Read the thread](https://github.com/surendranb/find-research-papers-mcp/issues/21) · 2026-09-09 · open · 0 comments

### Every tool call emits two events: tool_executed plus tool_<name> — double-counts usage ~2x

**DATA** — for every tool call, papers emits **two** events in the same second:

| proper event | count (30d) | duplicate event | count (30d) |
|---|---|---|---|
| `tool_executed` where `tool_name='get_paper'` | 2,173 | `tool_get_paper` | 2,028 |
| `tool_executed` where `tool_name='search_papers'` | 1,775 | `tool_search` | 2,059 |
| `tool_executed` where `tool_name='get_research_method'` | 48 | `tool_get_research_method` | 53 |
| `tool_executed` where `tool_name='list_sources'` | 23 |…

[Read the thread](https://github.com/surendranb/find-research-papers-mcp/issues/20) · 2026-09-09 · open · 0 comments

### search_papers latency: sources are queried sequentially — parallelize the fan-out + per-source time budget

**Root cause (code):** `search_all` in `papers_mcp/sources/__init__.py` loops over the 5 sources sequentially with blocking `requests` calls. Every search pays the SUM of source latencies (3–6s each, PubMed's two-step chain the slowest), so real calls take 15–26s.

**Evidence (data, Aug 21):** Both genuine users of the day waited 15–26s on nearly every call — the returning US/LM Studio user sat through 10 consecutive ~18s waits in one session (20 calls over two days), the Sri Lanka researcher…

[Read the thread](https://github.com/surendranb/find-research-papers-mcp/issues/9) · 2026-08-22 · open · 0 comments

## Most recent

The remaining reports are on [the project's issue tracker](https://github.com/surendranb/find-research-papers-mcp/issues).