Merge https://github.com/google/adk-python/pull/4041
## Description
This PR fixes false positive stale labels in the `adk_stale_agent`.
Previously, the agent was incorrectly identifying the issue as "stale" because it treated `adk-bot` (acting via PAT) as a human maintainer. Since the username lacks the `[bot]` suffix, administrative alerts (e.g., "Notification: The author has updated...") were counted as maintainer activity, inadvertently triggering the stale logic immediately after an author's edit.
## Changes Made
- **Hardcoded Bot Exclusion:** Added `BOT_NAME = "adk-bot"` and updated history parsing loops (comments, edits, timeline) to explicitly ignore this actor.
- **Bot Alert Skip:** Added logic to `continue` (skip) processing the bot's specific "Notification" comment so it is not recorded as the last activity on the timeline.
Co-authored-by: Xuan Yang <xygoogle@google.com>
COPYBARA_INTEGRATE_REVIEW=https://github.com/google/adk-python/pull/4041 from ryanaiagent:fix/stale-bot-logic f1500a94cb8c9d5090e9b1ef29690506120f7749
PiperOrigin-RevId: 852365962
Merge https://github.com/google/adk-python/pull/3700
### Description
This PR refactors the `adk_stale_agent` to address `429 RESOURCE_EXHAUSTED` errors encountered during workflow execution. The previous implementation was inefficient in fetching issue history (using pagination over the REST API) and lacked server-side filtering, causing excessive API calls and huge token consumption that breached Gemini API quotas.
The new implementation switches to a **GraphQL-first approach**, implements server-side filtering via the Search API, adds robust concurrency controls, and significantly improves code maintainability through modular refactoring.
### Root Cause of Failure
The previous workflow failed with the following error due to passing too much context to the LLM and processing too many irrelevant issues:
```text
google.genai.errors.ClientError: 429 RESOURCE_EXHAUSTED.
Quota exceeded for metric: generativelanguage.googleapis.com/generate_content_paid_tier_input_token_count
```
### Key Changes
#### 1. Optimization: REST → GraphQL (`agent.py`)
* **Old:** Fetched issue comments and timeline events using multiple paginated REST API calls (`/timeline`).
* **New:** Implemented `get_issue_state` using a single **GraphQL** query. This fetches comments, `userContentEdits`, and specific timeline events (Labels, Renames) in one network request.
* **Refactoring:** The complex analysis logic has been decomposed into focused helper functions (_fetch_graphql_data, _build_history_timeline, _replay_history_to_find_state) for better readability and testing.
* **Configurable:** Added GRAPHQL_COMMENT_LIMIT and GRAPHQL_TIMELINE_LIMIT settings to tune context depth
* **Impact:** Drastically reduces the data payload size and eliminates multiple API round-trips, significantly lowering the token count sent to the LLM.
#### 2. Optimization: Server-Side Filtering (`utils.py`)
* **Old:** Fetched *all* open issues via REST and filtered them in Python memory.
* **New:** Uses the GitHub Search API (`get_old_open_issue_numbers`) with `created:<DATE` syntax.
* **Impact:** Only fetches issue numbers that actually meet the age threshold, preventing the agent from wasting cycles and tokens on brand-new issues.
#### 3. Concurrency & Rate Limiting (`main.py` & `settings.py`)
* **Old:** Sequential execution loop.
* **New:** Implemented `asyncio.gather` with a configurable `CONCURRENCY_LIMIT` (set to 3).
* **New:** Added `urllib3` retry strategies (exponential backoff) in `utils.py` to handle GitHub API rate limits (HTTP 429) gracefully.
#### 4. Logic Improvements ("Ghost Edits")
* **New Feature:** The agent now detects "Ghost Edits" (where an author updates the issue description without posting a new comment).
* **Action:** If a silent edit is detected on a stale candidate, the agent now alerts maintainers instead of marking it stale, preventing false positives.
### File Comparison Summary
| File | Change |
| :--- | :--- |
| `main.py` | Switched from `InMemoryRunner` loop to `asyncio` chunked processing. Added execution timing and API usage logging. |
| `agent.py` | Replaced REST logic with GraphQL query. Added logic to handle silent body edits. Decomposed giant get_issue_state into helper functions with docstrings. Added _format_days helper. |
| `utils.py` | Added `HTTPAdapter` with Retries. Added `get_old_open_issue_numbers` using Search API. |
| `settings.py` | Removed `ISSUES_PER_RUN`; added configuration for CONCURRENCY_LIMIT, SLEEP_BETWEEN_CHUNKS, and GraphQL limits. |
| `PROMPT_INSTRUCTIONS.txt` | Simplified decision tree; removed date calculation responsibility from LLM. |
### Verification
The new logic minimizes token usage by offloading date calculations to Python and strictly limiting the context passed to the LLM to semantic intent analysis (e.g., "Is this a question?").
* **Metric Check:** The workflow now tracks API calls per issue to ensure we stay within limits.
* **Safety:** Silent edits by users now correctly reset the "Stale" timer.
* **Maintainability:** All complex logic is now isolated in typed helper functions with comprehensive docstrings.
Co-authored-by: Xuan Yang <xygoogle@google.com>
COPYBARA_INTEGRATE_REVIEW=https://github.com/google/adk-python/pull/3700 from ryanaiagent:feat/improve-stale-agent 888064eff125ae74f7c3a9ad6c74f98de80243a2
PiperOrigin-RevId: 838885530
George Weale
Rohit Yanamadala