fix: Optimize Stale Agent with GraphQL and Search API to resolve 429 Quota errors

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
This commit is contained in:
Rohit Yanamadala
2025-12-01 12:25:51 -08:00
committed by Copybara-Service
parent 2a1a41d3ec
commit cb19d0714c
7 changed files with 944 additions and 407 deletions
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# ADK Stale Issue Auditor Agent
This directory contains an autonomous agent designed to audit a GitHub repository for stale issues, helping to maintain repository hygiene and ensure that all open items are actionable.
This directory contains an autonomous, **GraphQL-powered** agent designed to audit a GitHub repository for stale issues. It maintains repository hygiene by ensuring all open items are actionable and responsive.
The agent operates as a "Repository Auditor," proactively scanning all open issues rather than waiting for a specific trigger. It uses a combination of deterministic Python tools and the semantic understanding of a Large Language Model (LLM) to make intelligent decisions about the state of a conversation.
Unlike traditional "Stale Bots" that only look at timestamps, this agent uses a **Unified History Trace** and an **LLM (Large Language Model)** to understand the *context* of a conversation. It distinguishes between a maintainer asking a question (stale candidate) vs. a maintainer providing a status update (active).
---
## Core Logic & Features
The agent's primary goal is to identify issues where a maintainer has requested information from the author, and to manage the lifecycle of that issue based on the author's response (or lack thereof).
The agent operates as a "Repository Auditor," proactively scanning open issues using a high-efficiency decision tree.
**The agent follows a precise decision tree:**
### 1. Smart State Verification (GraphQL)
Instead of making multiple expensive API calls, the agent uses a single **GraphQL** query per issue to reconstruct the entire history of the conversation. It combines:
* **Comments**
* **Description/Body Edits** ("Ghost Edits")
* **Title Renames**
* **State Changes** (Reopens)
1. **Audits All Open Issues:** On each run, the agent fetches a batch of the oldest open issues in the repository.
2. **Identifies Pending Issues:** It analyzes the full timeline of each issue to see if the last human action was a comment from a repository maintainer.
3. **Semantic Intent Analysis:** If the last comment was from a maintainer, the agent uses the LLM to determine if the comment was a **question or a request for clarification**.
4. **Marks as Stale:** If the maintainer's question has gone unanswered by the author for a configurable period (e.g., 7 days), the agent will:
* Apply a `stale` label to the issue.
* Post a comment notifying the author that the issue is now considered stale and will be closed if no further action is taken.
* Proactively add a `request clarification` label if it's missing, to make the issue's state clear.
5. **Handles Activity:** If any non-maintainer (the author or a third party) comments on an issue, the agent will automatically remove the `stale` label, marking the issue as active again.
6. **Closes Stale Issues:** If an issue remains in the `stale` state for another configurable period (e.g., 7 days) with no new activity, the agent will post a final comment and close the issue.
It sorts these events chronologically to determine the **Last Active Actor**.
### Self-Configuration
### 2. The "Last Actor" Rule
The agent follows a precise logic flow based on who acted last:
A key feature of this agent is its ability to self-configure. It does not require a hard-coded list of maintainer usernames. On each run, it uses the GitHub API to dynamically fetch the list of users with write access to the repository, ensuring its logic is always based on the current team.
* **If Author/User acted last:** The issue is **ACTIVE**.
* This includes comments, title changes, and *silent* description edits.
* **Action:** The agent immediately removes the `stale` label.
* **Silent Update Alert:** If the user edited the description but *did not* comment, the agent posts a specific alert: *"Notification: The author has updated the issue description..."* to ensure maintainers are notified (since GitHub does not trigger notifications for body edits).
* **Spam Prevention:** The agent checks if it has already alerted about a specific silent edit to avoid spamming the thread.
* **If Maintainer acted last:** The issue is **POTENTIALLY STALE**.
* The agent passes the text of the maintainer's last comment to the LLM.
### 3. Semantic Intent Analysis (LLM)
If the maintainer was the last person to speak, the LLM analyzes the comment text to determine intent:
* **Question/Request:** "Can you provide logs?" / "Please try v2.0."
* **Verdict:** **STALE** (Waiting on Author).
* **Action:** If the time threshold is met, the agent adds the `stale` label. It also checks for the `request clarification` label and adds it if missing.
* **Status Update:** "We are working on a fix." / "Added to backlog."
* **Verdict:** **ACTIVE** (Waiting on Maintainer).
* **Action:** No action taken. The issue remains open without stale labels.
### 4. Lifecycle Management
* **Marking Stale:** After `STALE_HOURS_THRESHOLD` (default: 7 days) of inactivity following a maintainer's question.
* **Closing:** After `CLOSE_HOURS_AFTER_STALE_THRESHOLD` (default: 7 days) of continued inactivity while marked stale.
---
## Performance & Safety
* **GraphQL Optimized:** Fetches comments, edits, labels, and timeline events in a single network request to minimize latency and API quota usage.
* **Search API Filtering:** Uses the GitHub Search API to pre-filter issues created recently, ensuring the bot doesn't waste cycles analyzing brand-new issues.
* **Rate Limit Aware:** Includes intelligent sleeping and retry logic (exponential backoff) to handle GitHub API rate limits (HTTP 429) gracefully.
* **Execution Metrics:** Logs the time taken and API calls consumed for every issue processed.
---
## Configuration
The agent is configured entirely via environment variables, which should be set as secrets in the GitHub Actions workflow environment.
The agent is configured via environment variables, typically set as secrets in GitHub Actions.
### Required Secrets
| Secret Name | Description |
| :--- | :--- |
| `GITHUB_TOKEN` | A GitHub Personal Access Token (PAT) with the required permissions. It's recommended to use a PAT from a dedicated "bot" account.
| `GOOGLE_API_KEY` | An API key for the Google AI (Gemini) model used for the agent's reasoning.
### Required PAT Permissions
The `GITHUB_TOKEN` requires the following **Repository Permissions**:
* **Issues**: `Read & write` (to read issues, add labels, comment, and close)
* **Administration**: `Read-only` (to read the list of repository collaborators/maintainers)
| `GITHUB_TOKEN` | A GitHub Personal Access Token (PAT) or Service Account Token with `repo` scope. |
| `GOOGLE_API_KEY` | An API key for the Google AI (Gemini) model used for reasoning. |
### Optional Configuration
These environment variables can be set in the workflow file to override the defaults in `settings.py`.
These variables control the timing thresholds and model selection.
| Variable Name | Description | Default |
| :--- | :--- | :--- |
| `STALE_HOURS_THRESHOLD` | The number of hours of inactivity after a maintainer's question before an issue is marked as `stale`. | `168` (7 days) |
| `CLOSE_HOURS_AFTER_STALE_THRESHOLD` | The number of hours after being marked `stale` before an issue is closed. | `168` (7 days) |
| `ISSUES_PER_RUN` | The maximum number of oldest open issues to process in a single workflow run. | `100` |
| `LLM_MODEL_NAME`| LLM model to use. | `gemini-2.5-flash` |
| `STALE_HOURS_THRESHOLD` | Hours of inactivity after a maintainer's question before marking as `stale`. | `168` (7 days) |
| `CLOSE_HOURS_AFTER_STALE_THRESHOLD` | Hours after being marked `stale` before the issue is closed. | `168` (7 days) |
| `LLM_MODEL_NAME`| The specific Gemini model version to use. | `gemini-2.5-flash` |
| `OWNER` | Repository owner (auto-detected in Actions). | (Environment dependent) |
| `REPO` | Repository name (auto-detected in Actions). | (Environment dependent) |
---
## Deployment
To deploy this agent, a GitHub Actions workflow file (`.github/workflows/stale-bot.yml`) is included. This workflow runs on a daily schedule and executes the agent's main script.
To deploy this agent, a GitHub Actions workflow file (`.github/workflows/stale-bot.yml`) is recommended.
### Directory Structure Note
Because this agent resides within the `adk-python` package structure, the workflow must ensure the script is executed correctly to handle imports.
Ensure the necessary repository secrets are configured and the `stale` and `request clarification` labels exist in the repository.