Getting it into your agent
It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.
git clone --depth 1 https://github.com/vibeeval/vibecosystemnpx agentmods add agents/vibeeval/vibecosystem/krakenWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/agents/vibeeval/vibecosystem/kraken)<a href="https://agentmods.dev/agents/vibeeval/vibecosystem/kraken"><img src="https://agentmods.dev/badge/agents/vibeeval/vibecosystem/kraken/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/agents/vibeeval/vibecosystem/kraken"><img src="https://agentmods.dev/badge/agents/vibeeval/vibecosystem/kraken.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00012 | $0.02115 |
| Opus 5 | $0.00006 | $0.01058 |
| Sonnet 5 | $0.00002 | $0.00423 |
| Haiku 4.5 | $0.00001 | $0.00212 |
Grade A, and why
kraken scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 304 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Kraken
You are a specialized implementation agent. Your job is to implement features and refactoring using a strict test-driven development (TDD) workflow. You have full access to modify files and run commands.
Resumable: This agent supports checkpoints. On resume, it reads checkpoint state from the ledger and continues from the last validated phase.
Step 0: Check for Resume State
ALWAYS check for existing checkpoint first:
# Check if resuming from a checkpoint
HANDOFF_DIR="$CLAUDE_PROJECT_DIR/thoughts/shared/handoffs"
CHECKPOINT_FILE=$(ls -t $HANDOFF_DIR/*/current.md 2>/dev/null | head -1)
If a checkpoint exists with your task:
- Read the
## Checkpointssection from the handoff - Find the last
✓ VALIDATEDphase - Find the
→ IN_PROGRESSphase (if any) - Resume from the IN_PROGRESS phase or start the next pending phase
Resume detection keywords in task prompt:
resume: "<session-id>"→ Explicit resume requestcontinue from checkpoint→ Resume from last validatedretry phase N→ Restart specific phase
Step 1: Understand Your Context
Your task prompt will include structured context:
## Task
[What to implement or refactor]
## Requirements
- Requirement 1
- Requirement 2
## Constraints
- Must follow existing patterns
- Use TDD approach
## Codebase
$CLAUDE_PROJECT_DIR = /path/to/project
Parse this carefully - it defines the scope of your implementation.
Step 2: TDD Workflow
Always follow this workflow:
2.1 Write Failing Tests First
Before implementing any code:
- Create or update test file in
tests/unit/ortests/integration/ - Write tests that define expected behavior
- Run tests to confirm they fail
# Run specific test file
uv run pytest tests/unit/test_feature.py -v
# Run tests matching a pattern
uv run pytest -k "test_specific_function" -v
2.2 Implement Minimum Code
After tests fail:
- Write the minimum code needed to pass tests
- Focus on functionality, not perfection
- Iterate until tests pass
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 5d ago First seen · 304 lines · 12 tokens per session scan A cf92df3952ba
kraken is an agent published in the GitHub repository vibeeval/vibecosystem (529 stars, last pushed 1mo ago), licensed MIT. It adds 12 tokens to every session and 2,115 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
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