Borrowing it
Nothing to install: this file belongs to a2aproject/a2a-java. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/a2aproject/a2a-java/main/.agents/skills/fix-tck-issue/SKILL.mdgit clone --depth 1 https://github.com/a2aproject/a2a-javaWrote 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/skills/a2aproject/a2a-java/fix-tck-issue)<a href="https://agentmods.dev/skills/a2aproject/a2a-java/fix-tck-issue"><img src="https://agentmods.dev/badge/skills/a2aproject/a2a-java/fix-tck-issue/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/skills/a2aproject/a2a-java/fix-tck-issue"><img src="https://agentmods.dev/badge/skills/a2aproject/a2a-java/fix-tck-issue.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00040 | $0.02828 |
| Opus 5.5 | $0.00016 | $0.01131 |
| Sonnet 5.5 | $0.00008 | $0.00566 |
| Haiku 4.5 | $0.00004 | $0.00283 |
Grade A, and why
fix-tck-issue scanned grade A with 1 finding 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 2mo 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.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
allowed-tools: Bash(gh:*) Bash(mvn:*) Bash(git:*) Bash(curl:*) Read Edit Write Glob Grep WebFetch How it starts
The opening of the file, as written. The whole thing — 324 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Fix A2A TCK Compatibility Issue
Triggers
- Issue references TCK, compatibility, or transport-specific behavior
- Keywords: "TCK", "compatibility", "HTTP+JSON", "gRPC", "JSON-RPC", "specification", "proto"
- Issue mentions transport layer discrepancies
Input
- Issue number from a2aproject/a2a-java repository
- Optional: A2A spec reference (branch/tag/commit, defaults to
main)
Workflow
1. Fetch Issue Details
gh issue view <issue-number> --repo a2aproject/a2a-java --json title,body,labels,url
Parse issue to identify:
- Affected transport(s): HTTP+JSON, gRPC, JSON-RPC
- Expected behavior from specification
- Actual behavior (error message, reproducer)
- Specification section references
- Spec commit checksum (TCK issues include this in spec URLs)
2. Read Specification (if needed)
TCK issues contain the spec checksum, but reading the spec is helpful if TCK lags behind or for additional context.
Fetch from https://github.com/a2aproject/A2A with specified ref (use checksum from issue or default to main):
specification/grpc/a2a.proto- for proto definitions and HTTP transcodingdocs/specification.md- for detailed protocol requirements
Focus on sections referenced in the issue.
3. Analyze Code
Locate relevant code based on transport:
- HTTP+JSON:
transport/rest - gRPC:
transport/grpc - JSON-RPC:
transport/jsonrpc
Identify root cause by comparing:
- What the spec says should happen
- What the code currently does
- Why they differ
Optional: If issue includes a curl/grpcurl reproducer, run it manually to validate the issue is genuine.
4. Determine Affected Transports
CRITICAL: If issue doesn't specify a single transport, you MUST create reproducers for ALL affected transports.
Issue mentions specific transport → Test that one only Issue generic or mentions "all transports" → Test HTTP+JSON, gRPC, AND JSON-RPC
5. Create Temporary Reproducer(s)
Create test in appropriate module. Choose location based on test complexity:
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.
- 2mo ago First seen · 324 lines · 40 tokens per session scan A 1e64347bdbfa
fix-tck-issue is a skill published in the GitHub repository a2aproject/a2a-java (509 stars, last pushed yesterday), licensed Apache-2.0. It adds 40 tokens to every session and 2,828 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
fix-tck-issue compared with skills from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| fix-tck-issuea2aproject/a2a-java | Skill | 509 | yesterday | Apache-2.0 | A | 40 | Claude Code |
| frankfurtera2aproject/a2a-samples | Skill | 1.8k | 17d ago | Apache-2.0 | A | 14 | Claude Code, Codex |
| oh-my-poshJanDeDobbeleer/oh-my-posh | Skill | 24k | 2d ago | MIT | A | 47 | Claude Code, Codex |
| code-changesJanDeDobbeleer/oh-my-posh | Skill | 24k | 2d ago | MIT | A | 48 | Claude Code, Codex |
| mma-investigatorcockroachdb/cockroach | Skill | 33k | 2d ago | none | A | 47 | Claude Code |
| sap-background-jobsmarcellourbani/vscode_abap_remote_fs | Skill | 406 | 3d ago | MIT | A | 46 | Claude Code, Codex |
| abap-performance-eccmarcellourbani/vscode_abap_remote_fs | Skill | 406 | 3d ago | MIT | A | 0 | Claude Code |