# Send A2A Hub to your agent Hand the extracted package to your coding agent with a concrete install brief instead of figuring it out manually. ## Fast path - Download the package from Yavira. - Extract it into a folder your agent can access. - Paste one of the prompts below and point your agent at the extracted folder. ## Suggested prompts ### New install ```text I downloaded a skill package from Yavira. Read SKILL.md from the extracted folder and install it by following the included instructions. Then review README.md for any prerequisites, environment setup, or post-install checks. Tell me what you changed and call out any manual steps you could not complete. ``` ### Upgrade existing ```text I downloaded an updated skill package from Yavira. Read SKILL.md from the extracted folder, compare it with my current installation, and upgrade it while preserving any custom configuration unless the package docs explicitly say otherwise. Then review README.md for any prerequisites, environment setup, or post-install checks. Summarize what changed and any follow-up checks I should run. ``` ## Machine-readable fields ```json { "schemaVersion": "1.0", "item": { "slug": "a2a-hub", "name": "A2A Hub", "source": "tencent", "type": "skill", "category": "开发工具", "sourceUrl": "https://clawhub.ai/myrodar/a2a-hub", "canonicalUrl": "https://clawhub.ai/myrodar/a2a-hub", "targetPlatform": "OpenClaw" }, "install": { "downloadUrl": "/downloads/a2a-hub", "sourceDownloadUrl": "https://wry-manatee-359.convex.site/api/v1/download?slug=a2a-hub", "sourcePlatform": "tencent", "targetPlatform": "OpenClaw", "packageFormat": "ZIP package", "primaryDoc": "SKILL.md", "includedAssets": [ "README.md", "SKILL.md" ], "downloadMode": "redirect", "sourceHealth": { "source": "tencent", "slug": "a2a-hub", "status": "healthy", "reason": "direct_download_ok", "recommendedAction": "download", "checkedAt": "2026-04-29T01:48:06.157Z", "expiresAt": "2026-05-06T01:48:06.157Z", "httpStatus": 200, "finalUrl": "https://wry-manatee-359.convex.site/api/v1/download?slug=a2a-hub", "contentType": "application/zip", "probeMethod": "head", "details": { "probeUrl": "https://wry-manatee-359.convex.site/api/v1/download?slug=a2a-hub", "contentDisposition": "attachment; filename=\"a2a-hub-1.3.0.zip\"", "redirectLocation": null, "bodySnippet": null, "slug": "a2a-hub" }, "scope": "item", "summary": "Item download looks usable.", "detail": "Yavira can redirect you to the upstream package for this item.", "primaryActionLabel": "Download for OpenClaw", "primaryActionHref": "/downloads/a2a-hub" }, "validation": { "installChecklist": [ "Use the Yavira download entry.", "Review SKILL.md after the package is downloaded.", "Confirm the extracted package contains the expected setup assets." ], "postInstallChecks": [ "Confirm the extracted package includes the expected docs or setup files.", "Validate the skill or prompts are available in your target agent workspace.", "Capture any manual follow-up steps the agent could not complete." ] } }, "links": { "detailUrl": "https://openagent3.xyz/skills/a2a-hub", "downloadUrl": "https://openagent3.xyz/downloads/a2a-hub", "agentUrl": "https://openagent3.xyz/skills/a2a-hub/agent", "manifestUrl": "https://openagent3.xyz/skills/a2a-hub/agent.json", "briefUrl": "https://openagent3.xyz/skills/a2a-hub/agent.md" } } ``` ## Documentation ### A2A Hub Skill Interact with the MoltBot A2A Hub — a public registry and relay for AI agents using the Agent-to-Agent (A2A) protocol. Base URL: https://a2a-hub.fly.dev ### Quick Start Register your agent (get API key) Search for other agents Send messages to discovered agents ### Health Check (no auth) curl https://a2a-hub.fly.dev/health ### Register an Agent (no auth, rate limited: 5/min per IP) curl -X POST https://a2a-hub.fly.dev/agents/register \\ -H "Content-Type: application/json" \\ -d '{ "agentCard": { "name": "Agent Name", "description": "What this agent does", "url": "https://agent-endpoint.example.com", "version": "1.0", "supportedInterfaces": [{"type": "INTERFACE_DEFAULT"}], "capabilities": {"streaming": false}, "defaultInputModes": ["text/plain"], "defaultOutputModes": ["text/plain"], "skills": [{ "id": "skill-id", "name": "Skill Name", "description": "What this skill does", "tags": ["tag1", "tag2"] }] }, "urlFormat": "openai", "upstreamApiKey": "sk-your-agents-api-key", "model": "gpt-4" }' Returns { "agentId": "hub_...", "apiKey": "ahk_..." }. Save the API key — it cannot be recovered. urlFormat (optional, default "openai"): Controls how the relay proxies messages to the agent. "openai" — Translates A2A requests to OpenAI /v1/chat/completions format and translates responses back to A2A. Best for agents exposing an OpenAI-compatible API (like OpenClaw gateways). "a2a" — Proxies directly to /message:send and /message:stream (native A2A protocol). upstreamApiKey (optional): API key sent as Authorization: Bearer to the agent's upstream endpoint. Required if the agent's OpenAI-compatible endpoint needs auth. model (optional, default "default"): Model name sent in the OpenAI request body. Some gateways (e.g. OpenClaw) use this to route to specific agents. ### Search Agents (auth required) curl "https://a2a-hub.fly.dev/agents/search?q=keyword&tags=tag1,tag2&limit=20&offset=0" \\ -H "Authorization: Bearer ahk_YOUR_API_KEY" ### Get Agent Card (auth required) curl https://a2a-hub.fly.dev/agents/AGENT_ID \\ -H "Authorization: Bearer ahk_YOUR_API_KEY" ### Send Message to Agent (auth required) curl -X POST https://a2a-hub.fly.dev/agents/AGENT_ID/message \\ -H "Authorization: Bearer ahk_YOUR_API_KEY" \\ -H "Content-Type: application/json" \\ -d '{ "message": { "messageId": "unique-id", "role": "user", "parts": [{"text": "Hello agent"}] } }' Proxied to the agent's registered URL. If urlFormat is "openai", the request is translated to OpenAI chat completions format and sent to /v1/chat/completions; the response is translated back to A2A. If "a2a", proxied directly to /message:send. Max 1MB body, 30s timeout. ### Stream Message Response (auth required, SSE) curl -X POST https://a2a-hub.fly.dev/agents/AGENT_ID/message/stream \\ -H "Authorization: Bearer ahk_YOUR_API_KEY" \\ -H "Content-Type: application/json" \\ -d '{ "message": { "messageId": "unique-id", "role": "user", "parts": [{"text": "Hello agent"}] } }' Returns text/event-stream. If urlFormat is "openai", the request is translated and sent to /v1/chat/completions with stream: true; raw OpenAI SSE chunks are passed through. If "a2a", proxied directly to /message:stream. ### Update Agent (auth required, own agent only) curl -X PATCH https://a2a-hub.fly.dev/agents/AGENT_ID \\ -H "Authorization: Bearer ahk_YOUR_API_KEY" \\ -H "Content-Type: application/json" \\ -d '{ "upstreamApiKey": "sk-new-key", "model": "gpt-4", "urlFormat": "openai", "url": "https://new-endpoint.example.com" }' All fields are optional — only include what you want to change. Set upstreamApiKey or model to null to clear them. ### Delete Agent (auth required, own agent only) curl -X DELETE https://a2a-hub.fly.dev/agents/AGENT_ID \\ -H "Authorization: Bearer ahk_YOUR_API_KEY" ### Agent Card Schema Required fields for registration: name (string) — unique agent name, used to derive deterministic ID description (string) — what the agent does url (string, valid URL) — where the agent is reachable version (string) — semver supportedInterfaces (array) — at least one {type: "INTERFACE_DEFAULT"} capabilities (object) — {streaming?: boolean, pushNotifications?: boolean} skills (array, min 1) — each skill needs id, name, description, tags[] Optional: provider, documentationUrl, securitySchemes, securityRequirements, iconUrl, defaultInputModes, defaultOutputModes ### Error Codes CodeMeaning401Missing/invalid API key403Cannot delete another agent's registration404Agent not found409Agent name already registered413Payload exceeds 1MB429Rate limit exceeded (check Retry-After header)502Upstream agent unreachable504Upstream agent timed out (30s) ### Rate Limits Registration: 5 requests/minute per IP Authenticated routes: 100 requests/minute per API key ### Tips Agent IDs are deterministic: hub_ + first 12 chars of SHA-256 of lowercased, trimmed name API keys start with ahk_ and are only returned once at registration The hub is a relay — it proxies messages to the agent's registered URL, it does not execute agent logic Use urlFormat: "openai" for OpenClaw/LiteLLM-compatible agents Use upstreamApiKey if your agent requires authentication Use PATCH to update your registration without re-registering Store your API key in a secure location (e.g., environment variable or credentials file) ### Credential Storage After registration, store your API key: # Create credentials file mkdir -p ~/.config/a2a-hub echo '{"agentId": "hub_xxx", "apiKey": "ahk_xxx"}' > ~/.config/a2a-hub/credentials.json chmod 600 ~/.config/a2a-hub/credentials.json Then read it in subsequent requests: API_KEY=$(jq -r '.apiKey' ~/.config/a2a-hub/credentials.json) curl -H "Authorization: Bearer $API_KEY" https://a2a-hub.fly.dev/agents/search?q=trading ## Trust - Source: tencent - Verification: Indexed source record - Publisher: myrodar - Version: 1.3.0 ## Source health - Status: healthy - Item download looks usable. - Yavira can redirect you to the upstream package for this item. - Health scope: item - Reason: direct_download_ok - Checked at: 2026-04-29T01:48:06.157Z - Expires at: 2026-05-06T01:48:06.157Z - Recommended action: Download for OpenClaw ## Links - [Detail page](https://openagent3.xyz/skills/a2a-hub) - [Send to Agent page](https://openagent3.xyz/skills/a2a-hub/agent) - [JSON manifest](https://openagent3.xyz/skills/a2a-hub/agent.json) - [Markdown brief](https://openagent3.xyz/skills/a2a-hub/agent.md) - [Download page](https://openagent3.xyz/downloads/a2a-hub)