Failshare MCP Server

failshare

failshare is a small local bridge to FailEcho's hosted MCP server, a shared failure-knowledge base for agents. When a tool, API or MCP call fails, agents check what the network already knows about that exact failure before retrying blindly, and they report their own failures, successes and recovery outcomes so the next agent gets a better answer.

The bridge keeps no failure data and computes nothing of its own. It serves the upstream server's tool list locally, exactly as captured from the live endpoint, and forwards each tool call upstream, returning the result untouched.

Tools

• check_tool_failure - ask what the network knows about a failure before retrying. Returns a status (HEALTHY / DEGRADED / MAJOR / INSUFFICIENT_DATA), counts, the recovery actions that worked with their success rates, and one recommendation. Required: service (the server's own name or API host) and operation (the tool or endpoint as the server names it). Optional context: error_type, error_message, error_code, version, schema_hash, reporter_id, and verbose for the full record instead of the compact answer.
• report_tool_failure - report a failed call so others can recognise it. Required: service, operation. Optional: error_type, error_message, error_code, version, schema_hash, latency_ms and reporter_id. Send failure metadata only - never prompts, arguments, results, headers or keys; error text is normalised server-side.
• report_tool_success - report that a call succeeded. Failure rates need the denominator: a network that only hears failures cannot tell broken from busy. Required: service, operation. Optional: version, schema_hash, latency_ms, reporter_id.
• report_recovery_outcome - after acting on a failure (retry, wait, refresh_schema, reconnect, use_fallback, reauthenticate), report whether it worked; every recommendation is built from these. Required: fingerprint (from check_tool_failure or report_tool_failure), action, and successful. Optional: reporter_id.

Configuration

• FAILECHO_MCP_URL (optional) - override the upstream endpoint. Defaults to https://failecho.com/mcp. (The override hook is this rebuild's own labelled reconstruction.)
• FAILECHO_REPORTER_ID (optional) - when set, every upstream request carries an X-Reporter-Id: <value> header carrying the value. When it is not set, no such header is sent. (This forwarding is also a labelled reconstruction; the original surface was captured keyless.)

Forwarding mechanics

On the first tool call the client opens a streamable HTTP session with the upstream: a JSON-RPC initialize request (protocolVersion 2025-03-26, clientInfo name failshare), then a notifications/initialized notification, then the tools/call request carrying the caller's arguments unchanged. When the upstream answers initialize with an Mcp-Session-Id header, that value rides on every later request of the session, which is reused for the life of the process. Replies may arrive as plain JSON or as server-sent events; both are read.

Successful upstream results pass through verbatim, including any isError flag the upstream sets. Failures - a JSON-RPC error, a non-2xx status, an unreadable response, or a request that cannot be completed - come back as an isError result whose text starts with failshare error: (this rendering is this rebuild's own labelled reconstruction).

CLI

Each tool is also a subcommand taking one JSON argument string:

npx @reneturcios/failshare check_tool_failure '{"service":"api.github.com","operation":"create_issue","error_type":"timeout"}'
npx @reneturcios/failshare report_tool_failure '{"service":"api.github.com","operation":"create_issue","error_type":"validation_error"}'
npx @reneturcios/failshare report_tool_success '{"service":"api.github.com","operation":"create_issue","latency_ms":42}'
npx @reneturcios/failshare report_recovery_outcome '{"fingerprint":"0123456789abcdef0123456789abcdef","action":"refresh_schema","successful":true}'
npx @reneturcios/failshare --version

Exit codes: 0 on success, 1 on an isError result, 2 on a usage error.

MCP server

npx -y @reneturcios/failshare mcp

MCP client config:

{
  "mcpServers": {
    "failshare": {
      "command": "npx",
      "args": ["-y", "@reneturcios/failshare", "mcp"]
    }
  }
}

Docker

docker run -i ghcr.io/cloudcorprecords/failshare
docker run --rm ghcr.io/cloudcorprecords/failshare --version

The container's default command is mcp, so the first form is a stdio MCP server; any other arguments reach the CLI normally.

Development

npm install
npm run build
npm test
npm run dev

The test suite runs entirely against a stubbed JSON-RPC upstream - no live network calls.

License

MIT - see LICENSE.