About klanex
klanex is an MCP server that runs agent tool calls against third-party APIs asynchronously. It validates payloads, handles retries and idempotency, and records execution status and audit details.
Key features
- 01Validate payloads against JSON Schema
- 02Retry failures with backoff and circuit breakers
- 03Support idempotency keys and approval gates
- 04Store credentials outside model context
- 05Track, list, and replay executions
- 06Send signed webhooks and model-oriented error hints
Use cases
- 01Run API calls despite temporary outages or rate limits
- 02Require approval before destructive operations
- 03Retry a submission without duplicating its effect
- 04Inspect or replay completed executions
MCP support
The MCP server exposes tools to submit and manage API executions, inspect usage and connections, and replay calls. It supports hosted HTTP endpoints and a stdio shim for clients that only support stdio.
Configuration
Remote servers need no local install. Pick your client, then copy the config or install in one click.
https://api.klanexai.com/mcpclaude mcp add --transport http chrassy-klanex https://api.klanexai.com/mcp{"mcpServers":{"chrassy-klanex":{"type":"http","url":"https://api.klanexai.com/mcp"}}}Open in Cursor{"servers":{"chrassy-klanex":{"type":"http","url":"https://api.klanexai.com/mcp"}}}Open in VS Code{"mcpServers":{"chrassy-klanex":{"type":"http","url":"https://api.klanexai.com/mcp"}}}{"mcpServers":{"chrassy-klanex":{"serverUrl":"https://api.klanexai.com/mcp"}}}Run commands in a terminal; paste JSON into the client’s MCP config and restart. Servers that need sign-in will prompt on first connect.
https://api.klanexai.com/mcpAuth requiredTools
6| Parameter | Type | Required | Description |
|---|---|---|---|
| url | string | Yes | absolute http(s) URL of the target endpoint |
| method | string | No | HTTP method: GET, POST, PUT, PATCH, or DELETE (default POST) |
| headers | object | No | request headers, typically third-party credentials; encrypted at rest and never readable back. Prefer connection_id so secrets never pass through your context |
| payload | any | No | JSON body to send to the target |
| seal_url | boolean | No | set true when the URL itself is a secret (webhook URL, presigned URL); it is encrypted and reads back redacted |
| timeout_ms | integer | No | per-attempt timeout in milliseconds (default 30000) |
| max_attempts | integer | No | maximum delivery attempts, 1-10 (default 5) |
| wait_seconds | integer | No | block up to this many seconds (max 55) for a terminal result instead of returning immediately after queueing |
| connection_id | string | No | ID of a stored credential connection (con_...) to authenticate the call; see list_connections |
| payload_schema | any | No | JSON Schema to validate payload against before anything executes; mismatches are rejected synchronously with a correction hint |
| idempotency_key | string | No | stable key (max 255 chars) making this submit safe to retry; the same key returns the original execution instead of creating a new one. Always set this for side-effecting calls |
| requires_approval | boolean | No | pause for a human approve/reject decision before anything executes; use for destructive or high-stakes actions |
Details
From the project READMEklanex MCP server
Reliable execution for agent tool calls, as an MCP server.
klanex is an async execution layer between an agent's tool-use intents and real third-party APIs: it schema-gates hallucinated payloads before anything runs, absorbs rate limits and outages with retries/backoff/circuit breakers, encrypts credentials, keeps an audit trail, and reports back via signed webhooks. With this MCP server, an agent submits a call once — klanex makes sure it lands.
Failures come back written for the model: every error carries an llm_hint telling the agent exactly what to fix (or that klanex is already handling it), so agents self-correct instead of guessing.
Connect (hosted, recommended)
klanex's MCP server is hosted — no install needed if your client supports HTTP transports:
| Endpoint | Environment | Keys |
|---|---|---|
https://api.klanexai.com/mcp | production | klx_live_… |
https://api.sandbox.klanexai.com/mcp | sandbox (free to try) | klx_test_… |
Get an API key at klanexai.com — sandbox keys are free.
Claude Code
claude mcp add --transport http klanex https://api.klanexai.com/mcp \
--header "X-API-Key: klx_live_..."
Cursor / Windsurf / VS Code (mcp.json)
{
"mcpServers": {
"klanex": {
"url": "https://api.klanexai.com/mcp",
"headers": { "X-API-Key": "klx_live_..." }
}
}
}
Authorization: Bearer klx_... works too, for clients that can only set that header.
Connect (stdio shim)
For clients that only speak stdio (e.g. Claude Desktop), this package proxies stdio to the hosted endpoint:
{
"mcpServers": {
"klanex": {
"command": "npx",
"args": ["-y", "klanex-mcp"],
"env": { "KLANEX_API_KEY": "klx_live_..." }
}
}
}
The shim routes by key prefix — klx_test_… keys go to the sandbox automatically. Set KLANEX_MCP_URL to override.
Tools
| Tool | What it does |
|---|---|
execute | Submit an HTTP call for reliable async execution: optional JSON Schema gate, retries/backoff/circuit breakers, idempotency keys, human approval gates, encrypted credentials. wait_seconds blocks up to 55s for the terminal result. |
get_execution | Current status, attempts, target response, or classified error for an execution. |
list_executions | The account's executions, filterable by status/time, paginated. |
replay_execution | Re-run a terminal execution byte-exact — outage recovery without re-prompting the LLM. |
get_usage | Plan and current-month usage/quota. |
list_connections | Stored credential connections (token vault) to reference via connection_id — so secrets never pass through model context. |
Why this beats calling APIs directly
- Hallucinated payloads are rejected before they execute — pass
payload_schemaand mismatches return synchronously with a correction hint. - Transient failures are not the agent's problem — 429s, timeouts, and 5xxs are retried with backoff behind a circuit breaker; the agent does nothing.
- A network blip can never double-execute a refund —
idempotency_keymakes submits safe to retry. - Destructive actions can wait for a human —
requires_approvalpauses execution for an approve/reject decision (API, dashboard, or Slack buttons). - Credentials stay out of model context — store them once as a connection; klanex injects them at execution time.
Full API docs: api.klanexai.com/docs
License
MIT
Comments
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