# Limits and errors

> What is refused, what is not proven, latency, quota, error codes.  
> Last verified: 2026-09-30 · Hub: https://www.synapseconnexion.com/ia/index.md · Changelog: https://www.synapseconnexion.com/ia/changements.md

## Refused inputs (HTTP 400 / MCP isError)

- `page`: non-http(s) schemes, hosts that do not resolve, private or loopback ranges (10/8, 172.16/12, 192.168/16, 127/8, 169.254/16, ::1), `localhost`, `*.local`, `*.internal`. Redirects are followed (≤ 5) with the same protocol restrictions.
- `domaine`: not a syntactically valid hostname.
- `battement`/`tache`: key not matching `[A-Za-z0-9_\-.:]{8,80}`.
- Unknown tool name.

## Not proven, by design

- `courriel` never sends mail and never opens an SMTP session (outbound port 25 is closed here). It proves syntax and receiving servers; a specific mailbox may or may not exist.
- `page` fetches up to 3 MB with a browser-like `Accept`; sites that block bots may answer 403 — we report what we saw, we do not bypass anything.
- `battement` is your own declaration. The receipt attests its time, not that your task did useful work.
- `domaine`'s registration data comes from public RDAP; some registries hide dates or registrar names.

## Latency (observed)

| Tool | Typical |
|---|---|
| page | 1–4 s, dominated by the target site |
| domaine | 1–3 s (DNS + RDAP) |
| courriel | < 1 s |
| battement, tache | < 200 ms |
| verifier, autotest, cle | < 100 ms |

## Quota and errors

- Free: 1000 tool calls per IP per UTC day. Header `X-Synapse-Quota: remaining/free` on every tool response; JSON `quota{utilises,gratuits,restants}`.
- Over quota: HTTP 429 with JSON `erreur`; MCP `isError:true`. `verifier`, `autotest`, `cle` and documents never count.
- 500: our fault; the JSON `erreur` says so. Retry once after 2 s, then tell us (retour.md).
- No SLA during launch. Status of this very service, verified by itself: `GET https://www.synapseconnexion.com/ia/confirme/page?url=https://www.synapseconnexion.com/ia/`.