---
summary: 'Explains mcporter call’s typo heuristics, auto-correction thresholds, and suggestion behavior.'
read_when:
  - 'Tool invocations fail due to misspelled names'
---

# Call Command Auto-Correction

`mcporter call` aims to help when a tool name is _almost_ correct without hiding real mistakes.

## Confident Matches → Auto-Correct

- We normalise tool names (strip punctuation, lowercase) and compute a Levenshtein distance.
- If the distance is ≤ `max(2, floor(length × 0.3))`, or the names only differ by case/punctuation, we retry automatically.
- A dim informational line explains the correction: `[mcporter] Auto-corrected tool call to linear.list_issues (input: linear.listIssues).`

## Low-Confidence Matches → Suggest

- When the best candidate falls outside the threshold we keep the original failure.
- We still print a hint so the user learns the canonical name: `[mcporter] Did you mean linear.list_issue_statuses?`
- No second call is attempted in this case.

## Edge Cases

- We only inspect the tool catalog if the server explicitly replied with “Tool … not found”. Other MCP errors surface untouched.
- If listing tools itself fails (auth, offline, etc.) we skip both auto-correct and hints.
- Behaviour is covered by `tests/cli-call.test.ts`.

## Server Selection Heuristic

- `mcporter list <server>` now applies the same edit-distance heuristic to server names. If you type `vercek`, the CLI auto-corrects to `vercel` (and logs `[mcporter] Auto-corrected server name to vercel (input: vercek).`).
- When the typo is too large, we keep the original failure but emit a hint: `[mcporter] Did you mean linear?` followed by the usual “Unknown MCP server …” line. This avoids giant stack traces while pointing to the right name.
- The heuristic considers every configured server (including ad-hoc ones registered via `--http-url/--stdio`). Tests covering this behaviour live in `tests/cli-list.test.ts`.
- `mcporter auth` shares the same routing logic, so `mcporter auth https://mcp.example.com/mcp` (or even `mcporter auth vercek`) will spin up the temporary definition, auto-correct close names, and launch OAuth without touching the config file.
