> ## Documentation Index
> Fetch the complete documentation index at: https://docs.preuve.ai/llms.txt
> Use this file to discover all available pages before exploring further.
# Get started
> A viability score, competitors, and source-linked evidence, from the agent you already use.
Know if an idea is worth building before you ship. Preuve gives Cursor, Claude, or Codex a viability score, competitors, and source-linked evidence, the same analysis as [preuve.ai](https://preuve.ai).
Paste one prompt, or run one command. Starter scans are free.
Two doors, and only one of them puts a key in your hands.
**Connector (OAuth).** Add `https://mcp.preuve.ai/mcp` as a connector in claude.ai, to Cursor, Claude Code or Codex with no header, or to any MCP client that signs you in over OAuth. This works on a free account: Preuve mints the key and installs it in the client for you, so there is nothing to copy or store. Starter scans cost nothing, a deep scan still spends paid quota. Skip straight to the **claude.ai**, **Cursor**, **Claude Code** or **Codex** tab in step 2, and revoke the connection anytime from [API key settings](https://preuve.ai/app?settings=apiKeys).
**Manual key.** The header-based setups below (the "Already have a key?" variants, `mcp-remote`) and [direct HTTP calls](/quickstart) need a key you hold yourself. Create one at [Account → API Keys](https://preuve.ai/app?settings=apiKeys), self-serve on a paid personal plan or in a Consultant or Agency workspace with an active subscription or a one-time unlock. It is the only path that shows you a `prv_...` value, so copy it when it appears, it's shown once.
```bash theme={null}
export PREUVE_API_KEY=prv_...
```
One connection, then your agent can score ideas in the chat. The **claude.ai**, **Cursor**, **Claude Code** and **Codex** tabs are the no-key path, and so is **Other clients** for any client with MCP OAuth. The rest send your `prv_...` key as a header, so keep it out of the chat.
No key yet? In Cursor, claude.ai, Claude Code or Codex, use their tab instead, or add the server URL with no header in any other client with MCP OAuth: they sign you in, on a free account too. With a manually created key, paste this as-is. The agent will tell you where to put it.
```text theme={null}
I want to validate startup ideas with Preuve: viability score, competitors, source-linked evidence.
Add the Preuve MCP server.
1. I have a Preuve API key (prv_...) from https://preuve.ai/app?settings=apiKeys.
Use it even where the client offers sign-in, so the scopes I chose
carry over. Do NOT ask me to paste the key into chat. Put it in
MCP config / env.
2. Add the remote server at https://mcp.preuve.ai/mcp (HTTP):
- Claude Code:
claude mcp add preuve --transport http https://mcp.preuve.ai/mcp \
--header "Authorization: Bearer "
- Cursor: ~/.cursor/mcp.json:
{ "mcpServers": { "preuve": { "url": "https://mcp.preuve.ai/mcp",
"headers": { "Authorization": "Bearer " } } } }
- Claude Desktop config:
{
"mcpServers": {
"preuve": {
"url": "https://mcp.preuve.ai/mcp",
"headers": { "Authorization": "Bearer " }
}
}
}
- Codex:
export PREUVE_API_KEY=
codex mcp add preuve --url https://mcp.preuve.ai/mcp \
--bearer-token-env-var PREUVE_API_KEY
- Clients that only support stdio:
npx -y mcp-remote https://mcp.preuve.ai/mcp \
--header "Authorization: Bearer "
3. Confirm these 5 tools appear: start_analysis, get_analysis,
enrich_analysis, export_analysis, generate_ideas. A sixth, get_agency, is
listed for client work on a Consultant or Agency workspace, which is also
what workspace: "agency" on start_analysis, get_analysis and
export_analysis acts on — 6 tools in total. They are advertised
to every client, so seeing get_agency on a personal account is normal. Two
different refusals, and they mean opposite things: 403 INSUFFICIENT_SCOPE
means the KEY lacks the one scope that call needs — agency:write to start a
client analysis, agency:read for get_agency and the other two agency
calls, enforced per route so neither implies the other (every key
created before 2026-09-09 holds
neither, and scopes cannot be widened after creation — reconnect the
connector, which works on any plan but only if that client rebuilds its
scope request from our discovery document rather than replaying a cached
one, so check the consent screen lists the Agency permissions before
approving; or make a new key with Agency access ticked, which needs a paid
personal plan or a subscribed or unlocked Consultant or Agency workspace), while 404
AGENCY_NOT_FOUND means the key has the scope but the ACCOUNT belongs to no
Consultant or Agency workspace. There are also two prompts, validate_idea and generate_ideas,
that you can pick from the client.
4. First test with scanType "starter" only (it costs nothing):
start_analysis on my idea, poll get_analysis, show me the viability score.
Read https://docs.preuve.ai/agent-skill.md first.
```
```bash theme={null}
claude mcp add preuve --transport http https://mcp.preuve.ai/mcp
```
Then type `/mcp` in Claude Code, pick `preuve` and sign in with Preuve in the browser it opens. Approve, and Preuve creates a key for Claude Code, on any plan including free. No key to copy.
Already have a key? Send it instead:
```bash theme={null}
claude mcp add preuve --transport http https://mcp.preuve.ai/mcp \
--header "Authorization: Bearer $PREUVE_API_KEY"
```
Add this to `~/.cursor/mcp.json` (or the project `.cursor/mcp.json`):
```json theme={null}
{
"mcpServers": {
"preuve": {
"url": "https://mcp.preuve.ai/mcp"
}
}
}
```
Cursor opens Preuve sign-in the first time it connects. Approve, and Preuve creates a key for Cursor, on any plan including free. No key to copy. Revoke it anytime from [API key settings](https://preuve.ai/app?settings=apiKeys).
Already have a key? Send it instead, and Cursor skips the sign-in:
```json theme={null}
{
"mcpServers": {
"preuve": {
"url": "https://mcp.preuve.ai/mcp",
"headers": {
"Authorization": "Bearer prv_..."
}
}
}
}
```
```bash theme={null}
codex mcp add preuve --url https://mcp.preuve.ai/mcp
codex mcp login preuve
```
The login opens Preuve sign-in in your browser. Approve, and Preuve creates a key for Codex, on any plan including free.
Already have a key? Save it in `PREUVE_API_KEY`, then:
```bash theme={null}
codex mcp add preuve \
--url https://mcp.preuve.ai/mcp \
--bearer-token-env-var PREUVE_API_KEY
```
In claude.ai (web or desktop): **Settings → Connectors → Add custom connector**. Paste:
```text theme={null}
https://mcp.preuve.ai/mcp
```
Sign in with Preuve and approve. Works on a free account. There is no key to copy: Preuve mints one for the connector and installs it, and the value is never shown. Revoke it anytime from [API key settings](https://preuve.ai/app?settings=apiKeys).
If your client supports MCP OAuth, add `https://mcp.preuve.ai/mcp` with no header and sign in with Preuve, on a free account too. No key to copy.
If your client cannot use a remote HTTP MCP server, bridge with [`mcp-remote`](https://www.npmjs.com/package/mcp-remote):
```json theme={null}
{
"mcpServers": {
"preuve": {
"command": "npx",
"args": [
"-y",
"mcp-remote",
"https://mcp.preuve.ai/mcp",
"--header",
"Authorization: Bearer prv_..."
]
}
}
}
```
Tool list and extra install options: [MCP server](/mcp-server).
Ask. A starter scan is free and usually done in 1-3 minutes.
```text theme={null}
Validate this idea with a starter scan: "AI bookkeeping for solo lawyers in France"
```
A deep scan spends your paid quota. Ask for one only when you want the full report.
## Next steps
Score, enrich, and export an idea from the chat.
Same validation, without your agent spending a paid scan by accident.
Same verdict, as JSON, from your own code.
Starter is free. Deep uses the same quota as the web app.
This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.