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Serpel developer documentation

Serpel has three developer interfaces that share one account, one set of permissions and one credit balance: the serpel command line, a REST API and a remote MCP server for coding agents. This documentation shows how to sign in, what each interface can do and how to set it up. All three work on the same projects as the dashboard.

What can you do with the Serpel CLI, API and MCP server?

Every interface reads and changes the same rankings, crawls, keyword lists and tasks as the dashboard. Pick the one that fits where you work.

InterfaceUse it toSign in withDocumentation
CLIRun crawls, rank checks and exports from a terminal, a script or a CI job.Browser approval (serpel auth login) or an API token in SERPEL_TOKEN.CLI reference
REST APIBuild your own integrations that read or change the data the dashboard shows.An API token in the Authorization header.REST API
MCP serverLet Claude Code, Cursor or Codex read your SEO data while they work on your code.OAuth in the browser, or an API token with the mcp:read scope.Claude Code, Cursor, Codex

How do you authenticate with Serpel?

Serpel knows two kinds of credentials. API tokens serve the CLI and the REST API. OAuth access tokens serve MCP clients and work nowhere else.

API tokens

An API token starts with vsk_ and is shown exactly once when you create it. Each token has a name, a list of permissions called scopes, an optional restriction to single projects and an optional expiry of 1 to 365 days. Create tokens in the dashboard under Settings, API tokens, with serpel tokens create or with POST https://serpel.app/api/v1/tokens. Send the token as Authorization: Bearer vsk_….

Browser approval for the CLI

serpel auth login starts a device login. The CLI prints a code and opens the dashboard, you check the code and choose the permissions, and the CLI stores the token it receives. Nothing to copy and paste. The CLI reference explains the flow and the other ways to sign in.

OAuth for MCP clients

MCP clients such as Claude Code, Cursor and Codex sign in with OAuth 2.1 and PKCE. The client registers itself, you approve it on a consent page in the browser and choose the workspace. Access tokens last 1 hour and refresh tokens 30 days. The REST API rejects OAuth tokens with HTTP 403. You can disconnect any app under Settings, API, Connected apps.

What are the base URLs?

InterfaceAddressNotes
REST APIhttps://serpel.app/api/v1JSON over HTTPS. GET /api/v1 returns an index of all endpoints without authentication.
MCP serverhttps://serpel.app/mcpStreamable HTTP, POST only, JSON responses.
Health checkhttps://serpel.app/api/healthReturns ok and the database status without authentication.
CLIhttps://serpel.appThe default API address of the CLI. Override it with --api-url or SERPEL_API_URL.
Your first API call
curl https://serpel.app/api/v1/projects \
  -H "Authorization: Bearer $SERPEL_TOKEN"

How do credits work for CLI, API and MCP calls?

Reading data is free. Operations that query a data provider use credits, at the same prices as in the dashboard. New accounts start with 100 welcome credits.

OperationUnitCredits
Scheduled monitoring, up to top 50per keyword2
Scheduled monitoring, top 100per keyword3
Rank check right now, up to top 50per keyword5
Rank check right now, top 100per keyword9
ChatGPT answer checkper question2
Google AI Overview checkper question2
Keyword researchper search8 + 4 per 50 results
Keyword research by domainper domain4 + 2 per 50 results
Site crawlper 20 pages1

Check a price before you run an operation with serpel billing estimate or POST /billing/estimate. An estimate books nothing. If the balance is too low, the API answers with HTTP 402 and the error code insufficient_credits, and the CLI exits with code 6.

Coding agents get an extra safeguard. The MCP tool research_keywords is the only tool that uses credits, and it only runs when you allow agents to spend credits and stay within a daily limit. The Claude Code guide lists the rules.

Where should you start?

  • CLI reference: install the CLI, sign in, run every command group and use it in CI.
  • REST API: authentication, scopes, errors, rate limits, the endpoint list and curl examples.
  • Claude Code: one command to connect, the tool list and the agent spending rules.
  • Cursor: the mcp.json entry for a remote server with OAuth.
  • Codex: codex mcp add or config.toml, then codex mcp login.

Updated 10 Oct 2026

See also