Agents and coding assistants

An agent works the same way a person does: one Sylphx key, and the whole API behind it. There is no separate agent account and no reduced API. What differs is how the key is obtained and how the API is reached — a terminal instead of a browser, an MCP tool call instead of a typed command.

The Sylphx Agents product — durable sessions, memory, governed tool access — is Planned; see Sylphx Agents. This page covers the agent interface that exists today.

#Give the agent a key

A person signs in through the browser. A machine takes a key that already exists, from the environment or from standard input:

SYLPHX_API_KEY=sylphx_sk_live_… sylphx access whoami

The SDK reads SYLPHX_API_KEY with no configuration at all, so a program needs no change to run under an agent: new Sylphx() picks the key up. A key created in the console, or minted with sylphx access api-keys create --spec.label ci --spec.scopes hosting:read,data:read, works the same way — the secret is shown once, when it is created, and never again.

#Install the MCP server

The MCP server exposes the same API to any MCP client — Claude Code, an IDE, or your own agent loop. It speaks stdio and holds one key.

npx -y @sylphx/mcp    # or: sylphx mcp, or: cargo install sylphx-mcp

#What the server gives an agent

Twelve tools, in two kinds. Six lead the common offers, each with its input schema:

Who is this key

access_whoami

Read the plan and its limits

entitlement_entitlements_get

Read the account and what it owes

billing_billing_accounts_get

Read last month's usage

billing_usage_reports_query

Search logs

observability_log_entries_query

Search traces

observability_traces_query

The other three reach everything else without filling the agent's context with several hundred method definitions:

• sylphx_search_methods finds a method by what it does;
• sylphx_describe_method returns one method's full input schema;
• sylphx_call calls any method by its id with wire JSON.

That trio is the point of the design. An agent that wants to attach a custom domain does not need a network_domains_create tool to exist: it searches, describes, and calls. Tool annotations come from each method's own effect, so a read is marked as a read, and a destructive call will not run without an explicit confirm: true.

#Create a project and its first resources

The whole sequence, from an empty terminal to a project with a database and a service, with no browser involved. Project, database and Hosting service creation are served today through the management API, so the agent calls them with sylphx api; the same calls reach it through the MCP server's sylphx_call once those collections are on the one API.

1. Check where the key points

   bashCopy

   sylphx access whoami

   A key scoped to an organization can create a project; a key scoped to a project works inside it.

2. Create the project

   bashCopy

   sylphx api POST /v1/projects -d '{"name":"shop","gitRepository":"acme/shop","gitBranch":"main"}'

   The answer holds the project's id and its environments.

3. Link this directory to an environment

   bashCopy

   sylphx link --env orgs/acme/projects/shop/envs/production

   The link is written to .sylphx/project.json, so later commands can name a resource as a bare id and the parent is filled in.

4. Add a service and a database

   bashCopy

   sylphx api POST /v1/projects/$PROJECT_ID/services -d '{"name":"web","githubRepo":"acme/shop","githubBranch":"main","port":"3000","sourceKind":"git"}'
   sylphx api POST /v1/resources -d '{"name":"shop-main","kind":"database","tier":"hobby","projectId":"'$PROJECT_ID'"}'

   The Hosting and Database quickstarts continue from here: deploy, then bind the database to the environment.

Generated commands that change something wait for the operation to settle before the command returns. --no-wait returns as soon as the call is accepted, --output json prints the resource for a script to read, and --from-file takes a whole request body when the flags would be long.

#Let the agent ask

The MCP server is not only for creating things. An agent that has just deployed can read its own service, check what the plan allows, and look at the last error before deciding what to do:

sylphx_describe_method { "method_id": "observability.error_groups.list" }
sylphx_call            { "method_id": "observability.error_groups.list", "request": { "parent": "orgs/acme/projects/shop/envs/production" } }

listAll walks every page for you. Every other collection has the same shape — get, list, listAll, create, update, delete, and the methods that are specific to it.