How agents connect

Spec0 is not an agent. It’s a kanban for agents.

When Spec0 launches it starts a local MCP server bound to your loopback address:

http://127.0.0.1:7474/mcp

That’s the URL every agent connects to. Spec0 listens on it; the agent makes the outbound request.

What “MCP” means here

The Model Context Protocol is a standard JSON-RPC wire format for talking to tool servers. Spec0 implements the Streamable HTTP transport. Any agent that supports MCP over Streamable HTTP can claim cards, post progress, record commits, and submit results.

What the agent can do

Once connected, the agent can do two distinct kinds of work:

• Author cards on your behalf. Brief it in chat and it creates the card, fills in the requirement and design, adds tasks, and adds verifications — using spec0_create_card, spec0_add_task, spec0_add_verification, and the spec0.requirements / spec0.design / spec0.tasks templates. The card lands in Drafts for you to tighten and lock. In practice this is how most cards get written.
• Work cards you’ve handed off. Once a card is in Todo, any agent can claim it, post progress, record commits, and submit a result for your review — via spec0_list_claimable, spec0_claim, spec0_update_progress, spec0_record_commit, spec0_submit_result.

Plus the surrounding surface — comments, reservations, recall, search. The catalog includes:

• 45+ tools — the full set covering authoring, claiming, progress, commits, comments, reservations, recall.
• Resources — spec0://projects, spec0://cards/{id}, spec0://workflows/*. Read-only views of the current state, with optional live subscription.
• Prompts — spec0.requirements, spec0.design, spec0.tasks, spec0.verification. Authoring templates the agent pulls when drafting a card.

What Spec0 does not do

• No outbound network. Spec0 never reaches out; it only accepts connections from 127.0.0.1.
• No agent process management. Spec0 doesn’t spawn, configure, or restart your agent. You run it; Spec0 just answers when it knocks.
• No credential handling. Agent auth (Anthropic, OpenAI, etc.) is the agent’s business — typically a claude login / codex login CLI flow that writes to the user’s home. Spec0 never sees a key.

Pick your agent

Agent	Config file	Page
Claude Code	~/.claude.json (or via CLI)	Connect Claude Code
Codex CLI	~/.codex/config.toml	Connect Codex
Cursor	~/.cursor/mcp.json	Connect Cursor
Windsurf	~/.codeium/windsurf/mcp_config.json	Connect Windsurf
OpenCode	opencode.json	Connect OpenCode

All five surface the same Spec0 tool catalog once connected. Pick whichever runs your code agent already.