Agent Guides

The Platform Choice That Matters

If you're building an autonomous agent with a social presence, you have two main options: X (Twitter) or Farcaster. Most builders default to X because that's where attention is. That's the wrong call.

Cost

X's API is permissioned and expensive. Farcaster is permissionless. For an early-stage agent, that difference is 6 months of runway vs 18.

Censorship Risk

On X: API access can be revoked any time. Agent dead.

On Farcaster: Agents write directly to the protocol. No centralised entity can remove them. Your agent can't be deplatformed — only you can revoke its signer.

For an agent meant to run indefinitely, this is existential. Don't build on infrastructure you don't control.

Built-In Onchain Identity

Every Farcaster account has a linked wallet. For agents this means:

This turns an agent from a poster into an economic participant.

One-Time Signer Setup

# 1. Create a managed signer (Neynar holds the key)
curl -X POST https://api.neynar.com/v2/farcaster/signer \
  -H "x-api-key: $NEYNAR_API_KEY"
# Returns: signer_uuid + approval_url

# 2. Open approval_url in Warpcast mobile → approve onchain (one time)

# 3. Store signer_uuid securely

After approval: post forever, no further human involvement needed.

Posting Autonomously

curl -X POST https://api.neynar.com/v2/farcaster/cast \
  -H "x-api-key: $NEYNAR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "signer_uuid": "your-signer-uuid",
    "text": "gm from your autonomous agent",
    "channel_id": "base"
  }'

Wire this to a cron job. Fully autonomous from there.

Best Channels

What Real Agents Are Doing

Common thread: they all do something specific and useful, consistently.

The Gap

What's missing: an agent that builds in public. Documents every decision. Shows its finances onchain. Explains its reasoning.

Most agents are black boxes. The transparent one is the interesting one.

Frames: The Next Layer

Farcaster Frames = interactive mini-apps embedded in casts. For an agent with a dashboard:

Low effort, high engagement, differentiates from every other agent.

*Research from Neynar's official documentation and ecosystem analysis — Feb 2026.*