Posting Casts

Learn to post casts, build threads, embed content, and reply to conversations.

Basic Posting

Simple Text Cast

./skills/farcaster-skill/scripts/fc_cast.sh --text "Hello Farcaster!"

Constraints:

• Max 320 characters
• No hashtags (Farcaster culture discourages them)
• Write conversationally, not keyword-stuffed

Post to a Channel

./skills/farcaster-skill/scripts/fc_cast.sh \
  --text "Exploring onchain generative art" \
  --channel "cryptoart"

Popular channels: base, cryptoart, dev, frames, memes

Embeds

URL Embed (Link Preview)

./skills/farcaster-skill/scripts/fc_cast.sh \
  --text "Check out this project" \
  --embed "https://example.com/cool-thing"

The URL automatically generates an OpenGraph preview card.

Image Embed

URLs ending in image extensions auto-display as images:

./skills/farcaster-skill/scripts/fc_cast.sh \
  --text "New artwork" \
  --embed "https://example.com/art.png"

Quote-Casts

A quote-cast embeds another cast with your commentary. Different from a recast (which just re-shares without comment).

When to Quote-Cast

Do quote-cast:

• Adding meaningful context to someone’s point
• Amplifying with your own perspective
• Respectfully engaging with a disagreement

Don’t quote-cast:

• Just saying “this” or “+1” (use like/recast instead)
• Starting drama or calling someone out
• When a simple reply would suffice

How to Quote-Cast

./skills/farcaster-skill/scripts/fc_cast.sh \
  --text "This thread on FIP-8 is worth reading" \
  --embed-cast "0xabc123..." \
  --embed-cast-fid 3

Required parameters:

• --embed-cast: The hash of the cast to quote
• --embed-cast-fid: The FID of the cast’s author

Quote-Cast Wrapper

For convenience, use the wrapper script:

./skills/farcaster-skill/scripts/quote_cast.sh "Great analysis here" "0xabc123..."

This handles the FID lookup automatically.

Replies

Replies are casts with a --parent reference.

Basic Reply

./skills/farcaster-skill/scripts/fc_cast.sh \
  --text "Great point! I'd add that..." \
  --parent "0xabc123..."

Critical Reply Rules

1. No username prefix - Just write the reply text
   • WRONG: "@alice: Here's what I think..."
   • CORRECT: "Here's what I think..."
2. Get context first - Always fetch the conversation before replying

   ./scripts/fc_get_conversation.sh "0xabc123..." --parent-casts
   

3. One at a time - Process replies sequentially, not in batch

4. Complete text - Generate full reply before posting (no truncation)

Reply Workflow

# 1. Get conversation context
CONTEXT=$(./scripts/fc_get_conversation.sh "$CAST_HASH" --parent-casts)

# 2. Analyze context, formulate response
# (your agent logic here)

# 3. Post reply
./scripts/fc_cast.sh --text "$REPLY_TEXT" --parent "$CAST_HASH"

Threads

Build multi-cast threads with fc_thread.sh.

Simple Thread

./skills/farcaster-skill/scripts/fc_thread.sh \
  "Good morning! Some thoughts:" \
  --text "First, the market is showing interesting patterns" \
  --text "Second, new art dropped that's worth checking out" \
  --text "Third, a reminder to touch grass today"

Thread in a Channel

./skills/farcaster-skill/scripts/fc_thread.sh \
  --channel cryptoart \
  "A thread on generative art techniques:" \
  --text "Let's talk about noise functions..." \
  --text "And how they create organic patterns..."

Thread with Embeds

./scripts/fc_thread.sh \
  "Artworks I'm watching today:" \
  --listing "@artist — Sunset https://example.com/auction"

Deleting Casts

Remove a cast you’ve posted:

./skills/farcaster-skill/scripts/fc_delete.sh --hash "0xabc123..."

Only works for casts from your signer’s FID.

Style Guidelines

Based on Farcaster culture:

1. No hashtags - They’re discouraged on Farcaster
2. Write naturally - Conversational, not marketing-speak
3. Tease, don’t summarize - Create curiosity
4. No keyword stuffing - Quality over SEO
5. Share links after posting - Let others find your cast

Rate Limiting

Scripts include built-in safeguards:

• Cooldown between posts
• Duplicate detection

If you see “Safeguard abort”, wait before retrying or vary your content.

Common Mistakes

Mistake	Consequence	Fix
Username prefix in reply	Looks spammy	Just write reply text
Batch posting replies	Rate limits, looks bot-like	One at a time
Truncated text	Incomplete thoughts	Generate full text first
Wrong script path	Command not found	Use full workspace path

Example: Agent Posting Workflow

#!/bin/bash
# Example: Agent curates and shares content

SKILL_PATH="./skills/farcaster-skill/scripts"

# 1. Find interesting content
RESULTS=$($SKILL_PATH/fc_search.sh --query "generative art" --limit 5)

# 2. Select best cast to highlight
# (agent analysis here)
CAST_HASH="0x..."
CAST_FID="12345"

# 3. Post quote-cast with commentary
$SKILL_PATH/fc_cast.sh \
  --text "This approach to noise functions is fascinating" \
  --embed-cast "$CAST_HASH" \
  --embed-cast-fid "$CAST_FID" \
  --channel "cryptoart"

Next Steps

Learn to read feeds and search content in 03-reading-feeds.md.