50c

AI developer tools via MCP. Pay-per-use from $0.01. No subscriptions.

Requirements: Node.js 18+

Quick Start

# Install and configure for your IDE
npx 50c install

# Set API key (get one at https://50c.ai)
50c config key YOUR_API_KEY

# Test it
50c hints "api design patterns"

MCP Integration

50c is an MCP (Model Context Protocol) server. After install, your AI IDE can use all tools directly.

Supported IDEs: Claude Desktop, Cursor, Windsurf, VS Code, Verdent, Cline, Continue, Roo Code

Manual Configuration

Add to your IDE's MCP config (~/.cursor/mcp.json, etc.):

{
  "mcpServers": {
    "50c": {
      "command": "npx",
      "args": ["-y", "50c@latest"],
      "env": {
        "FIFTYC_API_KEY": "YOUR_API_KEY"
      }
    }
  }
}

Tools

Free Tools (No API Key Required)

| Tool | Description | |------|-------------| | web_search | Internet search | | page_fetch | Fetch and extract URL content | | domain_check | Check domain availability | | fm_index, fm_find, fm_search, fm_lines | Fast file indexing and search | | dewey_* | Knowledge indexing (add, search, list) | | fog_check, fog_monitor | Context fog detection |

Paid Tools

| Tool | Cost | Description | |------|------|-------------| | hints | $0.05 | 5 brutal 2-word hints | | hints_plus | $0.10 | 10 expanded 4-word hints | | roast | $0.05 | Brutal code review with fixes | | genius | $0.50 | Deep problem solving | | genius_plus | $0.65 | Self-improving code generation | | bcalc | $0.15 | Mathematical discovery engine | | bcalc_why | $0.20 | Deep math explanations | | compute | $0.02 | Python code execution | | name_it | $0.03 | 5 names + domain availability | | price_it | $0.05 | SaaS pricing strategy | | one_liner | $0.02 | 8-word elevator pitch | | mind_opener | $0.08 | 5 curious angles on a problem | | prompt_expand | $0.10 | Expand idea into detailed concept | | handoff | $0.10 | Generate project handoff document |

Context Tools (Beacon)

| Tool | Cost | Description | |------|------|-------------| | beacon_compress | $0.02 | Smart context compression | | beacon_extract | $0.01 | Extract decisions/errors/entities | | fog_check | FREE | Check context fog level | | fog_monitor | FREE | Continuous fog monitoring | | fog_clear | $0.03 | Clear fog (compress/extract/reset) | | fog_checkpoint | $0.03 | Save conversation checkpoint | | caz_dedup | $0.02 | Content-addressable deduplication | | context_compress | $0.03 | CAZ + BM25 relevance compression |

Infrastructure Tools

| Tool | Description | |------|-------------| | cf_list_zones, cf_list_dns, cf_ssl_status | Cloudflare management (FREE) | | cf_create_dns, cf_purge_cache | Cloudflare write operations ($0.02) | | ux_contrast_check, ux_spacing_system | UI/UX utilities (FREE) | | ux_color_palette, ux_a11y_check, ux_roast | UI/UX analysis ($0.02-$0.05) |

Marketplace (50c-sub)

Create and share reusable AI macros:

| Tool | Cost | Description | |------|------|-------------| | sub_mint | $5.00 | Mint workflow as reusable macro | | sub_run | ~$2.00 | Run a minted macro | | sub_list, sub_get, sub_discover | FREE | Browse macros | | sub_clone | FREE | Clone public macro to your collection | | sub_set_public | FREE | List macro on marketplace |

Creators earn 60% revenue share on marketplace sales.

50c Team

Natural language orchestration - describe what you want, Team picks the right tools:

"roast my code and suggest fixes" → roast + hints
"check if coolstartup.ai is available" → domain_check  
"research AI trends and summarize" → web_search + genius

Enterprise-gated tools (require cv_ent_* API key + 50c-vault):

• team_ssh - SSH/SCP/SFTP to servers
• team_deploy - Deploy to production
• team_exec - Execute remote commands
• team_http - HTTP requests to your endpoints

CLI Commands

50c status              # Check connectivity
50c balance             # Check credit balance
50c config key <key>    # Set API key
50c config show         # Show config

# Direct tool calls
50c hints "topic"
50c roast "code snippet"
50c genius "complex problem"

Companion Packages

• 50c-vault - Secure credential storage with passphrase encryption

  npx 50c-vault init
  npx 50c-vault set MY_SECRET

Pricing

• Free tier: 40+ tools (search, file indexing, fog detection, etc.)
• Pay-per-use: 1 credit = $0.01, top up anytime
• No subscriptions: Credits never expire

Pre-Publish Verification

Thorough checks before publishing - catch embarrassing mistakes:

# Verify npm package before publish
50c pre_publish npm

# Verify arXiv paper
50c pre_publish arxiv

# Verify medical/clinical paper  
50c pre_publish medical

# Other profiles: github, science, math

Profiles: | Profile | Checks | Use Case | |---------|--------|----------| | npm | Version bump, links, secrets, syntax, deps | npm publish | | github | Tags, CI, release notes, secrets in history | GitHub release | | arxiv | LaTeX compile, refs, placeholders, code repo | arXiv submission | | medical | IRB, CONSORT, stats, endpoints, disclosures | Clinical papers | | science | Reproducibility, data, claims, figures | Scientific papers | | math | Proofs complete, definitions, notation | Math papers |

Returns: Score out of 100, pass/fail for each empirical check, manual review items.

Links

• Website: https://50c.ai
• Docs: https://docs.50c.ai
• Dashboard: https://50c.ai/dashboard.html