A working Reddit research agent in one MCP prompt: search, fetch top comments, summarize. Runs from Claude Desktop or Cursor at $0.001 per record.

A Reddit research agent — give it a topic, get back a structured summary of what people are actually saying — is one of the smallest useful agents you can ship in 2026. With UnifAPI as the MCP server, you write zero glue code: one MCP prompt tells Claude (or Cursor) to search Reddit, fan out to fetch top comments, and summarize. This walkthrough is the working version.

What the agent does

User prompt: "What is the Reddit consensus on Anthropic's latest model release this week?" Agent flow: search r/MachineLearning, r/singularity, and r/LocalLLaMA for the keyword, sort by recency, pull the top 5 threads, fetch the top 10 comments on each, summarize sentiment and surface the two most-upvoted takes.

Total records: 15 thread results + 50 comment fetches = 65 records, ~$0.065 per run. The output is a paragraph of synthesis plus two pull-quotes. That's the whole agent.

Step 1 — Reddit endpoints you'll call

Three endpoints carry the workflow. /v1/reddit/search — search by keyword across all of Reddit, with optional subreddit filter, sort by relevance / hot / new. /v1/reddit/post — fetch a single post by ID plus its comment tree. /v1/reddit/subreddit/posts — list recent posts in a specific subreddit.

The search endpoint returns post IDs, titles, scores, and subreddit. The post endpoint returns the full thread including top-level comments. That's enough to do summary-style research without ever leaving UnifAPI.

Step 2 — Add the MCP config

If you're running this from Claude Desktop, paste the standard MCP config block into ~/Library/Application Support/Claude/claude_desktop_config.json: an entry under mcpServers pointing at https://mcp.unifapi.com with Authorization: Bearer $UNIFAPI_KEY in the headers. Restart Claude.

For Cursor, edit ~/.cursor/mcp.json with the same shape. For the Claude Code CLI, run claude mcp add unifapi https://mcp.unifapi.com --header "Authorization: Bearer $UNIFAPI_KEY". Once it's connected, the Reddit tools show up automatically alongside the rest of the catalog.

Step 3 — The prompt

The whole agent is one prompt: "You're a Reddit researcher. For the topic the user names, search the three subreddits r/MachineLearning, r/singularity, and r/LocalLLaMA. Pull the top 5 threads by recency. For each thread, fetch the top 10 comments. Output: a one-paragraph sentiment summary, then the two highest-upvoted takes verbatim with attribution."

That's it. The model handles tool selection (reddit_search → reddit_post), pagination, and synthesis. The plumbing UnifAPI provides — one envelope, normalized cursor pagination, one error shape — is what makes the prompt this short.

What it costs to run

At $0.001 per record, the cost is bounded by record count, not call count. A typical run touches 65-100 records depending on how many comments the threads have. Daily runs across 5 topics: ~500 records, $0.50 / day, $15 / month. Hourly runs across 20 topics for a monitoring dashboard: ~50,000 records, $50 / month.

There's no tier to upgrade, no overage rate. If the workflow grows by 10x, the bill grows by 10x — no inflection points.

Extending it

Three obvious extensions. Cross-platform — swap one search call for parallel calls to Reddit, Twitter, and YouTube to get coverage outside Reddit's bubble. Time-series — store record IDs day-over-day and surface deltas (new threads, score changes). Filtering — add a sentiment classifier in the prompt to bucket comments before summarization.

All three are still one MCP server and one key. That's the value of a unified catalog: extending the agent is a prompt change, not a vendor procurement.