Provides tools for extracting Reddit URLs, resolving subreddits, creating research packs, searching Reddit, fetching threads and subreddit information, and tracking trends via Reddit.
Click on "Deploy Server".
Wait a few minutes for the server to deploy. Once ready, it will show a "Started" state.
In the chat, type @ followed by the MCP server name and your instructions, e.g., "@reddit-research-mcp search Reddit for latest AI trends"
That's it! The server will respond to your query, and you can continue using it as needed.
Here is a step-by-step guide with screenshots.
reddit-research-mcp is a fork/remake of the pi-reddit-research Pi extension by SaintNerona — github.com/SaintNerona/pi-reddit-research. It was converted from a Pi extension into a standalone MCP Server, with the core logic minimally changed.
MCP server for compact Reddit research packs.
Registers these tools:
reddit_url_extract — parse Reddit URLs, permalinks, post IDs, and comment IDs.
reddit_resolve_subreddits — find and rank subreddit candidates for a topic.
reddit_pack — build a compact evidence pack from posts and top comments.
reddit_search — search Reddit posts without fetching full comment threads.
reddit_thread — fetch one thread and top comments.
reddit_subreddits — raw subreddit search.
reddit_trends — inspect hot/top/new posts in one or more subreddits.
Related MCP server: Reddit MCP Server
{
"mcpServers": {
"reddit-research": {
"command": "npx",
"args": [
"-y",
"git+https://github.com/jhartum/reddit-research-mcp.git"
],
"env": {
"REDDIT_SESSION": "${REDDIT_SESSION}",
"REDDIT_TOKEN_V2": "${REDDIT_TOKEN_V2}"
}
}
}
}For local development:
git clone https://github.com/jhartum/reddit-research-mcp.git
cd reddit-research-mcp
npm install
npm run buildThen point your MCP client at node /path/to/reddit-research-mcp/dist/index.js.
Ask questions like:
"What does Reddit think about Claude Code vs OpenCode?"
"Find Reddit fixes for this error: ..."
"What settings do ComfyUI users recommend for ...?"
Since mid-2026, Reddit requires authentication for .json access. Create ~/.pi/agent/reddit-research.json:
{
"cookie": "reddit_session=abc123; token_v2=def456"
}Or reference a separate cookie file:
{
"cookieFile": "/home/user/.config/pi-reddit-research/cookie.txt"
}Advantages:
No env vars to manage
The server re-reads the config before requests, so you can update the cookie without restarting
cookieFile keeps the secret outside the JSON config and shell startup files
Security: your Reddit cookie is a secret. Do not commit it to git or public dotfiles.
Variable | Default | Description |
|
| Cache directory. |
|
| SQLite cache path. |
|
| User-Agent for Reddit JSON requests. |
|
| Minimum delay between Reddit requests. |
|
| Search/request cache TTL. |
|
| Thread cache TTL. |
|
| Subreddit cache TTL. |
|
| Topic-to-subreddit cache TTL. |
|
| Max compact output size. |
| — | Reddit session cookie value. Overrides config file. |
| — | Path to a file with the Cookie header value. Overrides config file. |
|
| Path to JSON config file. |
Cookie source priority (highest to lowest):
REDDIT_COOKIE env var
REDDIT_COOKIE_FILE env var → reads file
cookie field in JSON config
cookieFile field in JSON config → reads file
This server uses Reddit's .json endpoints with local SQLite caching. Since mid-2026, Reddit requires authentication for .json access. Set your cookie in ~/.pi/agent/reddit-research.json, via cookieFile, or via env vars to restore functionality.
Treat Reddit posts and comments as anecdotal evidence, not verified facts.
Open a private/incognito browser window (to avoid unrelated cookies).
Go to https://www.reddit.com/login and sign in.
F12 → Application → Cookies → reddit.com.
Method A (full Cookie header): Click any cookie → Ctrl+A → Ctrl+C, then pick "Copy as string" (Chrome) or paste into an editor and join with ; .
Method B (only reddit_session): Copy the value of the reddit_session cookie and use:
# Via config file:
echo '{"cookie": "reddit_session=YOUR_VALUE"}' > ~/.pi/agent/reddit-research.json
# Or keep the secret in a separate file:
mkdir -p ~/.config/reddit-research-mcp
printf '%s\n' 'reddit_session=YOUR_VALUE' > ~/.config/reddit-research-mcp/cookie.txt
printf '{"cookieFile":"%s/.config/reddit-research-mcp/cookie.txt"}\n' "$HOME" > ~/.pi/agent/reddit-research.json
# Or via env:
export REDDIT_COOKIE="reddit_session=YOUR_VALUE"Important: Avoid cookies with JSON values (like g_state={"i_l":1,...}) — they break the JSON config file. If you copy the full Cookie header, remove entries like g_state, eu_cookie, and seeker_session. Only reddit_session and token_v2 are needed for authentication.
The cookie expires after a few days. When that happens, just update it in the config or cookie file — the server will pick up the change automatically.
MIT
Build a compact Reddit research pack for opinions, bugs, fixes, comparisons, settings, alternatives, trends, guides, hardware, or general research.
| Name | Required | Description | Default |
|---|---|---|---|
| sort | No | Reddit search sort. Default relevance. | |
| time | No | Reddit time window. Default year. | |
| depth | No | How much evidence to collect: quick, normal, deep. Default normal. | |
| topic | Yes | Search topic, product, error string, repo URL/name, or comparison query. | |
| intent | No | Research intent. Default general. | |
| max_posts | No | Maximum posts to return. Capped by depth. | |
| subreddits | No | Optional comma-separated subreddit names, for example: LocalLLaMA, LocalLLM, ClaudeCode. Do not pass a JSON list. | |
| comments_per_post | No | Top comments per fetched thread. Default depends on depth. |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description must carry full behavioral burden. It mentions 'compact' but does not explain output size, performance constraints, or what happens internally. Lacks detail on how the pack is built.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Single-sentence description is concise and front-loads the core verb ('Build') and resource ('compact Reddit research pack'). However, listing 10 intents inline clutters slightly; a bulleted list would improve scannability. Still, no wasted words.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
With 8 parameters, no output schema, and no annotations, the description is too brief. It fails to explain what the 'pack' includes (e.g., summary, posts, comments) or how results are structured. Incomplete for the complexity involved.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Input schema has 100% coverage with descriptions for all parameters, so the schema does most of the work. The description adds no extra meaning beyond the schema (e.g., for 'depth' or 'intent'), so baseline 3 is appropriate.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states it builds a compact Reddit research pack and lists specific intents (opinions, bugs, etc.). This distinguishes it from siblings like reddit_search or reddit_trends, though not explicitly. It is specific and actionable.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance on when to use this tool vs. alternatives such as reddit_search or reddit_thread. It does not clarify when not to use it or provide context for selecting among the intents.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Resolve a topic into ranked subreddit candidates using Reddit subreddit search, post search, SQLite cache, and subreddit priority hints.
| Name | Required | Description | Default |
|---|---|---|---|
| limit | No | Maximum subreddit candidates. Default 10, max 25. | |
| topic | Yes | Topic, product, repo, tool, or community to resolve into subreddits. | |
| refresh | No | Bypass cached topic_subreddit_scores. Default false. |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description must fully disclose behavior. It mentions multiple data sources (search, cache, hints) and caching via SQLite, but does not detail output format, side effects, authentication needs, or rate limits. The description is moderately transparent but lacks important operational details.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single, concise sentence that efficiently communicates the tool's purpose and methodology. It avoids unnecessary words, though the use of technical terms like 'SQLite cache' and 'priority hints' could be slightly confusing without further context.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given three parameters and no output schema, the description does not specify the return format (e.g., list of strings, objects with scores). It adequately covers the input and method but leaves the agent to infer what the response looks like, which is a notable gap for a tool with no explicit output schema.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
All three parameters have schema descriptions (100% coverage), so the baseline is 3. The overall description adds context about ranking and ranking methods but does not provide additional semantic detail for individual parameters beyond what the schema already offers.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the tool resolves a topic into ranked subreddit candidates, which is a specific verb+resource combination. It distinguishes itself from sibling tools like reddit_search (general search) and reddit_subreddits (likely listing subreddits) by focusing on resolving a topic into a ranked list of candidates.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description provides no explicit guidance on when to use this tool versus siblings like reddit_search or reddit_subreddits. It does not state prerequisites, exclusions, or scenarios where another tool would be more appropriate. The usage context is only implied by the tool's purpose.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Search Reddit posts and return a compact list without fetching comment threads.
| Name | Required | Description | Default |
|---|---|---|---|
| sort | No | Sort: relevance, hot, top, new, comments. Default relevance. | |
| time | No | Time range. Default year. | |
| limit | No | Maximum posts. Default 8, max 25. | |
| query | Yes | Search query. | |
| subreddits | No | Optional comma-separated subreddit names, for example: LocalLLaMA, LocalLLM, ClaudeCode. Do not pass a JSON list. |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries full burden. It discloses the compact, no-comment behavior but omits auth needs, rate limits, or error handling. Acceptable for a simple search tool but not thorough.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Single sentence front-loads the tool's purpose and key differentiator. No fluff, every word is necessary and informative.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
No output schema or annotations exist. Description covers purpose and differentiator but lacks details on return format, error scenarios, or usage limits. Adequate for a search tool but could be more complete.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 100%, so the description adds minimal value beyond what the schema already provides. Parameters are well-documented in the schema, meeting the baseline.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
Description clearly states 'Search Reddit posts' (specific verb and resource) and distinguishes from siblings by noting it returns a compact list without fetching comment threads, which differentiates it from tools like reddit_thread.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
Description implies usage when needing a compact list without comments but does not explicitly state when to use or not use, nor name alternative tools. Sibling tools exist but are not referenced.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Find subreddit candidates for a topic.
| Name | Required | Description | Default |
|---|---|---|---|
| limit | No | Maximum communities. Default 10, max 25. | |
| query | Yes | Topic or community query. |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description lacks behavioral details beyond the basic function. No annotations are provided, and the description does not disclose whether it is a read-only operation, what the response contains, or any potential side effects. The minimal information only implies a search behavior.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single sentence with no extraneous text. It is concise and front-loaded, but it may be too terse for a tool that has sibling tools without differentiation.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the lack of output schema and annotations, the description should explain what 'subreddit candidates' means (e.g., returns subreddit names, counts, descriptions). It also does not clarify how this tool differs from similar sibling tools like 'reddit_search', leaving the agent underinformed.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Both parameters (query and limit) are described in the input schema with 100% coverage. The description adds no additional meaning (e.g., format, constraints) beyond what the schema already provides, so baseline score of 3 is appropriate.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description 'Find subreddit candidates for a topic' clearly states the action (find) and resource (subreddit candidates), but the term 'candidates' is somewhat vague and doesn't explicitly differentiate from sibling tools like 'reddit_search' or 'reddit_resolve_subreddits'.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance on when to use this tool versus alternatives (e.g., reddit_search, reddit_resolve_subreddits). There is no mention of prerequisites, exclusions, or context for optimal use.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Fetch one Reddit thread by URL or post id and return compact post details plus top comments.
| Name | Required | Description | Default |
|---|---|---|---|
| sort | No | Comment sort. Default top. | |
| url_or_id | Yes | Reddit post URL, permalink, or post id. | |
| top_comments | No | Top comments to show in compact output. Default 12, max 40. | |
| comment_limit | No | Comments requested from Reddit. Default 50, max 200. |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations provided, so description carries full burden. It states the tool fetches and returns 'compact post details plus top comments,' which is basic behavioral info. However, it omits critical details like authentication needs, rate limits, or side effects. Adequate but minimal.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single sentence that efficiently conveys the main action and result. It is front-loaded with the verb and resource. Could be slightly more structured but effective.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the absence of an output schema, the description should fully explain the return format. 'Compact post details plus top comments' is vague—what details? In what format? Also, with 4 parameters, the description does not clarify parameter behaviors or interactions. Incomplete for a fetch tool.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100% with parameter descriptions. The description does not add additional meaning beyond the schema. For example, it doesn't explain the relationship between 'top_comments' and 'comment_limit' or clarify defaults. Baseline score applies.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the verb 'Fetch' and the resource 'one Reddit thread' with specific identification methods (URL or post id). It distinguishes from sibling tools like reddit_search (search) and reddit_subreddits (subreddit info) by focusing on a single thread.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description implies usage when needing details of a specific thread but provides no explicit guidance on when to use or avoid this tool versus alternatives. No comparisons to siblings, leaving the agent to infer context.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Get hot, top, or new posts from one or more subreddits.
| Name | Required | Description | Default |
|---|---|---|---|
| time | No | Top time window. Used only for listing=top. Default week. | |
| limit | No | Maximum total posts. Default 10, max 30. | |
| listing | No | Listing type. Default hot. | |
| subreddits | Yes | Subreddit or comma-separated subreddit names, for example: artificial, technology, ArtificialInteligence. Do not pass a JSON list. |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Without annotations, the description must carry the full burden of behavioral disclosure. It only states what the tool does (get posts) but does not mention that it is a read-only operation, that it returns a list of posts, or any potential limits or side effects. The lack of any behavioral notes makes it less transparent.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single, clear sentence that efficiently conveys the core action and key options (listing types and subreddit plural support). It is front-loaded and contains no extraneous information.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the absence of an output schema, the description should explain what the tool returns (e.g., a list of posts with titles, URLs, scores). It does not, leaving the agent unsure of the response format. The tool is simple, but the description still lacks completeness for selecting and using the tool correctly.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100%, so the schema already documents all four parameters. The description adds minimal new meaning beyond what is in the schema; it reiterates 'hot, top, or new' which is already in the listing enum. No additional context or usage tips are provided for parameters like time or limit.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the tool retrieves posts with options for hot, top, or new listings from one or more subreddits. However, it does not differentiate from siblings like reddit_search or reddit_thread, missing an opportunity to specify this tool is for browsing aggregated per-subreddit content rather than searching across all of Reddit.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance is provided on when to use this tool versus alternatives. For example, it does not mention that this tool is best for popular posts across multiple subreddits, while reddit_search is for targeted keyword searches or reddit_thread for individual discussions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Parse a Reddit URL, permalink, t3 post id, or t1 comment id into normalized identifiers.
| Name | Required | Description | Default |
|---|---|---|---|
| url_or_id | Yes | Reddit URL, permalink, t3 post id, or t1 comment id. |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries full burden. It fails to disclose whether the tool is read-only, what 'normalized identifiers' means, or any side effects. The behavioral context is minimal.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
One sentence that is perfectly concise and front-loaded with the core action.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a simple parsing tool with one parameter, the description is adequate but does not explain what the 'normalized identifiers' output looks like. Without an output schema, the description should provide more details on the return format.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The single parameter's schema description already explains its purpose. The tool description essentially restates the schema, adding no new semantic value. Baseline 3 due to 100% schema coverage.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states it parses Reddit URLs, permalinks, t3 post IDs, or t1 comment IDs into normalized identifiers. It distinguishes from siblings like reddit_thread (fetches content) and reddit_search (searches).
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description implies usage when you have a Reddit identifier and need normalized identifiers, but it does not explicitly state when to use this tool versus alternatives, nor does it mention when not to use it.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Recent tool additions, removals, and schema changes observed during successful MCP inspections.
v0.1.0reddit_packreddit_resolve_subredditsreddit_searchreddit_subredditsreddit_threadreddit_trendsreddit_url_extractScored across 7 tools
Reddit_subreddits and reddit_resolve_subreddits both find subreddits for a topic, creating potential confusion. Reddit_search and reddit_trends both return posts but differ in scope and parameters, though still somewhat distinct. The remaining tools are well-differentiated.
Tool names lack a consistent pattern; some are nouns (reddit_pack, reddit_subreddits, reddit_thread, reddit_trends) while others are verbs (reddit_search) or verb-noun phrases (reddit_resolve_subreddits, reddit_url_extract). This mixed convention reduces predictability.
With 7 tools, the server covers essential Reddit research capabilities without being bloated or sparse. Each tool serves a distinct purpose within the domain, and the count feels well-scoped for a research-oriented MCP server.
The tool set covers major research workflows: finding subreddits, searching posts, fetching threads, and getting trends. Minor gaps exist, such as lacking a dedicated tool for subreddit-specific search or comment-only extraction, but these can be worked around.
Reddit MCP server: search posts, subreddit feeds, comments & user profiles as JSON. No API key.
Reddit & X data for AI agents over MCP. Semantic search, hosted, no Reddit API.
Reddit MCP — public Reddit data via JSON endpoints (no auth required)
