firecrawl developer search
Via the Firecrawl MCP (preferred)
This plugin bundles the Firecrawl MCP server. When it's connected, prefer the native firecrawl_developer_search tool over the CLI — it needs no local install and authenticates through the plugin's one-time browser sign-in. The firecrawl CLI commands below are the fallback for when the MCP isn't connected.
Semantic search over indexed developer sources. Each result carries an id, a url, a title, and the matched passages in markdown, so tables and code blocks survive intact.
The id prefix tells you what kind of source a hit is: doc:, issue:, pull_request:, or readme:.
When to use
- The question is about code behaviour, a library or framework, an API contract, an error message, or a known bug
- You want the issue that reported it, the merged PR that fixed it, or the doc page that defines the contract — not a blog post describing it
- Before falling back to a general web search: reach for the index first, the open web second
Not for this skill: comparisons and opinions ("X vs Y"), news and outages, or a project with no public repo or indexed docs. Those are firecrawl-search plus firecrawl-scrape questions.
Quick start
MCP (preferred):
firecrawl_developer_search(query: "tokio select cancellation safety", k: 10)
firecrawl_developer_search(query: "agent skill frontmatter conventions", skills: "only")
CLI fallback:
# Ask a developer question
firecrawl developer "axum middleware ordering" --limit 10 -o .firecrawl/dev-axum-middleware.json --json
# Search a literal error string plus the library name
firecrawl developer "ERR_REQUIRE_ESM in vitest config" -o .firecrawl/dev-esm-error.json --json
Put all scoping intent in the query text — the repo slug, the library name, the version, the error string. Semantic retrieval handles the scoping; there are no repo or type flags on the MCP tool or the CLI.
Options
| Option (MCP) |
Option (CLI) |
Description |
query |
<query> |
Natural-language question or search phrase (required) |
k |
--limit <n> |
Number of ranked results, 1–100 (default 10) |
skills |
— |
Set to "only" to search only agent-skill files |
| — |
-o, --output <path> |
Output file path |
| — |
--json / --pretty |
JSON output, compact or pretty |
Tips
- Match the query to the question. A literal error message wants the error string plus the library name. A conceptual "how do I do X" wants the whole question in natural language.
- Volatile parts hurt a match. If an error string returns nothing, strip paths, line numbers, ids, and addresses and retry — the invariant middle of the message is what's indexed.
- A merge supersedes a report. When an issue and a pull request disagree, the merged PR is the current behaviour. Read the resolution before answering, never the opening report alone.
- Quote the passage, cite the
url. The passages are the evidence — hand them over rather than paraphrasing into a claim the user can't check. title is often absent on doc: hits; fall back to url.
- Raise
k before giving up, and scrape when a hit is the right page. If a result is clearly the right page but the passage is the wrong part of it, scrape its url for the whole thing.
- Already running a web search?
firecrawl_search(query, categories: ["developer"]) folds developer hits into the same call as web results (they come back tagged category: "developer"). It exposes no passage control, so prefer the dedicated tool when the question is purely a code question.
- With the CLI, write results to
.firecrawl/ with -o to keep the context window clean. Naming convention: .firecrawl/dev-{topic}.json.
See also
1---2name: firecrawl-developer-search3description: Search an index built for coding agents — GitHub issues, merged pull requests, repository READMEs, and curated documentation sites — and get back the matched passages, not just links. Use this skill whenever the question is about code: how a library, framework, or API behaves, what an error message or stack trace means, whether a bug was reported or fixed, what a function returns, what a default is, or which repos do a given thing. Triggers on "why does <library> do X", "what does this error mean", "is this a known bug", "how do I use <library>", "what's the API for", pasted stack traces, and pasted error strings. Prefer this over a general web search for programming questions — it answers from the primary source instead of a blog post about it.4---56# firecrawl developer search78## Via the Firecrawl MCP (preferred)910This plugin bundles the Firecrawl MCP server. When it's connected, prefer the native **`firecrawl_developer_search`** tool over the CLI — it needs no local install and authenticates through the plugin's one-time browser sign-in. The `firecrawl` CLI commands below are the fallback for when the MCP isn't connected.1112Semantic search over indexed developer sources. Each result carries an `id`, a `url`, a title, and the **matched passages in markdown**, so tables and code blocks survive intact.1314The `id` prefix tells you what kind of source a hit is: `doc:`, `issue:`, `pull_request:`, or `readme:`.1516## When to use1718- The question is about code behaviour, a library or framework, an API contract, an error message, or a known bug19- You want the issue that reported it, the merged PR that fixed it, or the doc page that defines the contract — not a blog post describing it20- Before falling back to a general web search: reach for the index first, the open web second2122Not for this skill: comparisons and opinions ("X vs Y"), news and outages, or a project with no public repo or indexed docs. Those are [firecrawl-search](../firecrawl-search/SKILL.md) plus [firecrawl-scrape](../firecrawl-scrape/SKILL.md) questions.2324## Quick start2526MCP (preferred):2728```text29firecrawl_developer_search(query: "tokio select cancellation safety", k: 10)30firecrawl_developer_search(query: "agent skill frontmatter conventions", skills: "only")31```3233CLI fallback:3435```bash36# Ask a developer question37firecrawl developer "axum middleware ordering" --limit 10 -o .firecrawl/dev-axum-middleware.json --json3839# Search a literal error string plus the library name40firecrawl developer "ERR_REQUIRE_ESM in vitest config" -o .firecrawl/dev-esm-error.json --json41```4243Put all scoping intent in the query text — the repo slug, the library name, the version, the error string. Semantic retrieval handles the scoping; there are no repo or type flags on the MCP tool or the CLI.4445## Options4647| Option (MCP) | Option (CLI) | Description |48| -------------- | -------------------- | ---------------------------------------------------------- |49| `query` | `<query>` | Natural-language question or search phrase (required) |50| `k` | `--limit <n>` | Number of ranked results, 1–100 (default 10) |51| `skills` | — | Set to `"only"` to search only agent-skill files |52| — | `-o, --output <path>` | Output file path |53| — | `--json` / `--pretty` | JSON output, compact or pretty |5455## Tips5657- **Match the query to the question.** A literal error message wants the error string plus the library name. A conceptual "how do I do X" wants the whole question in natural language.58- **Volatile parts hurt a match.** If an error string returns nothing, strip paths, line numbers, ids, and addresses and retry — the invariant middle of the message is what's indexed.59- **A merge supersedes a report.** When an issue and a pull request disagree, the merged PR is the current behaviour. Read the resolution before answering, never the opening report alone.60- **Quote the passage, cite the `url`.** The passages are the evidence — hand them over rather than paraphrasing into a claim the user can't check. `title` is often absent on `doc:` hits; fall back to `url`.61- **Raise `k` before giving up, and scrape when a hit is the right page.** If a result is clearly the right page but the passage is the wrong part of it, [scrape](../firecrawl-scrape/SKILL.md) its `url` for the whole thing.62- Already running a web search? `firecrawl_search(query, categories: ["developer"])` folds developer hits into the same call as web results (they come back tagged `category: "developer"`). It exposes no passage control, so prefer the dedicated tool when the question is purely a code question.63- With the CLI, write results to `.firecrawl/` with `-o` to keep the context window clean. Naming convention: `.firecrawl/dev-{topic}.json`.6465## See also6667- [firecrawl-search](../firecrawl-search/SKILL.md) — general web search, and the `categories: ["developer"]` blend68- [firecrawl-scrape](../firecrawl-scrape/SKILL.md) — read a full page behind a promising hit69- [firecrawl-agent](../firecrawl-agent/SKILL.md) — autonomous multi-source research when one search won't settle it
firecrawl