firecrawl-developer-index

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Translated

Answer a developer question — code behaviour, a library or framework, an API contract, an error message, a known bug — from issues, merged pull requests, repository READMEs, and curated documentation sites with Firecrawl Developer. Always use this skill for any programming question whose answer belongs in a primary source rather than a general web page.

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Sourcefirecrawl/skills

Added on2026-08-05

NPX Install

npx skill4agent add firecrawl/skills firecrawl-developer-index

SKILL.md Content

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Firecrawl Developer Index

Answer a developer question from the primary source: the issue where the bug was reported, the merged pull request that fixed it, the README or documentation page that states the contract. A blog post that describes a behaviour is a weaker answer than the passage that defines it, so reach for the index first and the open web second.

There is no fixed recipe. Read the question, decide what kind it is, and choose the approach below. A literal error string wants a different move than "how do I do X". Don't run machinery a question doesn't call for.

The tools, and what each is uniquely good at

HTTP: GET|POST https://api.firecrawl.dev/v2/search/developer
MCP: firecrawl_developer_search(query, k?, skills?)
CLI: firecrawl developer <query> [--limit <n>] [--skills-only]
Ranked results over the whole index. Each carries
```
id
```
(
```
issue:owner/repo#123
```
),
```
type
```
(
```
doc
```
|
```
issue
```
|
```
pull_request
```
|
```
readme
```
),
```
url
```
,
```
title
```
, and the matched passages in markdown, so tables and code blocks survive. The default first move for a developer question. It is the only surface that returns the passages, which is what lets you answer instead of pointing at a page.
```
k
```
/
```
--limit
```
is 1–100 and defaults to 10.
```
skills="only"
```
/
```
--skills-only
```
restricts the search to agent-skill files. Keyless; send
```
Authorization: Bearer $FIRECRAWL_API_KEY
```
for higher rate limits.
MCP: firecrawl_search(query, categories: ["developer"])
CLI: firecrawl search <query> --categories developer
Developer hits in a
```
developer
```
group beside
```
web
```
, each with
```
url
```
,
```
title
```
,
```
description
```
(the matched passage),
```
position
```
, and
```
category: "developer"
```
— web results carry no
```
category
```
, so that is the field to key on when merging. Use this when you are already running a web search and want developer sources weighed in the same call. It exposes none of the filters and no passage control.
MCP: firecrawl_scrape(url)
/
firecrawl_search(query)
CLI: firecrawl scrape <url>
/
firecrawl search <query>
General web fetch and search, for what no primary source states: a comparison between two libraries, an outage, a migration write-up, a project with no public repository or indexed docs. Also the follow-through when a hit is the right page but you need all of it —
```
scrape
```
the result's
```
url
```
.

Filters, and what each one costs you

Only the HTTP surface takes these. On

GET

, pass

types=issue,pull_request

or repeat the parameter; on

POST

, pass arrays. All are optional.

```
types
```
— which of
```
doc
```
,
```
issue
```
,
```
pull_request
```
,
```
readme
```
to search. Defaults to all four. Narrowing here is the cheapest way to sharpen a query.
```
repos
```
(
```
owner/name
```
) scopes the repository half, meaning
```
issue
```
,
```
pull_request
```
, and
```
readme
```
;
```
sources
```
(documentation source ids, at most 20) scopes the documentation half, meaning
```
doc
```
. Passing both unions the halves rather than intersecting them. Both echo back in the response with
```
indexed: true|false
```
— that is how you tell "not in the index" from "found nothing".
A filter that cannot match any requested
```
type
```
is a
```
400
```
, not an empty list:
```
repos
```
with no repository type in
```
types
```
, or
```
sources
```
without
```
doc
```
.
```
passages
```
(1–5, default 1) is the maximum passages per result, not a guarantee. Raise it when one page is clearly the right page but the first passage is the wrong part of it.
```
language
```
,
```
topic
```
,
```
license
```
,
```
min_stars
```
,
```
max_stars
```
,
```
archived
```
,
```
fork
```
describe a repository. Most documentation pages in the index have no repository behind them, so no repository fact can admit or exclude one. Send any of these without a
```
sources
```
scope and the response holds repository evidence only —
```
issue
```
,
```
pull_request
```
,
```
readme
```
— with
```
coverage
```
reporting
```
doc
```
as
```
unavailable
```
. That is the design, not an index fault: do not retry it and do not report the index broken. To keep documentation, drop the repository filters, or scope the documentation half with
```
sources
```
and read
```
coverage
```
to confirm
```
doc
```
answered.

Match the approach to the question

Literal error message or stack-trace string → search the string itself plus the library name, with
```
types=["issue","pull_request"]
```
. Whoever hit it filed it. If nothing matches, strip the volatile parts (paths, line numbers, ids, addresses) and retry — the invariant middle of the message is what is indexed.
Conceptual "how do I do X" → the full question in natural language, all four types. The answer is usually a
```
doc
```
or a
```
readme
```
; raise
```
passages
```
before raising
```
k
```
.
Known bug → the issue reports it, the merged pull request fixes it, and the fix is what you want. Search
```
types=["issue","pull_request"]
```
, then re-query the issue's own terms scoped to its repo with
```
types=["pull_request"]
```
. A merged PR's passages tell you what changed and in which direction.
API contract ("what does X return", "is Y required", "what is the default") →
```
readme
```
and
```
doc
```
are authoritative and a blog post is not. Use
```
types=["readme","doc"]
```
. If the contract looks like it moved, follow up with
```
pull_request
```
for the change that moved it.
Version-specific behaviour → an issue's opening report describes the broken version; its resolution supersedes it. Raise
```
passages
```
to see further into the thread, and read the resolution and the linked pull request before answering. Never answer from an opening report alone.
Scoped to one library →
```
repos=["owner/name"]
```
when you know the slug, plus
```
sources
```
if you want its docs in the same call. If a scoped search comes back empty, read the echoed
```
indexed
```
flag first:
```
false
```
means nothing from that repo or source can ever match and no rephrasing will help — drop the scope and search the whole index, or go to the web.
Ecosystem-wide ("which libraries do X", "who else hit this") → no scope. Use
```
language
```
/
```
topic
```
/
```
min_stars
```
to keep to maintained repositories, accepting that this gives up all
```
doc
```
results.
Agent skills and tooling conventions →
```
skills="only"
```
/
```
--skills-only
```
.
Comparison, opinion, news, or an unindexed project → the open web.
```
firecrawl_search
```
, then
```
firecrawl_scrape
```
whatever deserves a full read. Combining is often right: take the contract from the index and the trade-off from the web.

Principles

Read
coverage
before concluding a source doesn't exist. Every response reports
```
ok
```
|
```
degraded
```
|
```
unavailable
```
|
```
skipped
```
per type.
```
skipped
```
means your own
```
types
```
value did not ask for that type.
```
degraded
```
or
```
unavailable
```
means the gap came from the index or from a filter you sent, not from your query — drop the filter or widen, rather than retrying the same call or reporting that nothing exists.
```
ok
```
with no hits of that type is a genuine miss: rephrase.
Quote the passage, cite the
url
. The passages are the evidence; hand them over rather than paraphrasing them into a claim the reader can't check.
```
title
```
is frequently absent on
```
doc
```
results — fall back to
```
url
```
.
A merge supersedes a report. When an issue and a pull request disagree, the merged pull request is the current behaviour. Say which one you read.
Scope last, not first. Search the whole index, then narrow with
```
types
```
,
```
repos
```
, or
```
sources
```
once you know what the hits look like. Scoping first hides the result that would have told you where to look.
Go to the web when the index has nothing to say. Trade-offs, ecosystem opinion, and anything about an unindexed project are web questions. Don't force them through the index, and don't dress a general web page up as a primary source.