Chat with GEO Metadata

geo_chat() connects GEO metadata tables to a large language model (LLM) so that you can explore them with natural language: find single-cell studies with more than 20 samples, which platforms dominate these datasets?, or filter to post-2020 human studies. Under the hood it delegates schema summarization, SQL querying, and dashboard filtering to the querychat package, so the model never needs the raw table serialized into the prompt — it queries your local copy with SQL instead.

Three functions cover the whole workflow:

geo_chat() creates and returns a QueryChat object
geo_shiny() creates it and immediately launches a Shiny app
geo_console() creates it and immediately starts a console chat

library(geokit)

Prerequisites

Install querychat if it is not already on your system. It is currently archived on CRAN, so install it from the posit-dev R-universe:
```
install.packages(
  "querychat",
  repos = c("https://posit-dev.r-universe.dev", getOption("repos"))
)
```
To chat with a plain data frame, querychat needs a local SQL engine: install either duckdb or RSQLite.
Configure an LLM client (see the next section).

Note: LLM answers are generated from your metadata by an external model, so treat them as suggestions and verify important selections yourself.

Choosing an LLM Client

The first argument of geo_chat(), client, is passed to querychat and accepts:

NULL (default): querychat uses the querychat.client option, the QUERYCHAT_CLIENT environment variable, or falls back to ellmer::chat_openai().
An ellmer Chat object, for full control over model, base URL, and system prompt:
```
client <- ellmer::chat_openai(model = "gpt-4o-mini")
```
A provider string understood by ellmer::chat(), such as "anthropic/claude-sonnet-4-5".

A function returning a Chat object — handy for OpenAI-compatible endpoints or custom credentials. querychat calls the function with system_prompt = NULL:

client <- \(system_prompt = NULL) ellmer::chat_openai_compatible(
  base_url = "https://example.com/v1",
  model = "my-model",
  api_key = Sys.getenv("MY_API_KEY"),
  system_prompt = system_prompt
)

API keys are read from environment variables by ellmer (e.g., OPENAI_API_KEY, ANTHROPIC_API_KEY); set them in your .Renviron.

From Search Results to a Chat Session

A typical session starts with geo_search(). The returned data frame can be handed to geo_chat() directly:

records <- geo_search(
  "diabetes[ALL] AND Homo sapiens[ORGN] AND GSE[ETYP]"
)

chat <- geo_chat(
  NULL,
  records,
  data_description = paste(
    "GEO DataSets records about diabetes in human, one row per record.",
    "The Contains column lists related GSM/GSE/GPL accessions."
  )
)

data_description gives the model background about what the columns mean, which noticeably improves query quality. Use extra_instructions for additional behavioral rules (both are passed through to querychat).

From a Metadata Database to a Chat Session

For richer series-level metadata, build a local database with geo_meta() first (see vignette("geometadb")) and chat with that table:

meta <- geo_meta(
  records[["Series Accession"]][1:20],
  odir = tempdir()
)

qc <- geo_chat(
  NULL,
  meta,
  data_description = paste(
    "One row per GEO Series fetched from SOFT metadata.",
    "Series_title, Series_summary and Series_overall_design describe each",
    "study; Series_sample_id lists its GSM accessions separated by '; '."
  )
)

The object returned by geo_chat() is a standard QueryChat object, so you can launch the interface whenever you are ready:

qc$app() # or qc$console() for the terminal

The convenience wrappers do both steps at once:

geo_shiny(NULL, records) # build + launch Shiny app
geo_console(NULL, records) # build + start console chat

A Self-Contained Example

The following example needs no LLM access — it only builds and destroys the chat object, which is useful to verify your installation:

records <- data.frame(
  `Series Accession` = c("GSE1", "GSE2"),
  Title = c("human diabetes study", "mouse liver study"),
  Type = c("Expression profiling by array", "RNA-seq"),
  Samples = c(12L, 8L),
  check.names = FALSE
)

chat <- geo_chat(NULL, records, cleanup = TRUE)
#> Warning: The "visualize" tool requires the {.pkg ggsql} package.
#> ℹ Install it with `install.packages("ggsql")`; continuing without the "visualize" tool.
#> This warning is displayed once per session.
#> duckdb keeps downloaded extensions and secrets in a temporary directory:
#> ℹ /tmp/Rtmpq6eTaI/duckdb
#> This is removed when the R session ends.
#> • Extensions are re-downloaded each session.
#> • Secrets are lost.
#> ℹ Run duckdb(shared_home = TRUE) (or create ~/.duckdb) to keep them (suitable for most users).
#> ℹ Run duckdb(shared_home = FALSE) to accept the temporary directory (and silence this message).
#> ℹ See ?duckdb_storage for details and alternatives.
chat$cleanup()

Session Information

sessionInfo()
#> R version 4.6.1 (2026-06-24)
#> Platform: x86_64-pc-linux-gnu
#> Running under: Ubuntu 26.04.1 LTS
#> 
#> Matrix products: default
#> BLAS:   /usr/lib/x86_64-linux-gnu/openblas-pthread/libblas.so.3 
#> LAPACK: /usr/lib/x86_64-linux-gnu/openblas-pthread/libopenblasp-r0.3.32.so;  LAPACK version 3.12.0
#> 
#> locale:
#>  [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C              
#>  [3] LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8    
#>  [5] LC_MONETARY=en_US.UTF-8    LC_MESSAGES=en_US.UTF-8   
#>  [7] LC_PAPER=en_US.UTF-8       LC_NAME=C                 
#>  [9] LC_ADDRESS=C               LC_TELEPHONE=C            
#> [11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C       
#> 
#> time zone: Etc/UTC
#> tzcode source: system (glibc)
#> 
#> attached base packages:
#> [1] stats     graphics  grDevices utils     datasets  methods   base     
#> 
#> other attached packages:
#> [1] tidyr_1.3.2    ggplot2_4.0.3  stringr_1.6.0  dplyr_1.2.1    geokit_0.0.2  
#> [6] rmarkdown_2.32
#> 
#> loaded via a namespace (and not attached):
#>  [1] querychat_0.4.1    sass_0.4.10        generics_0.1.4     stringi_1.8.9     
#>  [5] digest_0.6.39      magrittr_2.0.5     evaluate_1.0.5     grid_4.6.1        
#>  [9] RColorBrewer_1.1-3 fastmap_1.2.0      jsonlite_2.0.0     DBI_1.3.0         
#> [13] promises_1.5.0     httr_1.4.9         purrr_1.2.2        scales_1.4.0      
#> [17] XML_3.99-0.25      codetools_0.2-20   jquerylib_0.1.4    shiny_1.14.0      
#> [21] duckdb_2.0.0       cli_3.6.6          rlang_1.3.0        withr_3.0.3       
#> [25] cachem_1.1.0       yaml_2.3.12        otel_0.2.0         tools_4.6.1       
#> [29] httpuv_1.6.17      curl_8.1.0         mime_0.13          buildtools_1.0.0  
#> [33] vctrs_0.7.3        R6_2.6.1           lifecycle_1.0.5    pkgconfig_2.0.3   
#> [37] later_1.4.8        pillar_1.11.1      bslib_0.12.0       rentrez_1.2.4     
#> [41] gtable_0.3.6       Rcpp_1.1.2         glue_1.8.1         xfun_0.62         
#> [45] tibble_3.3.1       tidyselect_1.2.1   sys_3.4.3          knitr_1.52        
#> [49] xtable_1.8-8       farver_2.1.2       htmltools_0.5.9    maketools_1.3.2   
#> [53] compiler_4.6.1     S7_0.2.2