You did not specify an entrypoint in {}. Add `exports` mappi

Error message

You did not specify an entrypoint in {}. Add `exports` mapping in the configuration file, eg:
{}

What it means

A JSR package must expose an entrypoint through the `exports` field of its config file. This error is raised (by `error_missing_exports_field`) for a config that has a name but no exports mapping, and the message embeds a ready-to-paste deno.json snippet — using a suggested entrypoint (e.g. ./mod.ts or ./index.ts) when one is detected in the package.

Source

Thrown at cli/tools/publish/mod.rs:1596

  for entrypoint in SUGGESTED_ENTRYPOINTS {
    if deno_json.dir_path().join(entrypoint).exists() {
      suggested_entrypoint = Some(entrypoint);
      break;
    }
  }

  let exports_content = format!(
    r#"{{
  "name": "{}",
  "version": "{}",
  "exports": "{}"
}}"#,
    deno_json.json.name.as_deref().unwrap_or("@scope/name"),
    deno_json.json.name.as_deref().unwrap_or("0.0.0"),
    suggested_entrypoint.unwrap_or("<path_to_entrypoint>")
  );

  bail!(
    "You did not specify an entrypoint in {}. Add `exports` mapping in the configuration file, eg:\n{}",
    deno_json.specifier,
    exports_content
  );
}

#[allow(clippy::print_stderr, reason = "actually want to output")]
fn ring_bell() {
  // ASCII code for the bell character.
  eprint!("\x07");
}

#[cfg(test)]
mod tests {
  use std::collections::HashMap;

  use deno_ast::ModuleSpecifier;

View on GitHub (pinned to f7822238ca)

Solutions

Add an `exports` mapping to deno.json, e.g. `"exports": "./mod.ts"`, or a subpath map for multi-entry packages.
Point it at the file that should be the public entrypoint — the snippet's suggested path is usually correct.
If this package is not meant for JSR, mark it `"publish": false` instead of adding exports.

Example fix

// deno.json (before)
{
  "name": "@scope/pkg",
  "version": "1.0.0"
}
// deno.json (after)
{
  "name": "@scope/pkg",
  "version": "1.0.0",
  "exports": "./mod.ts"
}

Defensive patterns

Strategy: validation

Validate before calling

#!/usr/bin/env bash
node -e '
const c = JSON.parse(require("fs").readFileSync("deno.json", "utf8"));
if (!c.exports) { console.error("deno.json needs an exports entrypoint, e.g. \"exports\": \"./mod.ts\""); process.exit(1); }'

Prevention

Every JSR package config needs `name`, `version`, and `exports` — check all three in a pre-publish script.
Point exports at the real public entrypoint (commonly ./mod.ts) and cover extra subpaths with a map.
Mark non-published configs with `"publish": false` so they fail with a clearer error instead.

When it happens

Trigger: `deno publish` with a deno.json/jsr.json that defines `name` (and no `"publish": false`) but no `exports` field, so the package has no public entrypoint to publish.

Common situations: New packages scaffolded from a bare deno.json; converting an internal library to JSR; accidentally deleting or renaming the exports key.

Related errors

AI-assisted analysis of denoland/deno@f7822238ca (2026-08-20). Data as JSON: /api/errors/14645047fe09550e. Report an issue: GitHub.