diff --git a/.gitignore b/.gitignore
index e8920c7..38562b5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,4 +3,4 @@
 bootstrap
 compile_commands.json
 docs/
-test/runner
+test/test
diff --git a/Makefile b/Makefile
index 9a9f4cb..0a69287 100644
--- a/Makefile
+++ b/Makefile
@@ -8,10 +8,10 @@ build: include/*.h src/*.c
 bear: include/*.h src/*.c
 	@bear -- ${BUILD}
 
-test: test/runner
+test: test/test
 	$^
 
-test/runner: include/*.h src/*.c test/*.h test/*.c
-	clang -I include src/*.c test/*.c -o test/runner -lm
+test/test: include/*.h src/*.c test/*.h test/*.c
+	clang -I include src/*.c test/*.c -o test/test -lm
 
 .PHONY: test
diff --git a/README.md b/README.md
index 4a8ee23..5d0343e 100644
--- a/README.md
+++ b/README.md
@@ -5,6 +5,9 @@ CLI utility for defining custom project initialization scripts.
 TODO:
 - [ ] Add evaluator tests.
 - [ ] Color output to console.
+- [ ] string -> line, case insensitive
+- [ ] Ensure keys are alphanumeric, underscore
+- [ ] sophie
 
 ## Overview
 
@@ -21,17 +24,19 @@ this project will feel at home. Ultimately the goal is to create (optionally)
 interactive scripts like those mentioned in the above list to quickly scaffold
 your new projects in a consistent way.
 
+---
+
 We start with an example. Consider the following *spec*, which we'll name
-`example`:
+`touch` (this example exists as a [pre-packaged spec](./specs/touch)):
 ```json
 {
   "filename": {
-    "type": "STRING",
+    "type": "text",
     "prompt": "What file should I create for you? "
   }
 }
 ```
-and its associated *builder*:
+and its associated *runner*:
 ```bash
 #!/usr/bin/env bash
 
@@ -42,40 +47,131 @@ touch "$OUT/$FILENAME"
 Running `bootstrap` with these two files configured will invoke the following
 interactive script:
 ```bash
-> bootstrap example
-I: What file should I create for you? hello-world.txt
-O: Creating hello-world.txt
-
->
+$> bootstrap touch
+What file should I create for you? hello-world.txt
+Creating hello-world.txt
+$> ls
+... hello-world.txt ...
 ```
-Here the line prefixed with `I:` indicates a prompt that must be answered by
-the user. The line prefixed with `O:` indicates the output of the builder
-script. You should now see a new `hello-world.txt` file in your current working
+You should now see a new `hello-world.txt` file in your current working
 directory.
 
 ## Usage
 
-TODO
-
 ### Installation
 
 TODO
 
-### Specs and Builders
+### Runners
 
-TODO
+A spec refers to any directory containing a file named `runner`. The only
+requirement enforced by `bootstrap` is for this file to be an executable (e.g.
+`chmod +x`), but typically the `runner` is a shell script:
+```bash
+#!/usr/bin/env bash
+...
+```
+
+The `runner` is invoked with its current working directory set to that of the
+directory containing it. For instance, if we have a `runner` script living in
+directory `~/Documents/specs/example` with contents:
+```bash
+#!/usr/bin/env bash
+echo "$PWD"
+```
+the output of `bootstrap example` will *always* be e.g.
+```bash
+> bootstrap example
+/home/jrpotter/Documents/specs/example
+```
+regardless of where we call the `bootstrap` command.
+
+#### Exit Code
+
+`bootstrap` always invokes the `runner` using the system `sh` command:
+```bash
+> /bin/sh sh -c ./runner
+```
+The exit code emitted by `bootstrap` will mirror that returned by the `runner`
+executable.
+
+### Specs
+
+If interested in making the `runner` more flexible, you can provide different
+environment variables in the form of a `spec.json` file. This file must live
+in the same spec as the `runner`. When invoking `bootstrap`, the file is used to
+determine what prompts should be displayed to the user before executing the
+`runner` file. The user's responses are then included as environment variables
+to the `runner` process.
+
+The file contents should consist of a top-level JSON object and any number of
+child objects called *fields*. A typical `spec.json` file looks like:
+```json
+{
+  "fieldname": {
+    "type": "text",
+    "prompt": "Prompt for field> "
+  },
+  ...
+}
+```
+In this example, the first field is called `"fieldname"`. `bootstrap` sees this
+field and writes the prompt `"Prompt for field> "` to `stdout`. Since
+`"fieldname"` has type `"text"`, `bootstrap` will wait for the user to input
+a string (submitted with a newline).
+
+If the user were to enter, say `fieldvalue`, in response to the prompt,
+the `runner` script would then have access to an environment variable
+`FIELDNAME` set to `fieldvalue` on launch.
+
+#### Types
+
+The value of `type` determines how a field is prompted for. Note the value of
+`type` is case insenstive. The currently supported list of types are:
+
+* `text`
+  * The simplest prompt type. Takes in a free-form response submitted after a
+    newline (`\n`) is encountered.
+
+#### Root Directory
+
+All specs should exist in the same *root directory*. As an example of what this
+directory might look like, refer to `specs` at the top-level of this project.
+When invoking `bootstrap <name>`, `<name>` is expected to correspond to some
+spec found within the root directory.
+
+To tell `bootstrap` where your specs are located, you can provide the path to
+the root directory using the `-d` option like so:
+```bash
+> bootstrap -d ~/Documents/specs example
+...
+```
+
+If no option is set, `bootstrap` will fallback to using the value of the
+`BOOTSTRAP_ROOT_DIR` environment variable. If this also isn't set, `bootstrap`
+will abort with an appropriate error message.
 
 ### Other Environment Variables
 
-TODO
+By default, the `runner` command will have the following environment variables
+defined. Defining these fields in a `spec.json` file will override the default
+values:
+
+* `OUT`
+  * The directory `bootstrap` was invoked from. Named since this is usually
+    where you want to initialize new files of your project in.
 
 ### Supplied Specs
 
-TODO
+A number of specs are provided out of the box. If you installed `bootstrap`
+using `nix`, the `BOOTSTRAP_ROOT_DIR` will automatically be set to the location
+of these [specs](./specs). Keep in mind this list is very opinionated - they
+reflect my personal needs for projects. Feel free to specify a different specs
+root directory if these do not fit your needs.
 
-### Using With Nix
-
-TODO
+As a suggestion, use `nix` from within your `runner` scripts for maximum
+reproducibility. Refer to the provided specs for inspiration on how you can do
+this.
 
 ## Development
 
diff --git a/include/error.h b/include/error.h
index a8772d4..3108cda 100644
--- a/include/error.h
+++ b/include/error.h
@@ -45,10 +45,10 @@ enum ErrorCode {
   /// The `prompt` of a `spec.json` field is not a string.
   ERROR_VALIDATOR_FIELD_PROMPT_INVALID,
 
-  /// The `run.sh` file could not be found.
-  ERROR_EVALUATOR_RUN_SH_NOT_FOUND,
-  /// The `run.sh` file is not executable.
-  ERROR_EVALUATOR_RUN_SH_NOT_EXEC,
+  /// The `runner` file could not be found.
+  ERROR_EVALUATOR_RUNNER_NOT_FOUND,
+  /// The `runner` file is not executable.
+  ERROR_EVALUATOR_RUNNER_NOT_EXEC,
   /// A user response to a prompt is not valid.
   ERROR_EVALUATOR_RESPONSE_INVALID,
 };
diff --git a/include/evaluator.h b/include/evaluator.h
index 0df096c..c0e7170 100644
--- a/include/evaluator.h
+++ b/include/evaluator.h
@@ -1,6 +1,6 @@
 /**
 @file
-@brief `spec.json` and `run.sh` evaluator.
+@brief `spec.json` and `runner` evaluator.
 */
 #ifndef _BOOTSTRAP_EVALUATOR_H
 #define _BOOTSTRAP_EVALUATOR_H
@@ -10,21 +10,21 @@
 #include "validator.h"
 
 /**
-@brief Run the `run.sh` script found in the configured spec.
+@brief Run the `runner` file found in the configured spec.
 
 @param config
  A reference to the parameters describing the desired spec.
 @param fields
- The list of prompts to have answered by the user prior to executing `run.sh`.
+ The list of prompts to have answered by the user prior to executing `runner`.
  Responses are included as environment variables in the invoked subshell.
 @param error
  The out parameter containing a possible error. Set to a null pointer if no
  error occurs. Otherwise set to an @ref Error instance.
 @return
  If @p error is set, returns `EXIT_FAILURE`. Otherwise returns the exit code
- returned by `run.sh`.
+ returned by the `runner`.
 */
-int evaluate_run_sh(
+int evaluate_runner(
   const struct Config *const config,
   const struct DynArray *const fields,
   struct Error **error
diff --git a/include/validator.h b/include/validator.h
index 754866f..0f6d061 100644
--- a/include/validator.h
+++ b/include/validator.h
@@ -13,7 +13,7 @@
 @brief The types of fields `bootstrap` can handle.
 */
 enum FieldType {
-  FT_STRING = 1,
+  FT_TEXT = 1,
 };
 
 /**
@@ -25,12 +25,12 @@ file. For instance, the fields of:
 ```json
 {
   "abc": {
-    "type": "STRING",
-    "prompt": "ABC"
+    "type": "text",
+    "prompt": "ABC> "
   },
   "def": {
-    "type": "STRING",
-    "prompt": "DEF"
+    "type": "text",
+    "prompt": "DEF> "
   },
 }
 ```
diff --git a/main.c b/main.c
index 49c0f28..bcbc83d 100644
--- a/main.c
+++ b/main.c
@@ -38,7 +38,7 @@ static int run(const char *root_dir, const char *target) {
     goto cleanup_parsed;
   }
 
-  if ((retval = evaluate_run_sh(config, prompts, &error))) {
+  if ((retval = evaluate_runner(config, prompts, &error))) {
     if (error) {
       fprintf(stderr, "%s", error->message);
     }
diff --git a/specs/test/run.sh b/specs/test/run.sh
deleted file mode 100755
index c914ca6..0000000
--- a/specs/test/run.sh
+++ /dev/null
@@ -1,3 +0,0 @@
-#!/usr/bin/env bash
-
-echo "hello world"
diff --git a/specs/test/spec.json b/specs/test/spec.json
deleted file mode 100644
index a0e72c2..0000000
--- a/specs/test/spec.json
+++ /dev/null
@@ -1,6 +0,0 @@
-{
-  "display": {
-    "type": "STRING",
-    "prompt": "This is a prompt"
-  }
-}
diff --git a/specs/touch/runner b/specs/touch/runner
new file mode 100755
index 0000000..abee60d
--- /dev/null
+++ b/specs/touch/runner
@@ -0,0 +1,4 @@
+#!/usr/bin/env bash
+
+echo "Creating $FILENAME"
+touch "$OUT/$FILENAME"
diff --git a/specs/touch/spec.json b/specs/touch/spec.json
new file mode 100644
index 0000000..37cb2e7
--- /dev/null
+++ b/specs/touch/spec.json
@@ -0,0 +1,6 @@
+{
+  "filename": {
+    "type": "text",
+    "prompt": "What file should I create for you? "
+  }
+}
diff --git a/src/evaluator.c b/src/evaluator.c
index 45b7c54..228a99c 100644
--- a/src/evaluator.c
+++ b/src/evaluator.c
@@ -11,11 +11,11 @@
 #include "string_buf.h"
 #include "validator.h"
 
-static struct Error *find_run_sh(const struct Config *const config) {
+static struct Error *find_run_exec(const struct Config *const config) {
   assert(config);
 
   struct stat sb;
-  const char *segments[] = {config->root_dir, config->target, "run.sh"};
+  const char *segments[] = {config->root_dir, config->target, "runner"};
   char *filepath =
     join_path_segments(sizeof(segments) / sizeof(char *), segments);
   int stat_res = stat(filepath, &sb);
@@ -23,18 +23,18 @@ static struct Error *find_run_sh(const struct Config *const config) {
 
   if (stat_res == -1 && errno == ENOENT) {
     return ERROR_NEW(
-      ERROR_EVALUATOR_RUN_SH_NOT_FOUND,
+      ERROR_EVALUATOR_RUNNER_NOT_FOUND,
       "Could not find ",
       config->target,
-      "/run.sh"
+      "/runner"
     );
   }
 
   if (!(sb.st_mode & S_IXUSR)) {
     return ERROR_NEW(
-      ERROR_EVALUATOR_RUN_SH_NOT_EXEC,
+      ERROR_EVALUATOR_RUNNER_NOT_EXEC,
       config->target,
-      "/run.sh is not executable."
+      "/runner is not executable."
     );
   }
 
@@ -45,7 +45,7 @@ static const char *prompt_field(struct Field *field) {
   assert(field);
 
   switch (field->type) {
-  case FT_STRING:
+  case FT_TEXT:
     printf("%s", field->prompt);
     // TODO: Probably want this buffer size to be a bit more dynamic.
     char *input = calloc(1, 1024);
@@ -74,12 +74,12 @@ static void push_env(
   string_buf_sappend(env, "' ");
 }
 
-int evaluate_run_sh(
+int evaluate_runner(
   const struct Config *const config,
   const struct DynArray *const fields,
   struct Error **error
 ) {
-  *error = find_run_sh(config);
+  *error = find_run_exec(config);
   if (*error) {
     return EXIT_FAILURE;
   }
@@ -102,7 +102,7 @@ int evaluate_run_sh(
     }
   }
 
-  const char *segments[] = {config->root_dir, config->target, "run.sh"};
+  const char *segments[] = {config->root_dir, config->target, "runner"};
   const char *filepath =
     join_path_segments(sizeof(segments) / sizeof(char *), segments);
   const char *env = string_buf_convert(env_buf);
diff --git a/src/validator.c b/src/validator.c
index f899500..1ddd491 100644
--- a/src/validator.c
+++ b/src/validator.c
@@ -28,7 +28,7 @@ static struct Error *read_field(const cJSON *const field, struct Field **out) {
   }
 
   if (strcmp(type->valuestring, "STRING") == 0) {
-    (*out)->type = FT_STRING;
+    (*out)->type = FT_TEXT;
   } else {
     error = ERROR_NEW(
       ERROR_VALIDATOR_FIELD_TYPE_UNKNOWN,
diff --git a/test/runner.c b/test/test.c
similarity index 100%
rename from test/runner.c
rename to test/test.c