💻 Never leave your terminal for secrets
📟 Create easy and clean workflows for working with cloud environments
🔎 Scan for secrets and fight secret sprawl
Never leave your terminal to use secrets while developing, testing, and building your apps.
Instead of custom scripts, tokens in your .zshrc
files, visible EXPORT
s in your bash history, misplaced .env.production
files and more around your workstation -- just use teller
and connect it to any vault, key store, or cloud service you like (Teller support Hashicorp Vault, AWS Secrets Manager, Google Secret Manager, and many more).
You can use Teller to tidy your own environment or for your team as a process and best practice.
You can install teller
with homebrew:
$ brew tap spectralops/tap && brew install teller
You can now use teller
or tlr
(if you like shortcuts!) in your terminal.
teller
will pull variables from your various cloud providers, vaults and others, and will populate your current working session (in various ways!, see more below) so you can work safely and much more productively.
teller
needs a tellerfile. This is a .teller.yml
file that lives in your repo, or one that you point teller to with teller -c your-conf.yml
.
For those using Github Action, you can have a 1-click experience of installing Teller in your CI:
- name: Setup Teller
uses: spectralops/setup-teller@v1
- name: Run a Teller task (show, scan, run, etc.)
run: teller run [args]
For more, check our setup teller action on the marketplace.
Run teller new
and follow the wizard, pick the providers you like and it will generate a .teller.yml
for you.
Alternatively, you can use the following minimal template or view a full example:
project: project_name
opts:
stage: development
# remove if you don't like the prompt
confirm: Are you sure you want to run in {{stage}}?
providers:
# uses environment vars to configure
# https://github.com/hashicorp/vault/blob/api/v1.0.4/api/client.go#L28
hashicorp_vault:
env_sync:
path: secret/data/{{stage}}/services/billing
# this will fuse vars with the below .env file
# use if you'd like to grab secrets from outside of the project tree
dotenv:
env_sync:
path: ~/billing.env.{{stage}}
Now you can just run processes with:
$ teller run node src/server.js
Service is up.
Loaded configuration: Mailgun, SMTP
Port: 5050
Behind the scenes: teller
fetched the correct variables, placed those (and just those) in ENV
for the node
process to use.
Go and have a look at a collection of our best practices
Manually exporting and setting up environment variables for running a process with demo-like / production-like set up?
Got bitten by using .env.production
and exposing it in the local project itself?
Using teller
and a .teller.yml
file that exposes nothing to the prying eyes, you can work fluently and seamlessly with zero risk, also no need for quotes:
$ teller run -- your-process arg1 arg2... --switch1 ...
This will output the current variables teller
picks up. Only first 2 letters will be shown from each, of course.
$ teller show
Hardcoding secrets into your shell scripts and dotfiles?
In some cases it makes sense to eval variables into your current shell. For example in your .zshrc
it makes much more sense to use teller
, and not hardcode all those into the .zshrc
file itself.
In this case, this is what you should add:
eval "$(teller sh)"
Tired of grabbing all kinds of variables, setting those up, and worried about these appearing in your shell history as well?
Use this one liner from now on:
$ docker run --rm -it --env-file <(teller env) alpine sh
Teller can help you fight secret sprawl and hard coded secrets, as well as be the best productivity tool for working with your vault.
It can also integrate into your CI and serve as a shift-left security tool for your DevSecOps pipeline.
Look for your vault-kept secrets in your code by running:
$ teller scan
You can run it as a linter in your CI like so:
run: teller scan --silent
It will break your build if it finds something (returns exit code 1
).
Use Teller for productively and securely running your processes and you get this for free -- nothing to configure. If you have data that you're bringing that you're sure isn't sensitive, flag it in your teller.yml
:
dotenv:
env:
FOO:
path: ~/my-dot-env.env
severity: none # will skip scanning. possible values: high | medium | low | none
By default we treat all entries as sensitive, with value high
.
You can use teller
as a redaction tool across your infrastructure, and run processes while redacting their output as well as clean up logs and live tails of logs.
Run a process and redact its output in real time:
$ teller run --redact -- your-process arg1 arg2
Pipe any process output, tail or logs into teller to redact those, live:
$ cat some.log | teller redact
It should also work with tail -f
:
$ tail -f /var/log/apache.log | teller redact
Finally, if you've got some files you want to redact, you can do that too:
$ teller redact --in dirty.csv --out clean.csv
If you omit --in
Teller will take stdin
, and if you omit --out
Teller will output to stdout
.
You can detect secret drift by comparing values from different providers against each other. It might be that you want to pin a set of keys in different providers to always be the same value; when they aren't -- that means you have a drift.
In most cases, keys in providers would be similar which we call mirrored providers. Example:
Provider1:
MG_PASS=foo***
Provider2:
MG_PASS=foo*** # Both keys are called MG_PASS
To detected mirror drifts, we use teller mirror-drift
.
$ teller mirror-drift --source global-dotenv --target my-dotenv
Drifts detected: 2
changed [] global-dotenv FOO_BAR "n***** != my-dotenv FOO_BAR ne*****
missing [] global-dotenv FB 3***** ??
Use mirror-drift --sync ...
in order to declare that the two providers should represent a completely synchronized mirror (all keys, all values).
As always, the specific provider definitions are in your teller.yml
file.
Some times you want to check drift between two providers, and two unrelated keys. For example:
Provider1:
MG_PASS=foo***
Provider2:
MAILGUN_PASS=foo***
This poses a challenge. We need some way to "wire" the keys MG_PASS
and MAILGUN_PASS
and declare a relationship of source (MG_PASS
) and destination, or sink (MAILGUN_PASS
).
For this, you can label mappings as source
and couple with the appropriate sink as sink
, effectively creating a graph of wirings. We call this graph-drift
(use same label value for both to wire them together). Then, source values will be compared against sink values in your configuration:
providers:
dotenv:
env_sync:
path: ~/my-dot-env.env
source: s1
dotenv2:
kind: dotenv
env_sync:
path: ~/other-dot-env.env
sink: s1
And run
$ teller graph-drift dotenv dotenv2 -c your-config.yml
Have a kickstarter project you want to populate quickly with some variables (not secrets though!)?
Have a production project that just has to have a file to read that contains your variables?
You can use teller
to inject variables into your own templates (based on go templates).
With this template:
Hello, {{.Teller.EnvByKey "FOO_BAR" "default-value" }}!
Run:
$ teller template my-template.tmpl out.txt
Will get you, assuming FOO_BAR=Spock
:
Hello, Spock!
In cases where you want to sync between providers, you can do that with teller copy
.
Specific mapping key sync
$ teller copy --from dotenv1 --to dotenv2,heroku1
This will:
- Grab all mapped values from source (
dotenv1
) - For each target provider, find the matching mapped key, and copy the value from source into it
Full copy sync
$ teller copy --sync --from dotenv1 --to dotenv2,heroku1
This will:
- Grab all mapped values from source (
dotenv1
) - For each target provider, perform a full copy of values from source into the mapped
env_sync
key
Notes:
- The mapping per provider is as configured in your
teller.yaml
file, in theenv_sync
orenv
properties. - This sync will try to copy all values from the source.
Teller providers supporting write use cases which allow writing values into providers.
Remember, for this feature it still revolves around definitions in your teller.yml
file:
$ teller put FOO_BAR=$MY_NEW_PASS --providers dotenv -c .teller.write.yml
A few notes:
- Values are key-value pair in the format:
key=value
and you can specify multiple pairs at once - When you're specifying a literal sensitive value, make sure to use an ENV variable so that nothing sensitive is recorded in your history
- The flag
--providers
lets you push to one or more providers at once FOO_BAR
must be a mapped key in your configuration for each provider you want to update
Sometimes you don't have a mapped key in your configuration file and want to perform an ad-hoc write, you can do that with --path
:
$ teller put SMTP_PASS=newpass --path secret/data/foo --providers hashicorp_vault
A few notes:
- The pair
SMTP_PASS=newpass
will be pushed to the specified path - While you can push to multiple providers, please make sure the path semantics are the same
Teller providers support deleting values from providers.
This feature revolves around definitions in your teller.yml
file:
$ teller delete FOO_BAR --providers dotenv -c .teller.yml
A few notes:
-
You can specify multiple keys to delete, for example:
$ teller delete FOO BAR BAZ --providers dotenv
-
The flag
--providers
lets you push to one or more providers at once -
All keys must be a mapped key in your configuration for each provider you want to delete from
Sometimes you don't have a mapped key in your configuration file and want to perform an ad-hoc delete. You can do that with the --path
flag:
$ teller delete FOO BAR --path ~/my-env-file.env --providers dotenv
You can also delete all keys at once for a given path, without specifying them one by one:
$ teller delete --all-keys --path ~/my-env-file.env --providers dotenv
There are a few options that you can use:
-
carry_env - carry the environment from the parent process into the child process. By default we isolate the child process from the parent process. (default: false)
-
confirm - an interactive question to prompt the user before taking action (such as running a process). (default: empty)
-
opts - a dict for our own variable/setting substitution mechanism. For example:
opts:
region: env:AWS_REGION
stage: qa
And now you can use paths like /{{stage}}/{{region}}/billing-svc
where ever you want (this templating is available for the confirm question too).
If you prefix a value with env:
it will get pulled from your current environment.
You can export in a YAML format, suitable for GCloud:
$ teller yaml
Example format:
FOO: "1"
KEY: VALUE
You can export in a JSON format, suitable for piping through jq
or other workflows:
$ teller json
Example format:
{
"FOO": "1"
}
For each provider, there are a few points to understand:
- Sync - full sync support. Can we provide a path to a whole environment and have it synced (all keys, all values). Some of the providers support this and some don't.
- Key format - some of the providers expect a path-like key, some env-var like, and some don't care. We'll specify for each.
We use the following general structure to specify sync mapping for all providers:
# you can use either `env_sync` or `env` or both
env_sync:
path: ... # path to mapping
remap:
PROVIDER_VAR1: VAR3 # Maps PROVIDER_VAR1 to local env var VAR3
env:
VAR1:
path: ... # path to value or mapping
field: <key> # optional: use if path contains a k/v dict
decrypt: true | false # optional: use if provider supports encryption at the value side
severity: high | medium | low | none # optional: used for secret scanning, default is high. 'none' means not a secret
redact_with: "**XXX**" # optional: used as a placeholder swapping the secret with it. default is "**REDACTED**"
VAR2:
path: ...
Providers which support syncing a list of keys and values can be remapped to different environment variable keys. Typically, when teller syncs paths from env_sync
, the key returned from the provider is directly mapped to the environment variable key. In some cases it might be necessary to have the provider key mapped to a different variable without changing the provider settings. This can be useful when using env_sync
for Hashicorp Vault Dynamic Database credentials:
env_sync:
path: database/roles/my-role
remap:
username: PGUSER
password: PGPASSWORD
Additionally, you can remap key settings by using remap_with
instead of remap
:
env_sync:
path: database/roles/my-role
remap_with: # Use either remap or remap_with, not both.
username:
field: PGUSER
severity: none
password:
field: PGPASSWORD
severity: high
redact_with: "**XXX**"
After remapping, the local environment variable PGUSER
will contain the provider value for username
and PGPASSWORD
will contain the provider value for password
.
If you have the Vault CLI configured and working, there's no special action to take.
Configuration is environment based, as defined by client standard. See variables here.
- Sync -
yes
- Mapping -
yes
- Modes -
read+write
- Key format - path based, usually starts with
secret/data/
, and more generically[engine name]/data
hashicorp_vault:
env_sync:
path: secret/data/demo/billing/web/env
env:
SMTP_PASS:
path: secret/data/demo/wordpress
field: smtp
If you have the Consul CLI working and configured, there's no special action to take.
Configuration is environment based, as defined by client standard. See variables here.
- Sync -
yes
- Mapping -
yes
- Modes -
read+write
- Key format
env_sync
- path based, we use the last segment as the variable nameenv
- any string, no special requirement
consul:
env_sync:
path: ops/config
env:
SLACK_HOOK:
path: ops/config/slack
Requires an API key populated in your environment in: HEROKU_API_KEY
(you can fetch it from your ~/.netrc).
Generate new token with Heroku cli: heroku authorizations:create
then use the TOKEN value.
- Sync -
yes
- Mapping -
yes
- Modes -
read+write
- Key format
env_sync
- name of your Heroku appenv
- the actual env variable name in your Heroku settings
heroku:
env_sync:
path: my-app-dev
env:
MG_KEY:
path: my-app-dev
If you have etcdctl
already working there's no special action to take.
We follow how etcdctl
takes its authentication settings. These environment variables need to be populated
ETCDCTL_ENDPOINTS
For TLS:
ETCDCTL_CA_FILE
ETCDCTL_CERT_FILE
ETCDCTL_KEY_FILE
- Sync -
yes
- Mapping -
yes
- Modes -
read+write
- Key format
env_sync
- path basedenv
- path based
etcd:
env_sync:
path: /prod/billing-svc
env:
MG_KEY:
path: /prod/billing-svc/vars/mg
Your standard AWS_DEFAULT_REGION
, AWS_ACCESS_KEY_ID
, AWS_SECRET_ACCESS_KEY
need to be populated in your environment
- Sync -
yes
- Mapping -
yes
- Modes -
read+write+delete
- Key format
env_sync
- path basedenv
- path based
aws_secretsmanager:
env_sync:
path: /prod/billing-svc
env:
MG_KEY:
path: /prod/billing-svc/vars/mg
Your standard AWS_DEFAULT_REGION
, AWS_ACCESS_KEY_ID
, AWS_SECRET_ACCESS_KEY
need to be populated in your environment
- Sync -
no
- Mapping -
yes
- Modes -
read
, write: accepting PR - Key format
env
- path baseddecrypt
- available in this provider, will use KMS automatically
aws_ssm:
env:
FOO_BAR:
path: /prod/billing-svc/vars
decrypt: true
You should populate GOOGLE_APPLICATION_CREDENTIALS=account.json
in your environment to your relevant account.json
that you get from Google.
- Sync -
yes
- Mapping -
yes
- Modes -
read+write+delete
- Key format
env
- path based, needs to include a versionenv_sync
- your project's path (gets the secrets latest version), when using --sync a new secret version will be createddecrypt
- available in this provider, will use KMS automatically
google_secretmanager:
env_sync:
# secrets version is not relevant here since we are getting the latest version
path: projects/44882
env:
MG_KEY:
# need to supply the relevant version (versions/1)
path: projects/44882/secrets/MG_KEY/versions/1
No need. You'll be pointing to a one or more .env
files on your disk.
- Sync -
yes
- Mapping -
yes
- Modes -
read+write+delete
- Key format
env
- env key like
You can mix and match any number of files, sitting anywhere on your drive.
dotenv:
env_sync:
path: ~/my-dot-env.env
env:
MG_KEY:
path: ~/my-dot-env.env
Install the doppler cli then run doppler login
. You'll also need to configure your desired "project" for any given directory using doppler configure
. Alternatively, you can set a global project by running doppler configure set project <my-project>
from your home directory.
- Sync -
yes
- Mapping -
yes
- Modes -
read
- Key format
env
- env key like
doppler:
env_sync:
path: prd
env:
MG_KEY:
path: prd
field: OTHER_MG_KEY # (optional)
Requires an API key populated in your environment in: VERCEL_TOKEN
.
- Sync -
yes
- Mapping -
yes
- Modes -
read
, write: accepting PR - Key format
env_sync
- name of your Vercel appenv
- the actual env variable name in your Vercel settings
vercel:
env_sync:
path: my-app-dev
env:
MG_KEY:
path: my-app-dev
Requires a username and API key populated in your environment:
CONJUR_AUTHN_LOGIN
CONJUR_AUTHN_API_KEY
Requires a .conjurrc file in your User's home directory:
---
account: conjurdemo
plugins: []
appliance_url: https://conjur.example.com
cert_file: ""
account
is the organization account created during initial deploymentplugins
will be blankappliance_url
should be the Base URI for the Conjur servicecert_file
should be the public key certificate if running in self-signed mode
- Sync -
no
sync: accepting PR - Mapping -
yes
- Modes -
read+write
- Key format
env_sync
- not supported to comply with least-privilege modelenv
- the secret variable path in Conjur Secrets Manager
cyberark_conjur:
env:
DB_USERNAME:
path: /secrets/prod/pgsql/username
DB_PASSWORD:
path: /secrets/prod/pgsql/password
requires the following environment variables to be set:
CLOUDFLARE_API_KEY
: Your Cloudflare api key.
CLOUDFLARE_API_EMAIL
: Your email associated with the api key.
CLOUDFLARE_ACCOUNT_ID
: Your account ID.
- Sync -
yes
- Mapping -
yes
- Modes -
read
(write coming soon) - Key format
env_sync
- The KV namespace IDfield
- the actual key stored in the KV storeenv
- the actual key stored in the KV store
opts:
kv-namespace-id: <YOUR NAMESPACE ID>
providers:
cloudflare_workers_kv:
env_sync:
path: "{{kv-namespace-id}}"
remap:
# looks up the key `test_key` and maps it to `TEST`.
test_key: TEST
env:
SOME_SECRET:
path: "{{kv-namespace-id}}"
# Accesses the key `SOME_SECRET` in the KV namespace.
REMAPPED_KEY:
path: "{{kv-namespace-id}}"
# Accesses the field `SOME_KEY` in the KV namespace and maps it to REMAPPED_KEY.
field: SOME_KEY
$ teller put foo-secret=000000 --providers cloudflare_workers_secrets
$ teller put foo-secret=123 foo-secret2=456 --providers cloudflare_workers_secrets --sync # take from env_sync for using the same source for multiple secrets
$ teller delete foo-secret foo-secret2 --providers cloudflare_workers_secrets
requires the following environment variables to be set:
CLOUDFLARE_API_KEY
: Your Cloudflare api key.
CLOUDFLARE_API_EMAIL
: Your email associated with the api key.
CLOUDFLARE_ACCOUNT_ID
: Your account ID.
- Sync -
yes
- Mapping -
yes
- Modes -
write
- Key format
source
- The script namepath
- Name of the secret, when using--sync
the path will overridden by the given parameters
providers:
cloudflare_workers_secrets:
env_sync:
source: script-id
env:
foo-secret:
path: foo-secret
source: script-id
foo-secret2:
path: foo-secret
source: script-id
To integrate with the 1Password API, you should have system-to-system secret management running in your infrastructure/localhost more details here.
Requires the following environment variables to be set:
OP_CONNECT_HOST
- The hostname of the 1Password Connect API
OP_CONNECT_TOKEN
- The API token to be used to authenticate the client to a 1Password Connect API.
- Sync -
no
- Mapping -
yes
, returns all fields on specific secret item - Modes -
read+write
- Key format
env_sync
- Will return all the fields under the secret item.path
- Mandatory field: Secret item name. (expected unique secret item with the same name)source
- Mandatory field: vaultUUID to query
env
path
- Mandatory field: Secret item name. (expected unique secret item with the same name)source
- Mandatory field: vaultUUID to queryfield
- Mandatory field: the specific field name (notesPlain, {custom label name}, password, type etc).
1password:
env_sync:
path: security-note
source: VAULT-ID
env:
SECURITY_NOTE_TITLE:
path: security-note-title
source: VAULT-ID
field: lable1
NOTE_SECRET:
path: login-title
source: VAULT-ID
field: password
CREDIT_CARD:
path: credit-card-title
source: VAULT-ID
field: type
Example:
OP_CONNECT_HOST="http://localhost:8080" OP_CONNECT_TOKEN="" teller yaml
If you have the Gopass working and configured, there's no special action to take.
Configuration is environment based, as defined by client standard. See variables here.
- Sync -
yes
- Mapping -
yes
- Modes -
read+write
- Key format
env_sync
- path based, we use the last segment as the variable nameenv
- any string, no special requirement
gopass:
env_sync:
path: foo
env:
SLACK_HOOK:
path: path: foo/bar
Requires the following environment variables to be set:
LASTPASS_USERNAME
- LastPass username
LASTPASS_PASSWORD
- LastPass password
- Sync -
no
- Mapping -
no
- Modes -
read
- Key format
env_sync
- Will return all the fields under the secret item.path
- Mandatory field: Secret item ID.
env
path
- Mandatory field: Secret item ID.field
- Optional field: by default takingpassword
property. in case you want other property un-mark this line and set the LastPass property name.
$ teller put FROM_TELLER=00000 FROM_TELLER_2=00002 --providers github --sync # Add secrets with dynamic secrets name (take from env_sync)
$ teller put FROM_TELLER=1111 FROM_TELLER_2=222 --providers github # Add defined secrets name from env key (YAML key will be the name of the secret)
$ teller delete FROM_TELLER --providers github # Delete specific secret
$ teller delete FROM_TELLER FROM_TELLER_2 --providers github --all-keys --path={OWNER}/{REPO-NAME} # Delete all repo secrets, limited to 100 secrets per repository
requires the following environment variables to be set:
GITHUB_AUTH_TOKEN
: GitHub token.
- Sync -
yes
- Mapping -
yes
- Modes -
write
- Key format
path
- Contain the repo owner and the repo name with/
separator
providers:
github:
env_sync:
path: owner/repo-name
env:
FROM_TELLER:
path: owner/repo-name
FROM_TELLER_2:
path: owner/repo-name
requires the following environment variables to be set:
KEYPASS_PASSWORD
: Password database credentials
KEYPASS_DB_PATH
: Database path
- Sync -
no
- Mapping -
yes
- Modes -
read
providers:
keypass:
env_sync:
path: redis/config
# source: Optional, all fields is the default. Supported fields: Notes, Title, Password, URL, UserName
env:
ETC_DSN:
path: redis/config/foobar
# source: Optional, Password is the default. Supported fields: Notes, Title, Password, URL, UserName
Allows to work against filesystem structure. for example:
.
└── /folder
├── settings/
│ ├── billing-svc
│ └── all/
│ ├── foo
└── bar
- Sync -
yes
- Mapping -
yes
- Modes -
read+write
providers:
filesystem:
env_sync:
path: /folder/settings
env:
ETC_DSN:
path: /folder/bar
Load the environment variables from the parent process as needed.
No need.
- Sync -
yes
- Mapping -
yes
- Modes -
read
- Key format
env_sync
- Will return all the environment variables in the parent processpath
- Value isn't required or used
env
field
- Optional field: specific environment variable in the parent process
providers:
process_env:
env:
ETC_DSN:
# Optional: accesses the environment variable `SOME_KEY` and maps it to ETC_DSN
field: SOME_KEY
Two options for getting Azure authentication are available:
- Standard Azure environment variable. (Enable by default)
- For get credentials via az client add
AZURE_CLI=1
to your environment variable
Then set your vault-name by specific as environment variable: KVAULT_NAME
- Sync -
yes
- Mapping -
yes
- Modes -
read+write+delete
providers:
azure_keyvault:
env_sync:
path: azure
env:
FOO:
path: bar
- Stores that support key-value interfaces:
path
is the direct location of the value, no need for theenv
key orfield
. - Stores that support key-valuemap interfaces:
path
is the location of the map, while theenv
key orfield
(if exists) will be used to do the additional final addressing. - For env-sync (fetching value map out of a store), path will be a direct pointer at the key-valuemap
- Principle of non-recovery: where possible an error is return when it is not recoverable (nothing to do), but when it is -- providers should attempt recovery (e.g. retry API call)
- Missing key/value: it's possible that when trying to fetch value in a provider - it's missing. This is not an error, rather an indication of a missing entry is returned (
EnvEntry#IsFound
)
- We
vendor
our dependencies and push them to the repo. This creates an immutable, independent build, that's also free from risks of fetching unknown code in CI/release time.
For every provider, we are federating all authentication and authorization concern to the system of origin. In other words, if for example you connect to your organization's Hashicorp Vault, we assume you already have a secure way to do that, which is "blessed" by the organization.
In addition, we don't offer any way to specify connection details to these systems in writing (in configuration files or other), and all connection details, to all providers, should be supplied via environment variables.
That allows us to keep two important points:
- Don't undermine the user's security model and threat modeling for the sake of productivity (security AND productivity CAN be attained)
- Don't encourage the user to do what we're here for -- save secrets and sensitive details from being forgotten in various places.
- Add new provider
- Quick testing as you code:
make lint && make test
- Checking your work before PR, run also integration tests:
make integration
Testing is composed of unit tests and integration tests. Integration tests are based on testcontainers as well as live sandbox APIs (where containers are not available)
- Unit tests are a mix of pure and mocks based tests, abstracting each provider's interface with a custom client
- View integration tests
To run all unit tests without integration:
$ make test
To run all unit tests including container-based integration:
$ make integration
To run all unit tests including container and live API based integration (this is effectively all integration tests):
$ make integration_api
Running all tests:
$ make test
$ make integration_api
Linting is treated as a form of testing (using golangci
, configuration here), to run:
$ make lint
To all Contributors - you make this happen, thanks!
Teller follows CNCF Code of Conduct
Copyright (c) 2021 @jondot. See LICENSE for further details.